pragma solidity ^0.5.4;// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.


/**
 * @title Module
 * @dev Interface for a module.
 * A module MUST implement the addModule() method to ensure that a wallet with at least one module
 * can never end up in a "frozen" state.
 * @author Julien Niset - <julien@argent.xyz>
 */
interface Module {

    /**
     * @dev Inits a module for a wallet by e.g. setting some wallet specific parameters in storage.
     * @param _wallet The wallet.
     */
    function init(BaseWallet _wallet) external;

    /**
     * @dev Adds a module to a wallet.
     * @param _wallet The target wallet.
     * @param _module The modules to authorise.
     */
    function addModule(BaseWallet _wallet, Module _module) external;

    /**
    * @dev Utility method to recover any ERC20 token that was sent to the
    * module by mistake.
    * @param _token The token to recover.
    */
    function recoverToken(address _token) external;
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.


/**
 * @title BaseWallet
 * @dev Simple modular wallet that authorises modules to call its invoke() method.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract BaseWallet {

    // The implementation of the proxy
    address public implementation;
    // The owner
    address public owner;
    // The authorised modules
    mapping (address => bool) public authorised;
    // The enabled static calls
    mapping (bytes4 => address) public enabled;
    // The number of modules
    uint public modules;

    event AuthorisedModule(address indexed module, bool value);
    event EnabledStaticCall(address indexed module, bytes4 indexed method);
    event Invoked(address indexed module, address indexed target, uint indexed value, bytes data);
    event Received(uint indexed value, address indexed sender, bytes data);
    event OwnerChanged(address owner);

    /**
     * @dev Throws if the sender is not an authorised module.
     */
    modifier moduleOnly {
        require(authorised[msg.sender], "BW: msg.sender not an authorized module");
        _;
    }

    /**
     * @dev Inits the wallet by setting the owner and authorising a list of modules.
     * @param _owner The owner.
     * @param _modules The modules to authorise.
     */
    function init(address _owner, address[] calldata _modules) external {
        require(owner == address(0) && modules == 0, "BW: wallet already initialised");
        require(_modules.length > 0, "BW: construction requires at least 1 module");
        owner = _owner;
        modules = _modules.length;
        for (uint256 i = 0; i < _modules.length; i++) {
            require(authorised[_modules[i]] == false, "BW: module is already added");
            authorised[_modules[i]] = true;
            Module(_modules[i]).init(this);
            emit AuthorisedModule(_modules[i], true);
        }
        if (address(this).balance > 0) {
            emit Received(address(this).balance, address(0), "");
        }
    }

    /**
     * @dev Enables/Disables a module.
     * @param _module The target module.
     * @param _value Set to true to authorise the module.
     */
    function authoriseModule(address _module, bool _value) external moduleOnly {
        if (authorised[_module] != _value) {
            emit AuthorisedModule(_module, _value);
            if (_value == true) {
                modules += 1;
                authorised[_module] = true;
                Module(_module).init(this);
            } else {
                modules -= 1;
                require(modules > 0, "BW: wallet must have at least one module");
                delete authorised[_module];
            }
        }
    }

    /**
    * @dev Enables a static method by specifying the target module to which the call
    * must be delegated.
    * @param _module The target module.
    * @param _method The static method signature.
    */
    function enableStaticCall(address _module, bytes4 _method) external moduleOnly {
        require(authorised[_module], "BW: must be an authorised module for static call");
        enabled[_method] = _module;
        emit EnabledStaticCall(_module, _method);
    }

    /**
     * @dev Sets a new owner for the wallet.
     * @param _newOwner The new owner.
     */
    function setOwner(address _newOwner) external moduleOnly {
        require(_newOwner != address(0), "BW: address cannot be null");
        owner = _newOwner;
        emit OwnerChanged(_newOwner);
    }

    /**
     * @dev Performs a generic transaction.
     * @param _target The address for the transaction.
     * @param _value The value of the transaction.
     * @param _data The data of the transaction.
     */
    function invoke(address _target, uint _value, bytes calldata _data) external moduleOnly returns (bytes memory _result) {
        bool success;
        // solium-disable-next-line security/no-call-value
        (success, _result) = _target.call.value(_value)(_data);
        if (!success) {
            // solium-disable-next-line security/no-inline-assembly
            assembly {
                returndatacopy(0, 0, returndatasize)
                revert(0, returndatasize)
            }
        }
        emit Invoked(msg.sender, _target, _value, _data);
    }

    /**
     * @dev This method makes it possible for the wallet to comply to interfaces expecting the wallet to
     * implement specific static methods. It delegates the static call to a target contract if the data corresponds
     * to an enabled method, or logs the call otherwise.
     */
    function() external payable {
        if (msg.data.length > 0) {
            address module = enabled[msg.sig];
            if (module == address(0)) {
                emit Received(msg.value, msg.sender, msg.data);
            } else {
                require(authorised[module], "BW: must be an authorised module for static call");
                // solium-disable-next-line security/no-inline-assembly
                assembly {
                    calldatacopy(0, 0, calldatasize())
                    let result := staticcall(gas, module, 0, calldatasize(), 0, 0)
                    returndatacopy(0, 0, returndatasize())
                    switch result
                    case 0 {revert(0, returndatasize())}
                    default {return (0, returndatasize())}
                }
            }
        }
    }
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.



/**
 * @title Owned
 * @dev Basic contract to define an owner.
 * @author Julien Niset - <julien@argent.im>
 */
contract Owned {

    // The owner
    address public owner;

    event OwnerChanged(address indexed _newOwner);

    /**
     * @dev Throws if the sender is not the owner.
     */
    modifier onlyOwner {
        require(msg.sender == owner, "Must be owner");
        _;
    }

    constructor() public {
        owner = msg.sender;
    }

    /**
     * @dev Lets the owner transfer ownership of the contract to a new owner.
     * @param _newOwner The new owner.
     */
    function changeOwner(address _newOwner) external onlyOwner {
        require(_newOwner != address(0), "Address must not be null");
        owner = _newOwner;
        emit OwnerChanged(_newOwner);
    }
}

/**
 * ERC20 contract interface.
 */
contract ERC20 {
    function totalSupply() public view returns (uint);
    function decimals() public view returns (uint);
    function balanceOf(address tokenOwner) public view returns (uint balance);
    function allowance(address tokenOwner, address spender) public view returns (uint remaining);
    function transfer(address to, uint tokens) public returns (bool success);
    function approve(address spender, uint tokens) public returns (bool success);
    function transferFrom(address from, address to, uint tokens) public returns (bool success);
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.



/**
 * @title ModuleRegistry
 * @dev Registry of authorised modules.
 * Modules must be registered before they can be authorised on a wallet.
 * @author Julien Niset - <julien@argent.im>
 */
contract ModuleRegistry is Owned {

    mapping (address => Info) internal modules;
    mapping (address => Info) internal upgraders;

    event ModuleRegistered(address indexed module, bytes32 name);
    event ModuleDeRegistered(address module);
    event UpgraderRegistered(address indexed upgrader, bytes32 name);
    event UpgraderDeRegistered(address upgrader);

    struct Info {
        bool exists;
        bytes32 name;
    }

    /**
     * @dev Registers a module.
     * @param _module The module.
     * @param _name The unique name of the module.
     */
    function registerModule(address _module, bytes32 _name) external onlyOwner {
        require(!modules[_module].exists, "MR: module already exists");
        modules[_module] = Info({exists: true, name: _name});
        emit ModuleRegistered(_module, _name);
    }

    /**
     * @dev Deregisters a module.
     * @param _module The module.
     */
    function deregisterModule(address _module) external onlyOwner {
        require(modules[_module].exists, "MR: module does not exist");
        delete modules[_module];
        emit ModuleDeRegistered(_module);
    }

        /**
     * @dev Registers an upgrader.
     * @param _upgrader The upgrader.
     * @param _name The unique name of the upgrader.
     */
    function registerUpgrader(address _upgrader, bytes32 _name) external onlyOwner {
        require(!upgraders[_upgrader].exists, "MR: upgrader already exists");
        upgraders[_upgrader] = Info({exists: true, name: _name});
        emit UpgraderRegistered(_upgrader, _name);
    }

    /**
     * @dev Deregisters an upgrader.
     * @param _upgrader The _upgrader.
     */
    function deregisterUpgrader(address _upgrader) external onlyOwner {
        require(upgraders[_upgrader].exists, "MR: upgrader does not exist");
        delete upgraders[_upgrader];
        emit UpgraderDeRegistered(_upgrader);
    }

    /**
    * @dev Utility method enbaling the owner of the registry to claim any ERC20 token that was sent to the
    * registry.
    * @param _token The token to recover.
    */
    function recoverToken(address _token) external onlyOwner {
        uint total = ERC20(_token).balanceOf(address(this));
        ERC20(_token).transfer(msg.sender, total);
    }

    /**
     * @dev Gets the name of a module from its address.
     * @param _module The module address.
     * @return the name.
     */
    function moduleInfo(address _module) external view returns (bytes32) {
        return modules[_module].name;
    }

    /**
     * @dev Gets the name of an upgrader from its address.
     * @param _upgrader The upgrader address.
     * @return the name.
     */
    function upgraderInfo(address _upgrader) external view returns (bytes32) {
        return upgraders[_upgrader].name;
    }

    /**
     * @dev Checks if a module is registered.
     * @param _module The module address.
     * @return true if the module is registered.
     */
    function isRegisteredModule(address _module) external view returns (bool) {
        return modules[_module].exists;
    }

    /**
     * @dev Checks if a list of modules are registered.
     * @param _modules The list of modules address.
     * @return true if all the modules are registered.
     */
    function isRegisteredModule(address[] calldata _modules) external view returns (bool) {
        for (uint i = 0; i < _modules.length; i++) {
            if (!modules[_modules[i]].exists) {
                return false;
            }
        }
        return true;
    }

    /**
     * @dev Checks if an upgrader is registered.
     * @param _upgrader The upgrader address.
     * @return true if the upgrader is registered.
     */
    function isRegisteredUpgrader(address _upgrader) external view returns (bool) {
        return upgraders[_upgrader].exists;
    }
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.


/**
 * @title Storage
 * @dev Base contract for the storage of a wallet.
 * @author Julien Niset - <julien@argent.im>
 */
contract Storage {

    /**
     * @dev Throws if the caller is not an authorised module.
     */
    modifier onlyModule(BaseWallet _wallet) {
        require(_wallet.authorised(msg.sender), "TS: must be an authorized module to call this method");
        _;
    }
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.


interface IGuardianStorage{

    /**
     * @dev Lets an authorised module add a guardian to a wallet.
     * @param _wallet The target wallet.
     * @param _guardian The guardian to add.
     */
    function addGuardian(BaseWallet _wallet, address _guardian) external;

    /**
     * @dev Lets an authorised module revoke a guardian from a wallet.
     * @param _wallet The target wallet.
     * @param _guardian The guardian to revoke.
     */
    function revokeGuardian(BaseWallet _wallet, address _guardian) external;

    /**
     * @dev Checks if an account is a guardian for a wallet.
     * @param _wallet The target wallet.
     * @param _guardian The account.
     * @return true if the account is a guardian for a wallet.
     */
    function isGuardian(BaseWallet _wallet, address _guardian) external view returns (bool);
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.




/**
 * @title GuardianStorage
 * @dev Contract storing the state of wallets related to guardians and lock.
 * The contract only defines basic setters and getters with no logic. Only modules authorised
 * for a wallet can modify its state.
 * @author Julien Niset - <julien@argent.im>
 * @author Olivier Van Den Biggelaar - <olivier@argent.im>
 */
contract GuardianStorage is IGuardianStorage, Storage {

    struct GuardianStorageConfig {
        // the list of guardians
        address[] guardians;
        // the info about guardians
        mapping (address => GuardianInfo) info;
        // the lock's release timestamp
        uint256 lock;
        // the module that set the last lock
        address locker;
    }

    struct GuardianInfo {
        bool exists;
        uint128 index;
    }

    // wallet specific storage
    mapping (address => GuardianStorageConfig) internal configs;

    // *************** External Functions ********************* //

    /**
     * @dev Lets an authorised module add a guardian to a wallet.
     * @param _wallet The target wallet.
     * @param _guardian The guardian to add.
     */
    function addGuardian(BaseWallet _wallet, address _guardian) external onlyModule(_wallet) {
        GuardianStorageConfig storage config = configs[address(_wallet)];
        config.info[_guardian].exists = true;
        config.info[_guardian].index = uint128(config.guardians.push(_guardian) - 1);
    }

    /**
     * @dev Lets an authorised module revoke a guardian from a wallet.
     * @param _wallet The target wallet.
     * @param _guardian The guardian to revoke.
     */
    function revokeGuardian(BaseWallet _wallet, address _guardian) external onlyModule(_wallet) {
        GuardianStorageConfig storage config = configs[address(_wallet)];
        address lastGuardian = config.guardians[config.guardians.length - 1];
        if (_guardian != lastGuardian) {
            uint128 targetIndex = config.info[_guardian].index;
            config.guardians[targetIndex] = lastGuardian;
            config.info[lastGuardian].index = targetIndex;
        }
        config.guardians.length--;
        delete config.info[_guardian];
    }

    /**
     * @dev Returns the number of guardians for a wallet.
     * @param _wallet The target wallet.
     * @return the number of guardians.
     */
    function guardianCount(BaseWallet _wallet) external view returns (uint256) {
        return configs[address(_wallet)].guardians.length;
    }

    /**
     * @dev Gets the list of guaridans for a wallet.
     * @param _wallet The target wallet.
     * @return the list of guardians.
     */
    function getGuardians(BaseWallet _wallet) external view returns (address[] memory) {
        GuardianStorageConfig storage config = configs[address(_wallet)];
        address[] memory guardians = new address[](config.guardians.length);
        for (uint256 i = 0; i < config.guardians.length; i++) {
            guardians[i] = config.guardians[i];
        }
        return guardians;
    }

    /**
     * @dev Checks if an account is a guardian for a wallet.
     * @param _wallet The target wallet.
     * @param _guardian The account.
     * @return true if the account is a guardian for a wallet.
     */
    function isGuardian(BaseWallet _wallet, address _guardian) external view returns (bool) {
        return configs[address(_wallet)].info[_guardian].exists;
    }

    /**
     * @dev Lets an authorised module set the lock for a wallet.
     * @param _wallet The target wallet.
     * @param _releaseAfter The epoch time at which the lock should automatically release.
     */
    function setLock(BaseWallet _wallet, uint256 _releaseAfter) external onlyModule(_wallet) {
        configs[address(_wallet)].lock = _releaseAfter;
        if (_releaseAfter != 0 && msg.sender != configs[address(_wallet)].locker) {
            configs[address(_wallet)].locker = msg.sender;
        }
    }

    /**
     * @dev Checks if the lock is set for a wallet.
     * @param _wallet The target wallet.
     * @return true if the lock is set for the wallet.
     */
    function isLocked(BaseWallet _wallet) external view returns (bool) {
        return configs[address(_wallet)].lock > now;
    }

    /**
     * @dev Gets the time at which the lock of a wallet will release.
     * @param _wallet The target wallet.
     * @return the time at which the lock of a wallet will release, or zero if there is no lock set.
     */
    function getLock(BaseWallet _wallet) external view returns (uint256) {
        return configs[address(_wallet)].lock;
    }

    /**
     * @dev Gets the address of the last module that modified the lock for a wallet.
     * @param _wallet The target wallet.
     * @return the address of the last module that modified the lock for a wallet.
     */
    function getLocker(BaseWallet _wallet) external view returns (address) {
        return configs[address(_wallet)].locker;
    }
}/* The MIT License (MIT)

Copyright (c) 2016 Smart Contract Solutions, Inc.

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */



/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

    /**
    * @dev Multiplies two numbers, reverts on overflow.
    */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b);

        return c;
    }

    /**
    * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
    */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0); // Solidity only automatically asserts when dividing by 0
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
    * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
    */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a);
        uint256 c = a - b;

        return c;
    }

    /**
    * @dev Adds two numbers, reverts on overflow.
    */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a);

        return c;
    }

    /**
    * @dev Divides two numbers and returns the remainder (unsigned integer modulo),
    * reverts when dividing by zero.
    */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0);
        return a % b;
    }

    /**
    * @dev Returns ceil(a / b).
    */
    function ceil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a / b;
        if(a % b == 0) {
            return c;
        }
        else {
            return c + 1;
        }
    }

    // from DSMath - operations on fixed precision floats

    uint256 constant WAD = 10 ** 18;
    uint256 constant RAY = 10 ** 27;

    function wmul(uint256 x, uint256 y) internal pure returns (uint256 z) {
        z = add(mul(x, y), WAD / 2) / WAD;
    }
    function rmul(uint256 x, uint256 y) internal pure returns (uint256 z) {
        z = add(mul(x, y), RAY / 2) / RAY;
    }
    function wdiv(uint256 x, uint256 y) internal pure returns (uint256 z) {
        z = add(mul(x, WAD), y / 2) / y;
    }
    function rdiv(uint256 x, uint256 y) internal pure returns (uint256 z) {
        z = add(mul(x, RAY), y / 2) / y;
    }
}
// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.







/**
 * @title BaseModule
 * @dev Basic module that contains some methods common to all modules.
 * @author Julien Niset - <julien@argent.im>
 */
contract BaseModule is Module {

    // Empty calldata
    bytes constant internal EMPTY_BYTES = "";

    // The adddress of the module registry.
    ModuleRegistry internal registry;
    // The address of the Guardian storage
    GuardianStorage internal guardianStorage;

    /**
     * @dev Throws if the wallet is locked.
     */
    modifier onlyWhenUnlocked(BaseWallet _wallet) {
        // solium-disable-next-line security/no-block-members
        require(!guardianStorage.isLocked(_wallet), "BM: wallet must be unlocked");
        _;
    }

    event ModuleCreated(bytes32 name);
    event ModuleInitialised(address wallet);

    constructor(ModuleRegistry _registry, GuardianStorage _guardianStorage, bytes32 _name) public {
        registry = _registry;
        guardianStorage = _guardianStorage;
        emit ModuleCreated(_name);
    }

    /**
     * @dev Throws if the sender is not the target wallet of the call.
     */
    modifier onlyWallet(BaseWallet _wallet) {
        require(msg.sender == address(_wallet), "BM: caller must be wallet");
        _;
    }

    /**
     * @dev Throws if the sender is not the owner of the target wallet or the module itself.
     */
    modifier onlyWalletOwner(BaseWallet _wallet) {
        require(msg.sender == address(this) || isOwner(_wallet, msg.sender), "BM: must be an owner for the wallet");
        _;
    }

    /**
     * @dev Throws if the sender is not the owner of the target wallet.
     */
    modifier strictOnlyWalletOwner(BaseWallet _wallet) {
        require(isOwner(_wallet, msg.sender), "BM: msg.sender must be an owner for the wallet");
        _;
    }

    /**
     * @dev Inits the module for a wallet by logging an event.
     * The method can only be called by the wallet itself.
     * @param _wallet The wallet.
     */
    function init(BaseWallet _wallet) public onlyWallet(_wallet) {
        emit ModuleInitialised(address(_wallet));
    }

    /**
     * @dev Adds a module to a wallet. First checks that the module is registered.
     * @param _wallet The target wallet.
     * @param _module The modules to authorise.
     */
    function addModule(BaseWallet _wallet, Module _module) external strictOnlyWalletOwner(_wallet) {
        require(registry.isRegisteredModule(address(_module)), "BM: module is not registered");
        _wallet.authoriseModule(address(_module), true);
    }

    /**
    * @dev Utility method enbaling anyone to recover ERC20 token sent to the
    * module by mistake and transfer them to the Module Registry.
    * @param _token The token to recover.
    */
    function recoverToken(address _token) external {
        uint total = ERC20(_token).balanceOf(address(this));
        ERC20(_token).transfer(address(registry), total);
    }

    /**
     * @dev Helper method to check if an address is the owner of a target wallet.
     * @param _wallet The target wallet.
     * @param _addr The address.
     */
    function isOwner(BaseWallet _wallet, address _addr) internal view returns (bool) {
        return _wallet.owner() == _addr;
    }

    /**
     * @dev Helper method to invoke a wallet.
     * @param _wallet The target wallet.
     * @param _to The target address for the transaction.
     * @param _value The value of the transaction.
     * @param _data The data of the transaction.
     */
    function invokeWallet(address _wallet, address _to, uint256 _value, bytes memory _data) internal returns (bytes memory _res) {
        bool success;
        // solium-disable-next-line security/no-call-value
        (success, _res) = _wallet.call(abi.encodeWithSignature("invoke(address,uint256,bytes)", _to, _value, _data));
        if (success && _res.length > 0) { //_res is empty if _wallet is an "old" BaseWallet that can't return output values
            (_res) = abi.decode(_res, (bytes));
        } else if (_res.length > 0) {
            // solium-disable-next-line security/no-inline-assembly
            assembly {
                returndatacopy(0, 0, returndatasize)
                revert(0, returndatasize)
            }
        } else if (!success) {
            revert("BM: wallet invoke reverted");
        }
    }
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.



/**
 * @title RelayerModule
 * @dev Base module containing logic to execute transactions signed by eth-less accounts and sent by a relayer.
 * @author Julien Niset - <julien@argent.im>
 */
contract RelayerModule is BaseModule {

    uint256 constant internal BLOCKBOUND = 10000;

    mapping (address => RelayerConfig) public relayer;

    struct RelayerConfig {
        uint256 nonce;
        mapping (bytes32 => bool) executedTx;
    }

    event TransactionExecuted(address indexed wallet, bool indexed success, bytes32 signedHash);

    /**
     * @dev Throws if the call did not go through the execute() method.
     */
    modifier onlyExecute {
        require(msg.sender == address(this), "RM: must be called via execute()");
        _;
    }

    /* ***************** Abstract method ************************* */

    /**
    * @dev Gets the number of valid signatures that must be provided to execute a
    * specific relayed transaction.
    * @param _wallet The target wallet.
    * @param _data The data of the relayed transaction.
    * @return The number of required signatures.
    */
    function getRequiredSignatures(BaseWallet _wallet, bytes memory _data) internal view returns (uint256);

    /**
    * @dev Validates the signatures provided with a relayed transaction.
    * The method MUST throw if one or more signatures are not valid.
    * @param _wallet The target wallet.
    * @param _data The data of the relayed transaction.
    * @param _signHash The signed hash representing the relayed transaction.
    * @param _signatures The signatures as a concatenated byte array.
    */
    function validateSignatures(
        BaseWallet _wallet,
        bytes memory _data,
        bytes32 _signHash,
        bytes memory _signatures) internal view returns (bool);

    /* ************************************************************ */

    /**
    * @dev Executes a relayed transaction.
    * @param _wallet The target wallet.
    * @param _data The data for the relayed transaction
    * @param _nonce The nonce used to prevent replay attacks.
    * @param _signatures The signatures as a concatenated byte array.
    * @param _gasPrice The gas price to use for the gas refund.
    * @param _gasLimit The gas limit to use for the gas refund.
    */
    function execute(
        BaseWallet _wallet,
        bytes calldata _data,
        uint256 _nonce,
        bytes calldata _signatures,
        uint256 _gasPrice,
        uint256 _gasLimit
    )
        external
        returns (bool success)
    {
        uint startGas = gasleft();
        bytes32 signHash = getSignHash(address(this), address(_wallet), 0, _data, _nonce, _gasPrice, _gasLimit);
        require(checkAndUpdateUniqueness(_wallet, _nonce, signHash), "RM: Duplicate request");
        require(verifyData(address(_wallet), _data), "RM: the wallet authorized is different then the target of the relayed data");
        uint256 requiredSignatures = getRequiredSignatures(_wallet, _data);
        if ((requiredSignatures * 65) == _signatures.length) {
            if (verifyRefund(_wallet, _gasLimit, _gasPrice, requiredSignatures)) {
                if (requiredSignatures == 0 || validateSignatures(_wallet, _data, signHash, _signatures)) {
                    // solium-disable-next-line security/no-call-value
                    (success,) = address(this).call(_data);
                    refund(_wallet, startGas - gasleft(), _gasPrice, _gasLimit, requiredSignatures, msg.sender);
                }
            }
        }
        emit TransactionExecuted(address(_wallet), success, signHash);
    }

    /**
    * @dev Gets the current nonce for a wallet.
    * @param _wallet The target wallet.
    */
    function getNonce(BaseWallet _wallet) external view returns (uint256 nonce) {
        return relayer[address(_wallet)].nonce;
    }

    /**
    * @dev Generates the signed hash of a relayed transaction according to ERC 1077.
    * @param _from The starting address for the relayed transaction (should be the module)
    * @param _to The destination address for the relayed transaction (should be the wallet)
    * @param _value The value for the relayed transaction
    * @param _data The data for the relayed transaction
    * @param _nonce The nonce used to prevent replay attacks.
    * @param _gasPrice The gas price to use for the gas refund.
    * @param _gasLimit The gas limit to use for the gas refund.
    */
    function getSignHash(
        address _from,
        address _to,
        uint256 _value,
        bytes memory _data,
        uint256 _nonce,
        uint256 _gasPrice,
        uint256 _gasLimit
    )
        internal
        pure
        returns (bytes32)
    {
        return keccak256(
            abi.encodePacked(
                "\x19Ethereum Signed Message:\n32",
                keccak256(abi.encodePacked(byte(0x19), byte(0), _from, _to, _value, _data, _nonce, _gasPrice, _gasLimit))
        ));
    }

    /**
    * @dev Checks if the relayed transaction is unique.
    * @param _wallet The target wallet.
    * @param _signHash The signed hash of the transaction
    */
    function checkAndUpdateUniqueness(BaseWallet _wallet, uint256 /* _nonce */, bytes32 _signHash) internal returns (bool) {
        if (relayer[address(_wallet)].executedTx[_signHash] == true) {
            return false;
        }
        relayer[address(_wallet)].executedTx[_signHash] = true;
        return true;
    }

    /**
    * @dev Checks that a nonce has the correct format and is valid.
    * It must be constructed as nonce = {block number}{timestamp} where each component is 16 bytes.
    * @param _wallet The target wallet.
    * @param _nonce The nonce
    */
    function checkAndUpdateNonce(BaseWallet _wallet, uint256 _nonce) internal returns (bool) {
        if (_nonce <= relayer[address(_wallet)].nonce) {
            return false;
        }
        uint256 nonceBlock = (_nonce & 0xffffffffffffffffffffffffffffffff00000000000000000000000000000000) >> 128;
        if (nonceBlock > block.number + BLOCKBOUND) {
            return false;
        }
        relayer[address(_wallet)].nonce = _nonce;
        return true;
    }

    /**
    * @dev Recovers the signer at a given position from a list of concatenated signatures.
    * @param _signedHash The signed hash
    * @param _signatures The concatenated signatures.
    * @param _index The index of the signature to recover.
    */
    function recoverSigner(bytes32 _signedHash, bytes memory _signatures, uint _index) internal pure returns (address) {
        uint8 v;
        bytes32 r;
        bytes32 s;
        // we jump 32 (0x20) as the first slot of bytes contains the length
        // we jump 65 (0x41) per signature
        // for v we load 32 bytes ending with v (the first 31 come from s) then apply a mask
        // solium-disable-next-line security/no-inline-assembly
        assembly {
            r := mload(add(_signatures, add(0x20,mul(0x41,_index))))
            s := mload(add(_signatures, add(0x40,mul(0x41,_index))))
            v := and(mload(add(_signatures, add(0x41,mul(0x41,_index)))), 0xff)
        }
        require(v == 27 || v == 28); // solium-disable-line error-reason
        return ecrecover(_signedHash, v, r, s);
    }

    /**
    * @dev Refunds the gas used to the Relayer.
    * For security reasons the default behavior is to not refund calls with 0 or 1 signatures.
    * @param _wallet The target wallet.
    * @param _gasUsed The gas used.
    * @param _gasPrice The gas price for the refund.
    * @param _gasLimit The gas limit for the refund.
    * @param _signatures The number of signatures used in the call.
    * @param _relayer The address of the Relayer.
    */
    function refund(BaseWallet _wallet, uint _gasUsed, uint _gasPrice, uint _gasLimit, uint _signatures, address _relayer) internal {
        uint256 amount = 29292 + _gasUsed; // 21000 (transaction) + 7620 (execution of refund) + 672 to log the event + _gasUsed
        // only refund if gas price not null, more than 1 signatures, gas less than gasLimit
        if (_gasPrice > 0 && _signatures > 1 && amount <= _gasLimit) {
            if (_gasPrice > tx.gasprice) {
                amount = amount * tx.gasprice;
            } else {
                amount = amount * _gasPrice;
            }
            invokeWallet(address(_wallet), _relayer, amount, EMPTY_BYTES);
        }
    }

    /**
    * @dev Returns false if the refund is expected to fail.
    * @param _wallet The target wallet.
    * @param _gasUsed The expected gas used.
    * @param _gasPrice The expected gas price for the refund.
    */
    function verifyRefund(BaseWallet _wallet, uint _gasUsed, uint _gasPrice, uint _signatures) internal view returns (bool) {
        if (_gasPrice > 0 &&
            _signatures > 1 &&
            (address(_wallet).balance < _gasUsed * _gasPrice || _wallet.authorised(address(this)) == false)) {
            return false;
        }
        return true;
    }

    /**
    * @dev Checks that the wallet address provided as the first parameter of the relayed data is the same
    * as the wallet passed as the input of the execute() method.
    @return false if the addresses are different.
    */
    function verifyData(address _wallet, bytes memory _data) private pure returns (bool) {
        require(_data.length >= 36, "RM: Invalid dataWallet");
        address dataWallet;
        // solium-disable-next-line security/no-inline-assembly
        assembly {
            //_data = {length:32}{sig:4}{_wallet:32}{...}
            dataWallet := mload(add(_data, 0x24))
        }
        return dataWallet == _wallet;
    }

    /**
    * @dev Parses the data to extract the method signature.
    */
    function functionPrefix(bytes memory _data) internal pure returns (bytes4 prefix) {
        require(_data.length >= 4, "RM: Invalid functionPrefix");
        // solium-disable-next-line security/no-inline-assembly
        assembly {
            prefix := mload(add(_data, 0x20))
        }
    }
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.




/**
 * @title OnlyOwnerModule
 * @dev Module that extends BaseModule and RelayerModule for modules where the execute() method
 * must be called with one signature frm the owner.
 * @author Julien Niset - <julien@argent.im>
 */
contract OnlyOwnerModule is BaseModule, RelayerModule {

    // bytes4 private constant IS_ONLY_OWNER_MODULE = bytes4(keccak256("isOnlyOwnerModule()"));

   /**
    * @dev Returns a constant that indicates that the module is an OnlyOwnerModule.
    * @return The constant bytes4(keccak256("isOnlyOwnerModule()"))
    */
    function isOnlyOwnerModule() external pure returns (bytes4) {
        // return IS_ONLY_OWNER_MODULE;
        return this.isOnlyOwnerModule.selector;
    }

    /**
     * @dev Adds a module to a wallet. First checks that the module is registered.
     * Unlike its overrided parent, this method can be called via the RelayerModule's execute()
     * @param _wallet The target wallet.
     * @param _module The modules to authorise.
     */
    function addModule(BaseWallet _wallet, Module _module) external onlyWalletOwner(_wallet) {
        require(registry.isRegisteredModule(address(_module)), "BM: module is not registered");
        _wallet.authoriseModule(address(_module), true);
    }

    // *************** Implementation of RelayerModule methods ********************* //

    // Overrides to use the incremental nonce and save some gas
    function checkAndUpdateUniqueness(BaseWallet _wallet, uint256 _nonce, bytes32 /* _signHash */) internal returns (bool) {
        return checkAndUpdateNonce(_wallet, _nonce);
    }

    function validateSignatures(
        BaseWallet _wallet,
        bytes memory /* _data */,
        bytes32 _signHash,
        bytes memory _signatures
    )
        internal
        view
        returns (bool)
    {
        address signer = recoverSigner(_signHash, _signatures, 0);
        return isOwner(_wallet, signer); // "OOM: signer must be owner"
    }

    function getRequiredSignatures(BaseWallet /* _wallet */, bytes memory /* _data */) internal view returns (uint256) {
        return 1;
    }
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.


/**
 * @title BaseTransfer
 * @dev Module containing internal methods to execute or approve transfers
 * @author Olivier VDB - <olivier@argent.xyz>
 */
contract BaseTransfer is BaseModule {

    // Mock token address for ETH
    address constant internal ETH_TOKEN = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;

    // *************** Events *************************** //

    event Transfer(address indexed wallet, address indexed token, uint256 indexed amount, address to, bytes data);
    event Approved(address indexed wallet, address indexed token, uint256 amount, address spender);
    event CalledContract(address indexed wallet, address indexed to, uint256 amount, bytes data);
    event ApprovedAndCalledContract(
        address indexed wallet,
        address indexed to,
        address spender,
        address indexed token,
        uint256 amountApproved,
        uint256 amountSpent,
        bytes data
    );
    // *************** Internal Functions ********************* //

    /**
    * @dev Helper method to transfer ETH or ERC20 for a wallet.
    * @param _wallet The target wallet.
    * @param _token The ERC20 address.
    * @param _to The recipient.
    * @param _value The amount of ETH to transfer
    * @param _data The data to *log* with the transfer.
    */
    function doTransfer(BaseWallet _wallet, address _token, address _to, uint256 _value, bytes memory _data) internal {
        if (_token == ETH_TOKEN) {
            invokeWallet(address(_wallet), _to, _value, EMPTY_BYTES);
        } else {
            bytes memory methodData = abi.encodeWithSignature("transfer(address,uint256)", _to, _value);
            invokeWallet(address(_wallet), _token, 0, methodData);
        }
        emit Transfer(address(_wallet), _token, _value, _to, _data);
    }

    /**
    * @dev Helper method to approve spending the ERC20 of a wallet.
    * @param _wallet The target wallet.
    * @param _token The ERC20 address.
    * @param _spender The spender address.
    * @param _value The amount of token to transfer.
    */
    function doApproveToken(BaseWallet _wallet, address _token, address _spender, uint256 _value) internal {
        bytes memory methodData = abi.encodeWithSignature("approve(address,uint256)", _spender, _value);
        invokeWallet(address(_wallet), _token, 0, methodData);
        emit Approved(address(_wallet), _token, _value, _spender);
    }

    /**
    * @dev Helper method to call an external contract.
    * @param _wallet The target wallet.
    * @param _contract The contract address.
    * @param _value The ETH value to transfer.
    * @param _data The method data.
    */
    function doCallContract(BaseWallet _wallet, address _contract, uint256 _value, bytes memory _data) internal {
        invokeWallet(address(_wallet), _contract, _value, _data);
        emit CalledContract(address(_wallet), _contract, _value, _data);
    }

    /**
    * @dev Helper method to approve a certain amount of token and call an external contract.
    * The address that spends the _token and the address that is called with _data can be different.
    * @param _wallet The target wallet.
    * @param _token The ERC20 address.
    * @param _spender The spender address.
    * @param _amount The amount of tokens to transfer.
    * @param _contract The contract address.
    * @param _data The method data.
    */
    function doApproveTokenAndCallContract(
        BaseWallet _wallet,
        address _token,
        address _spender,
        uint256 _amount,
        address _contract,
        bytes memory _data
    )
        internal
    {
        uint256 existingAllowance = ERC20(_token).allowance(address(_wallet), _spender);
        uint256 totalAllowance = SafeMath.add(existingAllowance, _amount);
        // Approve the desired amount plus existing amount. This logic allows for potential gas saving later
        // when restoring the original approved amount, in cases where the _spender uses the exact approved _amount.
        bytes memory methodData = abi.encodeWithSignature("approve(address,uint256)", _spender, totalAllowance);

        invokeWallet(address(_wallet), _token, 0, methodData);
        invokeWallet(address(_wallet), _contract, 0, _data);

        // Calculate the approved amount that was spent after the call
        uint256 unusedAllowance = ERC20(_token).allowance(address(_wallet), _spender);
        uint256 usedAllowance = SafeMath.sub(totalAllowance, unusedAllowance);
        // Ensure the amount spent does not exceed the amount approved for this call
        require(usedAllowance <= _amount, "BT: insufficient amount for call");

        if (unusedAllowance != existingAllowance) {
            // Restore the original allowance amount if the amount spent was different (can be lower).
            methodData = abi.encodeWithSignature("approve(address,uint256)", _spender, existingAllowance);
            invokeWallet(address(_wallet), _token, 0, methodData);
        }

        emit ApprovedAndCalledContract(
            address(_wallet),
            _contract,
            _spender,
            _token,
            _amount,
            usedAllowance,
            _data);
    }
}
// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.



/**
 * @title LimitManager
 * @dev Module to manage a daily spending limit
 * @author Julien Niset - <julien@argent.im>
 */
contract LimitManager is BaseModule {

    // large limit when the limit can be considered disabled
    uint128 constant private LIMIT_DISABLED = uint128(-1); // 3.40282366920938463463374607431768211455e+38

    using SafeMath for uint256;

    struct LimitManagerConfig {
        // The daily limit
        Limit limit;
        // The current usage
        DailySpent dailySpent;
    }

    struct Limit {
        // the current limit
        uint128 current;
        // the pending limit if any
        uint128 pending;
        // when the pending limit becomes the current limit
        uint64 changeAfter;
    }

    struct DailySpent {
        // The amount already spent during the current period
        uint128 alreadySpent;
        // The end of the current period
        uint64 periodEnd;
    }

    // wallet specific storage
    mapping (address => LimitManagerConfig) internal limits;
    // The default limit
    uint256 public defaultLimit;

    // *************** Events *************************** //

    event LimitChanged(address indexed wallet, uint indexed newLimit, uint64 indexed startAfter);

    // *************** Constructor ********************** //

    constructor(uint256 _defaultLimit) public {
        defaultLimit = _defaultLimit;
    }

    // *************** External/Public Functions ********************* //

    /**
     * @dev Inits the module for a wallet by setting the limit to the default value.
     * @param _wallet The target wallet.
     */
    function init(BaseWallet _wallet) public onlyWallet(_wallet) {
        Limit storage limit = limits[address(_wallet)].limit;
        if (limit.current == 0 && limit.changeAfter == 0) {
            limit.current = uint128(defaultLimit);
        }
    }

    // *************** Internal Functions ********************* //

    /**
     * @dev Changes the daily limit.
     * The limit is expressed in ETH and the change is pending for the security period.
     * @param _wallet The target wallet.
     * @param _newLimit The new limit.
     * @param _securityPeriod The security period.
     */
    function changeLimit(BaseWallet _wallet, uint256 _newLimit, uint256 _securityPeriod) internal {
        Limit storage limit = limits[address(_wallet)].limit;
        // solium-disable-next-line security/no-block-members
        uint128 current = (limit.changeAfter > 0 && limit.changeAfter < now) ? limit.pending : limit.current;
        limit.current = current;
        limit.pending = uint128(_newLimit);
        // solium-disable-next-line security/no-block-members
        limit.changeAfter = uint64(now.add(_securityPeriod));
        // solium-disable-next-line security/no-block-members
        emit LimitChanged(address(_wallet), _newLimit, uint64(now.add(_securityPeriod)));
    }

     /**
     * @dev Disable the daily limit.
     * The change is pending for the security period.
     * @param _wallet The target wallet.
     * @param _securityPeriod The security period.
     */
    function disableLimit(BaseWallet _wallet, uint256 _securityPeriod) internal {
        changeLimit(_wallet, LIMIT_DISABLED, _securityPeriod);
    }

    /**
    * @dev Gets the current daily limit for a wallet.
    * @param _wallet The target wallet.
    * @return the current limit expressed in ETH.
    */
    function getCurrentLimit(BaseWallet _wallet) public view returns (uint256 _currentLimit) {
        Limit storage limit = limits[address(_wallet)].limit;
        _currentLimit = uint256(currentLimit(limit.current, limit.pending, limit.changeAfter));
    }

    /**
    * @dev Returns whether the daily limit is disabled for a wallet.
    * @param _wallet The target wallet.
    * @return true if the daily limit is disabled, false otherwise.
    */
    function isLimitDisabled(BaseWallet _wallet) public view returns (bool _limitDisabled) {
        uint256 currentLimit = getCurrentLimit(_wallet);
        _limitDisabled = currentLimit == LIMIT_DISABLED;
    }

    /**
    * @dev Gets a pending limit for a wallet if any.
    * @param _wallet The target wallet.
    * @return the pending limit (in ETH) and the time at chich it will become effective.
    */
    function getPendingLimit(BaseWallet _wallet) external view returns (uint256 _pendingLimit, uint64 _changeAfter) {
        Limit storage limit = limits[address(_wallet)].limit;
        // solium-disable-next-line security/no-block-members
        return ((now < limit.changeAfter)? (uint256(limit.pending), limit.changeAfter) : (0,0));
    }

    /**
    * @dev Gets the amount of tokens that has not yet been spent during the current period.
    * @param _wallet The target wallet.
    * @return the amount of tokens (in ETH) that has not been spent yet and the end of the period.
    */
    function getDailyUnspent(BaseWallet _wallet) external view returns (uint256 _unspent, uint64 _periodEnd) {
        uint256 limit = getCurrentLimit(_wallet);
        DailySpent storage expense = limits[address(_wallet)].dailySpent;
        // solium-disable-next-line security/no-block-members
        if (now > expense.periodEnd) {
            _unspent = limit;
            // solium-disable-next-line security/no-block-members
            _periodEnd = uint64(now + 24 hours);
        } else {
            _periodEnd = expense.periodEnd;
            if (expense.alreadySpent < limit) {
                _unspent = limit - expense.alreadySpent;
            }
        }
    }

    /**
    * @dev Helper method to check if a transfer is within the limit.
    * If yes the daily unspent for the current period is updated.
    * @param _wallet The target wallet.
    * @param _amount The amount for the transfer
    */
    function checkAndUpdateDailySpent(BaseWallet _wallet, uint _amount) internal returns (bool) {
        if (_amount == 0)
            return true;
        Limit storage limit = limits[address(_wallet)].limit;
        uint128 current = currentLimit(limit.current, limit.pending, limit.changeAfter);
        if (isWithinDailyLimit(_wallet, current, _amount)) {
            updateDailySpent(_wallet, current, _amount);
            return true;
        }
        return false;
    }

    /**
    * @dev Helper method to update the daily spent for the current period.
    * @param _wallet The target wallet.
    * @param _limit The current limit for the wallet.
    * @param _amount The amount to add to the daily spent.
    */
    function updateDailySpent(BaseWallet _wallet, uint128 _limit, uint _amount) internal {
        if (_limit != LIMIT_DISABLED) {
            DailySpent storage expense = limits[address(_wallet)].dailySpent;
            // solium-disable-next-line security/no-block-members
            if (expense.periodEnd < now) {
                // solium-disable-next-line security/no-block-members
                expense.periodEnd = uint64(now + 24 hours);
                expense.alreadySpent = uint128(_amount);
            } else {
                expense.alreadySpent += uint128(_amount);
            }
        }
    }

    /**
    * @dev Checks if a transfer amount is withing the daily limit for a wallet.
    * @param _wallet The target wallet.
    * @param _limit The current limit for the wallet.
    * @param _amount The transfer amount.
    * @return true if the transfer amount is withing the daily limit.
    */
    function isWithinDailyLimit(BaseWallet _wallet, uint _limit, uint _amount) internal view returns (bool) {
        if (_limit == LIMIT_DISABLED) {
            return true;
        }
        DailySpent storage expense = limits[address(_wallet)].dailySpent;
        // solium-disable-next-line security/no-block-members
        if (expense.periodEnd < now) {
            return (_amount <= _limit);
        } else {
            return (expense.alreadySpent + _amount <= _limit && expense.alreadySpent + _amount >= expense.alreadySpent);
        }
    }

    /**
    * @dev Helper method to get the current limit from a Limit struct.
    * @param _current The value of the current parameter
    * @param _pending The value of the pending parameter
    * @param _changeAfter The value of the changeAfter parameter
    */
    function currentLimit(uint128 _current, uint128 _pending, uint64 _changeAfter) internal view returns (uint128) {
        // solium-disable-next-line security/no-block-members
        if (_changeAfter > 0 && _changeAfter < now) {
            return _pending;
        }
        return _current;
    }

}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.



/**
 * @title TransferStorage
 * @dev Contract storing the state of wallets related to transfers (limit and whitelist).
 * The contract only defines basic setters and getters with no logic. Only modules authorised
 * for a wallet can modify its state.
 * @author Julien Niset - <julien@argent.im>
 */
contract TransferStorage is Storage {

    // wallet specific storage
    mapping (address => mapping (address => uint256)) internal whitelist;

    // *************** External Functions ********************* //

    /**
     * @dev Lets an authorised module add or remove an account from the whitelist of a wallet.
     * @param _wallet The target wallet.
     * @param _target The account to add/remove.
     * @param _value True for addition, false for revokation.
     */
    function setWhitelist(BaseWallet _wallet, address _target, uint256 _value) external onlyModule(_wallet) {
        whitelist[address(_wallet)][_target] = _value;
    }

    /**
     * @dev Gets the whitelist state of an account for a wallet.
     * @param _wallet The target wallet.
     * @param _target The account.
     * @return the epoch time at which an account strats to be whitelisted, or zero if the account is not whitelisted.
     */
    function getWhitelist(BaseWallet _wallet, address _target) external view returns (uint256) {
        return whitelist[address(_wallet)][_target];
    }
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.


/**
 * @title Managed
 * @dev Basic contract that defines a set of managers. Only the owner can add/remove managers.
 * @author Julien Niset - <julien@argent.im>
 */
contract Managed is Owned {

    // The managers
    mapping (address => bool) public managers;

    /**
     * @dev Throws if the sender is not a manager.
     */
    modifier onlyManager {
        require(managers[msg.sender] == true, "M: Must be manager");
        _;
    }

    event ManagerAdded(address indexed _manager);
    event ManagerRevoked(address indexed _manager);

    /**
    * @dev Adds a manager.
    * @param _manager The address of the manager.
    */
    function addManager(address _manager) external onlyOwner {
        require(_manager != address(0), "M: Address must not be null");
        if (managers[_manager] == false) {
            managers[_manager] = true;
            emit ManagerAdded(_manager);
        }
    }

    /**
    * @dev Revokes a manager.
    * @param _manager The address of the manager.
    */
    function revokeManager(address _manager) external onlyOwner {
        require(managers[_manager] == true, "M: Target must be an existing manager");
        delete managers[_manager];
        emit ManagerRevoked(_manager);
    }
}

contract KyberNetwork {

    function getExpectedRate(
        ERC20 src,
        ERC20 dest,
        uint srcQty
    )
        public
        view
        returns (uint expectedRate, uint slippageRate);

    function trade(
        ERC20 src,
        uint srcAmount,
        ERC20 dest,
        address payable destAddress,
        uint maxDestAmount,
        uint minConversionRate,
        address walletId
    )
        public
        payable
        returns(uint);
}
// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.





contract TokenPriceProvider is Managed {

    // Mock token address for ETH
    address constant internal ETH_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;

    using SafeMath for uint256;

    mapping(address => uint256) public cachedPrices;

    // Address of the KyberNetwork contract
    KyberNetwork public kyberNetwork;

    constructor(KyberNetwork _kyberNetwork) public {
        kyberNetwork = _kyberNetwork;
    }

    function setPrice(ERC20 _token, uint256 _price) public onlyManager {
        cachedPrices[address(_token)] = _price;
    }

    function setPriceForTokenList(ERC20[] calldata _tokens, uint256[] calldata _prices) external onlyManager {
        for (uint16 i = 0; i < _tokens.length; i++) {
            setPrice(_tokens[i], _prices[i]);
        }
    }

    /**
     * @dev Converts the value of _amount tokens in ether.
     * @param _amount the amount of tokens to convert (in 'token wei' twei)
     * @param _token the ERC20 token contract
     * @return the ether value (in wei) of _amount tokens with contract _token
     */
    function getEtherValue(uint256 _amount, address _token) external view returns (uint256) {
        uint256 decimals = ERC20(_token).decimals();
        uint256 price = cachedPrices[_token];
        return price.mul(_amount).div(10**decimals);
    }

    //
    // The following is added to be backward-compatible with Argent's old backend
    //

    function setKyberNetwork(KyberNetwork _kyberNetwork) external onlyManager {
        kyberNetwork = _kyberNetwork;
    }

    function syncPrice(ERC20 _token) external {
        require(address(kyberNetwork) != address(0), "Kyber sync is disabled");
        (uint256 expectedRate,) = kyberNetwork.getExpectedRate(_token, ERC20(ETH_TOKEN_ADDRESS), 10000);
        cachedPrices[address(_token)] = expectedRate;
    }

    function syncPriceForTokenList(ERC20[] calldata _tokens) external {
        require(address(kyberNetwork) != address(0), "Kyber sync is disabled");
        for (uint16 i = 0; i < _tokens.length; i++) {
            (uint256 expectedRate,) = kyberNetwork.getExpectedRate(_tokens[i], ERC20(ETH_TOKEN_ADDRESS), 10000);
            cachedPrices[address(_tokens[i])] = expectedRate;
        }
    }
}// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.










/**
 * @title TransferManager
 * @dev Module to transfer and approve tokens (ETH or ERC20) or data (contract call) based on a security context (daily limit, whitelist, etc).
 * This module is the V2 of TokenTransfer.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract TransferManager is BaseModule, RelayerModule, OnlyOwnerModule, BaseTransfer, LimitManager {

    bytes32 constant NAME = "TransferManager";

    bytes4 private constant ERC1271_ISVALIDSIGNATURE_BYTES = bytes4(keccak256("isValidSignature(bytes,bytes)"));
    bytes4 private constant ERC1271_ISVALIDSIGNATURE_BYTES32 = bytes4(keccak256("isValidSignature(bytes32,bytes)"));

    enum ActionType { Transfer }

    using SafeMath for uint256;

    struct TokenManagerConfig {
        // Mapping between pending action hash and their timestamp
        mapping (bytes32 => uint256) pendingActions;
    }

    // wallet specific storage
    mapping (address => TokenManagerConfig) internal configs;

    // The security period
    uint256 public securityPeriod;
    // The execution window
    uint256 public securityWindow;
    // The Token storage
    TransferStorage public transferStorage;
    // The Token price provider
    TokenPriceProvider public priceProvider;
    // The previous limit manager needed to migrate the limits
    LimitManager public oldLimitManager;

    // *************** Events *************************** //

    event AddedToWhitelist(address indexed wallet, address indexed target, uint64 whitelistAfter);
    event RemovedFromWhitelist(address indexed wallet, address indexed target);
    event PendingTransferCreated(address indexed wallet, bytes32 indexed id, uint256 indexed executeAfter,
    address token, address to, uint256 amount, bytes data);
    event PendingTransferExecuted(address indexed wallet, bytes32 indexed id);
    event PendingTransferCanceled(address indexed wallet, bytes32 indexed id);

    // *************** Constructor ********************** //

    constructor(
        ModuleRegistry _registry,
        TransferStorage _transferStorage,
        GuardianStorage _guardianStorage,
        address _priceProvider,
        uint256 _securityPeriod,
        uint256 _securityWindow,
        uint256 _defaultLimit,
        LimitManager _oldLimitManager
    )
        BaseModule(_registry, _guardianStorage, NAME)
        LimitManager(_defaultLimit)
        public
    {
        transferStorage = _transferStorage;
        priceProvider = TokenPriceProvider(_priceProvider);
        securityPeriod = _securityPeriod;
        securityWindow = _securityWindow;
        oldLimitManager = _oldLimitManager;
    }

    /**
     * @dev Inits the module for a wallet by setting up the isValidSignature (EIP 1271)
     * static call redirection from the wallet to the module and copying all the parameters
     * of the daily limit from the previous implementation of the LimitManager module.
     * @param _wallet The target wallet.
     */
    function init(BaseWallet _wallet) public onlyWallet(_wallet) {

        // setup static calls
        _wallet.enableStaticCall(address(this), ERC1271_ISVALIDSIGNATURE_BYTES);
        _wallet.enableStaticCall(address(this), ERC1271_ISVALIDSIGNATURE_BYTES32);

        // setup default limit for new deployment
        if (address(oldLimitManager) == address(0)) {
            super.init(_wallet);
            return;
        }
        // get limit from previous LimitManager
        uint256 current = oldLimitManager.getCurrentLimit(_wallet);
        (uint256 pending, uint64 changeAfter) = oldLimitManager.getPendingLimit(_wallet);
        // setup default limit for new wallets
        if (current == 0 && changeAfter == 0) {
            super.init(_wallet);
            return;
        }
        // migrate existing limit for existing wallets
        if (current == pending) {
            limits[address(_wallet)].limit.current = uint128(current);
        } else {
            limits[address(_wallet)].limit = Limit(uint128(current), uint128(pending), changeAfter);
        }
        // migrate daily pending if we are within a rolling period
        (uint256 unspent, uint64 periodEnd) = oldLimitManager.getDailyUnspent(_wallet);
        // solium-disable-next-line security/no-block-members
        if (periodEnd > now) {
            limits[address(_wallet)].dailySpent = DailySpent(uint128(current.sub(unspent)), periodEnd);
        }
    }

    // *************** External/Public Functions ********************* //

    /**
    * @dev lets the owner transfer tokens (ETH or ERC20) from a wallet.
    * @param _wallet The target wallet.
    * @param _token The address of the token to transfer.
    * @param _to The destination address
    * @param _amount The amoutn of token to transfer
    * @param _data The data for the transaction
    */
    function transferToken(
        BaseWallet _wallet,
        address _token,
        address _to,
        uint256 _amount,
        bytes calldata _data
    )
        external
        onlyWalletOwner(_wallet)
        onlyWhenUnlocked(_wallet)
    {
        if (isWhitelisted(_wallet, _to)) {
            // transfer to whitelist
            doTransfer(_wallet, _token, _to, _amount, _data);
        } else {
            uint256 etherAmount = (_token == ETH_TOKEN) ? _amount : priceProvider.getEtherValue(_amount, _token);
            if (checkAndUpdateDailySpent(_wallet, etherAmount)) {
                // transfer under the limit
                doTransfer(_wallet, _token, _to, _amount, _data);
            } else {
                // transfer above the limit
                (bytes32 id, uint256 executeAfter) = addPendingAction(ActionType.Transfer, _wallet, _token, _to, _amount, _data);
                emit PendingTransferCreated(address(_wallet), id, executeAfter, _token, _to, _amount, _data);
            }
        }
    }

    /**
    * @dev lets the owner approve an allowance of ERC20 tokens for a spender (dApp).
    * @param _wallet The target wallet.
    * @param _token The address of the token to transfer.
    * @param _spender The address of the spender
    * @param _amount The amount of tokens to approve
    */
    function approveToken(
        BaseWallet _wallet,
        address _token,
        address _spender,
        uint256 _amount
    )
        external
        onlyWalletOwner(_wallet)
        onlyWhenUnlocked(_wallet)
    {
        if (isWhitelisted(_wallet, _spender)) {
            // approve to whitelist
            doApproveToken(_wallet, _token, _spender, _amount);
        } else {
            // get current alowance
            uint256 currentAllowance = ERC20(_token).allowance(address(_wallet), _spender);
            if (_amount <= currentAllowance) {
                // approve if we reduce the allowance
                doApproveToken(_wallet, _token, _spender, _amount);
            } else {
                // check if delta is under the limit
                uint delta = _amount - currentAllowance;
                uint256 deltaInEth = priceProvider.getEtherValue(delta, _token);
                require(checkAndUpdateDailySpent(_wallet, deltaInEth), "TM: Approve above daily limit");
                // approve if under the limit
                doApproveToken(_wallet, _token, _spender, _amount);
            }
        }
    }

    /**
    * @dev lets the owner call a contract.
    * @param _wallet The target wallet.
    * @param _contract The address of the contract.
    * @param _value The amount of ETH to transfer as part of call
    * @param _data The encoded method data
    */
    function callContract(
        BaseWallet _wallet,
        address _contract,
        uint256 _value,
        bytes calldata _data
    )
        external
        onlyWalletOwner(_wallet)
        onlyWhenUnlocked(_wallet)
    {
        // Make sure we don't call a module, the wallet itself, or a supported ERC20
        authoriseContractCall(_wallet, _contract);

        if (isWhitelisted(_wallet, _contract)) {
            // call to whitelist
            doCallContract(_wallet, _contract, _value, _data);
        } else {
            require(checkAndUpdateDailySpent(_wallet, _value), "TM: Call contract above daily limit");
            // call under the limit
            doCallContract(_wallet, _contract, _value, _data);
        }
    }

    /**
    * @dev lets the owner do an ERC20 approve followed by a call to a contract.
    * We assume that the contract will pull the tokens and does not require ETH.
    * @param _wallet The target wallet.
    * @param _token The token to approve.
    * @param _spender The address to approve.
    * @param _amount The amount of ERC20 tokens to approve.
    * @param _contract The address of the contract.
    * @param _data The encoded method data
    */
    function approveTokenAndCallContract(
        BaseWallet _wallet,
        address _token,
        address _spender,
        uint256 _amount,
        address _contract,
        bytes calldata _data
    )
        external
        onlyWalletOwner(_wallet)
        onlyWhenUnlocked(_wallet)
    {
        // Make sure we don't call a module, the wallet itself, or a supported ERC20
        authoriseContractCall(_wallet, _contract);

        if (!isWhitelisted(_wallet, _spender)) {
            // check if the amount is under the daily limit
            // check the entire amount because the currently approved amount will be restored and should still count towards the daily limit
            uint256 valueInEth = priceProvider.getEtherValue(_amount, _token);
            require(checkAndUpdateDailySpent(_wallet, valueInEth), "TM: Approve above daily limit");
        }

        doApproveTokenAndCallContract(_wallet, _token, _spender, _amount, _contract, _data);
    }

    /**
     * @dev Adds an address to the whitelist of a wallet.
     * @param _wallet The target wallet.
     * @param _target The address to add.
     */
    function addToWhitelist(
        BaseWallet _wallet,
        address _target
    )
        external
        onlyWalletOwner(_wallet)
        onlyWhenUnlocked(_wallet)
    {
        require(!isWhitelisted(_wallet, _target), "TT: target already whitelisted");
        // solium-disable-next-line security/no-block-members
        uint256 whitelistAfter = now.add(securityPeriod);
        transferStorage.setWhitelist(_wallet, _target, whitelistAfter);
        emit AddedToWhitelist(address(_wallet), _target, uint64(whitelistAfter));
    }

    /**
     * @dev Removes an address from the whitelist of a wallet.
     * @param _wallet The target wallet.
     * @param _target The address to remove.
     */
    function removeFromWhitelist(
        BaseWallet _wallet,
        address _target
    )
        external
        onlyWalletOwner(_wallet)
        onlyWhenUnlocked(_wallet)
    {
        require(isWhitelisted(_wallet, _target), "TT: target not whitelisted");
        transferStorage.setWhitelist(_wallet, _target, 0);
        emit RemovedFromWhitelist(address(_wallet), _target);
    }

    /**
    * @dev Executes a pending transfer for a wallet.
    * The method can be called by anyone to enable orchestration.
    * @param _wallet The target wallet.
    * @param _token The token of the pending transfer.
    * @param _to The destination address of the pending transfer.
    * @param _amount The amount of token to transfer of the pending transfer.
    * @param _data The data associated to the pending transfer.
    * @param _block The block at which the pending transfer was created.
    */
    function executePendingTransfer(
        BaseWallet _wallet,
        address _token,
        address _to,
        uint _amount,
        bytes calldata _data,
        uint _block
    )
        external
        onlyWhenUnlocked(_wallet)
    {
        bytes32 id = keccak256(abi.encodePacked(ActionType.Transfer, _token, _to, _amount, _data, _block));
        uint executeAfter = configs[address(_wallet)].pendingActions[id];
        require(executeAfter > 0, "TT: unknown pending transfer");
        uint executeBefore = executeAfter.add(securityWindow);
        // solium-disable-next-line security/no-block-members
        require(executeAfter <= now && now <= executeBefore, "TT: transfer outside of the execution window");
        delete configs[address(_wallet)].pendingActions[id];
        doTransfer(_wallet, _token, _to, _amount, _data);
        emit PendingTransferExecuted(address(_wallet), id);
    }

    function cancelPendingTransfer(
        BaseWallet _wallet,
        bytes32 _id
    )
        external
        onlyWalletOwner(_wallet)
        onlyWhenUnlocked(_wallet)
    {
        require(configs[address(_wallet)].pendingActions[_id] > 0, "TT: unknown pending action");
        delete configs[address(_wallet)].pendingActions[_id];
        emit PendingTransferCanceled(address(_wallet), _id);
    }

    /**
     * @dev Lets the owner of a wallet change its daily limit.
     * The limit is expressed in ETH. Changes to the limit take 24 hours.
     * @param _wallet The target wallet.
     * @param _newLimit The new limit.
     */
    function changeLimit(BaseWallet _wallet, uint256 _newLimit) external onlyWalletOwner(_wallet) onlyWhenUnlocked(_wallet) {
        changeLimit(_wallet, _newLimit, securityPeriod);
    }

    /**
     * @dev Convenience method to disable the limit
     * The limit is disabled by setting it to an arbitrary large value.
     * @param _wallet The target wallet.
     */
    function disableLimit(BaseWallet _wallet) external onlyWalletOwner(_wallet) onlyWhenUnlocked(_wallet) {
        disableLimit(_wallet, securityPeriod);
    }

    /**
    * @dev Checks if an address is whitelisted for a wallet.
    * @param _wallet The target wallet.
    * @param _target The address.
    * @return true if the address is whitelisted.
    */
    function isWhitelisted(BaseWallet _wallet, address _target) public view returns (bool _isWhitelisted) {
        uint whitelistAfter = transferStorage.getWhitelist(_wallet, _target);
        // solium-disable-next-line security/no-block-members
        return whitelistAfter > 0 && whitelistAfter < now;
    }

    /**
    * @dev Gets the info of a pending transfer for a wallet.
    * @param _wallet The target wallet.
    * @param _id The pending transfer ID.
    * @return the epoch time at which the pending transfer can be executed.
    */
    function getPendingTransfer(BaseWallet _wallet, bytes32 _id) external view returns (uint64 _executeAfter) {
        _executeAfter = uint64(configs[address(_wallet)].pendingActions[_id]);
    }

    /**
    * @dev Implementation of EIP 1271.
    * Should return whether the signature provided is valid for the provided data.
    * @param _data Arbitrary length data signed on the behalf of address(this)
    * @param _signature Signature byte array associated with _data
    */
    function isValidSignature(bytes calldata _data, bytes calldata _signature) external view returns (bytes4) {
        bytes32 msgHash = keccak256(abi.encodePacked(_data));
        isValidSignature(msgHash, _signature);
        return ERC1271_ISVALIDSIGNATURE_BYTES;
    }

    /**
    * @dev Implementation of EIP 1271.
    * Should return whether the signature provided is valid for the provided data.
    * @param _msgHash Hash of a message signed on the behalf of address(this)
    * @param _signature Signature byte array associated with _msgHash
    */
    function isValidSignature(bytes32 _msgHash, bytes memory _signature) public view returns (bytes4) {
        require(_signature.length == 65, "TM: invalid signature length");
        address signer = recoverSigner(_msgHash, _signature, 0);
        require(isOwner(BaseWallet(msg.sender), signer), "TM: Invalid signer");
        return ERC1271_ISVALIDSIGNATURE_BYTES32;
    }

    // *************** Internal Functions ********************* //

    /**
     * @dev Creates a new pending action for a wallet.
     * @param _action The target action.
     * @param _wallet The target wallet.
     * @param _token The target token for the action.
     * @param _to The recipient of the action.
     * @param _amount The amount of token associated to the action.
     * @param _data The data associated to the action.
     * @return the identifier for the new pending action and the time when the action can be executed
     */
    function addPendingAction(
        ActionType _action,
        BaseWallet _wallet,
        address _token,
        address _to,
        uint _amount,
        bytes memory _data
    )
        internal
        returns (bytes32 id, uint256 executeAfter)
    {
        id = keccak256(abi.encodePacked(_action, _token, _to, _amount, _data, block.number));
        require(configs[address(_wallet)].pendingActions[id] == 0, "TM: duplicate pending action");
        // solium-disable-next-line security/no-block-members
        executeAfter = now.add(securityPeriod);
        configs[address(_wallet)].pendingActions[id] = executeAfter;
    }

    /**
    * @dev Make sure a contract call is not trying to call a module, the wallet itself, or a supported ERC20.
    * @param _wallet The target wallet.
    * @param _contract The address of the contract.
     */
    function authoriseContractCall(BaseWallet _wallet, address _contract) internal view {
        require(
            _contract != address(_wallet) && // not the wallet itself
            !_wallet.authorised(_contract) && // not an authorised module
            (priceProvider.cachedPrices(_contract) == 0 || isLimitDisabled(_wallet)), // not an ERC20 listed in the provider (or limit disabled)
            "TM: Forbidden contract");
    }

    // *************** Implementation of RelayerModule methods ********************* //

    // Overrides refund to add the refund in the daily limit.
    function refund(BaseWallet _wallet, uint _gasUsed, uint _gasPrice, uint _gasLimit, uint _signatures, address _relayer) internal {
        // 21000 (transaction) + 7620 (execution of refund) + 7324 (execution of updateDailySpent) + 672 to log the event + _gasUsed
        uint256 amount = 36616 + _gasUsed;
        if (_gasPrice > 0 && _signatures > 0 && amount <= _gasLimit) {
            if (_gasPrice > tx.gasprice) {
                amount = amount * tx.gasprice;
            } else {
                amount = amount * _gasPrice;
            }
            checkAndUpdateDailySpent(_wallet, amount);
            invokeWallet(address(_wallet), _relayer, amount, EMPTY_BYTES);
        }
    }

    // Overrides verifyRefund to add the refund in the daily limit.
    function verifyRefund(BaseWallet _wallet, uint _gasUsed, uint _gasPrice, uint _signatures) internal view returns (bool) {
        if (_gasPrice > 0 && _signatures > 0 && (
            address(_wallet).balance < _gasUsed * _gasPrice ||
            isWithinDailyLimit(_wallet, getCurrentLimit(_wallet), _gasUsed * _gasPrice) == false ||
            _wallet.authorised(address(this)) == false
        ))
        {
            return false;
        }
        return true;
    }
}

// ███████╗░█████╗░██████╗░██████╗░███████╗██████╗░░░░███████╗██╗
// ╚════██║██╔══██╗██╔══██╗██╔══██╗██╔════╝██╔══██╗░░░██╔════╝██║
// ░░███╔═╝███████║██████╔╝██████╔╝█████╗░░██████╔╝░░░█████╗░░██║
// ██╔══╝░░██╔══██║██╔═══╝░██╔═══╝░██╔══╝░░██╔══██╗░░░██╔══╝░░██║
// ███████╗██║░░██║██║░░░░░██║░░░░░███████╗██║░░██║██╗██║░░░░░██║
// ╚══════╝╚═╝░░╚═╝╚═╝░░░░░╚═╝░░░░░╚══════╝╚═╝░░╚═╝╚═╝╚═╝░░░░░╚═╝
// Copyright (C) 2020 zapper, nodar, suhail, seb, sumit, apoorv

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

///@author Zapper
///@notice This contract adds/removes liquidity to/from yEarn Vaults using ETH or ERC20 Tokens.
// SPDX-License-Identifier: GPLv2

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/math/SafeMath.sol

pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/ReentrancyGuard.sol

pragma solidity ^0.6.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() internal {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.6.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount)
        external
        returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Address.sol

pragma solidity ^0.6.2;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(
            address(this).balance >= amount,
            "Address: insufficient balance"
        );

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{value: amount}("");
        require(
            success,
            "Address: unable to send value, recipient may have reverted"
        );
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data)
        internal
        returns (bytes memory)
    {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                "Address: low-level call with value failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(
            address(this).balance >= value,
            "Address: insufficient balance for call"
        );
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 weiValue,
        string memory errorMessage
    ) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{value: weiValue}(
            data
        );
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/GSN/Context.sol

pragma solidity ^0.6.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal virtual view returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal virtual view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/access/Ownable.sol

pragma solidity ^0.6.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: yVault_ZapInOut_General_V1_2.sol

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

interface IUniswapV2Factory {
    function getPair(address tokenA, address tokenB)
        external
        view
        returns (address);
}

interface IUniswapRouter02 {
    //get estimated amountOut
    function getAmountsOut(uint256 amountIn, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);

    function getAmountsIn(uint256 amountOut, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);

    //token 2 token
    function swapExactTokensForTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapTokensForExactTokens(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    //eth 2 token
    function swapExactETHForTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function swapETHForExactTokens(
        uint256 amountOut,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    //token 2 eth
    function swapTokensForExactETH(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactTokensForETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);
}

interface yVault {
    function deposit(uint256) external;

    function withdraw(uint256) external;

    function getPricePerFullShare() external view returns (uint256);

    function token() external view returns (address);
}

interface ICurveZapInGeneral {
    function ZapIn(
        address _toWhomToIssue,
        address _IncomingTokenAddress,
        address _curvePoolExchangeAddress,
        uint256 _IncomingTokenQty,
        uint256 _minPoolTokens
    ) external payable returns (uint256 crvTokensBought);
}

interface ICurveZapOutGeneral {
    function ZapOut(
        address payable _toWhomToIssue,
        address _curveExchangeAddress,
        uint256 _tokenCount,
        uint256 _IncomingCRV,
        address _ToTokenAddress,
        uint256 _minToTokens
    ) external returns (uint256 ToTokensBought);
}

interface IAaveLendingPoolAddressesProvider {
    function getLendingPool() external view returns (address);

    function getLendingPoolCore() external view returns (address payable);
}

interface IAaveLendingPool {
    function deposit(
        address _reserve,
        uint256 _amount,
        uint16 _referralCode
    ) external payable;
}

interface IAToken {
    function redeem(uint256 _amount) external;

    function underlyingAssetAddress() external returns (address);
}

interface IWETH {
    function deposit() external payable;

    function withdraw(uint256) external;
}

contract yVault_ZapInOut_General_V1_4 is ReentrancyGuard, Ownable {
    using SafeMath for uint256;
    using Address for address;
    using SafeERC20 for IERC20;
    bool public stopped = false;
    uint16 public goodwill;

    IUniswapV2Factory
        private constant UniSwapV2FactoryAddress = IUniswapV2Factory(
        0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f
    );
    IUniswapRouter02 private constant uniswapRouter = IUniswapRouter02(
        0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
    );

    ICurveZapInGeneral public CurveZapInGeneral = ICurveZapInGeneral(
        0xBB7678acd5494cA06d9738DCBD2BdF1c6d58672f
    );
    ICurveZapOutGeneral public CurveZapOutGeneral = ICurveZapOutGeneral(
        0x4bF331Aa2BfB0869315fB81a350d109F4839f81b
    );
    
    IAaveLendingPoolAddressesProvider
        private constant lendingPoolAddressProvider = IAaveLendingPoolAddressesProvider(
        0x24a42fD28C976A61Df5D00D0599C34c4f90748c8
    );

    address private constant yCurveExchangeAddress = 0xbBC81d23Ea2c3ec7e56D39296F0cbB648873a5d3;
    address private constant sBtcCurveExchangeAddress = 0x7fC77b5c7614E1533320Ea6DDc2Eb61fa00A9714;
    address private constant bUSDCurveExchangeAddress = 0xb6c057591E073249F2D9D88Ba59a46CFC9B59EdB;
    
    address private constant yCurvePoolTokenAddress = 0xdF5e0e81Dff6FAF3A7e52BA697820c5e32D806A8;
    address private constant sBtcCurvePoolTokenAddress = 0x075b1bb99792c9E1041bA13afEf80C91a1e70fB3;
    address private constant bUSDCurvePoolTokenAddress = 0x3B3Ac5386837Dc563660FB6a0937DFAa5924333B;
    
    mapping(address => address) internal token2Exchange;

    address
        private constant ETHAddress = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    address
        private constant wethTokenAddress = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
    address
        private constant zgoodwillAddress = 0xE737b6AfEC2320f616297e59445b60a11e3eF75F;

    uint256
        private constant deadline = 0xf000000000000000000000000000000000000000000000000000000000000000;

    event Zapin(
        address _toWhomToIssue,
        address _toYVaultAddress,
        uint256 _Outgoing
    );

    event Zapout(
        address _toWhomToIssue,
        address _fromYVaultAddress,
        address _toTokenAddress,
        uint256 _tokensRecieved
    );

    constructor(uint16 _goodwill) public {
        goodwill = _goodwill;
        
        token2Exchange[yCurvePoolTokenAddress] = yCurveExchangeAddress;
        token2Exchange[bUSDCurvePoolTokenAddress] = bUSDCurveExchangeAddress;
        token2Exchange[sBtcCurvePoolTokenAddress] = sBtcCurveExchangeAddress;
    }

    // circuit breaker modifiers
    modifier stopInEmergency {
        if (stopped) {
            revert("Temporarily Paused");
        } else {
            _;
        }
    }

    function updateCurveZapIn(address CurveZapInGeneralAddress)
        public
        onlyOwner
    {
        require(CurveZapInGeneralAddress != address(0), "Invalid Address");
        CurveZapInGeneral = ICurveZapInGeneral(CurveZapInGeneralAddress);
    }
    
    function updateCurveZapOut(address CurveZapOutGeneralAddress)
        public
        onlyOwner
    {
        require(CurveZapOutGeneralAddress != address(0), "Invalid Address");
        CurveZapOutGeneral = ICurveZapOutGeneral(CurveZapOutGeneralAddress);
    }
    
    function addNewCurveExchange(address curvePoolToken, address curveExchangeAddress)
        public
        onlyOwner
    {
        require(curvePoolToken != address(0) && curveExchangeAddress != address(0), "Invalid Address");
        token2Exchange[curvePoolToken] = curveExchangeAddress;
    }

    /**
    @notice This function is used to add liquidity to yVaults
    @param _toWhomToIssue recipient address
    @param _toYVaultAddress The address of vault to add liquidity to
    @param _vaultType Type of underlying token: 0 token; 1 aToken; 2 LP token
    @param _fromTokenAddress The token used for investment (address(0x00) if ether)
    @param _amount The amount of ERC to invest
    @param _minTokensSwapped for slippage
    @return yTokensRec
     */
    function ZapIn(
        address _toWhomToIssue,
        address _toYVaultAddress,
        uint16 _vaultType,
        address _fromTokenAddress,
        uint256 _amount,
        uint256 _minTokensSwapped
    ) public payable nonReentrant stopInEmergency returns (uint256) {
        yVault vaultToEnter = yVault(_toYVaultAddress);
        address underlyingVaultToken = vaultToEnter.token();

        if (_fromTokenAddress == address(0)) {
            require(msg.value > 0, "ERR: No ETH sent");
        } else {
            require(_amount > 0, "Err: No Tokens Sent");
            require(msg.value == 0, "ERR: ETH sent with Token");

            IERC20(_fromTokenAddress).safeTransferFrom(
                msg.sender,
                address(this),
                _amount
            );
        }
        if (underlyingVaultToken == _fromTokenAddress) {
            IERC20(underlyingVaultToken).safeApprove(
                address(vaultToEnter),
                _amount
            );
            vaultToEnter.deposit(_amount);
        } else {
            // Curve Vaults
            if (_vaultType == 2) {
                address curveExchangeAddr = token2Exchange[underlyingVaultToken];
                
                uint256 tokensBought;
                if (_fromTokenAddress == address(0)) {
                    tokensBought = CurveZapInGeneral.ZapIn{value: msg.value}(
                        address(this),
                        address(0),
                        curveExchangeAddr,
                        msg.value,
                        _minTokensSwapped
                    );
                } else {
                    IERC20(_fromTokenAddress).safeApprove(
                        address(CurveZapInGeneral),
                        _amount
                    );
                    tokensBought = CurveZapInGeneral.ZapIn(
                        address(this),
                        _fromTokenAddress,
                        curveExchangeAddr,
                        _amount,
                        _minTokensSwapped
                    );
                }

                IERC20(underlyingVaultToken).safeApprove(
                    address(vaultToEnter),
                    tokensBought
                );
                vaultToEnter.deposit(tokensBought);
            } else if (_vaultType == 1) {
                address underlyingAsset = IAToken(underlyingVaultToken)
                    .underlyingAssetAddress();

                uint256 tokensBought;
                if (_fromTokenAddress == address(0)) {
                    tokensBought = _eth2Token(
                        underlyingAsset,
                        _minTokensSwapped
                    );
                } else {
                    tokensBought = _token2Token(
                        _fromTokenAddress,
                        underlyingAsset,
                        _amount,
                        _minTokensSwapped
                    );
                }

                IERC20(underlyingAsset).safeApprove(
                    lendingPoolAddressProvider.getLendingPoolCore(),
                    tokensBought
                );

                IAaveLendingPool(lendingPoolAddressProvider.getLendingPool())
                    .deposit(underlyingAsset, tokensBought, 0);

                uint256 aTokensBought = IERC20(underlyingVaultToken).balanceOf(
                    address(this)
                );
                IERC20(underlyingVaultToken).safeApprove(
                    address(vaultToEnter),
                    aTokensBought
                );
                vaultToEnter.deposit(aTokensBought);
            } else {
                uint256 tokensBought;
                if (_fromTokenAddress == address(0)) {
                    tokensBought = _eth2Token(
                        underlyingVaultToken,
                        _minTokensSwapped
                    );
                } else {
                    tokensBought = _token2Token(
                        _fromTokenAddress,
                        underlyingVaultToken,
                        _amount,
                        _minTokensSwapped
                    );
                }

                IERC20(underlyingVaultToken).safeApprove(
                    address(vaultToEnter),
                    tokensBought
                );
                vaultToEnter.deposit(tokensBought);
            }
        }

        uint256 yTokensRec = IERC20(address(vaultToEnter)).balanceOf(
            address(this)
        );

        //transfer goodwill
        uint256 goodwillPortion = _transferGoodwill(
            address(vaultToEnter),
            yTokensRec
        );

        IERC20(address(vaultToEnter)).safeTransfer(
            _toWhomToIssue,
            yTokensRec.sub(goodwillPortion)
        );

        emit Zapin(
            _toWhomToIssue,
            address(vaultToEnter),
            yTokensRec.sub(goodwillPortion)
        );

        return (yTokensRec.sub(goodwillPortion));
    }

    /**
    @notice This function is used to remove liquidity from yVaults
    @param _toWhomToIssue recipient address
    @param _ToTokenContractAddress The address of the token to withdraw
    @param _fromYVaultAddress The address of the vault to exit
    @param _vaultType Type of underlying token: 0 token; 1 aToken; 2 LP token
    @param _IncomingAmt The amount of vault tokens removed
    @param _minTokensRec for slippage
    @return toTokensReceived
     */  
    function ZapOut(
        address _toWhomToIssue,
        address _ToTokenContractAddress,
        address _fromYVaultAddress,
        uint16 _vaultType,
        uint256 _IncomingAmt,
        uint256 _minTokensRec
    ) public nonReentrant stopInEmergency returns (uint256) {
        yVault vaultToExit = yVault(_fromYVaultAddress);
        address underlyingVaultToken = vaultToExit.token();

        IERC20(address(vaultToExit)).safeTransferFrom(
            msg.sender,
            address(this),
            _IncomingAmt
        );
        
        uint256 goodwillPortion = _transferGoodwill(
            address(vaultToExit),
            _IncomingAmt
        );

        vaultToExit.withdraw(_IncomingAmt.sub(goodwillPortion));
        uint256 underlyingReceived = IERC20(underlyingVaultToken).balanceOf(
            address(this)
        );
        
        uint256 toTokensReceived;
        if(_ToTokenContractAddress == underlyingVaultToken) {
            IERC20(underlyingVaultToken).safeTransfer(
                _toWhomToIssue,
                underlyingReceived
            );
            toTokensReceived = underlyingReceived;
        } else {
            if(_vaultType == 2) {
                toTokensReceived = _withdrawFromCurve(
                    underlyingVaultToken,
                    underlyingReceived,
                    _toWhomToIssue,
                    _ToTokenContractAddress,
                    _minTokensRec
                );
            } else if(_vaultType == 1) {
                // unwrap atoken
                IAToken(underlyingVaultToken).redeem(underlyingReceived);
                address underlyingAsset = IAToken(underlyingVaultToken)
                        .underlyingAssetAddress();
                
                // swap
                if(_ToTokenContractAddress == address(0)) {
                    toTokensReceived = _token2Eth(
                        underlyingAsset,
                        underlyingReceived,
                        payable(_toWhomToIssue),
                        _minTokensRec
                    );
                } else {
                    toTokensReceived = _token2Token(
                        underlyingAsset,
                        _ToTokenContractAddress,
                        underlyingReceived,
                        _minTokensRec
                    );
                    IERC20(_ToTokenContractAddress).safeTransfer(
                        _toWhomToIssue,
                        toTokensReceived
                    );
                }
            } else {
                if(_ToTokenContractAddress == address(0)) {
                    toTokensReceived = _token2Eth(
                        underlyingVaultToken,
                        underlyingReceived,
                        payable(_toWhomToIssue),
                        _minTokensRec
                    );
                } else {
                    toTokensReceived = _token2Token(
                        underlyingVaultToken,
                        _ToTokenContractAddress,
                        underlyingReceived,
                        _minTokensRec
                    );
                    
                    IERC20(_ToTokenContractAddress).safeTransfer(
                        _toWhomToIssue,
                        toTokensReceived
                    );
                }
            }
        }
        
        emit Zapout(
            _toWhomToIssue,
            _fromYVaultAddress,
            _ToTokenContractAddress,
            toTokensReceived
        );
        
        return toTokensReceived;
    }
    
    function _withdrawFromCurve(
        address _CurvePoolToken,
        uint256 _tokenAmt,
        address _toWhomToIssue,
        address _ToTokenContractAddress,
        uint256 _minTokensRec
    ) internal returns(uint256) {
        IERC20(_CurvePoolToken).safeApprove(
            address(CurveZapOutGeneral),
            _tokenAmt
        );
        
        address curveExchangeAddr = token2Exchange[_CurvePoolToken];
        uint256 tokenCount = 4;
        
        if(curveExchangeAddr == sBtcCurveExchangeAddress) {
            tokenCount = 3;
        }
            
        return(
            CurveZapOutGeneral.ZapOut(
                payable(_toWhomToIssue),
                curveExchangeAddr,
                tokenCount,
                _tokenAmt,
                _ToTokenContractAddress,
                _minTokensRec
            )
        );
    }

    /**
    @notice This function is used to swap eth for tokens
    @param _tokenContractAddress Token address which we want to buy
    @param minTokens recieved after swap for slippage
    @return tokensBought The quantity of token bought
     */
    function _eth2Token(address _tokenContractAddress, uint256 minTokens)
        internal
        returns (uint256 tokensBought)
    {
        if(_tokenContractAddress == wethTokenAddress) {
            IWETH(wethTokenAddress).deposit{value: msg.value}();
            return msg.value;
        }

        address[] memory path = new address[](2);
        path[0] = wethTokenAddress;
        path[1] = _tokenContractAddress;
        tokensBought = uniswapRouter.swapExactETHForTokens{value: msg.value}(
            1,
            path,
            address(this),
            deadline
        )[path.length - 1];
        require(tokensBought >= minTokens, "ERR: High Slippage");
    }

    /**
    @notice This function is used to swap tokens
    @param _FromTokenContractAddress The token address to swap from
    @param _ToTokenContractAddress The token address to swap to
    @param tokens2Trade The amount of tokens to swap
    @param minTokens recieved after swap for slippage
    @return tokenBought The quantity of tokens bought
    */
    function _token2Token(
        address _FromTokenContractAddress,
        address _ToTokenContractAddress,
        uint256 tokens2Trade,
        uint256 minTokens
    ) internal returns (uint256 tokenBought) {
        if (_FromTokenContractAddress == _ToTokenContractAddress) {
            return tokens2Trade;
        }

        IERC20(_FromTokenContractAddress).safeApprove(
            address(uniswapRouter),
            tokens2Trade
        );

        if (_FromTokenContractAddress != wethTokenAddress) {
            if (_ToTokenContractAddress != wethTokenAddress) {
                address[] memory path = new address[](3);
                path[0] = _FromTokenContractAddress;
                path[1] = wethTokenAddress;
                path[2] = _ToTokenContractAddress;
                tokenBought = uniswapRouter.swapExactTokensForTokens(
                    tokens2Trade,
                    1,
                    path,
                    address(this),
                    deadline
                )[path.length - 1];
            } else {
                address[] memory path = new address[](2);
                path[0] = _FromTokenContractAddress;
                path[1] = wethTokenAddress;

                tokenBought = uniswapRouter.swapExactTokensForTokens(
                    tokens2Trade,
                    1,
                    path,
                    address(this),
                    deadline
                )[path.length - 1];
            }
        } else {
            address[] memory path = new address[](2);
            path[0] = wethTokenAddress;
            path[1] = _ToTokenContractAddress;
            tokenBought = uniswapRouter.swapExactTokensForTokens(
                tokens2Trade,
                1,
                path,
                address(this),
                deadline
            )[path.length - 1];
        }

        require(tokenBought > minTokens, "ERR: High Slippage");
    }
    
    function _token2Eth(
        address _FromTokenContractAddress,
        uint256 tokens2Trade,
        address payable _toWhomToIssue,
        uint256 minTokens
    ) internal returns (uint256) {
        if (_FromTokenContractAddress == wethTokenAddress) {
            IWETH(wethTokenAddress).withdraw(tokens2Trade);
            _toWhomToIssue.transfer(tokens2Trade);
            return tokens2Trade;
        }

        IERC20(_FromTokenContractAddress).safeApprove(
            address(uniswapRouter),
            tokens2Trade
        );

        address[] memory path = new address[](2);
        path[0] = _FromTokenContractAddress;
        path[1] = wethTokenAddress;
        uint256 ethBought = uniswapRouter.swapExactTokensForETH(
                            tokens2Trade,
                            1,
                            path,
                            _toWhomToIssue,
                            deadline
                        )[path.length - 1];
        
        require(ethBought > minTokens, "Error: High Slippage");
        return ethBought;
    }

    /**
    @notice This function is used to calculate and transfer goodwill
    @param _tokenContractAddress Token in which goodwill is deducted
    @param tokens2Trade The total amount of tokens to be zapped in
    @return goodwillPortion The quantity of goodwill deducted
     */
    function _transferGoodwill(
        address _tokenContractAddress,
        uint256 tokens2Trade
    ) internal returns (uint256 goodwillPortion) {
        goodwillPortion = SafeMath.div(
            SafeMath.mul(tokens2Trade, goodwill),
            10000
        );

        if (goodwillPortion == 0) {
            return 0;
        }

        IERC20(_tokenContractAddress).safeTransfer(
            zgoodwillAddress,
            goodwillPortion
        );
    }

    function set_new_goodwill(uint16 _new_goodwill) public onlyOwner {
        require(
            _new_goodwill >= 0 && _new_goodwill < 10000,
            "GoodWill Value not allowed"
        );
        goodwill = _new_goodwill;
    }

    function inCaseTokengetsStuck(IERC20 _TokenAddress) public onlyOwner {
        uint256 qty = _TokenAddress.balanceOf(address(this));
        IERC20(address(_TokenAddress)).safeTransfer(owner(), qty);
    }

    // - to Pause the contract
    function toggleContractActive() public onlyOwner {
        stopped = !stopped;
    }

    // - to withdraw any ETH balance sitting in the contract
    function withdraw() public onlyOwner {
        uint256 contractBalance = address(this).balance;
        address payable _to = payable(owner());
        _to.transfer(contractBalance);
    }
    
    receive() external payable{}
}

pragma solidity ^0.5.16;

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract Context {
    constructor () internal { }
    // solhint-disable-previous-line no-empty-blocks

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;
    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }
    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }
    function transfer(address recipient, uint256 amount) public returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }
    function approve(address spender, uint256 amount) public returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }
    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }
    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    function _mint(address account, uint256 amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }
    function _burn(address account, uint256 amount) internal {
        require(account != address(0), "ERC20: burn from the zero address");

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }
    function _approve(address owner, address spender, uint256 amount) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    function _burnFrom(address account, uint256 amount) internal {
        _burn(account, amount);
        _approve(account, _msgSender(), _allowances[account][_msgSender()].sub(amount, "ERC20: burn amount exceeds allowance"));
    }
}

contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    constructor (string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }
    function name() public view returns (string memory) {
        return _name;
    }
    function symbol() public view returns (string memory) {
        return _symbol;
    }
    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;

        return c;
    }
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

library Address {
    function isContract(address account) internal view returns (bool) {
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != 0x0 && codehash != accountHash);
    }
    function toPayable(address account) internal pure returns (address payable) {
        return address(uint160(account));
    }
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-call-value
        (bool success, ) = recipient.call.value(amount)("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}

library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    function callOptionalReturn(IERC20 token, bytes memory data) private {
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

interface Controller {
    function withdraw(address, uint) external;
    function balanceOf(address) external view returns (uint);
    function earn(address, uint) external;
}

contract yVault is ERC20, ERC20Detailed {
    using SafeERC20 for IERC20;
    using Address for address;
    using SafeMath for uint256;
    
    IERC20 public token;
    
    uint public min = 9500;
    uint public constant max = 10000;
    
    address public governance;
    address public controller;
    
    constructor (address _token, address _controller) public ERC20Detailed(
        string(abi.encodePacked("yearn ", ERC20Detailed(_token).name())),
        string(abi.encodePacked("y", ERC20Detailed(_token).symbol())),
        ERC20Detailed(_token).decimals()
    ) {
        token = IERC20(_token);
        governance = msg.sender;
        controller = _controller;
    }
    
    function balance() public view returns (uint) {
        return token.balanceOf(address(this))
                .add(Controller(controller).balanceOf(address(token)));
    }
    
    function setMin(uint _min) external {
        require(msg.sender == governance, "!governance");
        min = _min;
    }
    
    function setGovernance(address _governance) public {
        require(msg.sender == governance, "!governance");
        governance = _governance;
    }
    
    function setController(address _controller) public {
        require(msg.sender == governance, "!governance");
        controller = _controller;
    }
    
    // Custom logic in here for how much the vault allows to be borrowed
    // Sets minimum required on-hand to keep small withdrawals cheap
    function available() public view returns (uint) {
        return token.balanceOf(address(this)).mul(min).div(max);
    }
    
    function earn() public {
        uint _bal = available();
        token.safeTransfer(controller, _bal);
        Controller(controller).earn(address(token), _bal);
    }
    
    function depositAll() external {
        deposit(token.balanceOf(msg.sender));
    }
    
    function deposit(uint _amount) public {
        uint _pool = balance();
        uint _before = token.balanceOf(address(this));
        token.safeTransferFrom(msg.sender, address(this), _amount);
        uint _after = token.balanceOf(address(this));
        _amount = _after.sub(_before); // Additional check for deflationary tokens
        uint shares = 0;
        if (totalSupply() == 0) {
            shares = _amount;
        } else {
            shares = (_amount.mul(totalSupply())).div(_pool);
        }
        _mint(msg.sender, shares);
    }
    
    function withdrawAll() external {
        withdraw(balanceOf(msg.sender));
    }
    
    
    // Used to swap any borrowed reserve over the debt limit to liquidate to 'token'
    function harvest(address reserve, uint amount) external {
        require(msg.sender == controller, "!controller");
        require(reserve != address(token), "token");
        IERC20(reserve).safeTransfer(controller, amount);
    }
    
    // No rebalance implementation for lower fees and faster swaps
    function withdraw(uint _shares) public {
        uint r = (balance().mul(_shares)).div(totalSupply());
        _burn(msg.sender, _shares);
        
        // Check balance
        uint b = token.balanceOf(address(this));
        if (b < r) {
            uint _withdraw = r.sub(b);
            Controller(controller).withdraw(address(token), _withdraw);
            uint _after = token.balanceOf(address(this));
            uint _diff = _after.sub(b);
            if (_diff < _withdraw) {
                r = b.add(_diff);
            }
        }
        
        token.safeTransfer(msg.sender, r);
    }
    
    function getPricePerFullShare() public view returns (uint) {
        return balance().mul(1e18).div(totalSupply());
    }
}

pragma solidity ^0.5.16;

interface IERC20 {
    function totalSupply() external view returns (uint);
    function balanceOf(address account) external view returns (uint);
    function transfer(address recipient, uint amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint);
    function approve(address spender, uint amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
}

contract Context {
    constructor () internal { }
    // solhint-disable-previous-line no-empty-blocks

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }
}

contract ERC20 is Context, IERC20 {
    using SafeMath for uint;

    mapping (address => uint) private _balances;

    mapping (address => mapping (address => uint)) private _allowances;

    uint private _totalSupply;
    function totalSupply() public view returns (uint) {
        return _totalSupply;
    }
    function balanceOf(address account) public view returns (uint) {
        return _balances[account];
    }
    function transfer(address recipient, uint amount) public returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    function allowance(address owner, address spender) public view returns (uint) {
        return _allowances[owner][spender];
    }
    function approve(address spender, uint amount) public returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    function transferFrom(address sender, address recipient, uint amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    function increaseAllowance(address spender, uint addedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }
    function decreaseAllowance(address spender, uint subtractedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }
    function _transfer(address sender, address recipient, uint amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    function _mint(address account, uint amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }
    function _burn(address account, uint amount) internal {
        require(account != address(0), "ERC20: burn from the zero address");

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }
    function _approve(address owner, address spender, uint amount) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
}

contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    constructor (string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }
    function name() public view returns (string memory) {
        return _name;
    }
    function symbol() public view returns (string memory) {
        return _symbol;
    }
    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

library SafeMath {
    function add(uint a, uint b) internal pure returns (uint) {
        uint c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }
    function sub(uint a, uint b) internal pure returns (uint) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }
    function sub(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
        require(b <= a, errorMessage);
        uint c = a - b;

        return c;
    }
    function mul(uint a, uint b) internal pure returns (uint) {
        if (a == 0) {
            return 0;
        }

        uint c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }
    function div(uint a, uint b) internal pure returns (uint) {
        return div(a, b, "SafeMath: division by zero");
    }
    function div(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint c = a / b;

        return c;
    }
}

library Address {
    function isContract(address account) internal view returns (bool) {
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != 0x0 && codehash != accountHash);
    }
}

library SafeERC20 {
    using SafeMath for uint;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint value) internal {
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    function callOptionalReturn(IERC20 token, bytes memory data) private {
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

contract YFI is ERC20, ERC20Detailed {
  using SafeERC20 for IERC20;
  using Address for address;
  using SafeMath for uint;
  
  
  address public governance;
  mapping (address => bool) public minters;

  constructor () public ERC20Detailed("yearn.finance", "YFI", 18) {
      governance = msg.sender;
  }

  function mint(address account, uint amount) public {
      require(minters[msg.sender], "!minter");
      _mint(account, amount);
  }
  
  function setGovernance(address _governance) public {
      require(msg.sender == governance, "!governance");
      governance = _governance;
  }
  
  function addMinter(address _minter) public {
      require(msg.sender == governance, "!governance");
      minters[_minter] = true;
  }
  
  function removeMinter(address _minter) public {
      require(msg.sender == governance, "!governance");
      minters[_minter] = false;
  }
}

/**
 *Submitted for verification at Etherscan.io on 2020-05-05
*/

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// Copyright (C) 2015, 2016, 2017 Dapphub

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.4.18;

contract WETH9 {
    string public name     = "Wrapped Ether";
    string public symbol   = "WETH";
    uint8  public decimals = 18;

    event  Approval(address indexed src, address indexed guy, uint wad);
    event  Transfer(address indexed src, address indexed dst, uint wad);
    event  Deposit(address indexed dst, uint wad);
    event  Withdrawal(address indexed src, uint wad);

    mapping (address => uint)                       public  balanceOf;
    mapping (address => mapping (address => uint))  public  allowance;

    function() public payable {
        deposit();
    }
    function deposit() public payable {
        balanceOf[msg.sender] += msg.value;
        Deposit(msg.sender, msg.value);
    }
    function withdraw(uint wad) public {
        require(balanceOf[msg.sender] >= wad);
        balanceOf[msg.sender] -= wad;
        msg.sender.transfer(wad);
        Withdrawal(msg.sender, wad);
    }

    function totalSupply() public view returns (uint) {
        return this.balance;
    }

    function approve(address guy, uint wad) public returns (bool) {
        allowance[msg.sender][guy] = wad;
        Approval(msg.sender, guy, wad);
        return true;
    }

    function transfer(address dst, uint wad) public returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }

    function transferFrom(address src, address dst, uint wad)
        public
        returns (bool)
    {
        require(balanceOf[src] >= wad);

        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad);
            allowance[src][msg.sender] -= wad;
        }

        balanceOf[src] -= wad;
        balanceOf[dst] += wad;

        Transfer(src, dst, wad);

        return true;
    }
}


/*
                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

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  If, pursuant to or in connection with a single transaction or
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you grant is automatically extended to all recipients of the covered
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  A patent license is "discriminatory" if it does not include within
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contain the covered work, unless you entered into that arrangement,
or that patent license was granted, prior to 28 March 2007.

  Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.

  12. No Surrender of Others' Freedom.

  If conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License.  If you cannot convey a
covered work so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you may
not convey it at all.  For example, if you agree to terms that obligate you
to collect a royalty for further conveying from those to whom you convey
the Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.

  13. Use with the GNU Affero General Public License.

  Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU Affero General Public License into a single
combined work, and to convey the resulting work.  The terms of this
License will continue to apply to the part which is the covered work,
but the special requirements of the GNU Affero General Public License,
section 13, concerning interaction through a network will apply to the
combination as such.

  14. Revised Versions of this License.

  The Free Software Foundation may publish revised and/or new versions of
the GNU General Public License from time to time.  Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.

  Each version is given a distinguishing version number.  If the
Program specifies that a certain numbered version of the GNU General
Public License "or any later version" applies to it, you have the
option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation.  If the Program does not specify a version number of the
GNU General Public License, you may choose any version ever published
by the Free Software Foundation.

  If the Program specifies that a proxy can decide which future
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to choose that version for the Program.

  Later license versions may give you additional or different
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  15. Disclaimer of Warranty.

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APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
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  17. Interpretation of Sections 15 and 16.

  If the disclaimer of warranty and limitation of liability provided
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reviewing courts shall apply local law that most closely approximates
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Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<http://www.gnu.org/licenses/>.

  The GNU General Public License does not permit incorporating your program
into proprietary programs.  If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

*/

// hevm: flattened sources of /nix/store/8xb41r4qd0cjb63wcrxf1qmfg88p0961-dss-6fd7de0/src/dai.sol
pragma solidity =0.5.12;

////// /nix/store/8xb41r4qd0cjb63wcrxf1qmfg88p0961-dss-6fd7de0/src/lib.sol
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

/* pragma solidity 0.5.12; */

contract LibNote {
    event LogNote(
        bytes4   indexed  sig,
        address  indexed  usr,
        bytes32  indexed  arg1,
        bytes32  indexed  arg2,
        bytes             data
    ) anonymous;

    modifier note {
        _;
        assembly {
            // log an 'anonymous' event with a constant 6 words of calldata
            // and four indexed topics: selector, caller, arg1 and arg2
            let mark := msize                         // end of memory ensures zero
            mstore(0x40, add(mark, 288))              // update free memory pointer
            mstore(mark, 0x20)                        // bytes type data offset
            mstore(add(mark, 0x20), 224)              // bytes size (padded)
            calldatacopy(add(mark, 0x40), 0, 224)     // bytes payload
            log4(mark, 288,                           // calldata
                 shl(224, shr(224, calldataload(0))), // msg.sig
                 caller,                              // msg.sender
                 calldataload(4),                     // arg1
                 calldataload(36)                     // arg2
                )
        }
    }
}

////// /nix/store/8xb41r4qd0cjb63wcrxf1qmfg88p0961-dss-6fd7de0/src/dai.sol
// Copyright (C) 2017, 2018, 2019 dbrock, rain, mrchico

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

/* pragma solidity 0.5.12; */

/* import "./lib.sol"; */

contract Dai is LibNote {
    // --- Auth ---
    mapping (address => uint) public wards;
    function rely(address guy) external note auth { wards[guy] = 1; }
    function deny(address guy) external note auth { wards[guy] = 0; }
    modifier auth {
        require(wards[msg.sender] == 1, "Dai/not-authorized");
        _;
    }

    // --- ERC20 Data ---
    string  public constant name     = "Dai Stablecoin";
    string  public constant symbol   = "DAI";
    string  public constant version  = "1";
    uint8   public constant decimals = 18;
    uint256 public totalSupply;

    mapping (address => uint)                      public balanceOf;
    mapping (address => mapping (address => uint)) public allowance;
    mapping (address => uint)                      public nonces;

    event Approval(address indexed src, address indexed guy, uint wad);
    event Transfer(address indexed src, address indexed dst, uint wad);

    // --- Math ---
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x);
    }
    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x);
    }

    // --- EIP712 niceties ---
    bytes32 public DOMAIN_SEPARATOR;
    // bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address holder,address spender,uint256 nonce,uint256 expiry,bool allowed)");
    bytes32 public constant PERMIT_TYPEHASH = 0xea2aa0a1be11a07ed86d755c93467f4f82362b452371d1ba94d1715123511acb;

    constructor(uint256 chainId_) public {
        wards[msg.sender] = 1;
        DOMAIN_SEPARATOR = keccak256(abi.encode(
            keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
            keccak256(bytes(name)),
            keccak256(bytes(version)),
            chainId_,
            address(this)
        ));
    }

    // --- Token ---
    function transfer(address dst, uint wad) external returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }
    function transferFrom(address src, address dst, uint wad)
        public returns (bool)
    {
        require(balanceOf[src] >= wad, "Dai/insufficient-balance");
        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad, "Dai/insufficient-allowance");
            allowance[src][msg.sender] = sub(allowance[src][msg.sender], wad);
        }
        balanceOf[src] = sub(balanceOf[src], wad);
        balanceOf[dst] = add(balanceOf[dst], wad);
        emit Transfer(src, dst, wad);
        return true;
    }
    function mint(address usr, uint wad) external auth {
        balanceOf[usr] = add(balanceOf[usr], wad);
        totalSupply    = add(totalSupply, wad);
        emit Transfer(address(0), usr, wad);
    }
    function burn(address usr, uint wad) external {
        require(balanceOf[usr] >= wad, "Dai/insufficient-balance");
        if (usr != msg.sender && allowance[usr][msg.sender] != uint(-1)) {
            require(allowance[usr][msg.sender] >= wad, "Dai/insufficient-allowance");
            allowance[usr][msg.sender] = sub(allowance[usr][msg.sender], wad);
        }
        balanceOf[usr] = sub(balanceOf[usr], wad);
        totalSupply    = sub(totalSupply, wad);
        emit Transfer(usr, address(0), wad);
    }
    function approve(address usr, uint wad) external returns (bool) {
        allowance[msg.sender][usr] = wad;
        emit Approval(msg.sender, usr, wad);
        return true;
    }

    // --- Alias ---
    function push(address usr, uint wad) external {
        transferFrom(msg.sender, usr, wad);
    }
    function pull(address usr, uint wad) external {
        transferFrom(usr, msg.sender, wad);
    }
    function move(address src, address dst, uint wad) external {
        transferFrom(src, dst, wad);
    }

    // --- Approve by signature ---
    function permit(address holder, address spender, uint256 nonce, uint256 expiry,
                    bool allowed, uint8 v, bytes32 r, bytes32 s) external
    {
        bytes32 digest =
            keccak256(abi.encodePacked(
                "\x19\x01",
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH,
                                     holder,
                                     spender,
                                     nonce,
                                     expiry,
                                     allowed))
        ));

        require(holder != address(0), "Dai/invalid-address-0");
        require(holder == ecrecover(digest, v, r, s), "Dai/invalid-permit");
        require(expiry == 0 || now <= expiry, "Dai/permit-expired");
        require(nonce == nonces[holder]++, "Dai/invalid-nonce");
        uint wad = allowed ? uint(-1) : 0;
        allowance[holder][spender] = wad;
        emit Approval(holder, spender, wad);
    }
}

// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.5.4;

/**
 * @title Module
 * @dev Interface for a module.
 * A module MUST implement the addModule() method to ensure that a wallet with at least one module
 * can never end up in a "frozen" state.
 * @author Julien Niset - <julien@argent.xyz>
 */
interface Module {

    /**
     * @dev Inits a module for a wallet by e.g. setting some wallet specific parameters in storage.
     * @param _wallet The wallet.
     */
    function init(BaseWallet _wallet) external;

    /**
     * @dev Adds a module to a wallet.
     * @param _wallet The target wallet.
     * @param _module The modules to authorise.
     */
    function addModule(BaseWallet _wallet, Module _module) external;

    /**
    * @dev Utility method to recover any ERC20 token that was sent to the
    * module by mistake.
    * @param _token The token to recover.
    */
    function recoverToken(address _token) external;
}

/**
 * @title BaseWallet
 * @dev Simple modular wallet that authorises modules to call its invoke() method.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract BaseWallet {

    // The implementation of the proxy
    address public implementation;
    // The owner
    address public owner;
    // The authorised modules
    mapping (address => bool) public authorised;
    // The enabled static calls
    mapping (bytes4 => address) public enabled;
    // The number of modules
    uint public modules;

    event AuthorisedModule(address indexed module, bool value);
    event EnabledStaticCall(address indexed module, bytes4 indexed method);
    event Invoked(address indexed module, address indexed target, uint indexed value, bytes data);
    event Received(uint indexed value, address indexed sender, bytes data);
    event OwnerChanged(address owner);

    /**
     * @dev Throws if the sender is not an authorised module.
     */
    modifier moduleOnly {
        require(authorised[msg.sender], "BW: msg.sender not an authorized module");
        _;
    }

    /**
     * @dev Inits the wallet by setting the owner and authorising a list of modules.
     * @param _owner The owner.
     * @param _modules The modules to authorise.
     */
    function init(address _owner, address[] calldata _modules) external {
        require(owner == address(0) && modules == 0, "BW: wallet already initialised");
        require(_modules.length > 0, "BW: construction requires at least 1 module");
        owner = _owner;
        modules = _modules.length;
        for (uint256 i = 0; i < _modules.length; i++) {
            require(authorised[_modules[i]] == false, "BW: module is already added");
            authorised[_modules[i]] = true;
            Module(_modules[i]).init(this);
            emit AuthorisedModule(_modules[i], true);
        }
        if (address(this).balance > 0) {
            emit Received(address(this).balance, address(0), "");
        }
    }

    /**
     * @dev Enables/Disables a module.
     * @param _module The target module.
     * @param _value Set to true to authorise the module.
     */
    function authoriseModule(address _module, bool _value) external moduleOnly {
        if (authorised[_module] != _value) {
            emit AuthorisedModule(_module, _value);
            if (_value == true) {
                modules += 1;
                authorised[_module] = true;
                Module(_module).init(this);
            } else {
                modules -= 1;
                require(modules > 0, "BW: wallet must have at least one module");
                delete authorised[_module];
            }
        }
    }

    /**
    * @dev Enables a static method by specifying the target module to which the call
    * must be delegated.
    * @param _module The target module.
    * @param _method The static method signature.
    */
    function enableStaticCall(address _module, bytes4 _method) external moduleOnly {
        require(authorised[_module], "BW: must be an authorised module for static call");
        enabled[_method] = _module;
        emit EnabledStaticCall(_module, _method);
    }

    /**
     * @dev Sets a new owner for the wallet.
     * @param _newOwner The new owner.
     */
    function setOwner(address _newOwner) external moduleOnly {
        require(_newOwner != address(0), "BW: address cannot be null");
        owner = _newOwner;
        emit OwnerChanged(_newOwner);
    }

    /**
     * @dev Performs a generic transaction.
     * @param _target The address for the transaction.
     * @param _value The value of the transaction.
     * @param _data The data of the transaction.
     */
    function invoke(address _target, uint _value, bytes calldata _data) external moduleOnly returns (bytes memory _result) {
        bool success;
        // solium-disable-next-line security/no-call-value
        (success, _result) = _target.call.value(_value)(_data);
        if (!success) {
            // solium-disable-next-line security/no-inline-assembly
            assembly {
                returndatacopy(0, 0, returndatasize)
                revert(0, returndatasize)
            }
        }
        emit Invoked(msg.sender, _target, _value, _data);
    }

    /**
     * @dev This method makes it possible for the wallet to comply to interfaces expecting the wallet to
     * implement specific static methods. It delegates the static call to a target contract if the data corresponds
     * to an enabled method, or logs the call otherwise.
     */
    function() external payable {
        if (msg.data.length > 0) {
            address module = enabled[msg.sig];
            if (module == address(0)) {
                emit Received(msg.value, msg.sender, msg.data);
            } else {
                require(authorised[module], "BW: must be an authorised module for static call");
                // solium-disable-next-line security/no-inline-assembly
                assembly {
                    calldatacopy(0, 0, calldatasize())
                    let result := staticcall(gas, module, 0, calldatasize(), 0, 0)
                    returndatacopy(0, 0, returndatasize())
                    switch result
                    case 0 {revert(0, returndatasize())}
                    default {return (0, returndatasize())}
                }
            }
        }
    }
}

pragma solidity ^0.5.4;

/**
 * ERC20 contract interface.
 */
contract ERC20 {
    function totalSupply() public view returns (uint);
    function decimals() public view returns (uint);
    function balanceOf(address tokenOwner) public view returns (uint balance);
    function allowance(address tokenOwner, address spender) public view returns (uint remaining);
    function transfer(address to, uint tokens) public returns (bool success);
    function approve(address spender, uint tokens) public returns (bool success);
    function transferFrom(address from, address to, uint tokens) public returns (bool success);
}

contract KyberNetwork {

    function getExpectedRate(
        ERC20 src,
        ERC20 dest,
        uint srcQty
    )
        public
        view
        returns (uint expectedRate, uint slippageRate);

    function trade(
        ERC20 src,
        uint srcAmount,
        ERC20 dest,
        address payable destAddress,
        uint maxDestAmount,
        uint minConversionRate,
        address walletId
    )
        public
        payable
        returns(uint);
}

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

    /**
    * @dev Multiplies two numbers, reverts on overflow.
    */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b);

        return c;
    }

    /**
    * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
    */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0); // Solidity only automatically asserts when dividing by 0
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
    * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
    */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a);
        uint256 c = a - b;

        return c;
    }

    /**
    * @dev Adds two numbers, reverts on overflow.
    */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a);

        return c;
    }

    /**
    * @dev Divides two numbers and returns the remainder (unsigned integer modulo),
    * reverts when dividing by zero.
    */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0);
        return a % b;
    }

    /**
    * @dev Returns ceil(a / b).
    */
    function ceil(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a / b;
        if(a % b == 0) {
            return c;
        }
        else {
            return c + 1;
        }
    }
}

/**
 * @title Owned
 * @dev Basic contract to define an owner.
 * @author Julien Niset - <julien@argent.im>
 */
contract Owned {

    // The owner
    address public owner;

    event OwnerChanged(address indexed _newOwner);

    /**
     * @dev Throws if the sender is not the owner.
     */
    modifier onlyOwner {
        require(msg.sender == owner, "Must be owner");
        _;
    }

    constructor() public {
        owner = msg.sender;
    }

    /**
     * @dev Lets the owner transfer ownership of the contract to a new owner.
     * @param _newOwner The new owner.
     */
    function changeOwner(address _newOwner) external onlyOwner {
        require(_newOwner != address(0), "Address must not be null");
        owner = _newOwner;
        emit OwnerChanged(_newOwner);
    }
}

/**
 * @title Managed
 * @dev Basic contract that defines a set of managers. Only the owner can add/remove managers.
 * @author Julien Niset - <julien@argent.im>
 */
contract Managed is Owned {

    // The managers
    mapping (address => bool) public managers;

    /**
     * @dev Throws if the sender is not a manager.
     */
    modifier onlyManager {
        require(managers[msg.sender] == true, "M: Must be manager");
        _;
    }

    event ManagerAdded(address indexed _manager);
    event ManagerRevoked(address indexed _manager);

    /**
    * @dev Adds a manager. 
    * @param _manager The address of the manager.
    */
    function addManager(address _manager) external onlyOwner {
        require(_manager != address(0), "M: Address must not be null");
        if(managers[_manager] == false) {
            managers[_manager] = true;
            emit ManagerAdded(_manager);
        }        
    }

    /**
    * @dev Revokes a manager.
    * @param _manager The address of the manager.
    */
    function revokeManager(address _manager) external onlyOwner {
        require(managers[_manager] == true, "M: Target must be an existing manager");
        delete managers[_manager];
        emit ManagerRevoked(_manager);
    }
}

contract TokenPriceProvider is Managed {

    // Mock token address for ETH
    address constant internal ETH_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;

    using SafeMath for uint256;

    mapping(address => uint256) public cachedPrices;

    // Address of the KyberNetwork contract
    KyberNetwork public kyberNetwork;

    constructor(KyberNetwork _kyberNetwork) public {
        kyberNetwork = _kyberNetwork;
    }

    function setPrice(ERC20 _token, uint256 _price) public onlyManager {
        cachedPrices[address(_token)] = _price;
    }

    function setPriceForTokenList(ERC20[] calldata _tokens, uint256[] calldata _prices) external onlyManager {
        for(uint16 i = 0; i < _tokens.length; i++) {
            setPrice(_tokens[i], _prices[i]);
        }
    }

    /**
     * @dev Converts the value of _amount tokens in ether.
     * @param _amount the amount of tokens to convert (in 'token wei' twei)
     * @param _token the ERC20 token contract
     * @return the ether value (in wei) of _amount tokens with contract _token
     */
    function getEtherValue(uint256 _amount, address _token) external view returns (uint256) {
        uint256 decimals = ERC20(_token).decimals();
        uint256 price = cachedPrices[_token];
        return price.mul(_amount).div(10**decimals);
    }

    //
    // The following is added to be backward-compatible with Argent's old backend
    //

    function setKyberNetwork(KyberNetwork _kyberNetwork) external onlyManager {
        kyberNetwork = _kyberNetwork;
    }

    function syncPrice(ERC20 _token) external {
        require(address(kyberNetwork) != address(0), "Kyber sync is disabled");
        (uint256 expectedRate,) = kyberNetwork.getExpectedRate(_token, ERC20(ETH_TOKEN_ADDRESS), 10000);
        cachedPrices[address(_token)] = expectedRate;
    }

    function syncPriceForTokenList(ERC20[] calldata _tokens) external {
        require(address(kyberNetwork) != address(0), "Kyber sync is disabled");
        for(uint16 i = 0; i < _tokens.length; i++) {
            (uint256 expectedRate,) = kyberNetwork.getExpectedRate(_tokens[i], ERC20(ETH_TOKEN_ADDRESS), 10000);
            cachedPrices[address(_tokens[i])] = expectedRate;
        }
    }
}

/**
 *Submitted for verification at Etherscan.io on 2020-07-26
*/

// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;

        return c;
    }
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

library Address {
    function isContract(address account) internal view returns (bool) {
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != 0x0 && codehash != accountHash);
    }
    function toPayable(address account) internal pure returns (address payable) {
        return address(uint160(account));
    }
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-call-value
        (bool success, ) = recipient.call.value(amount)("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
}

library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    function callOptionalReturn(IERC20 token, bytes memory data) private {
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

interface Strategy {
    function want() external view returns (address);
    function deposit() external;
    function withdraw(address) external;
    function withdraw(uint) external;
    function withdrawAll() external returns (uint);
    function balanceOf() external view returns (uint);
}

interface Converter {
    function convert(address) external returns (uint);
}

interface OneSplitAudit {
    function swap(
        address fromToken,
        address destToken,
        uint256 amount,
        uint256 minReturn,
        uint256[] calldata distribution,
        uint256 flags
    )
        external
        payable
        returns(uint256 returnAmount);
    
    function getExpectedReturn(
        address fromToken,
        address destToken,
        uint256 amount,
        uint256 parts,
        uint256 flags // See constants in IOneSplit.sol
    )
        external
        view
        returns(
            uint256 returnAmount,
            uint256[] memory distribution
        );
}

contract Controller {
    using SafeERC20 for IERC20;
    using Address for address;
    using SafeMath for uint256;
    
    address public governance;
    address public strategist;
    
    address public onesplit;
    address public rewards;
    mapping(address => address) public vaults;
    mapping(address => address) public strategies;
    mapping(address => mapping(address => address)) public converters;
    
    mapping(address => mapping(address => bool)) public approvedStrategies;
    
    uint public split = 500;
    uint public constant max = 10000;
    
    constructor(address _rewards) public {
        governance = msg.sender;
        strategist = msg.sender;
        onesplit = address(0x50FDA034C0Ce7a8f7EFDAebDA7Aa7cA21CC1267e);
        rewards = _rewards;
    }
    
    function setRewards(address _rewards) public {
        require(msg.sender == governance, "!governance");
        rewards = _rewards;
    }
    
    function setStrategist(address _strategist) public {
        require(msg.sender == governance, "!governance");
        strategist = _strategist;
    }
    
    function setSplit(uint _split) public {
        require(msg.sender == governance, "!governance");
        split = _split;
    }
    
    function setOneSplit(address _onesplit) public {
        require(msg.sender == governance, "!governance");
        onesplit = _onesplit;
    }
    
    function setGovernance(address _governance) public {
        require(msg.sender == governance, "!governance");
        governance = _governance;
    }
    
    function setVault(address _token, address _vault) public {
        require(msg.sender == strategist || msg.sender == governance, "!strategist");
        require(vaults[_token] == address(0), "vault");
        vaults[_token] = _vault;
    }
    
    function approveStrategy(address _token, address _strategy) public {
        require(msg.sender == governance, "!governance");
        approvedStrategies[_token][_strategy] = true;
    }
    
    function revokeStrategy(address _token, address _strategy) public {
        require(msg.sender == governance, "!governance");
        approvedStrategies[_token][_strategy] = false;
    }
    
    function setConverter(address _input, address _output, address _converter) public {
        require(msg.sender == strategist || msg.sender == governance, "!strategist");
        converters[_input][_output] = _converter;
    }
    
    function setStrategy(address _token, address _strategy) public {
        require(msg.sender == strategist || msg.sender == governance, "!strategist");
        require(approvedStrategies[_token][_strategy] == true, "!approved");
        
        address _current = strategies[_token];
        if (_current != address(0)) {
           Strategy(_current).withdrawAll();
        }
        strategies[_token] = _strategy;
    }
    
    function earn(address _token, uint _amount) public {
        address _strategy = strategies[_token];
        address _want = Strategy(_strategy).want();
        if (_want != _token) {
            address converter = converters[_token][_want];
            IERC20(_token).safeTransfer(converter, _amount);
            _amount = Converter(converter).convert(_strategy);
            IERC20(_want).safeTransfer(_strategy, _amount);
        } else {
            IERC20(_token).safeTransfer(_strategy, _amount);
        }
        Strategy(_strategy).deposit();
    }
    
    function balanceOf(address _token) external view returns (uint) {
        return Strategy(strategies[_token]).balanceOf();
    }
    
    function withdrawAll(address _token) public {
        require(msg.sender == strategist || msg.sender == governance, "!strategist");
        Strategy(strategies[_token]).withdrawAll();
    }
    
    function inCaseTokensGetStuck(address _token, uint _amount) public {
        require(msg.sender == strategist || msg.sender == governance, "!governance");
        IERC20(_token).safeTransfer(msg.sender, _amount);
    }
    
    function inCaseStrategyTokenGetStuck(address _strategy, address _token) public {
        require(msg.sender == strategist || msg.sender == governance, "!governance");
        Strategy(_strategy).withdraw(_token);
    }
    
    function getExpectedReturn(address _strategy, address _token, uint parts) public view returns (uint expected) {
        uint _balance = IERC20(_token).balanceOf(_strategy);
        address _want = Strategy(_strategy).want();
        (expected,) = OneSplitAudit(onesplit).getExpectedReturn(_token, _want, _balance, parts, 0);
    }
    
    // Only allows to withdraw non-core strategy tokens ~ this is over and above normal yield
    function yearn(address _strategy, address _token, uint parts) public {
        require(msg.sender == strategist || msg.sender == governance, "!governance");
        // This contract should never have value in it, but just incase since this is a public call
        uint _before = IERC20(_token).balanceOf(address(this));
        Strategy(_strategy).withdraw(_token);
        uint _after =  IERC20(_token).balanceOf(address(this));
        if (_after > _before) {
            uint _amount = _after.sub(_before);
            address _want = Strategy(_strategy).want();
            uint[] memory _distribution;
            uint _expected;
            _before = IERC20(_want).balanceOf(address(this));
            IERC20(_token).safeApprove(onesplit, 0);
            IERC20(_token).safeApprove(onesplit, _amount);
            (_expected, _distribution) = OneSplitAudit(onesplit).getExpectedReturn(_token, _want, _amount, parts, 0);
            OneSplitAudit(onesplit).swap(_token, _want, _amount, _expected, _distribution, 0);
            _after = IERC20(_want).balanceOf(address(this));
            if (_after > _before) {
                _amount = _after.sub(_before);
                uint _reward = _amount.mul(split).div(max);
                earn(_want, _amount.sub(_reward));
                IERC20(_want).safeTransfer(rewards, _reward);
            }
        }
    }
    
    function withdraw(address _token, uint _amount) public {
        require(msg.sender == vaults[_token], "!vault");
        Strategy(strategies[_token]).withdraw(_amount);
    }
}

pragma solidity =0.6.6;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint) external;
}

contract UniswapV2Router02 is IUniswapV2Router02 {
    using SafeMath for uint;

    address public immutable override factory;
    address public immutable override WETH;

    modifier ensure(uint deadline) {
        require(deadline >= block.timestamp, 'UniswapV2Router: EXPIRED');
        _;
    }

    constructor(address _factory, address _WETH) public {
        factory = _factory;
        WETH = _WETH;
    }

    receive() external payable {
        assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract
    }

    // **** ADD LIQUIDITY ****
    function _addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin
    ) internal virtual returns (uint amountA, uint amountB) {
        // create the pair if it doesn't exist yet
        if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) {
            IUniswapV2Factory(factory).createPair(tokenA, tokenB);
        }
        (uint reserveA, uint reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB);
        if (reserveA == 0 && reserveB == 0) {
            (amountA, amountB) = (amountADesired, amountBDesired);
        } else {
            uint amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB);
            if (amountBOptimal <= amountBDesired) {
                require(amountBOptimal >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
                (amountA, amountB) = (amountADesired, amountBOptimal);
            } else {
                uint amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA);
                assert(amountAOptimal <= amountADesired);
                require(amountAOptimal >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
                (amountA, amountB) = (amountAOptimal, amountBDesired);
            }
        }
    }
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint amountA, uint amountB, uint liquidity) {
        (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin);
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA);
        TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB);
        liquidity = IUniswapV2Pair(pair).mint(to);
    }
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external virtual override payable ensure(deadline) returns (uint amountToken, uint amountETH, uint liquidity) {
        (amountToken, amountETH) = _addLiquidity(
            token,
            WETH,
            amountTokenDesired,
            msg.value,
            amountTokenMin,
            amountETHMin
        );
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken);
        IWETH(WETH).deposit{value: amountETH}();
        assert(IWETH(WETH).transfer(pair, amountETH));
        liquidity = IUniswapV2Pair(pair).mint(to);
        // refund dust eth, if any
        if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH);
    }

    // **** REMOVE LIQUIDITY ****
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair
        (uint amount0, uint amount1) = IUniswapV2Pair(pair).burn(to);
        (address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB);
        (amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0);
        require(amountA >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
        require(amountB >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
    }
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountToken, uint amountETH) {
        (amountToken, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, amountToken);
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline);
    }
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountToken, uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline);
    }

    // **** REMOVE LIQUIDITY (supporting fee-on-transfer tokens) ****
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountETH) {
        (, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, IERC20(token).balanceOf(address(this)));
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        amountETH = removeLiquidityETHSupportingFeeOnTransferTokens(
            token, liquidity, amountTokenMin, amountETHMin, to, deadline
        );
    }

    // **** SWAP ****
    // requires the initial amount to have already been sent to the first pair
    function _swap(uint[] memory amounts, address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            uint amountOut = amounts[i + 1];
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOut) : (amountOut, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap(
                amount0Out, amount1Out, to, new bytes(0)
            );
        }
    }
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
    }
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= msg.value, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
        // refund dust eth, if any
        if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]);
    }

    // **** SWAP (supporting fee-on-transfer tokens) ****
    // requires the initial amount to have already been sent to the first pair
    function _swapSupportingFeeOnTransferTokens(address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output));
            uint amountInput;
            uint amountOutput;
            { // scope to avoid stack too deep errors
            (uint reserve0, uint reserve1,) = pair.getReserves();
            (uint reserveInput, uint reserveOutput) = input == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
            amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
            amountOutput = UniswapV2Library.getAmountOut(amountInput, reserveInput, reserveOutput);
            }
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOutput) : (amountOutput, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            pair.swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) {
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        payable
        ensure(deadline)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        uint amountIn = msg.value;
        IWETH(WETH).deposit{value: amountIn}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn));
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        ensure(deadline)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        _swapSupportingFeeOnTransferTokens(path, address(this));
        uint amountOut = IERC20(WETH).balanceOf(address(this));
        require(amountOut >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).withdraw(amountOut);
        TransferHelper.safeTransferETH(to, amountOut);
    }

    // **** LIBRARY FUNCTIONS ****
    function quote(uint amountA, uint reserveA, uint reserveB) public pure virtual override returns (uint amountB) {
        return UniswapV2Library.quote(amountA, reserveA, reserveB);
    }

    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountOut)
    {
        return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
    }

    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountIn)
    {
        return UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
    }

    function getAmountsOut(uint amountIn, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsOut(factory, amountIn, path);
    }

    function getAmountsIn(uint amountOut, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsIn(factory, amountOut, path);
    }
}

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

library UniswapV2Library {
    using SafeMath for uint;

    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
        require(tokenA != tokenB, 'UniswapV2Library: IDENTICAL_ADDRESSES');
        (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2Library: ZERO_ADDRESS');
    }

    // calculates the CREATE2 address for a pair without making any external calls
    function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) {
        (address token0, address token1) = sortTokens(tokenA, tokenB);
        pair = address(uint(keccak256(abi.encodePacked(
                hex'ff',
                factory,
                keccak256(abi.encodePacked(token0, token1)),
                hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f' // init code hash
            ))));
    }

    // fetches and sorts the reserves for a pair
    function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB) {
        (address token0,) = sortTokens(tokenA, tokenB);
        (uint reserve0, uint reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }

    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB) {
        require(amountA > 0, 'UniswapV2Library: INSUFFICIENT_AMOUNT');
        require(reserveA > 0 && reserveB > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        amountB = amountA.mul(reserveB) / reserveA;
    }

    // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut) {
        require(amountIn > 0, 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint amountInWithFee = amountIn.mul(997);
        uint numerator = amountInWithFee.mul(reserveOut);
        uint denominator = reserveIn.mul(1000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }

    // given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn) {
        require(amountOut > 0, 'UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint numerator = reserveIn.mul(amountOut).mul(1000);
        uint denominator = reserveOut.sub(amountOut).mul(997);
        amountIn = (numerator / denominator).add(1);
    }

    // performs chained getAmountOut calculations on any number of pairs
    function getAmountsOut(address factory, uint amountIn, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[0] = amountIn;
        for (uint i; i < path.length - 1; i++) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i], path[i + 1]);
            amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }

    // performs chained getAmountIn calculations on any number of pairs
    function getAmountsIn(address factory, uint amountOut, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint i = path.length - 1; i > 0; i--) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
}

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
    }

    function safeTransfer(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
    }

    function safeTransferFrom(address token, address from, address to, uint value) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
    }

    function safeTransferETH(address to, uint value) internal {
        (bool success,) = to.call{value:value}(new bytes(0));
        require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
    }
}