Contract Source Code:

pragma solidity ^0.5.17;

library SafeMath {
  function add(uint a, uint b) internal pure returns (uint c) {
    c = a + b;
    require(c >= a);
  }
  function sub(uint a, uint b) internal pure returns (uint c) {
    require(b <= a);
    c = a - b;
  }
  function mul(uint a, uint b) internal pure returns (uint c) {
    c = a * b;
    require(a == 0 || c / a == b);
  }
  function div(uint a, uint b) internal pure returns (uint c) {
    require(b > 0);
    c = a / b;
  }
}

contract ERC20Interface {
    
  function totalSupply() 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 ApproveAndCallFallBack {
  function receiveApproval(address from, uint256 tokens, address token, bytes memory data) public;
}

contract Owned {
  address public Admininstrator;


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

  modifier onlyAdmin {
    require(msg.sender == Admininstrator, "Only authorized personnels");
    _;
  }

}

contract salescontract is Owned{
    
    
  using SafeMath for uint;
 
  address public token;
  
  uint public minBuy = 1 ether;
  uint public maxBuy = 6 ether;
  address payable public saleswallet;
  
  bool public startSales = false;
  uint public buyvalue;
 
  
  uint public _qtty;
  uint decimal = 10**18;

 
  mapping(address => uint) public buyamount;
  uint256 public price1 = 0.04 ether;
  uint256 public price2 = 0.05 ether;
  uint256 public currentprice = 0.04 ether;
  uint256 public totalSales = 0;
  uint256 public MaxSales = 3500*decimal;
 
  
  
 
  constructor() public { Admininstrator = msg.sender; }
   
 //========================================CONFIGURATIONS======================================
 
 
 function WalletSetup(address payable _salewallet) public onlyAdmin{saleswallet = _salewallet;}
 function setToken(address _tokenaddress) public onlyAdmin{token = _tokenaddress;}
 
 function setMaxSALES(uint _value) public onlyAdmin{MaxSales = _value;}
 
 
 function AllowSales(bool _status) public onlyAdmin{
     require(saleswallet != address(0));
     startSales = _status;}
	
	
 function () external payable {
    
    require(startSales == true, "Sales has not been initialized yet");
    require(msg.value >= minBuy && msg.value <= maxBuy, "Invalid buy amount, confirm the maximum and minimum buy amounts");
    require(token != 0x0000000000000000000000000000000000000000, "Selling token not yet configured");
    require((buyamount[msg.sender] + msg.value) <= maxBuy, "Ensure your total buy is not above maximum allowed per wallet");
    
    buyvalue = msg.value;
    if(totalSales >= MaxSales.div(2)){
        currentprice = price2;
    }
    _qtty = buyvalue.div(currentprice);
    require(ERC20Interface(token).balanceOf(address(this)) >= _qtty*decimal, "Insufficient tokens in the contract");
    
    saleswallet.transfer(msg.value);
    buyamount[msg.sender] += msg.value;
    totalSales += _qtty;
    require(ERC20Interface(token).transfer(msg.sender, _qtty*decimal), "Transaction failed");
      
       
   
    
   
  }
  
  	
 function buy() external payable {
    
    
    require(startSales == true, "Sales has not been initialized yet");
    require(msg.value >= minBuy && msg.value <= maxBuy, "Invalid buy amount, confirm the maximum and minimum buy amounts");
    require(token != 0x0000000000000000000000000000000000000000, "Selling token not yet configured");
    require((buyamount[msg.sender] + msg.value) <= maxBuy, "Ensure you total buy is not above maximum allowed per wallet");
    
    buyvalue = msg.value;
    if(totalSales >= MaxSales.div(2)){
        currentprice = price2;
    }
    _qtty = buyvalue.div(currentprice);
    require(ERC20Interface(token).balanceOf(address(this)) >= _qtty*decimal, "Insufficient tokens in the contract");
    
    saleswallet.transfer(msg.value);
    buyamount[msg.sender] += msg.value;
    totalSales += _qtty;
    require(ERC20Interface(token).transfer(msg.sender, _qtty*decimal), "Transaction failed");
      
        
    
   
  }
  


  function withdrawBal() public onlyAdmin returns(bool){
      
      require(saleswallet != address(0));
      uint bal = ERC20Interface(token).balanceOf(address(this));
      require(ERC20Interface(token).transfer(saleswallet, bal), "Transaction failed");
      
  }
 
 
}