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contracts...ERC20...Vendor.sol

// SPDX-License-Identifier: GPL-3.0

pragma solidity ^0.8.0;

import "./2.sol";

// Purpose: Smart Contract for a Vendor 

contract VendorAXC is Ownership {
    MyERC20 _myERC20;
    address private VOwner;
    uint TokensPerEther = 100;

    event TokenBuy(address indexed buyer, uint _value, uint _tokenQuantity);
    event TokenSell(address indexed seller, uint _tokenQuantity, uint _value);
    event BalanceWithdrawl(address indexed vendor, uint _balance);

    constructor(address MyERC20_) {
        VOwner = msg.sender;
        _myERC20 = MyERC20(MyERC20_);
    }

    function BuyToken() payable public returns(bool success) {
        require(msg.value >= 1 ether, "Minimum purchase is 1 ether!");

        uint tokenQuantity = (msg.value / 1 ether) * TokensPerEther;
        uint vendorTokenBalance = _myERC20.balanceOf(address(this));
        
        require(vendorTokenBalance >= tokenQuantity, "Insufficient Funds");

        // Calling transfer from 2.sol
        (bool sent) = _myERC20.transfer(msg.sender, tokenQuantity);
        require(sent, "Transfer Failed!");

        emit TokenBuy(msg.sender, msg.value, tokenQuantity);

        return true;
    }

    function SellToken(uint _amount) public payable returns(bool success) {
        uint _token = _amount % TokensPerEther;
        require(_token == 0, "Must sell in multiples of 100.");

        // Do we have permission? 
        uint limitQuantity = _myERC20.allowance(msg.sender, address(this));
        require(limitQuantity >= _amount, "Exceeded Maximum Allowance.");

        uint etherQuantity = _amount / TokensPerEther;

        // address(this).balance returns a value in wei, must convert
        uint vendorBalance = ((address(this).balance) / 1 ether);
        require(etherQuantity <= vendorBalance, "Insuficcent Vendor Balance");

        (bool succ) = _myERC20.transferFrom(msg.sender, address(this), _amount);
        require(succ, "Error when Transferring from sender to contract.");

        // Must pay in wei, so multiply by 1e18
        (bool sent,) = msg.sender.call{value: etherQuantity * 1e18}("");
        require(sent, "Error when Transferring from contract to sender");

        emit TokenSell(msg.sender, _amount, etherQuantity);

        return true;
    }

    function Withdrawl() public payable returns(bool success) {
        require(msg.sender == VOwner, "Only Vendor can Withdrawl.");

        uint contractBalance = address(this).balance;
        require(contractBalance >= 0, "No balance to withdrawl.");

        uint balance = address(this).balance;
        (bool succ,) = msg.sender.call{value: balance}("");
        require(succ, "Error when withdrawling.");

        emit BalanceWithdrawl(msg.sender, balance);

        return true;
    }
}