// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

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 MDEX is IERC20 {
    address public owner;
    mapping(address => uint) public override balanceOf;
    mapping(address => mapping(address => uint)) public override allowance;
    string public name;
    string public symbol;
    uint8 public decimals;
    uint public override totalSupply;
    bool private _entered;

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

    modifier onlyOwner() {
        require(msg.sender == owner, "Caller is not the owner");
        _;
    }

    modifier nonReentrant() {
        require(!_entered, "Reentrant call");
        _entered = true;
        _;
        _entered = false;
    }

    constructor(address multisigAddress) {
        require(multisigAddress != address(0), "Cannot add funds in zero address");
        symbol = "MDEX";
        name = "MasterDEX Token";
        decimals = 18;
        totalSupply = 300000000 * 10 ** decimals;
        balanceOf[multisigAddress] = totalSupply;
        owner = msg.sender;
        emit Transfer(address(0), multisigAddress, totalSupply);
    }

    function transfer(address recipient, uint amount) external override returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }

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

    function transferFrom(address sender, address recipient, uint amount) external override returns (bool) {
        uint256 currentAllowance = allowance[sender][msg.sender];
        require(currentAllowance >= amount, "Transfer amount exceeds allowance");
        _transfer(sender, recipient, amount);
        _approve(sender, msg.sender, currentAllowance - amount);
        return true;
    }

    function _transfer(address sender, address recipient, uint amount) internal {
        require(sender != address(0), "Transfer from the zero address");
        require(recipient != address(0), "Transfer to the zero address");
        require(balanceOf[sender] >= amount, "Transfer amount exceeds balance");
        
        balanceOf[sender] -= amount;
        balanceOf[recipient] += amount;
        emit Transfer(sender, recipient, amount);
    }

    function _approve(address _owner, address spender, uint amount) internal {
        require(_owner != address(0), "Approve from the zero address");
        require(spender != address(0), "Approve to the zero address");
        
        allowance[_owner][spender] = amount;
        emit Approval(_owner, spender, amount);
    }

    function withdrawToken(address _tokenContract, uint256 _amount) external onlyOwner {
        IERC20(_tokenContract).transfer(msg.sender, _amount);
    }

    function transferOwnership(address newOwner) public onlyOwner {
        require(newOwner != address(0), "New owner is the zero address");
        emit OwnershipTransferred(owner, newOwner);
        owner = newOwner;
    }
}

{
  "compilationTarget": {
    "MDEX.sol": "MDEX"
  },
  "evmVersion": "shanghai",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}