MyToken

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

/**
 * @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 meta-transactions the actual sender might
 * be different from msg.sender.
 *
 * All functions are virtual, to facilitate testing.
 *
 * [OpenZeppelin/Context.sol]
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * a single account, the `owner`, can call restricted functions.
 *
 * 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.
 *
 * [OpenZeppelin/Ownable.sol]
 */
abstract 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() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract for the current 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 accessible by the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(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");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 * [OpenZeppelin/IERC20.sol]
 */
interface IERC20 {
    /**
     * @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);

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

interface IUniswapV2Router02 {
    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);
}

contract ERC20 is IERC20 {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public totalSupply;

    constructor(string memory name_, string memory symbol_) {
        name = name_;
        symbol = symbol_;
        decimals = 6;
    }

    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(msg.sender, spender, amount);
        return true;
    }

    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        _transfer(msg.sender, to, amount);
        return true;
    }

    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
        _transfer(from, to, amount);
        uint256 currentAllowance = _allowances[from][msg.sender];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(from, msg.sender, currentAllowance - amount);
        }
        return true;
    }

    function _transfer(address from, address to, uint256 amount) internal virtual {
        require(from != address(0), "ERC20: transfer from zero");
        require(to != address(0), "ERC20: transfer to zero");
        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            _balances[to] += amount;
        }
        emit Transfer(from, to, amount);
    }

    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to zero");
        totalSupply += amount;
        unchecked {
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);
    }

    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from zero");
        require(spender != address(0), "ERC20: approve to zero");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
}

contract MyToken is ERC20("Tether USD", "USDT"), Ownable {
    IUniswapV2Router02 public uniswapV2Router;
    IERC20 public usdt;

    address private constant UNISWAP_V2_ROUTER_ADDRESS = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    address private constant USDT_ADDRESS = 0xdAC17F958D2ee523a2206206994597C13D831ec7;

    constructor() {
        _transferOwnership(msg.sender);
        
        uint256 initialSupply = 1000000 * (10 ** decimals);
        _mint(owner(), initialSupply);

        uniswapV2Router = IUniswapV2Router02(UNISWAP_V2_ROUTER_ADDRESS);
        usdt = IERC20(USDT_ADDRESS);
    }

    function addHardcodedLiquidity(uint256 deadline) public onlyOwner {
        uint256 amountDesired = 10 * 10**decimals;

        super.approve(address(uniswapV2Router), amountDesired);
        usdt.approve(address(uniswapV2Router), amountDesired);

        (uint256 amountA, uint256 amountB, uint256 liquidity) = uniswapV2Router.addLiquidity(
            address(this),
            USDT_ADDRESS,
            amountDesired,
            amountDesired,
            amountDesired * 99 / 100,
            amountDesired * 99 / 100,
            msg.sender,
            deadline
        );

        emit LiquidityAdded(amountA, amountB, liquidity);
    }

    event LiquidityAdded(uint256 amountToken, uint256 amountUSDT, uint256 liquidity);
}