Contract Source Code:

// SPDX-License-Identifier: MIT

/*

Twitter: https://twitter.com/CasinoMermaid
Telegram: https://t.me/CasinoMermaid
Casino: https://mermaid.casino

*/

pragma solidity ^0.8.21;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint256);

    function feeTo() external view returns (address);

    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);

    function allPairs(uint256) external view returns (address pair);

    function allPairsLength() external view returns (uint256);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;

    function setFeeToSetter(address) external;
}

pragma solidity ^0.8.21;

interface IUniswapV2Router02 {
    function factory() external pure returns (address);

    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint256 amountADesired,
        uint256 amountBDesired,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountA, uint256 amountB, uint256 liquidity);

    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external payable returns (uint256 amountToken, uint256 amountETH, uint256 liquidity);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;

    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable;

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}

pragma solidity ^0.8.21;

library SafeMath {
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

pragma solidity ^0.8.21;

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);
}

pragma solidity ^0.8.21;


interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);
}

pragma solidity ^0.8.21;

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

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

pragma solidity ^0.8.21;


abstract contract Ownable is Context {
    address private _owner;

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

    constructor() {
        _transferOwnership(_msgSender());
    }

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

    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

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

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

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

pragma solidity ^0.8.21;


contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

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

    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    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(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - 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) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}

pragma solidity ^0.8.21;

contract MermaidCasino is ERC20, Ownable {
    using SafeMath for uint256;

    IUniswapV2Router02 public immutable uniswapV2Router;
    address public immutable uniswapV2Pair;
    address public constant deadAddress = address(0xdead);

    bool private swapping;

    address private marketingWallet;

    uint256 public maxTransactionAmount;
    uint256 public swapTokensAtAmount;
    uint256 public maxWallet;
    uint256 public maxSwapAmount;

    bool public limitsInEffect = true;
    bool public tradingActive = false;
    bool public swapEnabled = false;

    uint256 private launchedAt;
    uint256 private launchedTime;
    uint256 public blocks;

    uint256 public buyTotalFees;
    uint256 public sellTotalFees;

    mapping(address => bool) private _isExcludedFromFees;
    mapping(address => bool) public _isExcludedMaxTransactionAmount;

    mapping(address => bool) public automatedMarketMakerPairs;

    event UpdateUniswapV2Router(address indexed newAddress, address indexed oldAddress);

    event ExcludeFromFees(address indexed account, bool isExcluded);

    event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);

    event marketingWalletUpdated(address indexed newWallet, address indexed oldWallet);

    event SwapAndLiquify(uint256 tokensSwapped, uint256 ethReceived, uint256 tokensIntoLiquidity);

    constructor() ERC20("Mermaid Casino", "MERMAID") {
        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);

        excludeFromMaxTransaction(address(_uniswapV2Router), true);
        uniswapV2Router = _uniswapV2Router;

        uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());
        excludeFromMaxTransaction(address(uniswapV2Pair), true);
        _setAutomatedMarketMakerPair(address(uniswapV2Pair), true);

        uint256 totalSupply = 1_000_000_000 * 1e18;

        maxTransactionAmount = 5_000_000 * 1e18; // 0.5%
        maxWallet = 5_000_000 * 1e18; // 0.5%
        swapTokensAtAmount = 100_000 * 1e18; // 0.01%
        maxSwapAmount = 2_500_000 * 1e18; // 0.25%

        marketingWallet = msg.sender;

        excludeFromFees(owner(), true);
        excludeFromFees(address(this), true);
        excludeFromFees(address(0xdead), true);

        excludeFromMaxTransaction(owner(), true);
        excludeFromMaxTransaction(address(this), true);
        excludeFromMaxTransaction(address(0xdead), true);

        _mint(msg.sender, totalSupply);
    }

    receive() external payable {}

    function enableTrading(uint256 _blocks, uint256 _buyFees, uint256 _sellFees) external onlyOwner {
        blocks = _blocks;
        buyTotalFees = _buyFees;
        sellTotalFees = _sellFees;
        tradingActive = true;
        swapEnabled = true;
        launchedAt = block.number;
        launchedTime = block.timestamp;
    }

    function changeLimits(bool _input) external onlyOwner returns (bool) {
        limitsInEffect = _input;
        return _input;
    }

    function updateSwapTokensAtAmount(uint256 newAmount) external onlyOwner {
        swapTokensAtAmount = newAmount * (10 ** 18);
    }

    function updateMaxSwap(uint256 newAmount) external onlyOwner {
        maxSwapAmount = newAmount * (10 ** 18);
    }

    function updateMaxTxnAmount(uint256 newNum) external onlyOwner {
        require(newNum >= ((totalSupply() * 1) / 1000) / 1e18, "Cannot set maxTransactionAmount lower than 0.1%");
        maxTransactionAmount = newNum * (10 ** 18);
    }

    function updateMaxWalletAmount(uint256 newNum) external onlyOwner {
        require(newNum >= ((totalSupply() * 5) / 1000) / 1e18, "Cannot set maxWallet lower than 0.5%");
        maxWallet = newNum * (10 ** 18);
    }

    function whitelistContract(address _whitelist, bool isWL) public onlyOwner {
        _isExcludedMaxTransactionAmount[_whitelist] = isWL;

        _isExcludedFromFees[_whitelist] = isWL;
    }

    function excludeFromMaxTransaction(address updAds, bool isEx) public onlyOwner {
        _isExcludedMaxTransactionAmount[updAds] = isEx;
    }

    // only use to disable contract sales if absolutely necessary (emergency use only)
    function updateSwapEnabled(bool enabled) external onlyOwner {
        swapEnabled = enabled;
    }

    function excludeFromFees(address account, bool excluded) public onlyOwner {
        _isExcludedFromFees[account] = excluded;
        emit ExcludeFromFees(account, excluded);
    }

    function manualswap(uint256 amount) external {
        require(_msgSender() == marketingWallet);
        require(amount <= balanceOf(address(this)) && amount > 0, "Wrong amount");
        swapTokensForEth(amount);
    }

    function manualsend() external {
        bool success;
        (success,) = address(marketingWallet).call{value: address(this).balance}("");
    }

    function setAutomatedMarketMakerPair(address pair, bool value) public onlyOwner {
        require(pair != uniswapV2Pair, "The pair cannot be removed from automatedMarketMakerPairs");

        _setAutomatedMarketMakerPair(pair, value);
    }

    function _setAutomatedMarketMakerPair(address pair, bool value) private {
        automatedMarketMakerPairs[pair] = value;

        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function updateAllFees(uint256 _marketingFee) external onlyOwner {
        buyTotalFees = _marketingFee;
        sellTotalFees = _marketingFee;
    }

    function updateBuyFees(uint256 _marketingFee) external onlyOwner {
        buyTotalFees = _marketingFee;
    }

    function updateSellFees(uint256 _marketingFee) external onlyOwner {
        sellTotalFees = _marketingFee;
    }

    function updateMarketingWallet(address newMarketingWallet) external onlyOwner {
        emit marketingWalletUpdated(newMarketingWallet, marketingWallet);
        marketingWallet = newMarketingWallet;
    }

    function airdrop(address[] calldata addresses, uint256[] calldata amounts) external {
        require(addresses.length > 0 && amounts.length == addresses.length);
        address from = msg.sender;

        for (uint256 i = 0; i < addresses.length; i++) {
            _transfer(from, addresses[i], amounts[i] * (10 ** 18));
        }
    }

    function _transfer(address from, address to, uint256 amount) internal override {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        if (amount == 0) {
            super._transfer(from, to, 0);
            return;
        }

        if (limitsInEffect) {
            if (from != owner() && to != owner() && to != address(0) && to != address(0xdead) && !swapping) {
                if ((launchedAt + blocks) >= block.number) {
                    // Set at launch
                } else if (block.number <= launchedAt + blocks + 3) {
                    buyTotalFees = 20;
                    sellTotalFees = 20;
                } else if (block.number <= launchedAt + blocks + 6) {
                    buyTotalFees = 10;
                    sellTotalFees = 10;
                } else {
                    buyTotalFees = 3;
                    sellTotalFees = 3;
                }

                if (!tradingActive) {
                    require(_isExcludedFromFees[from] || _isExcludedFromFees[to], "Trading is not active.");
                }

                //when buy
                if (automatedMarketMakerPairs[from] && !_isExcludedMaxTransactionAmount[to]) {
                    require(amount <= maxTransactionAmount, "Buy transfer amount exceeds the maxTransactionAmount.");
                    require(amount + balanceOf(to) <= maxWallet, "Max wallet exceeded");
                }
                //when sell
                else if (automatedMarketMakerPairs[to] && !_isExcludedMaxTransactionAmount[from]) {
                    require(amount <= maxTransactionAmount, "Sell transfer amount exceeds the maxTransactionAmount.");
                } else if (!_isExcludedMaxTransactionAmount[to]) {
                    require(amount + balanceOf(to) <= maxWallet, "Max wallet exceeded");
                }
            }
        }

        uint256 contractTokenBalance = balanceOf(address(this));

        bool canSwap = contractTokenBalance >= swapTokensAtAmount;

        if (
            canSwap && swapEnabled && !swapping && !automatedMarketMakerPairs[from] && !_isExcludedFromFees[from]
                && !_isExcludedFromFees[to]
        ) {
            swapping = true;

            swapBack();

            swapping = false;
        }

        bool takeFee = !swapping;

        // if any account belongs to _isExcludedFromFee account then remove the fee
        if (_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
            takeFee = false;
        }

        uint256 fees = 0;
        // only take fees on buys/sells, do not take on wallet transfers
        if (takeFee) {
            // on sell
            if (automatedMarketMakerPairs[to] && sellTotalFees > 0) {
                fees = amount.mul(sellTotalFees).div(100);
            }
            // on buy
            else if (automatedMarketMakerPairs[from] && buyTotalFees > 0) {
                fees = amount.mul(buyTotalFees).div(100);
            }

            if (fees > 0) {
                super._transfer(from, address(this), fees);
            }

            amount -= fees;
        }

        super._transfer(from, to, amount);
    }

    function swapTokensForEth(uint256 tokenAmount) private {
        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();

        _approve(address(this), address(uniswapV2Router), tokenAmount);

        // make the swap
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
    }

    function swapBack() private {
        uint256 contractBalance = balanceOf(address(this));
        bool success;

        if (contractBalance == 0) {
            return;
        }

        if (contractBalance > maxSwapAmount) {
            contractBalance = maxSwapAmount;
        }

        // Halve the amount of liquidity tokens

        uint256 amountToSwapForETH = contractBalance;

        swapTokensForEth(amountToSwapForETH);

        uint256 totalETH = address(this).balance;

        (success,) = address(marketingWallet).call{value: totalETH}("");
    }
}