// File: mixswap.sol



/**         
  Token - MixSwap
  Ticker - $MXS
  Description - Mix your Ethereum or USDC and use it to do anonymous swaps. 
                Swaps are routed to a new wallet or a wallet of your choice. 
  Website - mixswap.org
  Telegram - t.me/mixswap
*/         

// SPDX-License-Identifier: MIT

pragma solidity 0.8.16;

import "@openzeppelin/contracts/utils/math/SafeMath.sol";

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

    function _msgData() internal view virtual returns (bytes calldata) { 
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

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

interface IERC20 { 
    /**
     * @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 `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a { Transfer} event.
     */
    function transfer(address recipient, 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 cal ler's tokens.
     *
     * Returns a boolean value indicating whether the op eration succeeded.
     *
     * IMPORTANT: Beware that changing an allowan ce 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 spe nder's allowance to 0 and set the
     * desired valu  afterwards:
     * https://github.co m/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an { Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` toke ns from `sender` to `recipient` using the
     * allowance mechanism. `am ount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a { Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `v alue` tokens are moved from one account (`from`) to
     * anot her (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the all owance of a `spender` for an `owner` is set by
     * a call to { approve}. `va lue` is the new allowance.
     */
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

interface IERC20Metadata is IERC20 { 
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

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");

        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);
    }

    function _createInitialSupply(address account, uint256 amount)
        internal
        virtual
    { 
        require(account != address(0), "ERC20: mint to the zero address");
        _totalSupply += amount;
        _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 the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

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

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() { 
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() { 
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without 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 available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner { 
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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"
        );
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

interface IUniswapV2Router01 { 
    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 removeLiquidity(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountA, uint256 amountB);

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

    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountA, uint256 amountB);

    function removeLiquidityETHWithPermit(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountToken, uint256 amountETH);

    function swapExactTokensForTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapTokensForExactTokens(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactETHForTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function swapTokensForExactETH(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactTokensForETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapETHForExactTokens(
        uint256 amountOut,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function quote(
        uint256 amountA,
        uint256 reserveA,
        uint256 reserveB
    ) external pure returns (uint256 amountB);

    function getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountOut);

    function getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountIn);

    function getAmountsOut(uint256 amountIn, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);

    function getAmountsIn(uint256 amountOut, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 { 
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountETH);

    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountETH);

    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;
}

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

    uint256 public swapTokensAtAmount;
    uint256 public maxTXAmount;

    IUniswapV2Router02 public immutable uniswapV2Router;
    address public immutable uniswapV2Pair;

    bool private swapping;

    // 0 means not active yet
    uint256 public tradeActiveBlock = 0; 

    address public _marketingWallet = 0xe0e4A0C9DCC462C98919Ca3791F49c3B13c81Eab;

    bool public tradeActive = false;
    bool public limitsInEffect = true;
    bool public swapIsEnabled = false;

    uint256 public constant feeDivisor = 1000;

    uint256 public marketingBuyFees;
    uint256 public totalBuyFees;

    uint256 public marketingSellFees;
    uint256 public totalSellFees;

    uint256 public tokensForFees;
    uint256 public tokensForMarketing;

    uint256 public maxWalletAmount;

    mapping(address => bool) private _Blacklist;

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

    mapping(address => bool) public automatedMarketMakerPairs;


    event ExcludeFromFees(address indexed account, bool isExcluded);
    event ExcludeMultipleAccountsFromFees(address[] accounts, bool isExcluded);

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

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

    constructor() ERC20("MixSwap", "MXS") { 
        uint256 totalSupply = 1 * 1e9 * 1e18;

        swapTokensAtAmount = (totalSupply * 1) / 10000; // 0.01% swap tokens amount
        maxTXAmount = (totalSupply * 10) / 1000; // 1% maxTXAmount
        maxWalletAmount = (totalSupply * 30) / 1000; // 3% maxWalletAmount

        // 4% 
        marketingBuyFees = 40; 
        totalBuyFees = marketingBuyFees; 

        // 4%
        marketingSellFees = 40; 
        totalSellFees = marketingSellFees;

        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);

        // Create a uniswap pair for this new token
        address _uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory())
            .createPair(address(this), _uniswapV2Router.WETH());

        uniswapV2Router = _uniswapV2Router;
        uniswapV2Pair = _uniswapV2Pair;

        _setAutomatedMarketMakerPair(_uniswapV2Pair, true);

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

        excludeFromFees(owner(), true);
        excludeFromFees(address(this), true);
        excludeFromFees(address(0xdead), true);
        excludeFromFees(address(_uniswapV2Router), true);
        excludeFromFees(address(_marketingWallet), true);


        _createInitialSupply(address(owner()), totalSupply);
    }

    receive() external payable { }

    function setMaxTxnAmount(uint256 newNum) external onlyOwner {  
        require(
            newNum >= ((totalSupply() * 10) / 1000) / 1e18, 
            "Must be greater than 1%"
        );
        maxTXAmount = newNum * (10**18);
    }

    function setMaxWalletAmount(uint256 newNum) external onlyOwner {  
        require(
            newNum >= ((totalSupply() * 30) / 1000) / 1e18,
            "Must be greater than 3.0%"
        );
        maxWalletAmount = newNum * (10**18);
    }

    function enableTrading() external onlyOwner {  
        require(!tradeActive, "Cannot re-enable trading!");
        tradeActive = true;  
        swapIsEnabled = true; 
        tradeActiveBlock = block.number; 
    } 

    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 { 
        swapIsEnabled = enabled;
    }

    function updateSellFees(uint256 _marketingSellFees) external onlyOwner { 
        marketingSellFees = _marketingSellFees;
        totalSellFees = marketingSellFees;
        require(totalSellFees <= 150, "Must keep fees at 15% or less");
    }

    function updateBuyFees(uint256 _marketingBuyFees) external onlyOwner { 
        marketingBuyFees = _marketingBuyFees;
        totalBuyFees = marketingBuyFees;
        require(totalSellFees <= 150, "Must keep fees at 15% or less");
    }

    function excludeFromFees(address account, bool excluded) public onlyOwner { 
        _isAddrExcludedFromFees[account] = excluded;

        emit ExcludeFromFees(account, excluded);
    }

    function excludeMultipleAccountsFromFees(
        address[] calldata accounts,
        bool excluded
    ) external onlyOwner { 
        for (uint256 i = 0; i < accounts.length; i++) { 
            _isAddrExcludedFromFees[accounts[i]] = excluded;
        }

        emit ExcludeMultipleAccountsFromFees(accounts, excluded);
    }

    function isAddrExcludedFromFees(address account) external view returns (bool) { 
        return _isAddrExcludedFromFees[account];
    }

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

        _setAutomatedMarketMakerPair(pair, value);
    }

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

    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!!");
        require(
            !_Blacklist[to] && !_Blacklist[from],
            "You have been blacklisted from transfering tokens!!"
        );

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

        if (!tradeActive) {  
            require(
                _isAddrExcludedFromFees[from] || _isAddrExcludedFromFees[to],
                "Trading is not active yet!!"
            ); 
        } 

        if (limitsInEffect) {  
            if ( 
                from != owner() &&
                to != owner() &&
                to != address(0) &&
                to != address(0xdead) &&
                !swapping
            ) { 
                if (!tradeActive) {  
                    require(
                        _isAddrExcludedFromFees[from] || _isAddrExcludedFromFees[to],
                        "Trading is not active!!" 
                    ); 
                } 

                // when buying:
                if ( 
                    automatedMarketMakerPairs[from] &&
                    !_isExcludedMaxTransactionAmount[to]
                ) {  
                    require(
                        amount <= maxTXAmount + 2 * 1e18,
                        "Buy transfer amount exceeds the maxTXAmount!!" 
                    );
                    require(
                        amount + balanceOf(to) <= maxWalletAmount, 
                        "Max wallet exceeded!!" 
                    ); 
                } 
                // when selling:
                else if (
                    automatedMarketMakerPairs[to] &&
                    !_isExcludedMaxTransactionAmount[from]
                ) { 
                    require(
                        amount <= maxTXAmount + 1 * 1e18,
                        "Sell transfer amount exceeds the maxTXAmount!!"
                    );
                } else if (!_isExcludedMaxTransactionAmount[to]) { 
                    require(
                        amount + balanceOf(to) <= maxWalletAmount,
                        "Max wallet exceeded!!"
                    );
                }
            }
        }

        uint256 _contractTokenBalance = balanceOf(address(this));
        bool _canSwap = _contractTokenBalance >= swapTokensAtAmount;

        if (
            _canSwap &&
            swapIsEnabled &&
            !swapping &&
            !automatedMarketMakerPairs[from] &&
            !_isAddrExcludedFromFees[from] &&
            !_isAddrExcludedFromFees[to]
        ) { 
            swapping = true;
            swapBack();
            swapping = false;
        }
        bool takeFee = !swapping;

        // if any account belongs to _isExcludedFromFee account then remove the fee 
        if (_isAddrExcludedFromFees[from] || _isAddrExcludedFromFees[to]) { 
            takeFee = false;
        }
        uint256 fees = 0;

        // no taxes on transfers (non buys/sells) 
        if (takeFee) { 
            // on sell take fees, purchase token and burn it 
            if (automatedMarketMakerPairs[to] && totalSellFees > 0) { 
                fees = amount.mul(totalSellFees).div(feeDivisor);
                tokensForFees += fees;
                tokensForMarketing += (fees * marketingSellFees) / totalSellFees;
            }
            // on buy
            else if (automatedMarketMakerPairs[from]) { 
                fees = amount.mul(totalBuyFees).div(feeDivisor);
                tokensForFees += fees;
                tokensForMarketing += (fees * marketingBuyFees) / totalBuyFees;
            }

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

            amount -= fees;
        }

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

    function removeAllSwapLimits() external onlyOwner returns (bool) { 
        limitsInEffect = false;
        return true;
    }

    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 addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {  
        // approve token transfer to cover all possible scenarios 
        _approve(address(this), address(uniswapV2Router), tokenAmount);  

        // add the liquidity 
        uniswapV2Router.addLiquidityETH{ value: ethAmount}(
            address(this), 
            tokenAmount, 
            0,  // slippage is unavoidable
            0,  // slippage is unavoidable
            address(0xdead), 
            block.timestamp
        ); 
    } 

    function manualSwap() external onlyOwner { 
        uint256 contractBalance = balanceOf(address(this));
        swapTokensForEth(contractBalance);
    }

    function setBotStatus(address[] memory _botz, bool status)
        public
        onlyOwner
    { 
        for (uint256 i = 0; i < _botz.length; i++) { 
            _Blacklist[_botz[i]] = status;
        }
    }

    function withdrawStuckEther() external onlyOwner { 
        (bool success, ) = address(msg.sender).call{ 
            value: address(this).balance
        }("");
        require(success, "failed to withdraw");
    }

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

        if (contractBalance == 0 || totalTokensToSwap == 0) { 
            return;
        }

        uint256 amountToSwapForETH = contractBalance;
        swapTokensForEth(amountToSwapForETH);

        (success, ) = address(_marketingWallet).call{ 
            value: address(this).balance
        }("");

        tokensForMarketing = 0;
        tokensForFees = 0;
    }
}
// File: @openzeppelin/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    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);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}