// File: contracts/token.sol



//SPDX-License-Identifier: MIT

/**
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Features:
1- Dynamic Tax System: The token has a dynamic tax system that applies different tax rates for buying, selling, and transferring tokens. These taxes are adjustable by the contract owner, providing flexibility in managing the token's ecosystem.
2- Trading Limitations: The contract enforces limitations on trading, such as maximum buy, sell, and transfer amounts. It also has a maximum wallet holding limit to prevent concentration of tokens in a single wallet. These limitations can be adjusted by the contract owner.
3- Sell Cooldown Mechanism: The token has a sell cooldown mechanism that prevents users from selling tokens for a certain duration after their last sell. This feature can be toggled on and off, and the cooldown duration can be adjusted by the contract owner.
4- Dead Block Protection: To prevent users from exploiting the trading launch of the token, a "dead block" protection mechanism is in place. Users buying tokens within a specified number of blocks after trading is enabled will be charged a high tax rate (99%).
5- Automatic Liquidity and Treasury Management: The contract is designed to automatically swap a portion of collected tax into ETH and add liquidity to the trading pair on the decentralized exchange. It also sends a portion of the collected tax to the specified Treasury Wallet in ETH.                                                                                 
*/

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

pragma solidity 0.8.17;

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

interface DexRouter {
    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;
}

contract SCB is ERC20, Ownable {
    struct Tax {
        uint256 TreasuryTax;
        uint256 liquidityTax;
    }

    uint256 private constant _totalSupply = 1e7 * 1e18;

    //Router
    DexRouter public immutable uniswapRouter;
    address public immutable pairAddress;

    //Taxes
    Tax public buyTaxes = Tax(0, 0);
    Tax public sellTaxes = Tax(0, 0);
    Tax public transferTaxes = Tax(0, 0);
    uint256 public totalBuyFees;
    uint256 public totalSellFees;
    uint256 public totalTransferFees;

    //Whitelisting from taxes/maxwallet/txlimit/etc
    mapping(address => bool) private whitelisted;

    //Swapping
    uint256 public swapTokensAtAmount = _totalSupply / 100000; //after 0.001% of total supply, swap them
    bool public swapAndLiquifyEnabled = true;
    bool public isSwapping = false;
    bool public tradingStatus = false;

    //Limitations
    uint256 public maxBuy = _totalSupply;
    uint256 public maxSell = _totalSupply;
    uint256 public maxTx = _totalSupply;
    uint256 public maxWallet = (_totalSupply * 1) / 100;
    mapping(address => uint256) public lastSells;
    uint256 public sellCooldown;
    uint256 public deadBlocks = 3;
    uint256 public startingBlock;
    bool public sellCooldownEnabled = true;

    //Wallets
    address public TreasuryWallet = 0x74Adf47aD22a9C95EE58A6D956FA58924D697E0F;

    //Events
    event TradingStarted(uint256 indexed _startBlock);
    event TreasuryWalletChanged(address indexed _trWallet);
    event MaxBuyUpdated(uint256 indexed _maxBuy);
    event MaxSellUpdated(uint256 indexed _maxSell);
    event MaxTxUpdated(uint256 indexed _maxTx);
    event MaxWalletUpdated(uint256 indexed _maxWallet);
    event BuyFeesUpdated(uint256 indexed _lpFee, uint256 indexed _trFee);
    event SellFeesUpdated(uint256 indexed _lpFee, uint256 indexed _trFee);
    event TransferFeesUpdated(uint256 indexed _lpFee, uint256 indexed _trFee);
    event SwapThresholdUpdated(uint256 indexed _newThreshold);
    event SellCoolDownStatusUpdated(bool indexed _status);
    event SellCoolDownUpdated(uint256 indexed _newAmount);
    event InternalSwapStatusUpdated(bool indexed _status);
    event Whitelist(address indexed _target, bool indexed _status);
    event UpdatedDeadBlocks(uint indexed _deadBlocks);

    constructor() ERC20("Seismic CB", "SCB") {
        uniswapRouter = DexRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        pairAddress = DexFactory(uniswapRouter.factory()).createPair(
            address(this),
            uniswapRouter.WETH()
        );
        whitelisted[msg.sender] = true;
        whitelisted[address(uniswapRouter)] = true;
        whitelisted[address(this)] = true;
        _mint(msg.sender, _totalSupply);
    }

    function enableTrading() external onlyOwner {
        require(!tradingStatus, "trading is already enabled");
        tradingStatus = true;
        startingBlock = block.number;
        emit TradingStarted(startingBlock);
    }

    function setTreasuryWallet(address _newTreasury) external onlyOwner {
        require(
            _newTreasury != address(0),
            "can not set treasury to dead wallet"
        );
        TreasuryWallet = _newTreasury;
        emit TreasuryWalletChanged(_newTreasury);
    }

    function setMaxBuy(uint256 _mb) external onlyOwner {
        require(
            _mb >= (_totalSupply * 25) / 10000,
            "max buy must be greater than 0.25% of total supply"
        );
        maxBuy = _mb;
        emit MaxBuyUpdated(_mb);
    }

    function setMaxSell(uint256 _ms) external onlyOwner {
        require(
            _ms >= (_totalSupply * 25) / 10000,
            "max sell must be greter than 0.25% of total supply"
        );
        maxSell = _ms;
        emit MaxSellUpdated(_ms);
    }

    function setMaxTx(uint256 _mt) external onlyOwner {
        require(
            _mt >= (_totalSupply * 25) / 10000,
            "max transfer must be greater than 0.25% of total supply"
        );
        maxTx = _mt;
        emit MaxTxUpdated(_mt);
    }

    function setMaxWallet(uint256 _mx) external onlyOwner {
        require(
            _mx > (_totalSupply * 25) / 1000,
            "max wallet must be greater than 0.25% of total supply"
        );
        maxWallet = _mx;
        emit MaxWalletUpdated(_mx);
    }

    function setBuyTaxes(
        uint256 _lpTax,
        uint256 _TreasuryTax
    ) external onlyOwner {
        buyTaxes.TreasuryTax = _TreasuryTax;
        buyTaxes.liquidityTax = _lpTax;
        totalBuyFees = _lpTax + _TreasuryTax;
        require(
            totalBuyFees + totalSellFees <= 22,
            "Can not set buy fees higher than 22%"
        );
        emit BuyFeesUpdated(_lpTax, _TreasuryTax);
    }

    function setSellTaxes(
        uint256 _lpTax,
        uint256 _TreasuryTax
    ) external onlyOwner {
        sellTaxes.TreasuryTax = _TreasuryTax;
        sellTaxes.liquidityTax = _lpTax;
        totalSellFees = _lpTax + _TreasuryTax;
        require(
            totalBuyFees + totalSellFees <= 22,
            "Can not set buy fees higher than 22%"
        );
        emit SellFeesUpdated(_lpTax, _TreasuryTax);
    }

    function setSellCooldown(uint256 _sc) external onlyOwner {
        require(
            _sc >= 30 && _sc <= 10 minutes,
            "Can't set sell cooldown less than 30 seconds and more than 10 minutes"
        );
        sellCooldown = _sc;
        emit SellCoolDownUpdated(_sc);
    }

    function setDeadBlocks(uint256 _db) external onlyOwner {
        require(
            !tradingStatus,
            "can not adjust deadblocks after enabling the trades"
        );
        require(_db <= 10, "can not exceed 10 blocks for anti-bot");
        deadBlocks = _db;
        emit UpdatedDeadBlocks(_db);
    }

    function setTransferFees(
        uint256 _lpTax,
        uint256 _TreasuryTax
    ) external onlyOwner {
        transferTaxes.TreasuryTax = _TreasuryTax;
        transferTaxes.liquidityTax = _lpTax;
        totalTransferFees = _lpTax + _TreasuryTax;
        require(
            totalTransferFees <= 11,
            "Can not set transfer tax higher than 12%"
        );
        emit TransferFeesUpdated(_lpTax, _TreasuryTax);
    }

    function setSwapTokensAtAmount(uint256 _newAmount) external onlyOwner {
        require(
            _newAmount > 0 && _newAmount <= (_totalSupply * 5) / 1000,
            "SCB : Minimum swap amount must be greater than 0 and less than 0.5% of total supply!"
        );
        swapTokensAtAmount = _newAmount;
        emit SwapThresholdUpdated(swapTokensAtAmount);
    }

    function toggleSellCooldown() external onlyOwner {
        sellCooldownEnabled = (sellCooldownEnabled) ? false : true;
        emit SellCoolDownStatusUpdated(sellCooldownEnabled);
    }

    function toggleSwapping() external onlyOwner {
        swapAndLiquifyEnabled = (swapAndLiquifyEnabled) ? false : true;
        emit InternalSwapStatusUpdated(sellCooldownEnabled);
    }

    function setWhitelistStatus(
        address _wallet,
        bool _status
    ) external onlyOwner {
        whitelisted[_wallet] = _status;
        emit Whitelist(_wallet, _status);
    }

    function checkWhitelist(address _wallet) external view returns (bool) {
        return whitelisted[_wallet];
    }

    // this function is reponsible for managing tax, if _from or _to is whitelisted, we simply return _amount and skip all the limitations
    function _takeTax(
        address _from,
        address _to,
        uint256 _amount
    ) internal returns (uint256) {
        if (whitelisted[_from] || whitelisted[_to]) {
            return _amount;
        }
        bool isBuy = false;
        bool isSell = false;
        bool isTransfer = false;
        uint256 totalTax = totalTransferFees;
        if (_to == pairAddress) {
            totalTax = totalSellFees;
            require(
                _amount <= maxSell,
                "SCB : can not sell more than max sell"
            );
            isSell = true;
        } else if (_from == pairAddress) {
            totalTax = totalBuyFees;
            require(_amount <= maxBuy, "SCB : can not buy more than max buy");
            isBuy = true;
        } else {
            require(
                _amount <= maxTx,
                "SCB : can not transfer more than max tx"
            );
            if (tradingStatus) {
                lastSells[_to] = lastSells[_from]; //this makes sure that one can not transfer his tokens to another wallet to bypass sell cooldown
            }
            isTransfer = true;
        }
        // if is buy or sell, firstly dont let trades if is not enabled, secondly, elimniate dead block buyers
        if (isBuy || isSell) {
            require(tradingStatus, "Trading is not enabled yet!");
            if (isBuy) {
                if (startingBlock + deadBlocks >= block.number) {
                    totalTax = 99;
                }
            } else {
                if (sellCooldownEnabled) {
                    require(
                        lastSells[_from] + sellCooldown <= block.timestamp,
                        "sell cooldown"
                    );
                }
                lastSells[_from] = block.timestamp;
            }
        }
        // if is buy or transfer, we have to check max wallet
        if (isBuy || isTransfer) {
            require(
                balanceOf(_to) + _amount <= maxWallet,
                "can not hold more than max wallet"
            );
        }
        uint256 tax = 0;
        if (totalTax > 0) {
            tax = (_amount * totalTax) / 100;
            super._transfer(_from, address(this), tax);
        }
        return (_amount - tax);
    }

    function _transfer(
        address _from,
        address _to,
        uint256 _amount
    ) internal virtual override {
        require(_from != address(0), "transfer from address zero");
        require(_to != address(0), "transfer to address zero");
        uint256 toTransfer = _takeTax(_from, _to, _amount);

        bool canSwap = balanceOf(address(this)) >= swapTokensAtAmount;
        if (
            swapAndLiquifyEnabled &&
            pairAddress == _to &&
            canSwap &&
            !whitelisted[_from] &&
            !whitelisted[_to] &&
            !isSwapping
        ) {
            isSwapping = true;
            internalSwap();
            isSwapping = false;
        }
        super._transfer(_from, _to, toTransfer);
    }

    function internalSwap() internal {
        uint256 taxAmount = balanceOf(address(this));
        if (taxAmount == 0) {
            return;
        }
        //Getting total Fee Percentages And Caclculating Portinos for each tax type
        Tax memory bt = buyTaxes;
        Tax memory st = sellTaxes;
        Tax memory tt = transferTaxes;

        uint256 totalTaxes = totalBuyFees + totalSellFees + totalTransferFees;

        if (totalTaxes == 0) {
            return;
        }

        uint256 totalLPTax = bt.liquidityTax +
            st.liquidityTax +
            tt.liquidityTax;

        //Calculating portions for each type of tax (Treasury, burn, liquidity, rewards)
        uint256 lpPortion = (taxAmount * totalLPTax) / totalTaxes;
        uint256 TreasuryPortion = balanceOf(address(this)) - lpPortion;

        //Add Liquidty taxes to liqudity pool
        if (lpPortion > 0) {
            swapAndLiquify(lpPortion);
        }

        //sending to Treasury wallet
        if (TreasuryPortion > 0) {
            swapToETH(balanceOf(address(this)));
            (bool success, ) = TreasuryWallet.call{
                value: address(this).balance
            }("");
        }
    }

    function swapAndLiquify(uint256 _amount) internal {
        uint256 firstHalf = _amount / 2;
        uint256 otherHalf = _amount - firstHalf;
        uint256 initialETHBalance = address(this).balance;

        //Swapping first half to ETH
        swapToETH(firstHalf);
        uint256 received = address(this).balance - initialETHBalance;
        addLiquidity(otherHalf, received);
    }

    function swapToETH(uint256 _amount) internal {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapRouter.WETH();
        _approve(address(this), address(uniswapRouter), _amount);
        uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            _amount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    function addLiquidity(uint256 tokenAmount, uint256 ETHAmount) private {
        _approve(address(this), address(uniswapRouter), tokenAmount);
        uniswapRouter.addLiquidityETH{value: ETHAmount}(
            address(this),
            tokenAmount,
            0,
            0,
            0x000000000000000000000000000000000000dEaD,
            block.timestamp
        );
    }

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

    function withdrawStuckTokens(address erc20_token) external onlyOwner {
        bool success = IERC20(erc20_token).transfer(
            msg.sender,
            IERC20(erc20_token).balanceOf(address(this))
        );
        require(success, "trasfering tokens failed!");
    }

    receive() external payable {}
}
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

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

    /**
     * @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 `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, 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 caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

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

// File: @openzeppelin/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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;
        }
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract 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() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(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");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
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;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(address from, address to, uint256 amount) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    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;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

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

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    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;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

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

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

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    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);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
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);
}