// File: contracts/CREEBank.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
import "@openzeppelin/contracts/utils/Strings.sol";

error IncorrectSignature();
error DepositMoreCREE();
error RequireMoreCREELeft();

/// @custom:security-contact security@creebank.org
// Contract for CREEBank CREE Wallet, Version 1.0 
/*

https://creebank.org

_________________________________________ .__  _________   ________ ________   ________  ________   
\_   ___ \______   \_   _____/\_   _____/ |__|/   _____/  /  _____/ \_____  \  \_____  \ \______ \  
/    \  \/|       _/|    __)_  |    __)_  |  |\_____  \  /   \  ___  /   |   \  /   |   \ |    |  \ 
\     \___|    |   \|        \ |        \ |  |/        \ \    \_\  \/    |    \/    |    \|    `   \
 \______  /____|_  /_______  //_______  / |__/_______  /  \______  /\_______  /\_______  /_______  /
        \/       \/        \/         \/             \/          \/         \/         \/        \/ 

*/


contract CREEBank is Ownable, ReentrancyGuard {
    using ECDSA for bytes32;
    using SafeERC20 for IERC20;


    IERC20 public theToken;
    IERC20 public usdtToken;

    uint256 public withdrawalFee;
    uint256 public claimFee;
    uint256 public transferFee;
    uint256 public MIN_DEPOSIT = 1 * 1e18;
    
    mapping(address => AccountInfo) public accounts;
    mapping(address => mapping(uint256 => IndividualDeposit)) public individualDeposits;
    mapping(address => uint256) public individualDepositCount;

    mapping(bytes32 => bool) public usedSignatures;

    uint256 public totalDeposited;
    uint256 public totalDepositers;
    uint256 public globalCREERewardedAndClaimed;
    uint256 public claimMilestone;

    uint256 public lastServerCheckin;

    address private signingAddress;

    bool public isBankOpen;     // true (you can transfer/claim rewards with CREEBank) | false (default: CREEBank is not open, you can only withdraw/deposit)

    struct IndividualDeposit {
        uint256 amount;
        uint256 timestamp;
    }

    struct AccountInfo {
        uint256 totalAmount;
        uint256 firstDepositTS;
        uint256 lastDepositTS;
        uint256 totalCREEWorthClaimed;
        bool safeMode;
        uint256[11] claimedRewards; // 0-10 types of rewards, for tracking and updates only
    }


    event Deposited(address indexed from, address indexed to, uint256 amount);
    event Withdrawn(address indexed user, uint256 amount);
    event Transferred(address indexed from, address indexed to, uint256 amount);
    event RewardClaimed(address indexed from, address indexed to, uint256 cree_amount, uint8 rewardType, uint256 amount);


    constructor(address _aSignerAddress, address _theTokenAddress, address _usdtAddress) Ownable(msg.sender) {
        signingAddress = _aSignerAddress;
        theToken = IERC20(_theTokenAddress);
        usdtToken = IERC20(_usdtAddress);
    }    

    function setFees(uint256 _withdrawalFee, uint256 _claimFee, uint256 _transferFee) external onlyOwner {
        withdrawalFee = _withdrawalFee;
        claimFee = _claimFee;
        transferFee = _transferFee;
    }

    function setMinimal(uint256 _MIN_DEPOSIT) external onlyOwner {
        MIN_DEPOSIT = _MIN_DEPOSIT;
    }

    function setClaimMilestone(uint256 _claimMilestone) external onlyOwner {
        claimMilestone = _claimMilestone;
    }

    function setTheTokenAddress(address _TokenAddress) external onlyOwner {
        theToken = IERC20(_TokenAddress);
    }

    function setUSDTAddress(address _usdtAddress) external onlyOwner {
        usdtToken = IERC20(_usdtAddress);
    }

    function flipBankOpen() external onlyOwner {
        isBankOpen = !isBankOpen;
    }    
    
    function setSigningAddress(address newSigningAddress) external onlyOwner {
        signingAddress = newSigningAddress;
    }

    function getSigningAddress() external view onlyOwner returns (address) {
        return signingAddress;
    }   

    function serverCheckin() external onlyOwner {
        lastServerCheckin = block.number;
    }    

    function depositTo(uint256 _amount, address _recipient) public nonReentrant {

        if (_amount < MIN_DEPOSIT) revert DepositMoreCREE();
        require(theToken.allowance(msg.sender, address(this)) >= _amount, "Not enough allowance to transfer CREE");

        // Ensure the sender has at least MIN_DEPOSIT CREE left after the deposit
        uint256 balanceAfter = theToken.balanceOf(msg.sender) - _amount;
        if (balanceAfter < MIN_DEPOSIT) revert RequireMoreCREELeft();
        
        require(theToken.transferFrom(msg.sender, address(this), _amount), "Transfer failed");

        if (accounts[_recipient].totalAmount == 0) {
            totalDepositers += 1;  // Increment totalDepositers as it's a new account/depositor at _recipient address
            accounts[_recipient].firstDepositTS = block.timestamp;
        }

        accounts[_recipient].lastDepositTS = block.timestamp;

        uint256 index = individualDepositCount[_recipient];
        individualDeposits[_recipient][index] = IndividualDeposit(_amount, block.timestamp);
        individualDepositCount[_recipient]++;

        accounts[_recipient].totalAmount += _amount;

        totalDeposited += _amount;
        emit Deposited(msg.sender, _recipient, _amount);
    }    

    function depositToSelf(uint256 _amount) external nonReentrant {
        depositTo(_amount, msg.sender);
    }

    function getAllIndividualDeposits(address userAddress) external view returns (IndividualDeposit[] memory) {
        uint256 count = individualDepositCount[userAddress];
        IndividualDeposit[] memory deposits = new IndividualDeposit[](count);
        for (uint256 i = 0; i < count; i++) {
            deposits[i] = individualDeposits[userAddress][i];
        }
        return deposits;
    }

    function getClaimedRewards(address walletAddress) external view returns (uint256[11] memory) {
        return accounts[walletAddress].claimedRewards;
    }


    // Unlike traditional banking systems, and most crypto exchanges...
    // CREEBank's "withdraw" function is open 24/7 for holders to withdraw.
    // "safeMode" for real customers to lock their own accounts if they want, in cases where they are hacked. Users must lock their own account withdrawals as soon as possible.
    // "safeMode" is also an off-chain option required for low/no fee withdrawal, online spending, rewards claiming etc.
    function withdraw(uint256 _amount) external payable nonReentrant {
        require(accounts[msg.sender].totalAmount >= _amount, "Insufficient balance"); // double check? redundant?

        require( (accounts[msg.sender].totalAmount - _amount) >= MIN_DEPOSIT , "Require more CREE left");

        require( !accounts[msg.sender].safeMode , "Account in safeMode!");
        
        // If a withdrawal fee is set, ensure the correct fee has been sent with the transaction
        if (withdrawalFee > 0) {
            require(msg.value >= withdrawalFee, "Insufficient ETH for withdrawal");
        }

        transferAndUpdateAccount(msg.sender, _amount);

        emit Withdrawn(msg.sender, _amount);
    }

    // "safeMode" withdrawal checks CREEBank before going through, this is enabled or disabled by the user through CREEBank portal.
    function withdrawFromCREEBank(bytes calldata signature, uint256 _amount, uint256 _timestamp, uint256 _dynamicFee) external payable nonReentrant {
        require(accounts[msg.sender].totalAmount >= _amount, "Insufficient balance"); // double check? redundant?

        require( (accounts[msg.sender].totalAmount - _amount) >= MIN_DEPOSIT , "Require more CREE left");

        // use liveFee if set, if not, use withdrawal fee, ensure the correct fee has been sent with the transaction
        if (_dynamicFee > 0) {
            require(msg.value >= _dynamicFee, "Insufficient ETH for withdrawal");
        }
        else {
            require(msg.value >= withdrawalFee, "Insufficient ETH for withdrawal");
        }

        require(verifySignatureForWithdraw(msg.sender, msg.sender, _amount, _timestamp, _dynamicFee, signature), "Withdrawal unverified or expired");

        bytes32 signatureHash = keccak256(abi.encodePacked(signature));
        require(!usedSignatures[signatureHash], "Claim has already been made");
        usedSignatures[signatureHash] = true;

        lastServerCheckin = block.number; 

        transferAndUpdateAccount(msg.sender, _amount);

        emit Withdrawn(msg.sender, _amount);
    }

    function verifySignatureForWithdraw(
        address sender,
        address _recipient,
        uint256 _amount,
        uint256 _timestamp,
        uint256 _dynamicFee,
        bytes memory signature
    ) internal view returns(bool) {                
        // Check if _timestamp is within the last 1 hour
        if (_timestamp > block.number || (block.number - _timestamp) * 15 > 3600) {
            return false;
        }

        // String concatenation and conversion to hexadecimal
        string memory dataString = string(
            abi.encodePacked(
                Strings.toHexString(uint256(uint160(_recipient)), 20),
                Strings.toString(_amount),
                Strings.toString(_timestamp),
                Strings.toString(_dynamicFee),
                Strings.toHexString(uint256(uint160(sender)), 20)
            )
        );

        // Hashing
        bytes32 messageHash = keccak256(
            abi.encodePacked(
                "\x19Ethereum Signed Message:\n",
                Strings.toString(bytes(dataString).length),
                dataString
            )
        );

        // Signature verification
        return signingAddress == ECDSA.recover(
            messageHash,
            signature
        );
    }    

    // safety feature that can only be enabled/disabled from CREEBank portal by user.
    function flipSafeMode(bytes calldata signature, address _recipient, uint256 _timestamp, uint256 _dynamicFee) external payable nonReentrant {

        // use liveFee if set
        if (_dynamicFee > 0) {
            require(msg.value >= _dynamicFee, "Insufficient ETH for action");
        }

        require(verifySignature(msg.sender, _recipient, _timestamp, _dynamicFee, signature), "Signature unverified or expired");

        bytes32 signatureHash = keccak256(abi.encodePacked(signature));
        require(!usedSignatures[signatureHash], "This safeMode action already used");
        usedSignatures[signatureHash] = true;

        lastServerCheckin = block.number; 

        accounts[_recipient].safeMode = !accounts[_recipient].safeMode;
    }        

    function verifySignature(
        address sender,
        address _recipient,
        uint256 _timestamp,
        uint256 _dynamicFee,
        bytes memory signature
    ) internal view returns(bool) {                
        // Check if _timestamp is within the last 1 hour
        if (_timestamp > block.number || (block.number - _timestamp) * 15 > 3600) {
            return false;
        }

        // String concatenation and conversion to hexadecimal
        string memory dataString = string(
            abi.encodePacked(
                Strings.toHexString(uint256(uint160(_recipient)), 20),
                Strings.toString(_timestamp),
                Strings.toString(_dynamicFee),
                Strings.toHexString(uint256(uint160(sender)), 20)
            )
        );

        // Hashing
        bytes32 messageHash = keccak256(
            abi.encodePacked(
                "\x19Ethereum Signed Message:\n",
                Strings.toString(bytes(dataString).length),
                dataString
            )
        );

        // Signature verification
        return signingAddress == ECDSA.recover(
            messageHash,
            signature
        );
    }    

    // Like a bank account, users can choose to transfer to a target address from their CREE Wallet account
    function transferTo(uint256 _amount, address _recipient) external payable nonReentrant {
        require(isBankOpen, "CREEBank not open!");

        require(accounts[msg.sender].totalAmount >= _amount, "Insufficient balance"); // double check? redundant?
        if (accounts[msg.sender].totalAmount - _amount < MIN_DEPOSIT) revert RequireMoreCREELeft();
        
        if (transferFee > 0) {
            require(msg.value >= transferFee, "Insufficient ETH for transfer");
        }

        require( !accounts[msg.sender].safeMode , "Account in safeMode!");

        transferAndUpdateAccount(_recipient, _amount);

        emit Transferred(msg.sender, _recipient, _amount);
    }    

    // Like a bank account, users can choose to transfer to a target address from their CREE Wallet account
    function transferToFromCREEBank(bytes calldata signature, uint256 _amount, address _recipient, uint256 _timestamp, uint256 _dynamicFee) external payable nonReentrant {
        require(isBankOpen, "CREEBank not open!");

        require(accounts[msg.sender].totalAmount >= _amount, "Insufficient balance"); // double check? redundant?
        if (accounts[msg.sender].totalAmount - _amount < MIN_DEPOSIT) revert RequireMoreCREELeft();

        if (_dynamicFee > 0) {
            require(msg.value >= _dynamicFee, "Insufficient ETH for transfer");
        }
        else {
            require(msg.value >= transferFee, "Insufficient ETH for transfer");
        }


        require(verifySignatureForWithdraw(msg.sender, _recipient, _amount, _timestamp, _dynamicFee, signature), "Withdrawal unverified or expired");

        bytes32 signatureHash = keccak256(abi.encodePacked(signature));
        require(!usedSignatures[signatureHash], "Claim has already been made");
        usedSignatures[signatureHash] = true;

        lastServerCheckin = block.number; 

        transferAndUpdateAccount(_recipient, _amount);

        emit Transferred(msg.sender, _recipient, _amount);
    }        

    // modular code for withdraw() and transferTo()
    // should never fail, but if it ever does, the system can check & renumerate
    function transferAndUpdateAccount(address _recipient, uint256 _amount) internal {

        uint256 originalAmount = _amount;

        accounts[msg.sender].totalAmount -= _amount;
        if (accounts[msg.sender].totalAmount <= 0) {
            totalDepositers -= 1;  // Decrement totalDepositers as the depositor has withdrawn all tokens
        }

        totalDeposited -= _amount; // throws error and reverts if negative

        if (individualDepositCount[msg.sender] > 0) {
            int256 i = int256(individualDepositCount[msg.sender] - 1);  // Start at the last deposit
            while (i >= 0 && _amount > 0) {
                IndividualDeposit storage aDeposit = individualDeposits[msg.sender][uint256(i)];
                if (aDeposit.amount > 0) {
                    uint256 amountToWithdraw = aDeposit.amount > _amount ? _amount : aDeposit.amount;
                    aDeposit.amount -= amountToWithdraw;
                    _amount -= amountToWithdraw;

                    if (aDeposit.amount == 0) {
                        deleteDeposit(msg.sender, uint256(i));
                    }
                }
                i--;  // Decrement i to process the next older deposit
            }
        }

        // Proceed with the transfer (reentrancy in mind)
        require(theToken.transfer(_recipient, originalAmount), "Transfer failed");
    }

    function deleteDeposit(address user, uint256 index) internal {
        require(index < individualDepositCount[user], "Invalid index");

        // If it's not the last one, swap it with the last one
        if (index != individualDepositCount[user] - 1) {
            individualDeposits[user][index] = individualDeposits[user][individualDepositCount[user] - 1];
        }

        // Delete the last one and decrement the count
        delete individualDeposits[user][individualDepositCount[user] - 1];
        individualDepositCount[user]--;
    }    


    function verifySignatureForClaim(
        address sender,
        uint256 _creeWorthToClaim,
        uint8 _rewardType,
        uint256 _amountToClaim,
        uint256 _timestamp,
        uint256 _dynamicFee,
        bytes memory signature
    ) internal view returns(bool) {                
        // Check if _timestamp is within the last 1 hour
        if (_timestamp > block.number || (block.number - _timestamp) * 15 > 3600) {
            return false;
        }

        // String concatenation and conversion to hexadecimal
        string memory dataString = string(
            abi.encodePacked(
                Strings.toString(_creeWorthToClaim),
                Strings.toString(_rewardType),
                Strings.toString(_amountToClaim),
                Strings.toString(_timestamp),
                Strings.toString(_dynamicFee),
                Strings.toHexString(uint256(uint160(sender)), 20)
            )
        );

        // Hashing
        bytes32 messageHash = keccak256(
            abi.encodePacked(
                "\x19Ethereum Signed Message:\n",
                Strings.toString(bytes(dataString).length),
                dataString
            )
        );

        // Signature verification
        return signingAddress == ECDSA.recover(
            messageHash,
            signature
        );
    }

    // this function checks CREEBank before going through
    function claimRewardsFromCREEBank(bytes calldata signature, address _recipient, uint256 _creeWorthToClaim, uint8 _rewardType, uint256 _amountToClaim, uint256 _timestamp, uint256 _dynamicFee) external payable nonReentrant {
        // use liveFee if set, if not, use claim fee, ensure the correct fee has been sent with the transaction
        if (_dynamicFee > 0) {
            require(msg.value >= _dynamicFee, "Insufficient ETH for claim");
        }
        else {
            require(msg.value >= claimFee, "Insufficient ETH for claim");
        }

        require(verifySignatureForClaim(msg.sender, _creeWorthToClaim, _rewardType, _amountToClaim, _timestamp, _dynamicFee, signature), "Claim unverified or expired");

        bytes32 signatureHash = keccak256(abi.encodePacked(signature));
        require(!usedSignatures[signatureHash], "Claim has already been made");
        usedSignatures[signatureHash] = true;

        lastServerCheckin = block.number;

        updateAndTransferRewards(_creeWorthToClaim, _rewardType, _amountToClaim, _recipient);        
    }

    // this function transfers and log rewards, it does not calculate rewards.
    // rewards are calculated by CREEBank and/or calculateRewards()
    function updateAndTransferRewards(uint256 _creeWorthToClaim, uint8 _rewardType, uint256 _amount, address _recipient) internal {
        require(isBankOpen, "CREEBank not open!");

        // Reward and bonus hack protection
        require(claimMilestone > globalCREERewardedAndClaimed + _creeWorthToClaim, "claimMilestone reached. Contact support or try again later!");
        
        accounts[msg.sender].claimedRewards[_rewardType] += _amount;        
        accounts[msg.sender].totalCREEWorthClaimed += _creeWorthToClaim;
        globalCREERewardedAndClaimed += _creeWorthToClaim;        

        if (_rewardType == 0) {
            // Transfer ETH
            if (address(this).balance >= _amount) {
                payable(_recipient).transfer(_amount);
            }
            else {
                require(theToken.transfer(_recipient, _creeWorthToClaim), "CREE transfer failed");
            }
        } else if (_rewardType == 1) {
            // Transfer USDT
            if (usdtToken.balanceOf(address(this)) >= _amount) {
                usdtToken.safeTransfer(_recipient, _amount);
            }
            else {
                require(theToken.transfer(_recipient, _creeWorthToClaim), "CREE transfer failed");
            }
        } else if (_rewardType == 3) {
            // Transfer CREE
            require(theToken.transfer(_recipient, _amount), "CREE transfer failed");
        } else if (_rewardType == 2) {
            // We're not using WBTC because we want our users to receive the real BTC, and not its securities held on Ethereum.
            // 1. Our webservers call BTC scripts to transfer all real BTC rewards, directly to the user's BTC account set
            // 2. After which it will call this contract and update its BTC claimed rewards, accounts[msg.sender].claimedRewards[_rewardTypeBTC] += X BTC;
            // 3. If user choose to claim CREE by coming here to this point, then CREEBank will not update this contract again.
            require(theToken.transfer(_recipient, _creeWorthToClaim), "CREE transfer failed");

        }

        emit RewardClaimed(msg.sender, _recipient, _creeWorthToClaim, _rewardType, _amount);
    }


    // this function can only be called from CREEBank.org, in cases of BTC withdrawals on CREEBank.org, or other withdrawals
    // only updates records, no transfers
    // usually sent by server scripts or admins
    // once added, cannot be undone
    function addClaimedRewardsFromCREEBank(bytes calldata signature, address _user, address _recipient, uint256 _creeWorthClaimed, uint8 _rewardType, uint256 _claimedAmount, uint256 _timestamp) external nonReentrant {

        if(!verifySignatureForClaimUpdates(msg.sender, _user, _creeWorthClaimed, _rewardType, _claimedAmount, _timestamp, signature)) revert IncorrectSignature();
        lastServerCheckin = block.number;

        bytes32 signatureHash = keccak256(abi.encodePacked(signature));
        require(!usedSignatures[signatureHash], "Signature has already been used");
        usedSignatures[signatureHash] = true;        

        accounts[_user].claimedRewards[_rewardType] += _claimedAmount;
        accounts[_user].totalCREEWorthClaimed += _creeWorthClaimed;
        globalCREERewardedAndClaimed += _creeWorthClaimed;

        emit RewardClaimed(_user, _recipient, _creeWorthClaimed, _rewardType, _claimedAmount);
    }


    function verifySignatureForClaimUpdates(
        address sender,
        address _user,
        uint256 _creeWorthClaimed,
        uint8 _rewardType,
        uint256 _claimedAmount,
        uint256 _timestamp,
        bytes memory signature
    ) internal view returns(bool) {                
        /*
        if (_timestamp < block.timestamp - 1 hours || _timestamp > block.timestamp) {
            return false;
        }
        */
        // Check if _timestamp is within the last 1 hour
        if (_timestamp > block.number || (block.number - _timestamp) * 15 > 3600) {
            return false;
        }

        // String concatenation and conversion to hexadecimal
        string memory dataString = string(
            abi.encodePacked(
                Strings.toHexString(uint256(uint160(_user)), 20),
                Strings.toString(_creeWorthClaimed),
                Strings.toString(_rewardType),
                Strings.toString(_claimedAmount),
                Strings.toString(_timestamp),
                Strings.toHexString(uint256(uint160(sender)), 20)
            )
        );

        // Hashing
        bytes32 messageHash = keccak256(
            abi.encodePacked(
                "\x19Ethereum Signed Message:\n",
                Strings.toString(bytes(dataString).length),
                dataString
            )
        );

        // Signature verification
        return signingAddress == ECDSA.recover(
            messageHash,
            signature
        );
    }    


    // convenient functions for UI and public view. Do not use these functions in contract code, use the code within instead to save gas.
    function tokensInContract() external view returns(uint) {
        return theToken.balanceOf(address(this));
    }

    function usdtInContract() external view returns(uint) {
        return usdtToken.balanceOf(address(this));
    }    

    function ethInContract() external view returns(uint) {
        return address(this).balance;
    }    


    // Requires to use safeTransfer for Tether
    function withdrawAllUSDT() external onlyOwner {
        uint256 usdtBalance = usdtToken.balanceOf(address(this));
        usdtToken.safeTransfer(msg.sender, usdtBalance);
    }

    function withdrawSomeUSDT(uint256 amount) external onlyOwner {
        require(usdtToken.balanceOf(address(this)) >= amount, "Not enough tokens available to withdraw");
        usdtToken.safeTransfer(msg.sender, amount);
    }        

    function withdrawEth() external onlyOwner {
        require(address(this).balance > 0, "No ETH available to withdraw");
        payable(msg.sender).transfer(address(this).balance);
    }    

    function withdrawSomeEth(uint256 amount) external onlyOwner {
        require(address(this).balance >= amount, "Not enough ETH available to withdraw");
        payable(msg.sender).transfer(amount);
    }        

    function withdrawTokensInContract(uint256 amount) external onlyOwner {
        require(theToken.balanceOf(address(this)) >= amount, "Not enough CREE available to withdraw");
        theToken.safeTransfer(msg.sender, amount);
    }    

    // SECURITY and PROTECTION of funds transferred.
    // These functions allows the contract to receive Ether, withdraw and send tokens, so investments and capital will not be locked or lost forever.
    // Situations include users who directly send Ether to the CREEBank.
    receive() external payable {
    }

    // Handle unmatched function calls
    fallback() external payable {
    }        

}
// File: @openzeppelin/contracts/utils/Strings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Strings.sol)

pragma solidity ^0.8.20;

import {Math} from "./math/Math.sol";
import {SignedMath} from "./math/SignedMath.sol";

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant HEX_DIGITS = "0123456789abcdef";
    uint8 private constant ADDRESS_LENGTH = 20;

    /**
     * @dev The `value` string doesn't fit in the specified `length`.
     */
    error StringsInsufficientHexLength(uint256 value, uint256 length);

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        unchecked {
            uint256 length = Math.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), HEX_DIGITS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @dev Converts a `int256` to its ASCII `string` decimal representation.
     */
    function toStringSigned(int256 value) internal pure returns (string memory) {
        return string.concat(value < 0 ? "-" : "", toString(SignedMath.abs(value)));
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, Math.log256(value) + 1);
        }
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        uint256 localValue = value;
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = HEX_DIGITS[localValue & 0xf];
            localValue >>= 4;
        }
        if (localValue != 0) {
            revert StringsInsufficientHexLength(value, length);
        }
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal
     * representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), ADDRESS_LENGTH);
    }

    /**
     * @dev Returns true if the two strings are equal.
     */
    function equal(string memory a, string memory b) internal pure returns (bool) {
        return bytes(a).length == bytes(b).length && keccak256(bytes(a)) == keccak256(bytes(b));
    }
}

// File: @openzeppelin/contracts/utils/cryptography/ECDSA.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/ECDSA.sol)

pragma solidity ^0.8.20;

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS
    }

    /**
     * @dev The signature derives the `address(0)`.
     */
    error ECDSAInvalidSignature();

    /**
     * @dev The signature has an invalid length.
     */
    error ECDSAInvalidSignatureLength(uint256 length);

    /**
     * @dev The signature has an S value that is in the upper half order.
     */
    error ECDSAInvalidSignatureS(bytes32 s);

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with `signature` or an error. This will not
     * return address(0) without also returning an error description. Errors are documented using an enum (error type)
     * and a bytes32 providing additional information about the error.
     *
     * If no error is returned, then the address can be used for verification purposes.
     *
     * The `ecrecover` EVM precompile allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {MessageHashUtils-toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError, bytes32) {
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            /// @solidity memory-safe-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength, bytes32(signature.length));
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM precompile allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {MessageHashUtils-toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, signature);
        _throwError(error, errorArg);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     */
    function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError, bytes32) {
        unchecked {
            bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
            // We do not check for an overflow here since the shift operation results in 0 or 1.
            uint8 v = uint8((uint256(vs) >> 255) + 27);
            return tryRecover(hash, v, r, s);
        }
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     */
    function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
        (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, r, vs);
        _throwError(error, errorArg);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function tryRecover(
        bytes32 hash,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address, RecoverError, bytes32) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS, s);
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            return (address(0), RecoverError.InvalidSignature, bytes32(0));
        }

        return (signer, RecoverError.NoError, bytes32(0));
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
        (address recovered, RecoverError error, bytes32 errorArg) = tryRecover(hash, v, r, s);
        _throwError(error, errorArg);
        return recovered;
    }

    /**
     * @dev Optionally reverts with the corresponding custom error according to the `error` argument provided.
     */
    function _throwError(RecoverError error, bytes32 errorArg) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert ECDSAInvalidSignature();
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert ECDSAInvalidSignatureLength(uint256(errorArg));
        } else if (error == RecoverError.InvalidSignatureS) {
            revert ECDSAInvalidSignatureS(errorArg);
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {Context} from "../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.
 *
 * The initial owner is set to the address provided by the deployer. 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;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @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 {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @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 {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _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/utils/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/ReentrancyGuard.sol)

pragma solidity ^0.8.20;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant NOT_ENTERED = 1;
    uint256 private constant ENTERED = 2;

    uint256 private _status;

    /**
     * @dev Unauthorized reentrant call.
     */
    error ReentrancyGuardReentrantCall();

    constructor() {
        _status = NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be NOT_ENTERED
        if (_status == ENTERED) {
            revert ReentrancyGuardReentrantCall();
        }

        // Any calls to nonReentrant after this point will fail
        _status = ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == ENTERED;
    }
}

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";
import {IERC20Permit} from "../extensions/IERC20Permit.sol";
import {Address} from "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    /**
     * @dev An operation with an ERC20 token failed.
     */
    error SafeERC20FailedOperation(address token);

    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data);
        if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @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 value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` 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 value) external returns (bool);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/math/SignedMath.sol)

pragma solidity ^0.8.20;

/**
 * @dev Standard signed math utilities missing in the Solidity language.
 */
library SignedMath {
    /**
     * @dev Returns the largest of two signed numbers.
     */
    function max(int256 a, int256 b) internal pure returns (int256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two signed numbers.
     */
    function min(int256 a, int256 b) internal pure returns (int256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two signed numbers without overflow.
     * The result is rounded towards zero.
     */
    function average(int256 a, int256 b) internal pure returns (int256) {
        // Formula from the book "Hacker's Delight"
        int256 x = (a & b) + ((a ^ b) >> 1);
        return x + (int256(uint256(x) >> 255) & (a ^ b));
    }

    /**
     * @dev Returns the absolute unsigned value of a signed value.
     */
    function abs(int256 n) internal pure returns (uint256) {
        unchecked {
            // must be unchecked in order to support `n = type(int256).min`
            return uint256(n >= 0 ? n : -n);
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/math/Math.sol)

pragma solidity ^0.8.20;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Muldiv operation overflow.
     */
    error MathOverflowedMulDiv();

    enum Rounding {
        Floor, // Toward negative infinity
        Ceil, // Toward positive infinity
        Trunc, // Toward zero
        Expand // Away from zero
    }

    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     */
    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.
     */
    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.
     */
    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.
     */
    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.
     */
    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 largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds towards infinity instead
     * of rounding towards zero.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        if (b == 0) {
            // Guarantee the same behavior as in a regular Solidity division.
            return a / b;
        }

        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or
     * denominator == 0.
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) with further edits by
     * Uniswap Labs also under MIT license.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0 = x * y; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                // The surrounding unchecked block does not change this fact.
                // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            if (denominator <= prod1) {
                revert MathOverflowedMulDiv();
            }

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator.
            // Always >= 1. See https://cs.stackexchange.com/q/138556/92363.

            uint256 twos = denominator & (0 - denominator);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also
            // works in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
     * towards zero.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (unsignedRoundsUp(rounding) && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2 of a positive value rounded towards zero.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (unsignedRoundsUp(rounding) && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10 of a positive value rounded towards zero.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10 ** 64) {
                value /= 10 ** 64;
                result += 64;
            }
            if (value >= 10 ** 32) {
                value /= 10 ** 32;
                result += 32;
            }
            if (value >= 10 ** 16) {
                value /= 10 ** 16;
                result += 16;
            }
            if (value >= 10 ** 8) {
                value /= 10 ** 8;
                result += 8;
            }
            if (value >= 10 ** 4) {
                value /= 10 ** 4;
                result += 4;
            }
            if (value >= 10 ** 2) {
                value /= 10 ** 2;
                result += 2;
            }
            if (value >= 10 ** 1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (unsignedRoundsUp(rounding) && 10 ** result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256 of a positive value rounded towards zero.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (unsignedRoundsUp(rounding) && 1 << (result << 3) < value ? 1 : 0);
        }
    }

    /**
     * @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
     */
    function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
        return uint8(rounding) % 2 == 1;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)

pragma solidity ^0.8.20;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev The ETH balance of the account is not enough to perform the operation.
     */
    error AddressInsufficientBalance(address account);

    /**
     * @dev There's no code at `target` (it is not a contract).
     */
    error AddressEmptyCode(address target);

    /**
     * @dev A call to an address target failed. The target may have reverted.
     */
    error FailedInnerCall();

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        if (address(this).balance < amount) {
            revert AddressInsufficientBalance(address(this));
        }

        (bool success, ) = recipient.call{value: amount}("");
        if (!success) {
            revert FailedInnerCall();
        }
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason or custom error, it is bubbled
     * up by this function (like regular Solidity function calls). However, if
     * the call reverted with no returned reason, this function reverts with a
     * {FailedInnerCall} error.
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        if (address(this).balance < value) {
            revert AddressInsufficientBalance(address(this));
        }
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
     * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
     * unsuccessful call.
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata
    ) internal view returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            // only check if target is a contract if the call was successful and the return data is empty
            // otherwise we already know that it was a contract
            if (returndata.length == 0 && target.code.length == 0) {
                revert AddressEmptyCode(target);
            }
            return returndata;
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
     * revert reason or with a default {FailedInnerCall} error.
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            return returndata;
        }
    }

    /**
     * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
     */
    function _revert(bytes memory returndata) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert FailedInnerCall();
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 *
 * ==== Security Considerations
 *
 * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
 * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
 * considered as an intention to spend the allowance in any specific way. The second is that because permits have
 * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
 * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
 * generally recommended is:
 *
 * ```solidity
 * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
 *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
 *     doThing(..., value);
 * }
 *
 * function doThing(..., uint256 value) public {
 *     token.safeTransferFrom(msg.sender, address(this), value);
 *     ...
 * }
 * ```
 *
 * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
 * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
 * {SafeERC20-safeTransferFrom}).
 *
 * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
 * contracts should have entry points that don't rely on permit.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     *
     * CAUTION: See Security Considerations above.
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }
}