// File: @chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface AggregatorV3Interface {
  function decimals() external view returns (uint8);

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

  function version() external view returns (uint256);

  function getRoundData(uint80 _roundId)
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  function latestRoundData()
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );
}

// 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/security/ReentrancyGuard.sol



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

pragma solidity ^0.8.0;

/**
 * @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;

    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
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // 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/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/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: contracts/Presale.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";

contract TokenPreSale is Ownable, ReentrancyGuard {
    struct Presale {
        uint256 price;
        uint256 tokensToSell;
        uint256 inSale;
    }

    struct userTokens {
        uint256 totalQuantity;
        uint256 ethAmountSent;
        uint256 usdcAmountSent;
        uint256 usdtAmountSent;
        uint256 claimedQuantity;
    }

    struct PresaleStatus {
        bool completed;
        bool isSuccess;
    }

    struct funds {
        uint256 ethAmountReceived;
        uint256 usdcAmountReceived;
        uint256 usdtAmountReceived;
    }

    IERC20 public token;
    IERC20 public constant usdc =
        IERC20(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48);
    IERC20 public constant usdt =
        IERC20(0xdAC17F958D2ee523a2206206994597C13D831ec7);

    AggregatorV3Interface public constant priceFeedUsdcUsd =
        AggregatorV3Interface(0x8fFfFfd4AfB6115b954Bd326cbe7B4BA576818f6);
    AggregatorV3Interface public constant priceFeedUsdtUsd =
        AggregatorV3Interface(0x3E7d1eAB13ad0104d2750B8863b489D65364e32D);
    AggregatorV3Interface public constant priceFeedEthUsd =
        AggregatorV3Interface(0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419);

    bool public paused;
    Presale public presale;
    PresaleStatus public presaleStatus;
    uint256 public tokensReservedForUsers;
    mapping(address => userTokens) public user;
    funds private fundsReceived;

    event PresaleCreated(uint256 _startTime);

    event PresaleUpdated(
        bytes32 indexed key,
        uint256 prevValue,
        uint256 newValue,
        uint256 timestamp
    );

    event TokensBought(
        address indexed user,
        uint256 tokensBought,
        uint256 amountPaid,
        uint256 timestamp
    );

    event TokensClaimed(
        address indexed user,
        uint256 amount,
        uint256 timestamp
    );

    event PresalePaused(uint256 timestamp);
    event PresaleUnpaused(uint256 timestamp);

    bytes32 private constant ADMIN_ROLE = keccak256("ADMIN_ROLE");
    mapping(bytes32 => mapping(address => bool)) public roles;

    constructor() Ownable() {
        grantAdminRole(msg.sender);
    }

    function setToken(address _token) external onlyOwner {
        token = IERC20(_token);
    }

    function grantAdminRole(address _admin) public onlyOwner {
        require(!roles[ADMIN_ROLE][_admin], "Already owner");
        roles[ADMIN_ROLE][_admin] = true;
    }

    function revokeAdminRole(address _admin) external onlyOwner {
        require(roles[ADMIN_ROLE][_admin], "Not an owner");
        roles[ADMIN_ROLE][_admin] = false;
    }

    function hasAdminRole(address _admin) external view returns (bool) {
        return roles[ADMIN_ROLE][_admin];
    }

    modifier onlyAdmin() {
        require(
            roles[ADMIN_ROLE][msg.sender],
            "Access Denied, only admins allowed"
        );
        _;
    }

    function checkSaleState(uint256 amount) private view {
        require(amount > 0 && amount <= presale.inSale, "Invalid sale amount");
    }

    function pausePresale() external onlyAdmin {
        require(!paused, "Already paused");
        paused = true;
        emit PresalePaused(block.timestamp);
    }

    function unPausePresale() external onlyAdmin {
        require(paused, "Not paused");
        paused = false;
        emit PresaleUnpaused(block.timestamp);
    }

    function fundsReceive() external view onlyAdmin returns (funds memory) {
        return fundsReceived;
    }

    // input tokens in wei
    function createPresale(
        uint256 _price,
        uint256 _tokenAmountToSell
    ) external onlyAdmin {
        require(_price > 0, "Price should be greater than zero");
        require(
            _tokenAmountToSell > 0,
            "Tokens to sell should be greater than zero"
        );

        presale = Presale({
            price: _price,
            tokensToSell: _tokenAmountToSell,
            inSale: _tokenAmountToSell
        });

        emit PresaleCreated(block.timestamp);
    }

    function setGaryPrice(uint256 _newPrice) external onlyAdmin {
        require(_newPrice > 0, "Zero price");
        require(!paused, "Cann't change when paused");

        uint256 prevValue = presale.price;
        presale.price = _newPrice;

        emit PresaleUpdated(
            bytes32("PRICE"),
            prevValue,
            _newPrice,
            block.timestamp
        );
    }

    // input tokens in wei
    function addTokenAmountForSale(
        uint256 _tokenAmountToSale
    ) external onlyAdmin {
        require(!paused, "Cann't change when paused");

        uint256 prevValue = presale.tokensToSell;
        presale.tokensToSell += _tokenAmountToSale;
        presale.inSale += _tokenAmountToSale;
        emit PresaleUpdated(
            bytes32("TokenAmount"),
            prevValue,
            presale.tokensToSell,
            block.timestamp
        );
    }

    function getTokenAmountForEth(
        uint256 _ethAmount
    ) public view returns (uint256 tokenQuantity) {
        uint256 tokenQuantityIn1Eth = (((1e18 / presale.price) *
            1e18 *
            getLatestEthPrice()) / 1e8);
        return (tokenQuantityIn1Eth * _ethAmount) / 1e18;
    }

    function getLatestEthPrice() public view returns (uint256) {
        (
            uint256 roundID,
            int price,
            uint256 startedAt,
            uint256 timeStamp,
            uint80 answeredInRound
        ) = priceFeedEthUsd.latestRoundData();

        return uint256(price);
    }

    function buyWithEth() external payable nonReentrant returns (bool) {
        require(!paused, "Presale paused");
        require(!presaleStatus.completed, "presale is no longer active");

        userTokens storage _user = user[msg.sender];
        uint256 tokenQuantityToPurchase = getTokenAmountForEth(msg.value);
        checkSaleState(tokenQuantityToPurchase);

        fundsReceived.ethAmountReceived += msg.value;
        presale.inSale -= tokenQuantityToPurchase;
        tokensReservedForUsers += tokenQuantityToPurchase;

        if (_user.totalQuantity > 0) {
            _user.totalQuantity += tokenQuantityToPurchase;
            _user.ethAmountSent += msg.value;
        } else {
            user[msg.sender] = userTokens({
                totalQuantity: tokenQuantityToPurchase,
                ethAmountSent: msg.value,
                usdcAmountSent: 0,
                usdtAmountSent: 0,
                claimedQuantity: 0
            });
        }

        emit TokensBought(
            msg.sender,
            tokenQuantityToPurchase,
            msg.value,
            block.timestamp
        );
        return true;
    }

    function getTokenAmountForUsdc(
        uint256 usdcToSpent
    ) public view returns (uint256 tokenQuantity) {
        uint256 tokenQuantityIn1Usdc = (((1e18 / presale.price) *
            1e18 *
            getLatestUsdcPrice()) / 1e8);
        return (usdcToSpent * tokenQuantityIn1Usdc) / 1e6;
    }

    function getLatestUsdcPrice() public view returns (uint256) {
        (
            uint256 roundID,
            int price,
            uint256 startedAt,
            uint256 timeStamp,
            uint80 answeredInRound
        ) = priceFeedUsdcUsd.latestRoundData();

        return uint256(price);
    }

    // input tokens with wei
    function buyWithUsdc(
        uint256 usdcToSpent
    ) external nonReentrant returns (bool) {
        require(!paused, "Presale paused");
        require(!presaleStatus.completed, "presale is no longer active");

        userTokens storage _user = user[msg.sender];
        uint256 tokenQuantityToPurchase = getTokenAmountForUsdc(usdcToSpent);
        checkSaleState(tokenQuantityToPurchase);
        usdc.transferFrom(msg.sender, address(this), usdcToSpent);

        fundsReceived.usdcAmountReceived += usdcToSpent;
        presale.inSale -= tokenQuantityToPurchase;
        tokensReservedForUsers += tokenQuantityToPurchase;

        if (_user.totalQuantity > 0) {
            _user.totalQuantity += tokenQuantityToPurchase;
            _user.usdcAmountSent += usdcToSpent;
        } else {
            user[msg.sender] = userTokens({
                totalQuantity: tokenQuantityToPurchase,
                ethAmountSent: 0,
                usdcAmountSent: usdcToSpent,
                usdtAmountSent: 0,
                claimedQuantity: 0
            });
        }

        emit TokensBought(
            msg.sender,
            tokenQuantityToPurchase * 1e18,
            usdcToSpent,
            block.timestamp
        );
        return true;
    }

    function getTokenAmountForUsdt(
        uint256 usdtToSpent
    ) public view returns (uint256 tokenQuantity) {
        uint256 tokenQuantityIn1USDT = (((1e18 / presale.price) *
            1e18 *
            getLatestUsdtPrice()) / 1e8);
        return (usdtToSpent * tokenQuantityIn1USDT) / 1e6;
    }

    function getLatestUsdtPrice() public view returns (uint256) {
        (
            uint256 roundID,
            int price,
            uint256 startedAt,
            uint256 timeStamp,
            uint80 answeredInRound
        ) = priceFeedUsdtUsd.latestRoundData();

        return uint256(price);
    }

    // input tokens with wei
    function buyWithUsdt(
        uint256 usdtToSpent
    ) external nonReentrant returns (bool) {
        require(!paused, "Presale paused");
        require(!presaleStatus.completed, "presale is no longer active");

        userTokens storage _user = user[msg.sender];
        uint256 tokenQuantityToPurchase = getTokenAmountForUsdt(usdtToSpent);
        checkSaleState(tokenQuantityToPurchase);
        usdt.transferFrom(msg.sender, address(this), usdtToSpent);

        fundsReceived.usdtAmountReceived += usdtToSpent;
        presale.inSale -= tokenQuantityToPurchase;
        tokensReservedForUsers += tokenQuantityToPurchase;

        if (_user.totalQuantity > 0) {
            _user.totalQuantity += tokenQuantityToPurchase;
            _user.usdtAmountSent += usdtToSpent;
        } else {
            user[msg.sender] = userTokens({
                totalQuantity: tokenQuantityToPurchase,
                ethAmountSent: 0,
                usdcAmountSent: 0,
                usdtAmountSent: usdtToSpent,
                claimedQuantity: 0
            });
        }

        emit TokensBought(
            msg.sender,
            tokenQuantityToPurchase * 1e18,
            usdtToSpent,
            block.timestamp
        );
        return true;
    }

    function withdrawFunds() external onlyAdmin nonReentrant {
        if (presaleStatus.completed && !presaleStatus.isSuccess) {
            uint256 ethAmountReceived = fundsReceived.ethAmountReceived;
            uint256 usdcAmountReceived = fundsReceived.usdcAmountReceived;
            uint256 usdtAmountReceived = fundsReceived.usdtAmountReceived;

            uint256 ethBalance = address(this).balance;
            uint256 usdcBalance = usdc.balanceOf(address(this));
            uint256 usdtBalance = usdt.balanceOf(address(this));

            if (ethBalance > ethAmountReceived) {
                payable(msg.sender).transfer(ethBalance - ethAmountReceived);
            }

            if (usdcBalance > usdcAmountReceived) {
                usdc.transfer(msg.sender, usdcBalance - usdcAmountReceived);
            }

            if (usdtBalance > usdtAmountReceived) {
                usdt.transfer(msg.sender, usdtBalance - usdtAmountReceived);
            }
        } else {
            uint256 ethAmount = address(this).balance;
            if (ethAmount > 0) {
                payable(msg.sender).transfer(ethAmount);
            }

            uint256 usdcBalance = usdc.balanceOf(address(this));
            if (usdcBalance > 0) {
                usdc.transfer(msg.sender, usdcBalance);
            }

            uint256 usdtBalance = usdt.balanceOf(address(this));
            if (usdtBalance > 0) {
                usdt.transfer(msg.sender, usdtBalance);
            }
        }
    }

    function withdrawRemainingTokens() external onlyAdmin {
        require(
            presaleStatus.completed,
            "Cann't withdraw untill presale status is not updated"
        );

        uint256 remainingTokens = token.balanceOf(address(this)) -
            tokensReservedForUsers;

        if (remainingTokens > 0) {
            token.transfer(msg.sender, remainingTokens);
        }
    }

    function updatePresaleStatus(
        bool _success
    ) external nonReentrant onlyAdmin {
        require(!presaleStatus.completed, "Can only be called once");
        presaleStatus.completed = true;
        presaleStatus.isSuccess = _success;

        if (_success) {
            require(
                token.balanceOf(address(this)) >= tokensReservedForUsers,
                "Cann't change status unless sufficient tokens are sent"
            );
        } else {
            uint256 ethAmountReceived = fundsReceived.ethAmountReceived;
            uint256 usdcAmountReceived = fundsReceived.usdcAmountReceived;
            uint256 usdtAmountReceived = fundsReceived.usdtAmountReceived;

            uint256 ethBalance = address(this).balance;
            uint256 usdcBalance = usdc.balanceOf(address(this));
            uint256 usdtBalance = usdt.balanceOf(address(this));

            bool areFundsSufficient = ethBalance >= ethAmountReceived &&
                usdcBalance >= usdcAmountReceived &&
                usdtBalance >= usdtAmountReceived;

            require(
                areFundsSufficient,
                "Cann't change status unless funds are sufficient for refund"
            );

            tokensReservedForUsers = 0;
            uint256 remainingTokens = token.balanceOf(address(this));
            token.transfer(msg.sender, remainingTokens);
        }
    }

    function claimableAmount(
        address _userAddress
    ) public view returns (uint256) {
        userTokens memory _userTokens = user[_userAddress];

        uint claimAmount = _userTokens.totalQuantity -
            _userTokens.claimedQuantity;
        require(_userTokens.totalQuantity > 0, "Nothing to claim");
        require(claimAmount > 0, "Already claimed");

        return claimAmount;
    }

    function claimTokens() public nonReentrant returns (bool) {
        require(!paused, "Cann't claim tokens, presale is paused");
        require(presaleStatus.completed, "Presale is not marked completed yet");
        require(
            presaleStatus.isSuccess,
            "Cann't claim tokens, presale is failed"
        );

        userTokens storage _user = user[msg.sender];
        uint claimAmount = _user.totalQuantity - _user.claimedQuantity;
        tokensReservedForUsers -= claimAmount;
        _user.claimedQuantity = claimAmount;

        require(claimAmount > 0, "Already Claimed");

        token.transfer(msg.sender, claimAmount);
        emit TokensClaimed(msg.sender, claimAmount, block.timestamp);
        return true;
    }

    function claimRefund() external nonReentrant {
        require(!paused, "Cann't claim Refund, presale is paused");
        require(presaleStatus.completed, "Presale is not marked completed yet");
        require(
            !presaleStatus.isSuccess,
            "Cann't claim Refund, presale is successful"
        );

        userTokens storage _user = user[msg.sender];

        if (_user.ethAmountSent > 0) {
            uint256 ethAmount = _user.ethAmountSent;
            _user.ethAmountSent = 0;
            payable(msg.sender).transfer(ethAmount);
        }

        if (_user.usdcAmountSent > 0) {
            uint256 usdcAmount = _user.usdcAmountSent;
            _user.usdcAmountSent = 0;
            usdc.transfer(msg.sender, usdcAmount);
        }

        if (_user.usdtAmountSent > 0) {
            uint256 usdtAmount = _user.usdtAmountSent;
            _user.usdtAmountSent = 0;
            usdt.transfer(msg.sender, usdtAmount);
        }
    }
}