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



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

interface LinkTokenInterface {
  function allowance(address owner, address spender) external view returns (uint256 remaining);

  function approve(address spender, uint256 value) external returns (bool success);

  function balanceOf(address owner) external view returns (uint256 balance);

  function decimals() external view returns (uint8 decimalPlaces);

  function decreaseApproval(address spender, uint256 addedValue) external returns (bool success);

  function increaseApproval(address spender, uint256 subtractedValue) external;

  function name() external view returns (string memory tokenName);

  function symbol() external view returns (string memory tokenSymbol);

  function totalSupply() external view returns (uint256 totalTokensIssued);

  function transfer(address to, uint256 value) external returns (bool success);

  function transferAndCall(
    address to,
    uint256 value,
    bytes calldata data
  ) external returns (bool success);

  function transferFrom(
    address from,
    address to,
    uint256 value
  ) external returns (bool success);
}

// File: @chainlink/contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol



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

interface VRFCoordinatorV2Interface {
  /**
   * @notice Get configuration relevant for making requests
   * @return minimumRequestConfirmations global min for request confirmations
   * @return maxGasLimit global max for request gas limit
   * @return s_provingKeyHashes list of registered key hashes
   */
  function getRequestConfig()
    external
    view
    returns (
      uint16,
      uint32,
      bytes32[] memory
    );

  /**
   * @notice Request a set of random words.
   * @param keyHash - Corresponds to a particular oracle job which uses
   * that key for generating the VRF proof. Different keyHash's have different gas price
   * ceilings, so you can select a specific one to bound your maximum per request cost.
   * @param subId  - The ID of the VRF subscription. Must be funded
   * with the minimum subscription balance required for the selected keyHash.
   * @param minimumRequestConfirmations - How many blocks you'd like the
   * oracle to wait before responding to the request. See SECURITY CONSIDERATIONS
   * for why you may want to request more. The acceptable range is
   * [minimumRequestBlockConfirmations, 200].
   * @param callbackGasLimit - How much gas you'd like to receive in your
   * fulfillRandomWords callback. Note that gasleft() inside fulfillRandomWords
   * may be slightly less than this amount because of gas used calling the function
   * (argument decoding etc.), so you may need to request slightly more than you expect
   * to have inside fulfillRandomWords. The acceptable range is
   * [0, maxGasLimit]
   * @param numWords - The number of uint256 random values you'd like to receive
   * in your fulfillRandomWords callback. Note these numbers are expanded in a
   * secure way by the VRFCoordinator from a single random value supplied by the oracle.
   * @return requestId - A unique identifier of the request. Can be used to match
   * a request to a response in fulfillRandomWords.
   */
  function requestRandomWords(
    bytes32 keyHash,
    uint64 subId,
    uint16 minimumRequestConfirmations,
    uint32 callbackGasLimit,
    uint32 numWords
  ) external returns (uint256 requestId);

  /**
   * @notice Create a VRF subscription.
   * @return subId - A unique subscription id.
   * @dev You can manage the consumer set dynamically with addConsumer/removeConsumer.
   * @dev Note to fund the subscription, use transferAndCall. For example
   * @dev  LINKTOKEN.transferAndCall(
   * @dev    address(COORDINATOR),
   * @dev    amount,
   * @dev    abi.encode(subId));
   */
  function createSubscription() external returns (uint64 subId);

  /**
   * @notice Get a VRF subscription.
   * @param subId - ID of the subscription
   * @return balance - LINK balance of the subscription in juels.
   * @return reqCount - number of requests for this subscription, determines fee tier.
   * @return owner - owner of the subscription.
   * @return consumers - list of consumer address which are able to use this subscription.
   */
  function getSubscription(uint64 subId)
    external
    view
    returns (
      uint96 balance,
      uint64 reqCount,
      address owner,
      address[] memory consumers
    );

  /**
   * @notice Request subscription owner transfer.
   * @param subId - ID of the subscription
   * @param newOwner - proposed new owner of the subscription
   */
  function requestSubscriptionOwnerTransfer(uint64 subId, address newOwner) external;

  /**
   * @notice Request subscription owner transfer.
   * @param subId - ID of the subscription
   * @dev will revert if original owner of subId has
   * not requested that msg.sender become the new owner.
   */
  function acceptSubscriptionOwnerTransfer(uint64 subId) external;

  /**
   * @notice Add a consumer to a VRF subscription.
   * @param subId - ID of the subscription
   * @param consumer - New consumer which can use the subscription
   */
  function addConsumer(uint64 subId, address consumer) external;

  /**
   * @notice Remove a consumer from a VRF subscription.
   * @param subId - ID of the subscription
   * @param consumer - Consumer to remove from the subscription
   */
  function removeConsumer(uint64 subId, address consumer) external;

  /**
   * @notice Cancel a subscription
   * @param subId - ID of the subscription
   * @param to - Where to send the remaining LINK to
   */
  function cancelSubscription(uint64 subId, address to) external;

  /*
   * @notice Check to see if there exists a request commitment consumers
   * for all consumers and keyhashes for a given sub.
   * @param subId - ID of the subscription
   * @return true if there exists at least one unfulfilled request for the subscription, false
   * otherwise.
   */
  function pendingRequestExists(uint64 subId) external view returns (bool);
}

// File: @chainlink/contracts/src/v0.8/VRFConsumerBaseV2.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

/** ****************************************************************************
 * @notice Interface for contracts using VRF randomness
 * *****************************************************************************
 * @dev PURPOSE
 *
 * @dev Reggie the Random Oracle (not his real job) wants to provide randomness
 * @dev to Vera the verifier in such a way that Vera can be sure he's not
 * @dev making his output up to suit himself. Reggie provides Vera a public key
 * @dev to which he knows the secret key. Each time Vera provides a seed to
 * @dev Reggie, he gives back a value which is computed completely
 * @dev deterministically from the seed and the secret key.
 *
 * @dev Reggie provides a proof by which Vera can verify that the output was
 * @dev correctly computed once Reggie tells it to her, but without that proof,
 * @dev the output is indistinguishable to her from a uniform random sample
 * @dev from the output space.
 *
 * @dev The purpose of this contract is to make it easy for unrelated contracts
 * @dev to talk to Vera the verifier about the work Reggie is doing, to provide
 * @dev simple access to a verifiable source of randomness. It ensures 2 things:
 * @dev 1. The fulfillment came from the VRFCoordinator
 * @dev 2. The consumer contract implements fulfillRandomWords.
 * *****************************************************************************
 * @dev USAGE
 *
 * @dev Calling contracts must inherit from VRFConsumerBase, and can
 * @dev initialize VRFConsumerBase's attributes in their constructor as
 * @dev shown:
 *
 * @dev   contract VRFConsumer {
 * @dev     constructor(<other arguments>, address _vrfCoordinator, address _link)
 * @dev       VRFConsumerBase(_vrfCoordinator) public {
 * @dev         <initialization with other arguments goes here>
 * @dev       }
 * @dev   }
 *
 * @dev The oracle will have given you an ID for the VRF keypair they have
 * @dev committed to (let's call it keyHash). Create subscription, fund it
 * @dev and your consumer contract as a consumer of it (see VRFCoordinatorInterface
 * @dev subscription management functions).
 * @dev Call requestRandomWords(keyHash, subId, minimumRequestConfirmations,
 * @dev callbackGasLimit, numWords),
 * @dev see (VRFCoordinatorInterface for a description of the arguments).
 *
 * @dev Once the VRFCoordinator has received and validated the oracle's response
 * @dev to your request, it will call your contract's fulfillRandomWords method.
 *
 * @dev The randomness argument to fulfillRandomWords is a set of random words
 * @dev generated from your requestId and the blockHash of the request.
 *
 * @dev If your contract could have concurrent requests open, you can use the
 * @dev requestId returned from requestRandomWords to track which response is associated
 * @dev with which randomness request.
 * @dev See "SECURITY CONSIDERATIONS" for principles to keep in mind,
 * @dev if your contract could have multiple requests in flight simultaneously.
 *
 * @dev Colliding `requestId`s are cryptographically impossible as long as seeds
 * @dev differ.
 *
 * *****************************************************************************
 * @dev SECURITY CONSIDERATIONS
 *
 * @dev A method with the ability to call your fulfillRandomness method directly
 * @dev could spoof a VRF response with any random value, so it's critical that
 * @dev it cannot be directly called by anything other than this base contract
 * @dev (specifically, by the VRFConsumerBase.rawFulfillRandomness method).
 *
 * @dev For your users to trust that your contract's random behavior is free
 * @dev from malicious interference, it's best if you can write it so that all
 * @dev behaviors implied by a VRF response are executed *during* your
 * @dev fulfillRandomness method. If your contract must store the response (or
 * @dev anything derived from it) and use it later, you must ensure that any
 * @dev user-significant behavior which depends on that stored value cannot be
 * @dev manipulated by a subsequent VRF request.
 *
 * @dev Similarly, both miners and the VRF oracle itself have some influence
 * @dev over the order in which VRF responses appear on the blockchain, so if
 * @dev your contract could have multiple VRF requests in flight simultaneously,
 * @dev you must ensure that the order in which the VRF responses arrive cannot
 * @dev be used to manipulate your contract's user-significant behavior.
 *
 * @dev Since the block hash of the block which contains the requestRandomness
 * @dev call is mixed into the input to the VRF *last*, a sufficiently powerful
 * @dev miner could, in principle, fork the blockchain to evict the block
 * @dev containing the request, forcing the request to be included in a
 * @dev different block with a different hash, and therefore a different input
 * @dev to the VRF. However, such an attack would incur a substantial economic
 * @dev cost. This cost scales with the number of blocks the VRF oracle waits
 * @dev until it calls responds to a request. It is for this reason that
 * @dev that you can signal to an oracle you'd like them to wait longer before
 * @dev responding to the request (however this is not enforced in the contract
 * @dev and so remains effective only in the case of unmodified oracle software).
 */
abstract contract VRFConsumerBaseV2 {
  error OnlyCoordinatorCanFulfill(address have, address want);
  address private immutable vrfCoordinator;

  /**
   * @param _vrfCoordinator address of VRFCoordinator contract
   */
  constructor(address _vrfCoordinator) {
    vrfCoordinator = _vrfCoordinator;
  }

  /**
   * @notice fulfillRandomness handles the VRF response. Your contract must
   * @notice implement it. See "SECURITY CONSIDERATIONS" above for important
   * @notice principles to keep in mind when implementing your fulfillRandomness
   * @notice method.
   *
   * @dev VRFConsumerBaseV2 expects its subcontracts to have a method with this
   * @dev signature, and will call it once it has verified the proof
   * @dev associated with the randomness. (It is triggered via a call to
   * @dev rawFulfillRandomness, below.)
   *
   * @param requestId The Id initially returned by requestRandomness
   * @param randomWords the VRF output expanded to the requested number of words
   */
  function fulfillRandomWords(uint256 requestId, uint256[] memory randomWords) internal virtual;

  // rawFulfillRandomness is called by VRFCoordinator when it receives a valid VRF
  // proof. rawFulfillRandomness then calls fulfillRandomness, after validating
  // the origin of the call
  function rawFulfillRandomWords(uint256 requestId, uint256[] memory randomWords) external {
    if (msg.sender != vrfCoordinator) {
      revert OnlyCoordinatorCanFulfill(msg.sender, vrfCoordinator);
    }
    fulfillRandomWords(requestId, randomWords);
  }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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 anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _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/Pausable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)

pragma solidity ^0.8.0;

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

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// File: @openzeppelin/contracts/security/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @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.
 */
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].
     */
    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/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (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/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../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;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @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, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: @openzeppelin/contracts/token/ERC721/ERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.2) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: address zero is not a valid owner");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _ownerOf(tokenId);
        require(owner != address(0), "ERC721: invalid token ID");
        return owner;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        _requireMinted(tokenId);

        string memory baseURI = _baseURI();
        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return "";
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not token owner or approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        _requireMinted(tokenId);

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");

        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: caller is not token owner or approved");
        _safeTransfer(from, to, tokenId, data);
    }

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * `data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @dev Returns the owner of the `tokenId`. Does NOT revert if token doesn't exist
     */
    function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
        return _owners[tokenId];
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _ownerOf(tokenId) != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId, 1);

        // Check that tokenId was not minted by `_beforeTokenTransfer` hook
        require(!_exists(tokenId), "ERC721: token already minted");

        unchecked {
            // Will not overflow unless all 2**256 token ids are minted to the same owner.
            // Given that tokens are minted one by one, it is impossible in practice that
            // this ever happens. Might change if we allow batch minting.
            // The ERC fails to describe this case.
            _balances[to] += 1;
        }

        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);

        _afterTokenTransfer(address(0), to, tokenId, 1);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     * This is an internal function that does not check if the sender is authorized to operate on the token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId, 1);

        // Update ownership in case tokenId was transferred by `_beforeTokenTransfer` hook
        owner = ERC721.ownerOf(tokenId);

        // Clear approvals
        delete _tokenApprovals[tokenId];

        unchecked {
            // Cannot overflow, as that would require more tokens to be burned/transferred
            // out than the owner initially received through minting and transferring in.
            _balances[owner] -= 1;
        }
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);

        _afterTokenTransfer(owner, address(0), tokenId, 1);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId, 1);

        // Check that tokenId was not transferred by `_beforeTokenTransfer` hook
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");

        // Clear approvals from the previous owner
        delete _tokenApprovals[tokenId];

        unchecked {
            // `_balances[from]` cannot overflow for the same reason as described in `_burn`:
            // `from`'s balance is the number of token held, which is at least one before the current
            // transfer.
            // `_balances[to]` could overflow in the conditions described in `_mint`. That would require
            // all 2**256 token ids to be minted, which in practice is impossible.
            _balances[from] -= 1;
            _balances[to] += 1;
        }
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);

        _afterTokenTransfer(from, to, tokenId, 1);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits an {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Reverts if the `tokenId` has not been minted yet.
     */
    function _requireMinted(uint256 tokenId) internal view virtual {
        require(_exists(tokenId), "ERC721: invalid token ID");
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    /// @solidity memory-safe-assembly
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting and burning. If {ERC721Consecutive} is
     * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s tokens will be transferred to `to`.
     * - When `from` is zero, the tokens will be minted for `to`.
     * - When `to` is zero, ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     * - `batchSize` is non-zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize
    ) internal virtual {}

    /**
     * @dev Hook that is called after any token transfer. This includes minting and burning. If {ERC721Consecutive} is
     * used, the hook may be called as part of a consecutive (batch) mint, as indicated by `batchSize` greater than 1.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s tokens were transferred to `to`.
     * - When `from` is zero, the tokens were minted for `to`.
     * - When `to` is zero, ``from``'s tokens were burned.
     * - `from` and `to` are never both zero.
     * - `batchSize` is non-zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 firstTokenId,
        uint256 batchSize
    ) internal virtual {}

    /**
     * @dev Unsafe write access to the balances, used by extensions that "mint" tokens using an {ownerOf} override.
     *
     * WARNING: Anyone calling this MUST ensure that the balances remain consistent with the ownership. The invariant
     * being that for any address `a` the value returned by `balanceOf(a)` must be equal to the number of tokens such
     * that `ownerOf(tokenId)` is `a`.
     */
    // solhint-disable-next-line func-name-mixedcase
    function __unsafe_increaseBalance(address account, uint256 amount) internal {
        _balances[account] += amount;
    }
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

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

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
     * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
     * understand this adds an external call which potentially creates a reentrancy vulnerability.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @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://diligence.consensys.net/posts/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/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @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, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * 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.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @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`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) 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(errorMessage);
        }
    }
}

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



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

pragma solidity ^0.8.0;

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

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

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



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

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @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 up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (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; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1);

            ///////////////////////////////////////////////
            // 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.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            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 (rounding == Rounding.Up && 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 down.
     *
     * 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 + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * 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 + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * 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 + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * 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 10, 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 + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

import "./math/Math.sol";

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

    /**
     * @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), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @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) {
        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] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        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);
    }
}

// File: @uniswap/v3-core/contracts/interfaces/callback/IUniswapV3SwapCallback.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.5.0;

/// @title Callback for IUniswapV3PoolActions#swap
/// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
interface IUniswapV3SwapCallback {
    /// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#swap.
    /// @dev In the implementation you must pay the pool tokens owed for the swap.
    /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
    /// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
    /// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
    /// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
    /// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
    /// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
    /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#swap call
    function uniswapV3SwapCallback(
        int256 amount0Delta,
        int256 amount1Delta,
        bytes calldata data
    ) external;
}

// File: @uniswap/v3-periphery/contracts/interfaces/IQuoter.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
pragma abicoder v2;

/// @title Quoter Interface
/// @notice Supports quoting the calculated amounts from exact input or exact output swaps
/// @dev These functions are not marked view because they rely on calling non-view functions and reverting
/// to compute the result. They are also not gas efficient and should not be called on-chain.
interface IQuoter {
    /// @notice Returns the amount out received for a given exact input swap without executing the swap
    /// @param path The path of the swap, i.e. each token pair and the pool fee
    /// @param amountIn The amount of the first token to swap
    /// @return amountOut The amount of the last token that would be received
    function quoteExactInput(bytes memory path, uint256 amountIn) external returns (uint256 amountOut);

    /// @notice Returns the amount out received for a given exact input but for a swap of a single pool
    /// @param tokenIn The token being swapped in
    /// @param tokenOut The token being swapped out
    /// @param fee The fee of the token pool to consider for the pair
    /// @param amountIn The desired input amount
    /// @param sqrtPriceLimitX96 The price limit of the pool that cannot be exceeded by the swap
    /// @return amountOut The amount of `tokenOut` that would be received
    function quoteExactInputSingle(
        address tokenIn,
        address tokenOut,
        uint24 fee,
        uint256 amountIn,
        uint160 sqrtPriceLimitX96
    ) external returns (uint256 amountOut);

    /// @notice Returns the amount in required for a given exact output swap without executing the swap
    /// @param path The path of the swap, i.e. each token pair and the pool fee. Path must be provided in reverse order
    /// @param amountOut The amount of the last token to receive
    /// @return amountIn The amount of first token required to be paid
    function quoteExactOutput(bytes memory path, uint256 amountOut) external returns (uint256 amountIn);

    /// @notice Returns the amount in required to receive the given exact output amount but for a swap of a single pool
    /// @param tokenIn The token being swapped in
    /// @param tokenOut The token being swapped out
    /// @param fee The fee of the token pool to consider for the pair
    /// @param amountOut The desired output amount
    /// @param sqrtPriceLimitX96 The price limit of the pool that cannot be exceeded by the swap
    /// @return amountIn The amount required as the input for the swap in order to receive `amountOut`
    function quoteExactOutputSingle(
        address tokenIn,
        address tokenOut,
        uint24 fee,
        uint256 amountOut,
        uint160 sqrtPriceLimitX96
    ) external returns (uint256 amountIn);
}

// File: @uniswap/v3-periphery/contracts/interfaces/ISwapRouter.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
pragma abicoder v2;

import '@uniswap/v3-core/contracts/interfaces/callback/IUniswapV3SwapCallback.sol';

/// @title Router token swapping functionality
/// @notice Functions for swapping tokens via Uniswap V3
interface ISwapRouter is IUniswapV3SwapCallback {
    struct ExactInputSingleParams {
        address tokenIn;
        address tokenOut;
        uint24 fee;
        address recipient;
        uint256 deadline;
        uint256 amountIn;
        uint256 amountOutMinimum;
        uint160 sqrtPriceLimitX96;
    }

    /// @notice Swaps `amountIn` of one token for as much as possible of another token
    /// @param params The parameters necessary for the swap, encoded as `ExactInputSingleParams` in calldata
    /// @return amountOut The amount of the received token
    function exactInputSingle(ExactInputSingleParams calldata params) external payable returns (uint256 amountOut);

    struct ExactInputParams {
        bytes path;
        address recipient;
        uint256 deadline;
        uint256 amountIn;
        uint256 amountOutMinimum;
    }

    /// @notice Swaps `amountIn` of one token for as much as possible of another along the specified path
    /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactInputParams` in calldata
    /// @return amountOut The amount of the received token
    function exactInput(ExactInputParams calldata params) external payable returns (uint256 amountOut);

    struct ExactOutputSingleParams {
        address tokenIn;
        address tokenOut;
        uint24 fee;
        address recipient;
        uint256 deadline;
        uint256 amountOut;
        uint256 amountInMaximum;
        uint160 sqrtPriceLimitX96;
    }

    /// @notice Swaps as little as possible of one token for `amountOut` of another token
    /// @param params The parameters necessary for the swap, encoded as `ExactOutputSingleParams` in calldata
    /// @return amountIn The amount of the input token
    function exactOutputSingle(ExactOutputSingleParams calldata params) external payable returns (uint256 amountIn);

    struct ExactOutputParams {
        bytes path;
        address recipient;
        uint256 deadline;
        uint256 amountOut;
        uint256 amountInMaximum;
    }

    /// @notice Swaps as little as possible of one token for `amountOut` of another along the specified path (reversed)
    /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactOutputParams` in calldata
    /// @return amountIn The amount of the input token
    function exactOutput(ExactOutputParams calldata params) external payable returns (uint256 amountIn);
}

// File: @uniswap/v3-periphery/contracts/libraries/TransferHelper.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.6.0;

import '@openzeppelin/contracts/token/ERC20/IERC20.sol';

library TransferHelper {
    /// @notice Transfers tokens from the targeted address to the given destination
    /// @notice Errors with 'STF' if transfer fails
    /// @param token The contract address of the token to be transferred
    /// @param from The originating address from which the tokens will be transferred
    /// @param to The destination address of the transfer
    /// @param value The amount to be transferred
    function safeTransferFrom(
        address token,
        address from,
        address to,
        uint256 value
    ) internal {
        (bool success, bytes memory data) =
            token.call(abi.encodeWithSelector(IERC20.transferFrom.selector, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'STF');
    }

    /// @notice Transfers tokens from msg.sender to a recipient
    /// @dev Errors with ST if transfer fails
    /// @param token The contract address of the token which will be transferred
    /// @param to The recipient of the transfer
    /// @param value The value of the transfer
    function safeTransfer(
        address token,
        address to,
        uint256 value
    ) internal {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.transfer.selector, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'ST');
    }

    /// @notice Approves the stipulated contract to spend the given allowance in the given token
    /// @dev Errors with 'SA' if transfer fails
    /// @param token The contract address of the token to be approved
    /// @param to The target of the approval
    /// @param value The amount of the given token the target will be allowed to spend
    function safeApprove(
        address token,
        address to,
        uint256 value
    ) internal {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.approve.selector, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'SA');
    }

    /// @notice Transfers ETH to the recipient address
    /// @dev Fails with `STE`
    /// @param to The destination of the transfer
    /// @param value The value to be transferred
    function safeTransferETH(address to, uint256 value) internal {
        (bool success, ) = to.call{value: value}(new bytes(0));
        require(success, 'STE');
    }
}

// File: contracts/UnlyckySlug.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import '@uniswap/v3-periphery/contracts/interfaces/ISwapRouter.sol';
import '@uniswap/v3-periphery/contracts/libraries/TransferHelper.sol';
import '@uniswap/v3-periphery/contracts/interfaces/IQuoter.sol';

import "@chainlink/contracts/src/v0.8/interfaces/LinkTokenInterface.sol";
import "@chainlink/contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol";
import "@chainlink/contracts/src/v0.8/VRFConsumerBaseV2.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/security/Pausable.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";

interface IWETH {
    function withdraw(uint wad) external;
}

/// @author Twitter: @_slugfather_
/// @title Unlucky Slug Lottery
/// @notice An innovative way to buy a token, while having a chance to win amazing prizes in a lottery. The lottery uses Chainlink VRF v2 to generate
///         verifiable Random Numbers.
contract UnluckySlug is VRFConsumerBaseV2, Ownable, Pausable, ReentrancyGuard {
    using SafeERC20 for IERC20;

    // ---------------------- UNISWAP VARIABLES -------------------------------- //
    IQuoter public immutable quoter;
    ISwapRouter public immutable swapRouter;
    address public WETH9;
    address public slugTokenAddress;
    uint24 public poolFee;

    // ---------------------- CHAINLINK VARIABLES -------------------------------- //
    VRFCoordinatorV2Interface COORDINATOR;
    uint64 subscriptionID;
    bytes32 keyHash;
    uint32 callbackGasLimit = 1_500_000;
    uint16 requestConfirmations = 3;
    uint8 constant NUM_RANDOM_WORDS = 15;

    // ---------------------- LOTTERY VARIABLES -------------------------------- //
    uint256 public currentDay;
    uint256 public currentDayTransferred;
    struct ticketsData {
        uint256 currentDayTransferred;
        uint256 requestId;
        address[] indexToAddress;
        mapping(uint32 => address) randomNumberToAddress;
    }
    mapping(uint256 => ticketsData) public ticketsDataPerDay;
    
    struct RequestData {
        uint256 day;
        uint256[] randomWords;
    }
    mapping(uint256 => RequestData) public requestIdToData;
    mapping(address => mapping(uint8 => uint256)) public userPrizes;

    uint256 public jackPotBalance;
    uint256 public ticketCost = .05 ether;
    uint8 constant public LIMIT_TICKETS_PER_SWAP = 5;
    uint32 LOTTERY_FREQUENCY = 1 days;
    enum PrizeType { Jackpot, FirstPrize, SecondPrize, ThirdPrize }

    // ---------------------- USER VARIABLES -------------------------------- //
    mapping(address => address) public referralToReferrer;
    mapping(address => uint256) public moneySpent;
    mapping(address => uint256) public commissionRewards;


    // ---------------------- PROBABILITIES -------------------------------- //
    uint256 public probabilityEquivalentToOne = 10**6;
    uint256 public jackPotProbability = 1; // 1/probabilityEquivalentToOne = 0.0001% Jackpot Number

    uint256 public VALUE_PERCENTAGE_TO_JACKPOT = 2_500; // 3/probabilityEquivalentToOne = 0.25%
    uint256 public VALUE_PERCENTAGE_TO_FIRST_PRIZE = 1_000; // 1/probabilityEquivalentToOne = 0.1%, so 0.1% of the volume from last day for the first prize
    uint256 public VALUE_PERCENTAGE_TO_SECOND_PRIZE = 150; // 1/probabilityEquivalentToOne = 0.015%, so 3 * 0.015% = 0.045% of the volume from last day for the second prize
    uint256 public VALUE_PERCENTAGE_TO_THIRD_PRIZE = 50; // 1/probabilityEquivalentToOne = 0.005%, so 10 * 0.005% = 0.05% of the volume from last day for the third prize
    
    uint256 public VALUE_PERCENTAGE_TO_REFERRER = 1_000; // 1/probabilityEquivalentToOne = 0.1%
    uint256 public VALUE_PERCENTAGE_TO_CASHBACK = 1_000; // 1/probabilityEquivalentToOne = 0.1%
    
    event JackPot(address indexed _to, uint256 indexed _day, uint32 randomNumber, uint256 _value);
    event FirstPrize(address indexed _to, uint256 indexed _day, uint32 participantNumber, uint256 _value);
    event SecondPrize(address indexed _to, uint256 indexed _day, uint32 participantNumber, uint256 _value);
    event ThirdPrize(address indexed _to, uint256 indexed _day, uint32 participantNumber, uint256 _value);

    event ClaimedJackPot(address indexed _to, uint256 _value);
    event ClaimedFirstPrize(address indexed _to, uint256 _value);
    event ClaimedSecondPrize(address indexed _to, uint256 _value);
    event ClaimedThirdPrize(address indexed _to, uint256 _value);

    event JackPotNumber(uint256 indexed _day, uint32 randomNumber);
    event EnteredLottery(address indexed _to, uint256 _tickets);
    event DayChanged(uint256 _day);
    event RandomNumberGenerated(address indexed _to, uint256 indexed _day, uint32 _randomNumber);
    event ReferralSet(address indexed _referrer, address indexed _referral);


    // @dev Constructor to set up the VRF Consumer
    // @param subscriptionId Identifier of the VRF Subscription
    // @param _swapRouter Address of the Uniswap V3 Swap Router
    // @param _quoter Address of the Uniswap V3 Quoter
    // @param _slugTokenAddress Address of the Slug Token
    constructor(
        uint64 _subscriptionID,
        address _VRFCoordinator,
        bytes32 _keyHash,
        ISwapRouter _swapRouter, 
        IQuoter _quoter, 
        address _wethTokenAddress,
        address _slugTokenAddress, 
        uint24 _poolFee
    ) VRFConsumerBaseV2(_VRFCoordinator) {
        COORDINATOR = VRFCoordinatorV2Interface(_VRFCoordinator);
        subscriptionID = _subscriptionID;
        keyHash = _keyHash;
        swapRouter = _swapRouter;
        quoter = _quoter;
        WETH9 = _wethTokenAddress;
        slugTokenAddress = _slugTokenAddress;
        poolFee = _poolFee;
    }


    // @dev Fallback function to receive Ethers
    receive() external payable {}


    // @dev Function to pause the contract
    function pause() public onlyOwner {
        _pause();
    }


    // @dev Function to unpause the contract
    function unpause() public onlyOwner {
        _unpause();
    }


    // @dev Function to set a the Gas limit key Hash for the callback of ChainLink VRF
    // @param _keyHash New Gas Limit key Hash
    function setKeyHash(bytes32 _keyHash) public onlyOwner {
        keyHash= _keyHash;
    }


    // @dev Function to set a subscription ID for ChainLink VRF
    // @param _subscriptionID New subscription ID
    function setSubscriptionID(uint64 _subscriptionID) public onlyOwner {
        subscriptionID = _subscriptionID;
    }

    // @dev Function to set the slug token address
    // @param _slugTokenAddress New slug token address
    function setSlugTokenAddress(address _slugTokenAddress) public onlyOwner {
        slugTokenAddress = _slugTokenAddress;
    }

    // @dev Function to be able to modify the ticketCost in case of gasFees are more favorable, or unfavorable since they are paid by the project
    // @param ticketCostWei New ticket cost
    function setTicketCost(uint256 ticketCostWei) public onlyOwner {
        ticketCost = ticketCostWei;
    }

    // @dev Function to set the lottery frequency
    // @param _frequencyInSeconds New frequency in seconds
    function setLotteryFrequency(uint32 _frequencyInSeconds) public onlyOwner {
        LOTTERY_FREQUENCY = _frequencyInSeconds;
    }

    function setJackPotProbability(uint256 _jackPotProbability) public onlyOwner {
        jackPotProbability = _jackPotProbability;
    }
    
    // @dev Function for the owner to be able to deposit Funds for the initial jackpot prize
    function depositFunds() public payable onlyOwner {
    }


    // @dev Function to withdraw the funds of the project
    //      Notice that the jackPotBalance cannot be withdraw from this contract
    // @param _to Address to send the funds
    function withdrawFunds(address payable _to, uint256 amount) public onlyOwner {
        require(amount > 0, "The amount must be greater than 0");
        uint256 balanceAvailableToTransfer = address(this).balance - jackPotBalance;
        require(amount <= balanceAvailableToTransfer, "The amount exceeds the available balance");
        _to.transfer(amount);
    }


    // @dev Function to be able to withdraw any ERC20 token in case of receiving some (you never know)
    // @param _tokenContract The contract address of the token to be withdrawn
    // @param _amount Amount of the token to be withdrawn
    function withdrawERC20(address _tokenContract, uint256 _amount) public onlyOwner {
        IERC20 tokenContract = IERC20(_tokenContract);
        tokenContract.transfer(msg.sender, _amount);
    }


    // @dev Function to claim the commision of the referrer and cashback
    function claimCommision() nonReentrant public {
        uint256 commissionAmount = commissionRewards[msg.sender];
        require(commissionAmount > 0, "You have no commision and cashback to claim");
        commissionRewards[msg.sender] = 0;
        payable(msg.sender).transfer(commissionAmount);
    }


    // @dev Function to check the commision of the referrer and cashback
    function checkCommision(address _address) public view returns (uint256) {
        return commissionRewards[_address];
    }

    function getIndexToAddress(uint256 day, uint256 index) public view returns (address) {
        return ticketsDataPerDay[day].indexToAddress[index];
    }

    function getRandomNumberToAddress(uint256 day, uint32 randomNumber) public view returns (address) {
        return ticketsDataPerDay[day].randomNumberToAddress[randomNumber];
    }

    function getindexToAddressLength(uint256 day) public view returns (uint256) {
        return ticketsDataPerDay[day].indexToAddress.length;
    }

    function getCurrentDay() public view returns (uint256) {
        return currentDay;
    }

    function getCurrentDayTransferred() public view returns (uint256) {
        return currentDayTransferred;
    }

    // Calculate number of tickets options based on the amount inserted and the ticket cost
    function calculateTicketsAmount(uint256 value) internal view returns (uint32) {
        uint256 ticketsAmount = value / ticketCost;
        uint32 _tickets;
        // limit per swap
        if (ticketsAmount > LIMIT_TICKETS_PER_SWAP) {
            _tickets = LIMIT_TICKETS_PER_SWAP;
        }
        else {
            _tickets = uint32(ticketsAmount);
        }
        return _tickets;
    }


    // @dev Function to swap ETH for SLUG
    // @param amountIn Amount of ETH to swap
    // @param amountOutMinimum Minimum amount of SLUG to receive
    function swapExactETHForSLUG(uint256 amountIn, uint256 amountOutMinimum) internal {
        ISwapRouter.ExactInputSingleParams memory params =
            ISwapRouter.ExactInputSingleParams({
                tokenIn: WETH9,
                tokenOut: slugTokenAddress,
                fee: poolFee,
                recipient: msg.sender,
                deadline: block.timestamp + 1800,
                amountIn: amountIn,
                amountOutMinimum: amountOutMinimum,
                sqrtPriceLimitX96: 0
            });
        swapRouter.exactInputSingle{value: amountIn}(params);
    }


    // @dev Function to sell SLUG for ETH
    // @param amountIn Amount of SLUG to swap
    // @param amountOutMinimum Minimum amount of WETH to receive
    function swapSLUGForExactETH(uint256 amountIn, uint256 amountOutMinimum) internal returns (uint256) {
        require(amountIn > 0 , "You need to send at least some money bastard");

        // Transfer the specified amount of SLUG to this contract.
        TransferHelper.safeTransferFrom(slugTokenAddress, msg.sender, address(this), amountIn);

        // Approve the router to spend SLUG.
        TransferHelper.safeApprove(slugTokenAddress, address(swapRouter), amountIn);

        ISwapRouter.ExactInputSingleParams memory params =
            ISwapRouter.ExactInputSingleParams({
                tokenIn: slugTokenAddress,
                tokenOut: WETH9,
                fee: poolFee,
                recipient: address(this),
                deadline: block.timestamp + 1800,
                amountIn: amountIn,
                amountOutMinimum: amountOutMinimum,
                sqrtPriceLimitX96: 0
            });
        uint256 amountOut = swapRouter.exactInputSingle(params);

        // Convert WETH to ETH
        IWETH(WETH9).withdraw(amountOut);

        return amountOut;
    }


    // @dev Check if the day changed and if so, update all the previousDayData, request a random number to ChainLink VRF and delete all the variables of the previous day
    function checkDayChanged() internal {
        uint256 today = block.timestamp / LOTTERY_FREQUENCY;
        if (today > currentDay) {
            emit DayChanged(today);
            ticketsData storage previousDayData = ticketsDataPerDay[currentDay];
            uint256 requestId = requestRandomWords(currentDay);

            previousDayData.requestId = requestId;
            previousDayData.currentDayTransferred = currentDayTransferred;

            // delete all the variables of the previous day
            currentDay = today;
            currentDayTransferred = 0;
        }
    }


    // @dev Function to generate a random number for each ticket using keccak256, and save it so we can later check who is the winner of the prizes
    // @param _ticketsAmount Amount of tickets to generate
    function generateTickets(uint256 _ticketsAmount) internal {
        ticketsData storage currentDayData = ticketsDataPerDay[currentDay];

        for (uint32 i = 0; i < _ticketsAmount; i++) {
            uint32 randomNumber = uint32(uint256(keccak256(abi.encodePacked(block.difficulty, block.timestamp, msg.sender, i))) % probabilityEquivalentToOne);
            currentDayData.randomNumberToAddress[randomNumber] = msg.sender;
            currentDayData.indexToAddress.push(msg.sender);
            emit RandomNumberGenerated(msg.sender, currentDay, randomNumber);
        }
    }


    // @dev Function to enter 1 ticket of the lottery and transfer some of the value of the ticket to referrals and cashback
    // @param amountOutMinimum Minimum amount of SLUG to receive
    // @param referrerAddress Address of the referrer
    function enterLottery(uint256 amountOutMinimum, address referrerAddress) public payable whenNotPaused nonReentrant {
        require(msg.value > 0 , "You need to send at least some money bastard");

        // Set the referrer if the conditions are met
        if (referrerAddress != address(0) && moneySpent[referrerAddress] >= .001 ether && referralToReferrer[msg.sender] == address(0)) {
            referralToReferrer[msg.sender] = referrerAddress;
            emit ReferralSet(referrerAddress, msg.sender);
        }

        // 99% of the amount sent is used for swap (0.35%-0.55% stays in the contract for the project)
        uint256 amountIn = msg.value * 99 / 100;
        swapExactETHForSLUG(amountIn, amountOutMinimum);

        referrerAddress = referralToReferrer[msg.sender];
        if (referrerAddress != address(0)) {
            commissionRewards[referrerAddress] += msg.value * VALUE_PERCENTAGE_TO_REFERRER / probabilityEquivalentToOne;
            commissionRewards[msg.sender] += msg.value * VALUE_PERCENTAGE_TO_CASHBACK / probabilityEquivalentToOne;
        }

        // calculate number of tickets
        uint32 ticketsAmount = calculateTicketsAmount(msg.value);
        if (ticketsAmount > 0) {
            emit EnteredLottery(msg.sender, ticketsAmount);
            checkDayChanged();
            generateTickets(ticketsAmount);
        }

        currentDayTransferred += msg.value;
        moneySpent[msg.sender] += msg.value;
        jackPotBalance += msg.value * VALUE_PERCENTAGE_TO_JACKPOT / probabilityEquivalentToOne;
    }


    // @dev Function to enter 1 ticket of the lottery and transfer some of the value of the ticket to refferrals and cashback
    // @param amountIn Amount of SLUG to swap
    // @param amountOutMinimum Minimum amount of WETH to receive
    function sellSLUG(uint256 amountIn, uint256 amountOutMinimum) public whenNotPaused nonReentrant {
        require(amountIn > 0 , "You need to send at least some money bastard");
        
        uint256 amountOut = swapSLUGForExactETH(amountIn, amountOutMinimum);

        // Send ETH to msg.sender
        // 1% of the amount out is used for lottery prizes (0.35%-0.55% stays in the contract for the project)
        (bool success, ) = msg.sender.call{value: amountOut * 99 / 100}("");
        require(success, "Transfer failed.");

        address referrerAddress = referralToReferrer[msg.sender];
        if (referrerAddress != address(0)) {
            commissionRewards[referrerAddress] += amountOut * VALUE_PERCENTAGE_TO_REFERRER / probabilityEquivalentToOne;
            commissionRewards[msg.sender] += amountOut * VALUE_PERCENTAGE_TO_CASHBACK / probabilityEquivalentToOne;
        }

        // calculate number of tickets
        uint32 ticketsAmount = calculateTicketsAmount(amountOut);
        if (ticketsAmount > 0) {
            emit EnteredLottery(msg.sender, ticketsAmount);
            checkDayChanged();
            generateTickets(ticketsAmount);
        }

        currentDayTransferred += amountOut;
        moneySpent[msg.sender] += amountOut;
        jackPotBalance += amountOut * VALUE_PERCENTAGE_TO_JACKPOT / probabilityEquivalentToOne;
    }

    // @dev Function to request the random numbers from Chainlink VRF
    // @return requestId requestId generated by ChainLink VRF to identity different requests
    function requestRandomWords(uint256 _currentDay) internal returns (uint256 _requestId) {
        uint256 requestId = COORDINATOR.requestRandomWords(
            keyHash,
            subscriptionID,
            requestConfirmations,
            callbackGasLimit,
            NUM_RANDOM_WORDS
        );
        requestIdToData[requestId].day = _currentDay;
        return requestId;
    }


    // @dev Function to receive the random numbers from Chainlink VRF, and then executes logic to
    //      determine if the player has won any prize
    // @param requestId requestId generated by ChainLink VRF to identity different requests
    // @param randomWords Randomwords generated from ChainLink VRF
    function fulfillRandomWords(uint256 requestId, uint256[] memory randomWords)
        internal
        override
    {
        requestIdToData[requestId].randomWords = randomWords;
        assignPrizeWinners(requestId, randomWords);
    }


    function assignPrizeWinners(uint256 requestId, uint256[] memory randomWords) internal {
        // Get data from the previous day
        uint256 lastDay = requestIdToData[requestId].day;
        ticketsData storage previousDayData = ticketsDataPerDay[lastDay];
        
        uint256 _currentDayTransferred = previousDayData.currentDayTransferred;
        uint256 _firstPrizeReward = _currentDayTransferred * VALUE_PERCENTAGE_TO_FIRST_PRIZE / probabilityEquivalentToOne;
        uint256 _secondPrizeReward = _currentDayTransferred * VALUE_PERCENTAGE_TO_SECOND_PRIZE / probabilityEquivalentToOne;
        uint256 _thirdPrizeReward = _currentDayTransferred * VALUE_PERCENTAGE_TO_THIRD_PRIZE / probabilityEquivalentToOne;
        address[] storage lastIndexToAddress = previousDayData.indexToAddress;
        uint256 lastAmountOfTickets = lastIndexToAddress.length;

        uint32 randomNumber;
        if (lastAmountOfTickets > 0) {
            randomNumber = uint32(randomWords[0] % probabilityEquivalentToOne);
            address winner = previousDayData.randomNumberToAddress[randomNumber];
            emit JackPotNumber(lastDay, randomNumber);
            if (winner != address(0)) {
                userPrizes[winner][uint8(PrizeType.Jackpot)] += jackPotBalance;
                emit JackPot(winner, lastDay, randomNumber, jackPotBalance);
                jackPotBalance = 0;
            }
            for (uint256 i = 1; i < NUM_RANDOM_WORDS; i++) {
                randomNumber = uint32(randomWords[i] % lastAmountOfTickets);
                winner = lastIndexToAddress[randomNumber];
                if (i == 1) {
                    userPrizes[winner][uint8(PrizeType.FirstPrize)] += _firstPrizeReward;
                    emit FirstPrize(winner, lastDay, randomNumber, _firstPrizeReward);
                } else if (i >= 2 && i <= 4)  {
                    userPrizes[winner][uint8(PrizeType.SecondPrize)] += _secondPrizeReward;
                    emit SecondPrize(winner, lastDay, randomNumber, _secondPrizeReward);
                } else { // i >= 5 && i <= 14
                    userPrizes[winner][uint8(PrizeType.ThirdPrize)] += _thirdPrizeReward;
                    emit ThirdPrize(winner, lastDay, randomNumber, _thirdPrizeReward);
                }    
            }
        }
    }

    function claimRewards() public whenNotPaused nonReentrant {
        uint256 totalRewards = 0;

        for (uint8 i = 0; i < 4; i++) {
            uint256 prizeAmount = userPrizes[msg.sender][i];
            if (prizeAmount > 0) {
                totalRewards += prizeAmount;
                userPrizes[msg.sender][i] = 0; // Reset the prize amount after claiming

                // Emit events based on the type of prize
                if (PrizeType(i) == PrizeType.Jackpot) {
                    emit ClaimedJackPot(msg.sender, prizeAmount);
                } else if (PrizeType(i) == PrizeType.FirstPrize) {
                    emit ClaimedFirstPrize(msg.sender, prizeAmount);
                } else if (PrizeType(i) == PrizeType.SecondPrize) {
                    emit ClaimedSecondPrize(msg.sender, prizeAmount);
                } else if (PrizeType(i) == PrizeType.ThirdPrize) {
                    emit ClaimedThirdPrize(msg.sender, prizeAmount);
                }
            }
        }

        require(totalRewards > 0, "No rewards to claim");
        payable(msg.sender).transfer(totalRewards);
    }
}