// File: 1.GAMETIME.sol



// SPDX-License-Identifier: MIT
// DumplingZai v69696969 
// "I smash keyboards and vomit smart contracts"


pragma solidity ^0.8.7;

import "./2.IERC20.sol";
import "./3.Ownable.sol";
import "./4.Pausable.sol";
import "./5.IERC721.sol";
import "./6.VRFV2WrapperConsumerBase.sol";
import "./7.ConfirmedOwner.sol";
import "./8.IERC721Receiver.sol";
import "./9.AccessControl.sol";

contract GAMETIME is 
    AccessControl,
    VRFV2WrapperConsumerBase,
    ConfirmedOwner,
    Pausable,
    IERC721Receiver
    {
    
    // ==== Variables declaration ====
        // ==== Game related ====
        IERC721[] public rewardNFTs; // NFT rewards array
        uint256[] public rewardNFTIds; // NFT token ID array
        uint256 public rewardETHPerWinner; // ETH rewards
        uint256 public gameRound = 1; //for clearing participant mapping
        uint256 public gameStarted = 0;
        uint256 public numberOfWinners;  
        uint256 public costPerEntry; //amount of eth per entry
        uint256 public maxAllowedEntries; // maximum number of entry
        uint256 public numberOfCurrentEntries; // current entry number
        uint256 private entriesTracker; // internal tracker
        uint256 public prizeMode; // 0 for NFT prize, 1 for ETH prize
        address[] public winnerList; //storing of winners per round
        mapping(address => Participant) public participants; // mapping of each unique participants
        mapping(uint256 => mapping(uint256 => address)) public participantByEntryIndexPerRound; //for new participantByEntryIndex each round
        mapping(address => mapping(uint256 => PrizeInfo[])) Winners; // mapping of each winner to their prizes
        mapping(uint256 => address[]) public winnersPerRound;

        struct PrizeInfo { // record of each selected winner and their prize 
            address nft; 
            uint256 prizeAmountOrId; 
            bool claimed; 
            uint256 round;
        }

        struct Participant { // record of each unique participants information
            uint256 lastParticipatedRound;
            uint256 numberOfEntries;
        }

        // ==== Chainlink VRF related ====
        uint256 public randomResult; //stores result of the chainlink randomizer 
        uint32 private callbackGasLimit = 300000; // gas limit to call on VRF
        uint16 private requestConfirmations = 3;
        uint32 private numWords = 1;
        address private linkAddress = 0x514910771AF9Ca656af840dff83E8264EcF986CA; //$LINK tokens address 
        address private wrapperAddress = 0x5A861794B927983406fCE1D062e00b9368d97Df6; //ChainLink wrapper address
  
        // ==== Automation related ====
        bytes32 public constant AUTOMATOR_ROLE = keccak256("AUTOMATOR_ROLE"); //Automator initalisation

    constructor()
        ConfirmedOwner(msg.sender)
        VRFV2WrapperConsumerBase(linkAddress, wrapperAddress)
    {}

    //==== Game & Rewards Settings ====    
    function setRewardsNFT(IERC721[] memory _rewardNFTs, uint256[] memory _rewardNFTIds) external onlyOwnerOrAutomator {
        require(_rewardNFTs.length == _rewardNFTIds.length, "NFTs and IDs arrays should have the same length");
        require(_rewardNFTs.length >= numberOfWinners, "The number of rewards is lesser than the number of winners");
        rewardNFTs = _rewardNFTs;
        rewardNFTIds = _rewardNFTIds;
    }

    function setRewardsETHPerWinner(uint256 _rewardETHPerWinner) external onlyOwnerOrAutomator {
        rewardETHPerWinner = _rewardETHPerWinner;
    }

    function gameSetup(uint256 _entryCost, uint256 _maxEntries, uint256 _numberOfWinners, uint256 _prizeMode) external onlyOwnerOrAutomator {
        costPerEntry = _entryCost;
        maxAllowedEntries = _maxEntries;
        numberOfWinners = _numberOfWinners;
        prizeMode = _prizeMode;
        gameStarted = 1;
    }
    
    function resetGame() external onlyOwnerOrAutomator {
        // Increment the game round
        gameRound++;

        // Reset the current entries, max entries, reward NFTs, and reward NFT IDs
        numberOfCurrentEntries = 0;
        maxAllowedEntries = 0;
        numberOfWinners = 0;
        delete rewardNFTs;
        delete rewardNFTIds;
        delete winnerList;
        gameStarted = 0;
        entriesTracker = 0;
        rewardETHPerWinner = 0;
        costPerEntry = 0;
    }

    function clearRewards() external onlyOwnerOrAutomator {
        delete rewardNFTs;
        delete rewardNFTIds;
        rewardETHPerWinner = 0;
    }

    function setGameRound(uint256 round) public onlyOwnerOrAutomator {
        gameRound = round;
    }

    function pause() external onlyOwner {
        _pause();
    }

    function unpause() external onlyOwner {
        _unpause();
    }

    // ==== Game Operations ====
    function enterGame() external payable whenNotPaused {
        require(msg.value >= costPerEntry, "ETH sent should equal or more than the cost per entry");
        require(msg.value % costPerEntry == 0, "ETH sent should be as a multiple of cost per entry");
        uint256 numOfEntries = msg.value / costPerEntry;
        require(numberOfCurrentEntries + numOfEntries <= maxAllowedEntries, "Exceeds maximum entries allowed");
         // If it's a new round, reset their entries
        if(participants[msg.sender].lastParticipatedRound < gameRound) {
            participants[msg.sender].numberOfEntries = 0; // reset their entries
        }

        for (uint256 i = 0; i < numOfEntries; i++) {
            participantByEntryIndexPerRound[gameRound][numberOfCurrentEntries] = msg.sender;
            numberOfCurrentEntries++; //increment the new current entries number
            entriesTracker++; //internal entries tracker
            participants[msg.sender].numberOfEntries++; //increment number of times user entered the game
        }   
        participants[msg.sender].lastParticipatedRound = gameRound; // update their participation round
    }

    function pickWinners() public onlyOwnerOrAutomator whenNotPaused {
        require(entriesTracker == maxAllowedEntries, "Maximum entries not reached");
        require(numberOfWinners <= entriesTracker, "More winner than entries");
        
        for(uint256 i = 0; i < numberOfWinners; i++) {
            uint256 index = uint256(keccak256(abi.encodePacked(randomResult, i))) % entriesTracker; //generate random index 
            address payable winner = payable(participantByEntryIndexPerRound[gameRound][index]); //identify winner
            winnerList.push(winner);
            PrizeInfo memory prize;
            if (prizeMode == 0){
                uint256 nftIndex = randomResult % rewardNFTs.length; //generate random index 
                IERC721 rewardNFT = rewardNFTs[nftIndex]; //NFT selected
                uint256 rewardNFTId = rewardNFTIds[nftIndex];
                require(rewardNFT.ownerOf(rewardNFTId) == address(this), "Contract doesn't own the NFT");
                prize = PrizeInfo(address(rewardNFTs[nftIndex]), rewardNFTIds[nftIndex], false, gameRound);
                Winners[winner][gameRound].push(prize); 

                //removing winner from pool for next selection 
                rewardNFTs[nftIndex] = rewardNFTs[rewardNFTs.length - 1]; // swap distributed NFT address to last position
                rewardNFTs.pop(); //remove that NFT address 
                rewardNFTIds[nftIndex] = rewardNFTIds[rewardNFTIds.length - 1]; //swap distrbuted NFT token ID to last position
                rewardNFTIds.pop(); //remove that NFT token ID
            }
            else if (prizeMode == 1){ //ETH prize to be given out
                require(address(this).balance >= rewardETHPerWinner, "Contract doesn't have enough ETH");
                prize = PrizeInfo(address(0), rewardETHPerWinner, false, gameRound); // NFT address is 0x0 for ETH prize
                Winners[winner][gameRound].push(prize);
            }

            //Shift array to fill gap and remove last position to avoid duplicate winners
            for (uint256 j = index; j < numberOfCurrentEntries - 1; j++) {
                participantByEntryIndexPerRound[gameRound][j] = participantByEntryIndexPerRound[gameRound][j + 1];
            }
            delete participantByEntryIndexPerRound[gameRound][numberOfCurrentEntries - 1];
            entriesTracker--;
        }
        gameStarted = 2;
    }

    
    function claimPrizes(address winner) external {
        require(Winners[winner][gameRound].length > 0, "No prizes in this round");

        for(uint256 i = 0; i < Winners[winner][gameRound].length; i++) {
            // Only allow claiming of prizes that haven't been claimed yet
            if (!Winners[winner][gameRound][i].claimed) {
                if (Winners[winner][gameRound][i].nft == address(0)) {
                    // ETH prize
                    require(address(this).balance >= Winners[winner][gameRound][i].prizeAmountOrId, "Contract doesn't have enough ETH");
                    payable(winner).transfer(Winners[winner][gameRound][i].prizeAmountOrId); // transfer ETH to winner
                } else {
                    // NFT prize
                    IERC721 rewardNFT = IERC721(Winners[winner][gameRound][i].nft);
                    uint256 rewardNFTId = Winners[winner][gameRound][i].prizeAmountOrId;
                    require(rewardNFT.ownerOf(rewardNFTId) == address(this), "Contract doesn't own the NFT");
                    rewardNFT.transferFrom(address(this), winner, rewardNFTId); // transfer NFT to winner
                }
                Winners[winner][gameRound][i].claimed = true;
            }
        }
    }
    
    
    // ==== Game information query ====
    function getContractETHBalance() external view returns (uint256) {
        return address(this).balance;
    }

    function getTokenBalance(address token) external view returns (uint256) {
        return IERC20(token).balanceOf(address(this));
    }

    function getParticipantEntries(address participantAddress) external view returns (uint256) {
        if (participants[participantAddress].lastParticipatedRound < gameRound) {
            return 0;
        } else {
            return participants[participantAddress].numberOfEntries;
        }
    }

    function winnerCheck (address winner) external view returns (bool) {
        PrizeInfo[] storage prizeInfo = Winners[winner][gameRound];
        if (prizeInfo.length > 0) {
            for(uint256 i = 0; i < prizeInfo.length; i++) {
                if (!prizeInfo[i].claimed) {
                    return true;
                }
            }
        }
        return false;
    }

    function getWinnerListLength() public view returns (uint) {
        return winnerList.length;
    }

    // ==== Random generator =====
    function requestRandomNumber() external onlyOwnerOrAutomator returns (uint256 requestId) {
        require(LINK.balanceOf(address(this)) >= 0.25 ether, "Not enough LINK to pay fee");
        return requestRandomness(callbackGasLimit, requestConfirmations, numWords);
    }

    function fulfillRandomWords(uint256 , uint256[] memory randomWords)
        internal
        override
    {
        randomResult = randomWords[0];
    }

    // ==== Withdraw assets ====
    function withdrawETH(address payable _to) external onlyOwner {
        require(address(this).balance > 0, "No balance to withdraw");
        (bool success, ) = _to.call{value: address(this).balance}("");
        require(success, "Transfer failed.");
    }

    function withdrawERC20(address token, address to) external onlyOwner {
        IERC20 erc20Token = IERC20(token);
        uint256 balance = erc20Token.balanceOf(address(this));
        require(balance > 0, "No tokens to withdraw");
        erc20Token.transfer(to, balance);
    }

    function withdrawNFTs(address nft, uint256 id, address to) external onlyOwner {
        IERC721 erc721Token = IERC721(nft);
        require(erc721Token.ownerOf(id) == address(this), "The contract doesn't own this NFT");
        erc721Token.transferFrom(address(this), to, id);
    }

    // ===== Others =====
    function onERC721Received(address, address, uint256, bytes memory) external virtual override returns (bytes4) {
        return this.onERC721Received.selector;
    }
    

    function addAutomator(address _automator) external onlyOwner {
        grantRole(AUTOMATOR_ROLE, _automator);
    }

    function removeAutomator(address automator) external onlyOwner {
    revokeRole(AUTOMATOR_ROLE, automator);
    }

    modifier onlyOwnerOrAutomator() {
        require(owner() == _msgSender() || hasRole(AUTOMATOR_ROLE, _msgSender()), "Caller is not the owner or an automator");
        _;
    }

    receive() external payable {}//to receive ETH

}



// File: 10.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: 11.VRFV2WrapperInterface.sol



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

interface VRFV2WrapperInterface {
  /**
   * @return the request ID of the most recent VRF V2 request made by this wrapper. This should only
   * be relied option within the same transaction that the request was made.
   */
  function lastRequestId() external view returns (uint256);

  /**
   * @notice Calculates the price of a VRF request with the given callbackGasLimit at the current
   * @notice block.
   *
   * @dev This function relies on the transaction gas price which is not automatically set during
   * @dev simulation. To estimate the price at a specific gas price, use the estimatePrice function.
   *
   * @param _callbackGasLimit is the gas limit used to estimate the price.
   */
  function calculateRequestPrice(uint32 _callbackGasLimit) external view returns (uint256);

  /**
   * @notice Estimates the price of a VRF request with a specific gas limit and gas price.
   *
   * @dev This is a convenience function that can be called in simulation to better understand
   * @dev pricing.
   *
   * @param _callbackGasLimit is the gas limit used to estimate the price.
   * @param _requestGasPriceWei is the gas price in wei used for the estimation.
   */
  function estimateRequestPrice(uint32 _callbackGasLimit, uint256 _requestGasPriceWei) external view returns (uint256);
}

// File: 12.ConfirmedOwnerWithProposal.sol



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

import "./13.OwnableInterface.sol";

/**
 * @title The ConfirmedOwner contract
 * @notice A contract with helpers for basic contract ownership.
 */
contract ConfirmedOwnerWithProposal is OwnableInterface {
  address private s_owner;
  address private s_pendingOwner;

  event OwnershipTransferRequested(address indexed from, address indexed to);
  event OwnershipTransferred(address indexed from, address indexed to);

  constructor(address newOwner, address pendingOwner) {
    require(newOwner != address(0), "Cannot set owner to zero");

    s_owner = newOwner;
    if (pendingOwner != address(0)) {
      _transferOwnership(pendingOwner);
    }
  }

  /**
   * @notice Allows an owner to begin transferring ownership to a new address,
   * pending.
   */
  function transferOwnership(address to) public override onlyOwner {
    _transferOwnership(to);
  }

  /**
   * @notice Allows an ownership transfer to be completed by the recipient.
   */
  function acceptOwnership() external override {
    require(msg.sender == s_pendingOwner, "Must be proposed owner");

    address oldOwner = s_owner;
    s_owner = msg.sender;
    s_pendingOwner = address(0);

    emit OwnershipTransferred(oldOwner, msg.sender);
  }

  /**
   * @notice Get the current owner
   */
  function owner() public view override returns (address) {
    return s_owner;
  }

  /**
   * @notice validate, transfer ownership, and emit relevant events
   */
  function _transferOwnership(address to) private {
    require(to != msg.sender, "Cannot transfer to self");

    s_pendingOwner = to;

    emit OwnershipTransferRequested(s_owner, to);
  }

  /**
   * @notice validate access
   */
  function _validateOwnership() internal view {
    require(msg.sender == s_owner, "Only callable by owner");
  }

  /**
   * @notice Reverts if called by anyone other than the contract owner.
   */
  modifier onlyOwner() {
    _validateOwnership();
    _;
  }
}

// File: 13.OwnableInterface.sol



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

interface OwnableInterface {
  function owner() external returns (address);

  function transferOwnership(address recipient) external;

  function acceptOwnership() external;
}

// File: 14.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: 15.SignedMath.sol



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

pragma solidity ^0.8.0;

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

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

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

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

// File: 16.IAccessControl.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)

pragma solidity ^0.8.19;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

// File: 17.Strings.sol



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

pragma solidity ^0.8.19;

import "./18.Math.sol";
import "./15.SignedMath.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 `int256` to its ASCII `string` decimal representation.
     */
    function toString(int256 value) internal pure returns (string memory) {
        return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
    }

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

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        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);
    }

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

// File: 18.Math.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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) {
                // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                // The surrounding unchecked block does not change this fact.
                // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1, "Math: mulDiv overflow");

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

// File: 19.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: 2.IERC20.sol



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

pragma solidity ^0.8.0;

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

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

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

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

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

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

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

// File: 20.ERC165.sol



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

pragma solidity ^0.8.0;

import "./19.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: 3.Ownable.sol



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

pragma solidity ^0.8.0;

import "./14.Context.sol";

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

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

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

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

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

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

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

// File: 4.Pausable.sol



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

pragma solidity ^0.8.0;

import "./14.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: 5.IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "./19.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: 6.VRFV2WrapperConsumerBase.sol



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


import "./10.LinkTokenInterface.sol";
import "./11.VRFV2WrapperInterface.sol";
/** *******************************************************************************
 * @notice Interface for contracts using VRF randomness through the VRF V2 wrapper
 * ********************************************************************************
 * @dev PURPOSE
 *
 * @dev Create VRF V2 requests without the need for subscription management. Rather than creating
 * @dev and funding a VRF V2 subscription, a user can use this wrapper to create one off requests,
 * @dev paying up front rather than at fulfillment.
 *
 * @dev Since the price is determined using the gas price of the request transaction rather than
 * @dev the fulfillment transaction, the wrapper charges an additional premium on callback gas
 * @dev usage, in addition to some extra overhead costs associated with the VRFV2Wrapper contract.
 * *****************************************************************************
 * @dev USAGE
 *
 * @dev Calling contracts must inherit from VRFV2WrapperConsumerBase. The consumer must be funded
 * @dev with enough LINK to make the request, otherwise requests will revert. To request randomness,
 * @dev call the 'requestRandomness' function with the desired VRF parameters. This function handles
 * @dev paying for the request based on the current pricing.
 *
 * @dev Consumers must implement the fullfillRandomWords function, which will be called during
 * @dev fulfillment with the randomness result.
 */
abstract contract VRFV2WrapperConsumerBase {
  LinkTokenInterface internal immutable LINK;
  VRFV2WrapperInterface internal immutable VRF_V2_WRAPPER;

  /**
   * @param _link is the address of LinkToken
   * @param _vrfV2Wrapper is the address of the VRFV2Wrapper contract
   */
  constructor(address _link, address _vrfV2Wrapper) {
    LINK = LinkTokenInterface(_link);
    VRF_V2_WRAPPER = VRFV2WrapperInterface(_vrfV2Wrapper);
  }

  /**
   * @dev Requests randomness from the VRF V2 wrapper.
   *
   * @param _callbackGasLimit is the gas limit that should be used when calling the consumer's
   *        fulfillRandomWords function.
   * @param _requestConfirmations is the number of confirmations to wait before fulfilling the
   *        request. A higher number of confirmations increases security by reducing the likelihood
   *        that a chain re-org changes a published randomness outcome.
   * @param _numWords is the number of random words to request.
   *
   * @return requestId is the VRF V2 request ID of the newly created randomness request.
   */
  function requestRandomness(
    uint32 _callbackGasLimit,
    uint16 _requestConfirmations,
    uint32 _numWords
  ) internal returns (uint256 requestId) {
    LINK.transferAndCall(
      address(VRF_V2_WRAPPER),
      VRF_V2_WRAPPER.calculateRequestPrice(_callbackGasLimit),
      abi.encode(_callbackGasLimit, _requestConfirmations, _numWords)
    );
    return VRF_V2_WRAPPER.lastRequestId();
  }

  /**
   * @notice fulfillRandomWords handles the VRF V2 wrapper response. The consuming contract must
   * @notice implement it.
   *
   * @param _requestId is the VRF V2 request ID.
   * @param _randomWords is the randomness result.
   */
  function fulfillRandomWords(uint256 _requestId, uint256[] memory _randomWords) internal virtual;

  function rawFulfillRandomWords(uint256 _requestId, uint256[] memory _randomWords) external {
    require(msg.sender == address(VRF_V2_WRAPPER), "only VRF V2 wrapper can fulfill");
    fulfillRandomWords(_requestId, _randomWords);
  }
}

// File: 7.ConfirmedOwner.sol



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

import "./12.ConfirmedOwnerWithProposal.sol";

/**
 * @title The ConfirmedOwner contract
 * @notice A contract with helpers for basic contract ownership.
 */
contract ConfirmedOwner is ConfirmedOwnerWithProposal {
  constructor(address newOwner) ConfirmedOwnerWithProposal(newOwner, address(0)) {}
}

// File: 8.IERC721Receiver.sol



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

pragma solidity ^0.8.19;

/**
 * @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: 9.AccessControl.sol



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

pragma solidity ^0.8.0;

import "./16.IAccessControl.sol";
import "./14.Context.sol";
import "./17.Strings.sol";
import "./20.ERC165.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```solidity
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```solidity
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it. We recommend using {AccessControlDefaultAdminRules}
 * to enforce additional security measures for this role.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role);
        _;
    }

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

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `_msgSender()` is missing `role`.
     * Overriding this function changes the behavior of the {onlyRole} modifier.
     *
     * Format of the revert message is described in {_checkRole}.
     *
     * _Available since v4.6._
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        Strings.toHexString(account),
                        " is missing role ",
                        Strings.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleGranted} event.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleRevoked} event.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     *
     * May emit a {RoleRevoked} event.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * May emit a {RoleGranted} event.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleGranted} event.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleRevoked} event.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}