// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.2.2
// Creator: Chiru Labs

pragma solidity ^0.8.4;

/**
 * @dev Interface of ERC721A.
 */
interface IERC721A {
    /**
     * The caller must own the token or be an approved operator.
     */
    error ApprovalCallerNotOwnerNorApproved();

    /**
     * The token does not exist.
     */
    error ApprovalQueryForNonexistentToken();

    /**
     * Cannot query the balance for the zero address.
     */
    error BalanceQueryForZeroAddress();

    /**
     * Cannot mint to the zero address.
     */
    error MintToZeroAddress();

    /**
     * The quantity of tokens minted must be more than zero.
     */
    error MintZeroQuantity();

    /**
     * The token does not exist.
     */
    error OwnerQueryForNonexistentToken();

    /**
     * The caller must own the token or be an approved operator.
     */
    error TransferCallerNotOwnerNorApproved();

    /**
     * The token must be owned by `from`.
     */
    error TransferFromIncorrectOwner();

    /**
     * Cannot safely transfer to a contract that does not implement the
     * ERC721Receiver interface.
     */
    error TransferToNonERC721ReceiverImplementer();

    /**
     * Cannot transfer to the zero address.
     */
    error TransferToZeroAddress();

    /**
     * The token does not exist.
     */
    error URIQueryForNonexistentToken();

    /**
     * The `quantity` minted with ERC2309 exceeds the safety limit.
     */
    error MintERC2309QuantityExceedsLimit();

    /**
     * The `extraData` cannot be set on an unintialized ownership slot.
     */
    error OwnershipNotInitializedForExtraData();

    // =============================================================
    //                            STRUCTS
    // =============================================================

    struct TokenOwnership {
        // The address of the owner.
        address addr;
        // Stores the start time of ownership with minimal overhead for tokenomics.
        uint64 startTimestamp;
        // Whether the token has been burned.
        bool burned;
        // Arbitrary data similar to `startTimestamp` that can be set via {_extraData}.
        uint24 extraData;
    }

    // =============================================================
    //                         TOKEN COUNTERS
    // =============================================================

    /**
     * @dev Returns the total number of tokens in existence.
     * Burned tokens will reduce the count.
     * To get the total number of tokens minted, please see {_totalMinted}.
     */
    function totalSupply() external view returns (uint256);

    // =============================================================
    //                            IERC165
    // =============================================================

    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);

    // =============================================================
    //                            IERC721
    // =============================================================

    /**
     * @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`,
     * 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 be 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,
        bytes calldata data
    ) external;

    /**
     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom}
     * whenever possible.
     *
     * 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);

    // =============================================================
    //                        IERC721Metadata
    // =============================================================

    /**
     * @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);

    // =============================================================
    //                           IERC2309
    // =============================================================

    /**
     * @dev Emitted when tokens in `fromTokenId` to `toTokenId`
     * (inclusive) is transferred from `from` to `to`, as defined in the
     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309) standard.
     *
     * See {_mintERC2309} for more details.
     */
    event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);
}

/**
 * @dev Interface of ERC721 token receiver.
 */
interface ERC721A__IERC721Receiver {
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

/**
 * @title ERC721A
 *
 * @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)
 * Non-Fungible Token Standard, including the Metadata extension.
 * Optimized for lower gas during batch mints.
 *
 * Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)
 * starting from `_startTokenId()`.
 *
 * Assumptions:
 *
 * - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
 * - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).
 */
contract ERC721A is IERC721A {
    // Reference type for token approval.
    struct TokenApprovalRef {
        address value;
    }

    // =============================================================
    //                           CONSTANTS
    // =============================================================

    // Mask of an entry in packed address data.
    uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;

    // The bit position of `numberMinted` in packed address data.
    uint256 private constant _BITPOS_NUMBER_MINTED = 64;

    // The bit position of `numberBurned` in packed address data.
    uint256 private constant _BITPOS_NUMBER_BURNED = 128;

    // The bit position of `aux` in packed address data.
    uint256 private constant _BITPOS_AUX = 192;

    // Mask of all 256 bits in packed address data except the 64 bits for `aux`.
    uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;

    // The bit position of `startTimestamp` in packed ownership.
    uint256 private constant _BITPOS_START_TIMESTAMP = 160;

    // The bit mask of the `burned` bit in packed ownership.
    uint256 private constant _BITMASK_BURNED = 1 << 224;

    // The bit position of the `nextInitialized` bit in packed ownership.
    uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;

    // The bit mask of the `nextInitialized` bit in packed ownership.
    uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;

    // The bit position of `extraData` in packed ownership.
    uint256 private constant _BITPOS_EXTRA_DATA = 232;

    // Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
    uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;

    // The mask of the lower 160 bits for addresses.
    uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;

    // The maximum `quantity` that can be minted with {_mintERC2309}.
    // This limit is to prevent overflows on the address data entries.
    // For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
    // is required to cause an overflow, which is unrealistic.
    uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;

    // The `Transfer` event signature is given by:
    // `keccak256(bytes("Transfer(address,address,uint256)"))`.
    bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
    0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;

    // =============================================================
    //                            STORAGE
    // =============================================================

    // The next token ID to be minted.
    uint256 private _currentIndex;

    // The number of tokens burned.
    uint256 private _burnCounter;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to ownership details
    // An empty struct value does not necessarily mean the token is unowned.
    // See {_packedOwnershipOf} implementation for details.
    //
    // Bits Layout:
    // - [0..159]   `addr`
    // - [160..223] `startTimestamp`
    // - [224]      `burned`
    // - [225]      `nextInitialized`
    // - [232..255] `extraData`
    mapping(uint256 => uint256) private _packedOwnerships;

    // Mapping owner address to address data.
    //
    // Bits Layout:
    // - [0..63]    `balance`
    // - [64..127]  `numberMinted`
    // - [128..191] `numberBurned`
    // - [192..255] `aux`
    mapping(address => uint256) private _packedAddressData;

    // Mapping from token ID to approved address.
    mapping(uint256 => TokenApprovalRef) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    // =============================================================
    //                          CONSTRUCTOR
    // =============================================================

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _currentIndex = _startTokenId();
    }

    // =============================================================
    //                   TOKEN COUNTING OPERATIONS
    // =============================================================

    /**
     * @dev Returns the starting token ID.
     * To change the starting token ID, please override this function.
     */
    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }

    /**
     * @dev Returns the next token ID to be minted.
     */
    function _nextTokenId() internal view virtual returns (uint256) {
        return _currentIndex;
    }

    /**
     * @dev Returns the total number of tokens in existence.
     * Burned tokens will reduce the count.
     * To get the total number of tokens minted, please see {_totalMinted}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        // Counter underflow is impossible as _burnCounter cannot be incremented
        // more than `_currentIndex - _startTokenId()` times.
    unchecked {
        return _currentIndex - _burnCounter - _startTokenId();
    }
    }

    /**
     * @dev Returns the total amount of tokens minted in the contract.
     */
    function _totalMinted() internal view virtual returns (uint256) {
        // Counter underflow is impossible as `_currentIndex` does not decrement,
        // and it is initialized to `_startTokenId()`.
    unchecked {
        return _currentIndex - _startTokenId();
    }
    }

    /**
     * @dev Returns the total number of tokens burned.
     */
    function _totalBurned() internal view virtual returns (uint256) {
        return _burnCounter;
    }

    // =============================================================
    //                    ADDRESS DATA OPERATIONS
    // =============================================================

    /**
     * @dev Returns the number of tokens in `owner`'s account.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        if (owner == address(0)) revert BalanceQueryForZeroAddress();
        return _packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**
     * Returns the number of tokens minted by `owner`.
     */
    function _numberMinted(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) & _BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**
     * Returns the number of tokens burned by or on behalf of `owner`.
     */
    function _numberBurned(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> _BITPOS_NUMBER_BURNED) & _BITMASK_ADDRESS_DATA_ENTRY;
    }

    /**
     * Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
     */
    function _getAux(address owner) internal view returns (uint64) {
        return uint64(_packedAddressData[owner] >> _BITPOS_AUX);
    }

    /**
     * Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).
     * If there are multiple variables, please pack them into a uint64.
     */
    function _setAux(address owner, uint64 aux) internal virtual {
        uint256 packed = _packedAddressData[owner];
        uint256 auxCasted;
        // Cast `aux` with assembly to avoid redundant masking.
        assembly {
            auxCasted := aux
        }
        packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
        _packedAddressData[owner] = packed;
    }

    // =============================================================
    //                            IERC165
    // =============================================================

    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30000 gas.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        // The interface IDs are constants representing the first 4 bytes
        // of the XOR of all function selectors in the interface.
        // See: [ERC165](https://eips.ethereum.org/EIPS/eip-165)
        // (e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`)
        return
        interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
        interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
        interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
    }

    // =============================================================
    //                        IERC721Metadata
    // =============================================================

    /**
     * @dev Returns the token collection name.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @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, it can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }

    // =============================================================
    //                     OWNERSHIPS OPERATIONS
    // =============================================================

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        return address(uint160(_packedOwnershipOf(tokenId)));
    }

    /**
     * @dev Gas spent here starts off proportional to the maximum mint batch size.
     * It gradually moves to O(1) as tokens get transferred around over time.
     */
    function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnershipOf(tokenId));
    }

    /**
     * @dev Returns the unpacked `TokenOwnership` struct at `index`.
     */
    function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnerships[index]);
    }

    /**
     * @dev Initializes the ownership slot minted at `index` for efficiency purposes.
     */
    function _initializeOwnershipAt(uint256 index) internal virtual {
        if (_packedOwnerships[index] == 0) {
            _packedOwnerships[index] = _packedOwnershipOf(index);
        }
    }

    /**
     * Returns the packed ownership data of `tokenId`.
     */
    function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
        uint256 curr = tokenId;

    unchecked {
        if (_startTokenId() <= curr)
            if (curr < _currentIndex) {
                uint256 packed = _packedOwnerships[curr];
                // If not burned.
                if (packed & _BITMASK_BURNED == 0) {
                    // Invariant:
                    // There will always be an initialized ownership slot
                    // (i.e. `ownership.addr != address(0) && ownership.burned == false`)
                    // before an unintialized ownership slot
                    // (i.e. `ownership.addr == address(0) && ownership.burned == false`)
                    // Hence, `curr` will not underflow.
                    //
                    // We can directly compare the packed value.
                    // If the address is zero, packed will be zero.
                    while (packed == 0) {
                        packed = _packedOwnerships[--curr];
                    }
                    return packed;
                }
            }
    }
        revert OwnerQueryForNonexistentToken();
    }

    /**
     * @dev Returns the unpacked `TokenOwnership` struct from `packed`.
     */
    function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
        ownership.addr = address(uint160(packed));
        ownership.startTimestamp = uint64(packed >> _BITPOS_START_TIMESTAMP);
        ownership.burned = packed & _BITMASK_BURNED != 0;
        ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
    }

    /**
     * @dev Packs ownership data into a single uint256.
     */
    function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
        assembly {
        // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
            owner := and(owner, _BITMASK_ADDRESS)
        // `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
            result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
        }
    }

    /**
     * @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
     */
    function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
        // For branchless setting of the `nextInitialized` flag.
        assembly {
        // `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
            result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
        }
    }

    // =============================================================
    //                      APPROVAL OPERATIONS
    // =============================================================

    /**
     * @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) public virtual override {
        address owner = ownerOf(tokenId);

        if (_msgSenderERC721A() != owner)
            if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                revert ApprovalCallerNotOwnerNorApproved();
            }

        _tokenApprovals[tokenId].value = to;
        emit Approval(owner, to, tokenId);
    }

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

        return _tokenApprovals[tokenId].value;
    }

    /**
     * @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) public virtual override {
        _operatorApprovals[_msgSenderERC721A()][operator] = approved;
        emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
    }

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @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. See {_mint}.
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return
        _startTokenId() <= tokenId &&
        tokenId < _currentIndex && // If within bounds,
        _packedOwnerships[tokenId] & _BITMASK_BURNED == 0; // and not burned.
    }

    /**
     * @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.
     */
    function _isSenderApprovedOrOwner(
        address approvedAddress,
        address owner,
        address msgSender
    ) private pure returns (bool result) {
        assembly {
        // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
            owner := and(owner, _BITMASK_ADDRESS)
        // Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
            msgSender := and(msgSender, _BITMASK_ADDRESS)
        // `msgSender == owner || msgSender == approvedAddress`.
            result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
        }
    }

    /**
     * @dev Returns the storage slot and value for the approved address of `tokenId`.
     */
    function _getApprovedSlotAndAddress(uint256 tokenId)
    private
    view
    returns (uint256 approvedAddressSlot, address approvedAddress)
    {
        TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
        // The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.
        assembly {
            approvedAddressSlot := tokenApproval.slot
            approvedAddress := sload(approvedAddressSlot)
        }
    }

    // =============================================================
    //                      TRANSFER OPERATIONS
    // =============================================================

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *
     * 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
    ) public virtual override {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

        // The nested ifs save around 20+ gas over a compound boolean condition.
        if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
            if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();

        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);

        // Clear approvals from the previous owner.
        assembly {
            if approvedAddress {
            // This is equivalent to `delete _tokenApprovals[tokenId]`.
                sstore(approvedAddressSlot, 0)
            }
        }

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
    unchecked {
        // We can directly increment and decrement the balances.
        --_packedAddressData[from]; // Updates: `balance -= 1`.
        ++_packedAddressData[to]; // Updates: `balance += 1`.

        // Updates:
        // - `address` to the next owner.
        // - `startTimestamp` to the timestamp of transfering.
        // - `burned` to `false`.
        // - `nextInitialized` to `true`.
        _packedOwnerships[tokenId] = _packOwnershipData(
            to,
            _BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
        );

        // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
        if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
            uint256 nextTokenId = tokenId + 1;
            // If the next slot's address is zero and not burned (i.e. packed value is zero).
            if (_packedOwnerships[nextTokenId] == 0) {
                // If the next slot is within bounds.
                if (nextTokenId != _currentIndex) {
                    // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                    _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                }
            }
        }
    }

        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
    }

    /**
     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, '');
    }

    /**
     * @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 memory _data
    ) public virtual override {
        transferFrom(from, to, tokenId);
        if (to.code.length != 0)
            if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                revert TransferToNonERC721ReceiverImplementer();
            }
    }

    /**
     * @dev Hook that is called before a set of serially-ordered token IDs
     * are about to be transferred. This includes minting.
     * And also called before burning one token.
     *
     * `startTokenId` - the first token ID to be transferred.
     * `quantity` - the amount to be transferred.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, `tokenId` will be burned by `from`.
     * - `from` and `to` are never both zero.
     */
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**
     * @dev Hook that is called after a set of serially-ordered token IDs
     * have been transferred. This includes minting.
     * And also called after one token has been burned.
     *
     * `startTokenId` - the first token ID to be transferred.
     * `quantity` - the amount to be transferred.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
     * transferred to `to`.
     * - When `from` is zero, `tokenId` has been minted for `to`.
     * - When `to` is zero, `tokenId` has been burned by `from`.
     * - `from` and `to` are never both zero.
     */
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**
     * @dev Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.
     *
     * `from` - Previous owner of the given token ID.
     * `to` - Target address that will receive the token.
     * `tokenId` - Token ID to be transferred.
     * `_data` - Optional data to send along with the call.
     *
     * Returns whether the call correctly returned the expected magic value.
     */
    function _checkContractOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (
            bytes4 retval
        ) {
            return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
        } catch (bytes memory reason) {
            if (reason.length == 0) {
                revert TransferToNonERC721ReceiverImplementer();
            } else {
                assembly {
                    revert(add(32, reason), mload(reason))
                }
            }
        }
    }

    // =============================================================
    //                        MINT OPERATIONS
    // =============================================================

    /**
     * @dev Mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `quantity` must be greater than 0.
     *
     * Emits a {Transfer} event for each mint.
     */
    function _mint(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = _currentIndex;
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are incredibly unrealistic.
        // `balance` and `numberMinted` have a maximum limit of 2**64.
        // `tokenId` has a maximum limit of 2**256.
    unchecked {
        // Updates:
        // - `balance += quantity`.
        // - `numberMinted += quantity`.
        //
        // We can directly add to the `balance` and `numberMinted`.
        _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);

        // Updates:
        // - `address` to the owner.
        // - `startTimestamp` to the timestamp of minting.
        // - `burned` to `false`.
        // - `nextInitialized` to `quantity == 1`.
        _packedOwnerships[startTokenId] = _packOwnershipData(
            to,
            _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
        );

        uint256 toMasked;
        uint256 end = startTokenId + quantity;

        // Use assembly to loop and emit the `Transfer` event for gas savings.
        // The duplicated `log4` removes an extra check and reduces stack juggling.
        // The assembly, together with the surrounding Solidity code, have been
        // delicately arranged to nudge the compiler into producing optimized opcodes.
        assembly {
        // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
            toMasked := and(to, _BITMASK_ADDRESS)
        // Emit the `Transfer` event.
            log4(
            0, // Start of data (0, since no data).
            0, // End of data (0, since no data).
            _TRANSFER_EVENT_SIGNATURE, // Signature.
            0, // `address(0)`.
            toMasked, // `to`.
            startTokenId // `tokenId`.
            )

            for {
                let tokenId := add(startTokenId, 1)
            } iszero(eq(tokenId, end)) {
                tokenId := add(tokenId, 1)
            } {
            // Emit the `Transfer` event. Similar to above.
                log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)
            }
        }
        if (toMasked == 0) revert MintToZeroAddress();

        _currentIndex = end;
    }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**
     * @dev Mints `quantity` tokens and transfers them to `to`.
     *
     * This function is intended for efficient minting only during contract creation.
     *
     * It emits only one {ConsecutiveTransfer} as defined in
     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),
     * instead of a sequence of {Transfer} event(s).
     *
     * Calling this function outside of contract creation WILL make your contract
     * non-compliant with the ERC721 standard.
     * For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309
     * {ConsecutiveTransfer} event is only permissible during contract creation.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `quantity` must be greater than 0.
     *
     * Emits a {ConsecutiveTransfer} event.
     */
    function _mintERC2309(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();
        if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) revert MintERC2309QuantityExceedsLimit();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are unrealistic due to the above check for `quantity` to be below the limit.
    unchecked {
        // Updates:
        // - `balance += quantity`.
        // - `numberMinted += quantity`.
        //
        // We can directly add to the `balance` and `numberMinted`.
        _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);

        // Updates:
        // - `address` to the owner.
        // - `startTimestamp` to the timestamp of minting.
        // - `burned` to `false`.
        // - `nextInitialized` to `quantity == 1`.
        _packedOwnerships[startTokenId] = _packOwnershipData(
            to,
            _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
        );

        emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);

        _currentIndex = startTokenId + quantity;
    }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**
     * @dev Safely mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement
     * {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
     * - `quantity` must be greater than 0.
     *
     * See {_mint}.
     *
     * Emits a {Transfer} event for each mint.
     */
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal virtual {
        _mint(to, quantity);

    unchecked {
        if (to.code.length != 0) {
            uint256 end = _currentIndex;
            uint256 index = end - quantity;
            do {
                if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {
                    revert TransferToNonERC721ReceiverImplementer();
                }
            } while (index < end);
            // Reentrancy protection.
            if (_currentIndex != end) revert();
        }
    }
    }

    /**
     * @dev Equivalent to `_safeMint(to, quantity, '')`.
     */
    function _safeMint(address to, uint256 quantity) internal virtual {
        _safeMint(to, quantity, '');
    }

    // =============================================================
    //                        BURN OPERATIONS
    // =============================================================

    /**
     * @dev Equivalent to `_burn(tokenId, false)`.
     */
    function _burn(uint256 tokenId) internal virtual {
        _burn(tokenId, false);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        address from = address(uint160(prevOwnershipPacked));

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

        if (approvalCheck) {
            // The nested ifs save around 20+ gas over a compound boolean condition.
            if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
                if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
        }

        _beforeTokenTransfers(from, address(0), tokenId, 1);

        // Clear approvals from the previous owner.
        assembly {
            if approvedAddress {
            // This is equivalent to `delete _tokenApprovals[tokenId]`.
                sstore(approvedAddressSlot, 0)
            }
        }

        // Underflow of the sender's balance is impossible because we check for
        // ownership above and the recipient's balance can't realistically overflow.
        // Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.
    unchecked {
        // Updates:
        // - `balance -= 1`.
        // - `numberBurned += 1`.
        //
        // We can directly decrement the balance, and increment the number burned.
        // This is equivalent to `packed -= 1; packed += 1 << _BITPOS_NUMBER_BURNED;`.
        _packedAddressData[from] += (1 << _BITPOS_NUMBER_BURNED) - 1;

        // Updates:
        // - `address` to the last owner.
        // - `startTimestamp` to the timestamp of burning.
        // - `burned` to `true`.
        // - `nextInitialized` to `true`.
        _packedOwnerships[tokenId] = _packOwnershipData(
            from,
            (_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) | _nextExtraData(from, address(0), prevOwnershipPacked)
        );

        // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
        if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
            uint256 nextTokenId = tokenId + 1;
            // If the next slot's address is zero and not burned (i.e. packed value is zero).
            if (_packedOwnerships[nextTokenId] == 0) {
                // If the next slot is within bounds.
                if (nextTokenId != _currentIndex) {
                    // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                    _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                }
            }
        }
    }

        emit Transfer(from, address(0), tokenId);
        _afterTokenTransfers(from, address(0), tokenId, 1);

        // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
    unchecked {
        _burnCounter++;
    }
    }

    // =============================================================
    //                     EXTRA DATA OPERATIONS
    // =============================================================

    /**
     * @dev Directly sets the extra data for the ownership data `index`.
     */
    function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
        uint256 packed = _packedOwnerships[index];
        if (packed == 0) revert OwnershipNotInitializedForExtraData();
        uint256 extraDataCasted;
        // Cast `extraData` with assembly to avoid redundant masking.
        assembly {
            extraDataCasted := extraData
        }
        packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);
        _packedOwnerships[index] = packed;
    }

    /**
     * @dev Called during each token transfer to set the 24bit `extraData` field.
     * Intended to be overridden by the cosumer contract.
     *
     * `previousExtraData` - the value of `extraData` before transfer.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, `tokenId` will be burned by `from`.
     * - `from` and `to` are never both zero.
     */
    function _extraData(
        address from,
        address to,
        uint24 previousExtraData
    ) internal view virtual returns (uint24) {}

    /**
     * @dev Returns the next extra data for the packed ownership data.
     * The returned result is shifted into position.
     */
    function _nextExtraData(
        address from,
        address to,
        uint256 prevOwnershipPacked
    ) private view returns (uint256) {
        uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);
        return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;
    }

    // =============================================================
    //                       OTHER OPERATIONS
    // =============================================================

    /**
     * @dev Returns the message sender (defaults to `msg.sender`).
     *
     * If you are writing GSN compatible contracts, you need to override this function.
     */
    function _msgSenderERC721A() internal view virtual returns (address) {
        return msg.sender;
    }

    /**
     * @dev Converts a uint256 to its ASCII string decimal representation.
     */
    function _toString(uint256 value) internal pure virtual returns (string memory str) {
        assembly {
        // The maximum value of a uint256 contains 78 digits (1 byte per digit),
        // but we allocate 0x80 bytes to keep the free memory pointer 32-byte word aligned.
        // We will need 1 32-byte word to store the length,
        // and 3 32-byte words to store a maximum of 78 digits. Total: 0x20 + 3 * 0x20 = 0x80.
            str := add(mload(0x40), 0x80)
        // Update the free memory pointer to allocate.
            mstore(0x40, str)

        // Cache the end of the memory to calculate the length later.
            let end := str

        // We write the string from rightmost digit to leftmost digit.
        // The following is essentially a do-while loop that also handles the zero case.
        // prettier-ignore
            for { let temp := value } 1 {} {
                str := sub(str, 1)
            // Write the character to the pointer.
            // The ASCII index of the '0' character is 48.
                mstore8(str, add(48, mod(temp, 10)))
            // Keep dividing `temp` until zero.
                temp := div(temp, 10)
            // prettier-ignore
                if iszero(temp) { break }
            }

            let length := sub(end, str)
        // Move the pointer 32 bytes leftwards to make room for the length.
            str := sub(str, 0x20)
        // Store the length.
            mstore(str, length)
        }
    }
}

/**
 * @dev Interface of ERC721AQueryable.
 */
interface IERC721AQueryable is IERC721A {
    /**
     * Invalid query range (`start` >= `stop`).
     */
    error InvalidQueryRange();

    /**
     * @dev Returns the `TokenOwnership` struct at `tokenId` without reverting.
     *
     * If the `tokenId` is out of bounds:
     *
     * - `addr = address(0)`
     * - `startTimestamp = 0`
     * - `burned = false`
     * - `extraData = 0`
     *
     * If the `tokenId` is burned:
     *
     * - `addr = <Address of owner before token was burned>`
     * - `startTimestamp = <Timestamp when token was burned>`
     * - `burned = true`
     * - `extraData = <Extra data when token was burned>`
     *
     * Otherwise:
     *
     * - `addr = <Address of owner>`
     * - `startTimestamp = <Timestamp of start of ownership>`
     * - `burned = false`
     * - `extraData = <Extra data at start of ownership>`
     */
    function explicitOwnershipOf(uint256 tokenId) external view returns (TokenOwnership memory);

    /**
     * @dev Returns an array of `TokenOwnership` structs at `tokenIds` in order.
     * See {ERC721AQueryable-explicitOwnershipOf}
     */
    function explicitOwnershipsOf(uint256[] memory tokenIds) external view returns (TokenOwnership[] memory);

    /**
     * @dev Returns an array of token IDs owned by `owner`,
     * in the range [`start`, `stop`)
     * (i.e. `start <= tokenId < stop`).
     *
     * This function allows for tokens to be queried if the collection
     * grows too big for a single call of {ERC721AQueryable-tokensOfOwner}.
     *
     * Requirements:
     *
     * - `start < stop`
     */
    function tokensOfOwnerIn(
        address owner,
        uint256 start,
        uint256 stop
    ) external view returns (uint256[] memory);

    /**
     * @dev Returns an array of token IDs owned by `owner`.
     *
     * This function scans the ownership mapping and is O(`totalSupply`) in complexity.
     * It is meant to be called off-chain.
     *
     * See {ERC721AQueryable-tokensOfOwnerIn} for splitting the scan into
     * multiple smaller scans if the collection is large enough to cause
     * an out-of-gas error (10K collections should be fine).
     */
    function tokensOfOwner(address owner) external view returns (uint256[] memory);
}

/**
 * @title ERC721AQueryable.
 *
 * @dev ERC721A subclass with convenience query functions.
 */
abstract contract ERC721AQueryable is ERC721A, IERC721AQueryable {
    /**
     * @dev Returns the `TokenOwnership` struct at `tokenId` without reverting.
     *
     * If the `tokenId` is out of bounds:
     *
     * - `addr = address(0)`
     * - `startTimestamp = 0`
     * - `burned = false`
     * - `extraData = 0`
     *
     * If the `tokenId` is burned:
     *
     * - `addr = <Address of owner before token was burned>`
     * - `startTimestamp = <Timestamp when token was burned>`
     * - `burned = true`
     * - `extraData = <Extra data when token was burned>`
     *
     * Otherwise:
     *
     * - `addr = <Address of owner>`
     * - `startTimestamp = <Timestamp of start of ownership>`
     * - `burned = false`
     * - `extraData = <Extra data at start of ownership>`
     */
    function explicitOwnershipOf(uint256 tokenId) public view virtual override returns (TokenOwnership memory) {
        TokenOwnership memory ownership;
        if (tokenId < _startTokenId() || tokenId >= _nextTokenId()) {
            return ownership;
        }
        ownership = _ownershipAt(tokenId);
        if (ownership.burned) {
            return ownership;
        }
        return _ownershipOf(tokenId);
    }

    /**
     * @dev Returns an array of `TokenOwnership` structs at `tokenIds` in order.
     * See {ERC721AQueryable-explicitOwnershipOf}
     */
    function explicitOwnershipsOf(uint256[] calldata tokenIds)
    external
    view
    virtual
    override
    returns (TokenOwnership[] memory)
    {
    unchecked {
        uint256 tokenIdsLength = tokenIds.length;
        TokenOwnership[] memory ownerships = new TokenOwnership[](tokenIdsLength);
        for (uint256 i; i != tokenIdsLength; ++i) {
            ownerships[i] = explicitOwnershipOf(tokenIds[i]);
        }
        return ownerships;
    }
    }

    /**
     * @dev Returns an array of token IDs owned by `owner`,
     * in the range [`start`, `stop`)
     * (i.e. `start <= tokenId < stop`).
     *
     * This function allows for tokens to be queried if the collection
     * grows too big for a single call of {ERC721AQueryable-tokensOfOwner}.
     *
     * Requirements:
     *
     * - `start < stop`
     */
    function tokensOfOwnerIn(
        address owner,
        uint256 start,
        uint256 stop
    ) external view virtual override returns (uint256[] memory) {
    unchecked {
        if (start >= stop) revert InvalidQueryRange();
        uint256 tokenIdsIdx;
        uint256 stopLimit = _nextTokenId();
        // Set `start = max(start, _startTokenId())`.
        if (start < _startTokenId()) {
            start = _startTokenId();
        }
        // Set `stop = min(stop, stopLimit)`.
        if (stop > stopLimit) {
            stop = stopLimit;
        }
        uint256 tokenIdsMaxLength = balanceOf(owner);
        // Set `tokenIdsMaxLength = min(balanceOf(owner), stop - start)`,
        // to cater for cases where `balanceOf(owner)` is too big.
        if (start < stop) {
            uint256 rangeLength = stop - start;
            if (rangeLength < tokenIdsMaxLength) {
                tokenIdsMaxLength = rangeLength;
            }
        } else {
            tokenIdsMaxLength = 0;
        }
        uint256[] memory tokenIds = new uint256[](tokenIdsMaxLength);
        if (tokenIdsMaxLength == 0) {
            return tokenIds;
        }
        // We need to call `explicitOwnershipOf(start)`,
        // because the slot at `start` may not be initialized.
        TokenOwnership memory ownership = explicitOwnershipOf(start);
        address currOwnershipAddr;
        // If the starting slot exists (i.e. not burned), initialize `currOwnershipAddr`.
        // `ownership.address` will not be zero, as `start` is clamped to the valid token ID range.
        if (!ownership.burned) {
            currOwnershipAddr = ownership.addr;
        }
        for (uint256 i = start; i != stop && tokenIdsIdx != tokenIdsMaxLength; ++i) {
            ownership = _ownershipAt(i);
            if (ownership.burned) {
                continue;
            }
            if (ownership.addr != address(0)) {
                currOwnershipAddr = ownership.addr;
            }
            if (currOwnershipAddr == owner) {
                tokenIds[tokenIdsIdx++] = i;
            }
        }
        // Downsize the array to fit.
        assembly {
            mstore(tokenIds, tokenIdsIdx)
        }
        return tokenIds;
    }
    }

    /**
     * @dev Returns an array of token IDs owned by `owner`.
     *
     * This function scans the ownership mapping and is O(`totalSupply`) in complexity.
     * It is meant to be called off-chain.
     *
     * See {ERC721AQueryable-tokensOfOwnerIn} for splitting the scan into
     * multiple smaller scans if the collection is large enough to cause
     * an out-of-gas error (10K collections should be fine).
     */
    function tokensOfOwner(address owner) external view virtual override returns (uint256[] memory) {
    unchecked {
        uint256 tokenIdsIdx;
        address currOwnershipAddr;
        uint256 tokenIdsLength = balanceOf(owner);
        uint256[] memory tokenIds = new uint256[](tokenIdsLength);
        TokenOwnership memory ownership;
        for (uint256 i = _startTokenId(); tokenIdsIdx != tokenIdsLength; ++i) {
            ownership = _ownershipAt(i);
            if (ownership.burned) {
                continue;
            }
            if (ownership.addr != address(0)) {
                currOwnershipAddr = ownership.addr;
            }
            if (currOwnershipAddr == owner) {
                tokenIds[tokenIdsIdx++] = i;
            }
        }
        return tokenIds;
    }
    }
}


/**
 * @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;
    }
}

/**
 * @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);
    }
}

contract AstroLama is ERC721AQueryable, Ownable {
    string public constant collectionName = "Astro Lama";
    string public constant collectionSymbol = "LAMA";
    uint256 public constant maxQuantityForMint = 5;
    uint256 public mintPrice = 0.036 ether;
    uint256 public mintWLPrice = 0.015 ether;
    uint256 public maxTotalSupply = 10_000;
    uint256 public mintStartAt = 0;
    uint256 public mintWlStartAt = 0;

    mapping(address => bool) public whitelist;
    mapping(uint256 => uint256) private randomId;

    string public baseTokenURI;
    string public hiddenBaseTokenURI;
    string public _contractURI;
    string public baseExtension = ".json";

    event Mint(address indexed to, uint256 quantity, uint256 _nextId, string _tokenUri);

    constructor() ERC721A(collectionName, collectionSymbol) {}

    modifier callerIsUser() {
        require(tx.origin == msg.sender, "The caller is another contract");
        _;
    }

    function gift(address to, uint256 quantity) external onlyOwner {
        if (to != owner()) {
            require(_numberMinted(to) + quantity <= maxQuantityForMint, "Gift quantity limit 5 per address");
        }
        require(totalSupply() + quantity <= maxTotalSupply, "Total supply would be exceeded");
        uint256 _nextId = randomizeTokens(quantity);
        _safeMint(to, quantity);

        emit Mint(to, quantity, _nextId, baseTokenURI);
    }

    function mint(uint256 quantity) external payable callerIsUser {
        uint256 currentPrice = quantity * mintPrice;

        require(block.timestamp >= mintStartAt, "Mint not started");
        require(quantity <= maxQuantityForMint, "Mint quantity limit 5");
        require(_numberMinted(_msgSenderERC721A()) + quantity <= maxQuantityForMint, "Mint quantity limit 5 per address");
        require(msg.value >= currentPrice, "Not enough payed");
        require(totalSupply() + quantity <= maxTotalSupply, "Total supply would be exceeded");

        uint256 _nextId = randomizeTokens(quantity);
        _safeMint(_msgSenderERC721A(), quantity);

        refundIfOver(currentPrice);

        emit Mint(_msgSenderERC721A(), quantity, _nextId, baseTokenURI);
    }

    function mintPrivate(uint256 quantity) external payable callerIsUser {
        uint256 currentPrice = quantity * mintWLPrice;

        require(block.timestamp >= mintWlStartAt, "Mint not started");
        require(whitelist[_msgSenderERC721A()], "Not in white list");
        require(_numberMinted(_msgSenderERC721A()) + quantity <= maxQuantityForMint, "Mint quantity limit 5 per address");
        require(quantity <= maxQuantityForMint, "Mint quantity limit 5");
        require(msg.value >= currentPrice, "Not enough payed");
        require(totalSupply() + quantity <= maxTotalSupply, "Total supply would be exceeded");

        uint256 _nextId = randomizeTokens(quantity);
        _safeMint(_msgSenderERC721A(), quantity);

        refundIfOver(currentPrice);

        emit Mint(_msgSenderERC721A(), quantity, _nextId, baseTokenURI);
    }

    function refundIfOver(uint256 price) private {
        require(msg.value >= price, "Need to send more ETH.");
        if (msg.value > price) {
            payable(msg.sender).transfer(msg.value - price);
        }
    }

    function setBaseURI(string calldata baseURI) public onlyOwner {
        baseTokenURI = baseURI;
    }

    function setHiddenBaseURI(string calldata hiddenBaseURI) public onlyOwner {
        hiddenBaseTokenURI = hiddenBaseURI;
    }

    function setContractURI(string calldata contractURI_) public onlyOwner {
        _contractURI = contractURI_;
    }

    function setBaseExtension(string calldata extension) public onlyOwner {
        baseExtension = extension;
    }

    function changeMintPrice(uint256 newPrice) public onlyOwner {
        mintPrice = newPrice;
    }

    function changeMintStartDate(uint256 timestamp) public onlyOwner {
        mintStartAt = timestamp;
    }

    function changeMintWLStartDate(uint256 timestamp) public onlyOwner {
        mintWlStartAt = timestamp;
    }

    function changeTotalSupply(uint256 newSupply) public onlyOwner {
        maxTotalSupply = newSupply;
    }

    function getMintPrice() public view returns (uint256) {
        return mintPrice;
    }

    function numberMinted(address owner) public view returns (uint256) {
        return _numberMinted(owner);
    }

    function _baseURI() internal override view virtual returns (string memory) {
        return baseTokenURI;
    }

    function _hiddenBaseURI() internal view virtual returns (string memory) {
        return hiddenBaseTokenURI;
    }

    function _startTokenId() internal override view virtual returns (uint256) {
        return 1;
    }

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) public view virtual returns (string memory) {
        if (!_exists(tokenId)) revert URIQueryForNonexistentToken();

        string memory baseURI = _baseURI();
        string memory hiddenBaseURI = _hiddenBaseURI();
        string memory fileName = toHex(
            keccak256(
                abi.encodePacked(_toString(tokenId), '-', _toString(randomId[tokenId]))
            )
        );
        return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, fileName, baseExtension)) : hiddenBaseURI;
    }

    function withdraw() public onlyOwner {
        (bool success, ) = msg.sender.call{value: address(this).balance}("");
        require(success, "Transfer failed");
    }

    function addAddressToWhitelist(address user) onlyOwner public returns(bool success) {
        if (!whitelist[user]) {
            whitelist[user] = true;
            success = true;
        }
    }

    function addAddressesToWhitelist(address[] calldata users) onlyOwner external returns(bool success) {
    unchecked {
        for (uint256 i = 0; i < users.length; i++) {
            if (addAddressToWhitelist(users[i])) {
                success = true;
            }
        }
    }
    }

    function removeAddressFromWhitelist(address user) onlyOwner public returns(bool success) {
        if (whitelist[user]) {
            whitelist[user] = false;
            success = true;
        }
    }

    function removeAddressesFromWhitelist(address[] calldata users) onlyOwner external returns(bool success) {
    unchecked {
        for (uint256 i = 0; i < users.length; i++) {
            if (removeAddressFromWhitelist(users[i])) {
                success = true;
            }
        }
    }
    }

    function random(uint256 id) internal view virtual returns (uint256) {
        return uint256(keccak256(abi.encodePacked(block.timestamp, block.difficulty, msg.sender, _toString(id))));
    }

    function randomizeTokens(uint256 quantity) internal returns (uint256) {
        uint256 _next = _nextTokenId();
    unchecked {
        for (uint256 i = _next; i < _next + quantity; i++) {
            randomId[i] = random(i) % 3;
        }
    }
        return _next;
    }

    function toHex(bytes32 data) internal pure returns (string memory) {
        return string(abi.encodePacked(toHex16(bytes16(data)), toHex16(bytes16(data << 128))));
    }

    function toHex16(bytes16 data) internal pure returns (bytes32 result) {
        result =
        (bytes32(data) & 0xFFFFFFFFFFFFFFFF000000000000000000000000000000000000000000000000) |
        ((bytes32(data) & 0x0000000000000000FFFFFFFFFFFFFFFF00000000000000000000000000000000) >> 64);
        result =
        (result & 0xFFFFFFFF000000000000000000000000FFFFFFFF000000000000000000000000) |
        ((result & 0x00000000FFFFFFFF000000000000000000000000FFFFFFFF0000000000000000) >> 32);
        result =
        (result & 0xFFFF000000000000FFFF000000000000FFFF000000000000FFFF000000000000) |
        ((result & 0x0000FFFF000000000000FFFF000000000000FFFF000000000000FFFF00000000) >> 16);
        result =
        (result & 0xFF000000FF000000FF000000FF000000FF000000FF000000FF000000FF000000) |
        ((result & 0x00FF000000FF000000FF000000FF000000FF000000FF000000FF000000FF0000) >> 8);
        result =
        ((result & 0xF000F000F000F000F000F000F000F000F000F000F000F000F000F000F000F000) >> 4) |
        ((result & 0x0F000F000F000F000F000F000F000F000F000F000F000F000F000F000F000F00) >> 8);
        result = bytes32(
            0x3030303030303030303030303030303030303030303030303030303030303030 +
            uint256(result) +
            (((uint256(result) + 0x0606060606060606060606060606060606060606060606060606060606060606) >> 4) &
            0x0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F) *
            7
        );
    }
}