// File: Gateways.sol



// SPDX-License-Identifier: MIT

// 999 Gateways // 0.003 // Max 3 // Welcome Travelers //

// 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);
}

// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

/**
 * @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;
  }
}

// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
  bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

  /**
   * @dev Converts a `uint256` to its ASCII `string` decimal representation.
   */
  function toString(uint256 value) internal pure returns (string memory) {
    // Inspired by OraclizeAPI's implementation - MIT licence
    // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

    if (value == 0) {
      return "0";
    }
    uint256 temp = value;
    uint256 digits;
    while (temp != 0) {
      digits++;
      temp /= 10;
    }
    bytes memory buffer = new bytes(digits);
    while (value != 0) {
      digits -= 1;
      buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
      value /= 10;
    }
    return string(buffer);
  }

  /**
   * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
   */
  function toHexString(uint256 value) internal pure returns (string memory) {
    if (value == 0) {
      return "0x00";
    }
    uint256 temp = value;
    uint256 length = 0;
    while (temp != 0) {
      length++;
      temp >>= 8;
    }
    return toHexString(value, length);
  }

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

// 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;
  }
}

// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)

pragma solidity ^0.8.1;

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

    return account.code.length > 0;
  }

  /**
   * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
   * `recipient`, forwarding all available gas and reverting on errors.
   *
   * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
   * of certain opcodes, possibly making contracts go over the 2300 gas limit
   * imposed by `transfer`, making them unable to receive funds via
   * `transfer`. {sendValue} removes this limitation.
   *
   * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
   *
   * IMPORTANT: because control is transferred to `recipient`, care must be
   * taken to not create reentrancy vulnerabilities. Consider using
   * {ReentrancyGuard} or the
   * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
   */
  function sendValue(address payable recipient, uint256 amount) internal {
    require(address(this).balance >= amount, "Address: insufficient balance");

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

  /**
   * @dev Performs a Solidity function call using a low level `call`. A
   * plain `call` is an unsafe replacement for a function call: use this
   * function instead.
   *
   * If `target` reverts with a revert reason, it is bubbled up by this
   * function (like regular Solidity function calls).
   *
   * Returns the raw returned data. To convert to the expected return value,
   * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
   *
   * Requirements:
   *
   * - `target` must be a contract.
   * - calling `target` with `data` must not revert.
   *
   * _Available since v3.1._
   */
  function functionCall(address target, bytes memory data)
    internal
    returns (bytes memory)
  {
    return functionCall(target, data, "Address: low-level call failed");
  }

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

  /**
   * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
   * but also transferring `value` wei to `target`.
   *
   * Requirements:
   *
   * - the calling contract must have an ETH balance of at least `value`.
   * - the called Solidity function must be `payable`.
   *
   * _Available since v3.1._
   */
  function functionCallWithValue(
    address target,
    bytes memory data,
    uint256 value
  ) internal returns (bytes memory) {
    return
      functionCallWithValue(
        target,
        data,
        value,
        "Address: low-level call with value failed"
      );
  }

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

    (bool success, bytes memory returndata) = target.call{value: value}(data);
    return verifyCallResult(success, returndata, errorMessage);
  }

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

  /**
   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
   * but performing a static call.
   *
   * _Available since v3.3._
   */
  function functionStaticCall(
    address target,
    bytes memory data,
    string memory errorMessage
  ) internal view returns (bytes memory) {
    require(isContract(target), "Address: static call to non-contract");

    (bool success, bytes memory returndata) = target.staticcall(data);
    return verifyCallResult(success, returndata, errorMessage);
  }

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

  /**
   * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
   * but performing a delegate call.
   *
   * _Available since v3.4._
   */
  function functionDelegateCall(
    address target,
    bytes memory data,
    string memory errorMessage
  ) internal returns (bytes memory) {
    require(isContract(target), "Address: delegate call to non-contract");

    (bool success, bytes memory returndata) = target.delegatecall(data);
    return verifyCallResult(success, returndata, errorMessage);
  }

  /**
   * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
   * revert reason using the provided one.
   *
   * _Available since v4.3._
   */
  function verifyCallResult(
    bool success,
    bytes memory returndata,
    string memory errorMessage
  ) internal pure returns (bytes memory) {
    if (success) {
      return returndata;
    } else {
      // Look for revert reason and bubble it up if present
      if (returndata.length > 0) {
        // The easiest way to bubble the revert reason is using memory via assembly

        assembly {
          let returndata_size := mload(returndata)
          revert(add(32, returndata), returndata_size)
        }
      } else {
        revert(errorMessage);
      }
    }
  }
}

// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

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

// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

/**
 * @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`, 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
  ) external;

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

  /**
   * @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 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);

  /**
   * @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;
}
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

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

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

// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

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

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

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

// Creator: Chiru Labs

pragma solidity ^0.8.4;

error ApprovalCallerNotOwnerNorApproved();
error ApprovalQueryForNonexistentToken();
error ApproveToCaller();
error ApprovalToCurrentOwner();
error BalanceQueryForZeroAddress();
error MintToZeroAddress();
error MintZeroQuantity();
error OwnerQueryForNonexistentToken();
error TransferCallerNotOwnerNorApproved();
error TransferFromIncorrectOwner();
error TransferToNonERC721ReceiverImplementer();
error TransferToZeroAddress();
error URIQueryForNonexistentToken();

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension. Built to optimize for lower gas during batch mints.
 *
 * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
 *
 * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
 *
 * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
 */
contract ERC721A is Context, ERC165, IERC721, IERC721Metadata {
  using Address for address;
  using Strings for uint256;

  // Compiler will pack this into a single 256bit word.
  struct TokenOwnership {
    // The address of the owner.
    address addr;
    // Keeps track of the start time of ownership with minimal overhead for tokenomics.
    uint64 startTimestamp;
    // Whether the token has been burned.
    bool burned;
  }

  // Compiler will pack this into a single 256bit word.
  struct AddressData {
    // Realistically, 2**64-1 is more than enough.
    uint64 balance;
    // Keeps track of mint count with minimal overhead for tokenomics.
    uint64 numberMinted;
    // Keeps track of burn count with minimal overhead for tokenomics.
    uint64 numberBurned;
    // For miscellaneous variable(s) pertaining to the address
    // (e.g. number of whitelist mint slots used).
    // If there are multiple variables, please pack them into a uint64.
    uint64 aux;
  }

  // The tokenId of the next token to be minted.
  uint256 internal _currentIndex;

  // The number of tokens burned.
  uint256 internal _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 _ownershipOf implementation for details.
  mapping(uint256 => TokenOwnership) internal _ownerships;

  // Mapping owner address to address data
  mapping(address => AddressData) private _addressData;

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

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

  constructor(string memory name_, string memory symbol_) {
    _name = name_;
    _symbol = symbol_;
    _currentIndex = _startTokenId();
  }

  /**
   * To change the starting tokenId, please override this function.
   */
  function _startTokenId() internal view virtual returns (uint256) {
    return 0;
  }

  /**
   * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
   */
  function totalSupply() public view returns (uint256) {
    // Counter underflow is impossible as _burnCounter cannot be incremented
    // more than _currentIndex - _startTokenId() times
    unchecked {
      return _currentIndex - _burnCounter - _startTokenId();
    }
  }

  /**
   * Returns the total amount of tokens minted in the contract.
   */
  function _totalMinted() internal view returns (uint256) {
    // Counter underflow is impossible as _currentIndex does not decrement,
    // and it is initialized to _startTokenId()
    unchecked {
      return _currentIndex - _startTokenId();
    }
  }

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

  /**
   * @dev See {IERC721-balanceOf}.
   */
  function balanceOf(address owner) public view override returns (uint256) {
    if (owner == address(0)) revert BalanceQueryForZeroAddress();
    return uint256(_addressData[owner].balance);
  }

  /**
   * Returns the number of tokens minted by `owner`.
   */
  function _numberMinted(address owner) internal view returns (uint256) {
    return uint256(_addressData[owner].numberMinted);
  }

  /**
   * Returns the number of tokens burned by or on behalf of `owner`.
   */
  function _numberBurned(address owner) internal view returns (uint256) {
    return uint256(_addressData[owner].numberBurned);
  }

  /**
   * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
   */
  function _getAux(address owner) internal view returns (uint64) {
    return _addressData[owner].aux;
  }

  /**
   * Sets the auxillary 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 {
    _addressData[owner].aux = aux;
  }

  /**
   * Gas spent here starts off proportional to the maximum mint batch size.
   * It gradually moves to O(1) as tokens get transferred around in the collection over time.
   */
  function _ownershipOf(uint256 tokenId)
    internal
    view
    returns (TokenOwnership memory)
  {
    uint256 curr = tokenId;

    unchecked {
      if (_startTokenId() <= curr && curr < _currentIndex) {
        TokenOwnership memory ownership = _ownerships[curr];
        if (!ownership.burned) {
          if (ownership.addr != address(0)) {
            return ownership;
          }
          // Invariant:
          // There will always be an ownership that has an address and is not burned
          // before an ownership that does not have an address and is not burned.
          // Hence, curr will not underflow.
          while (true) {
            curr--;
            ownership = _ownerships[curr];
            if (ownership.addr != address(0)) {
              return ownership;
            }
          }
        }
      }
    }
    revert OwnerQueryForNonexistentToken();
  }

  /**
   * @dev See {IERC721-ownerOf}.
   */
  function ownerOf(uint256 tokenId) public view override returns (address) {
    return _ownershipOf(tokenId).addr;
  }

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

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

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

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

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

  /**
   * @dev See {IERC721-approve}.
   */
  function approve(address to, uint256 tokenId) public override {
    address owner = ERC721A.ownerOf(tokenId);
    if (to == owner) revert ApprovalToCurrentOwner();

    if (_msgSender() != owner && !isApprovedForAll(owner, _msgSender())) {
      revert ApprovalCallerNotOwnerNorApproved();
    }

    _approve(to, tokenId, owner);
  }

  /**
   * @dev See {IERC721-getApproved}.
   */
  function getApproved(uint256 tokenId) public view override returns (address) {
    if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

    return _tokenApprovals[tokenId];
  }

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

    _operatorApprovals[_msgSender()][operator] = approved;
    emit ApprovalForAll(_msgSender(), operator, approved);
  }

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

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

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

  /**
   * @dev See {IERC721-safeTransferFrom}.
   */
  function safeTransferFrom(
    address from,
    address to,
    uint256 tokenId,
    bytes memory _data
  ) public virtual override {
    _transfer(from, to, tokenId);
    if (
      to.isContract() &&
      !_checkContractOnERC721Received(from, to, tokenId, _data)
    ) {
      revert TransferToNonERC721ReceiverImplementer();
    }
  }

  /**
   * @dev Returns whether `tokenId` exists.
   *
   * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
   *
   * Tokens start existing when they are minted (`_mint`),
   */
  function _exists(uint256 tokenId) internal view returns (bool) {
    return
      _startTokenId() <= tokenId &&
      tokenId < _currentIndex &&
      !_ownerships[tokenId].burned;
  }

  /**
   * @dev Equivalent to `_safeMint(to, quantity, '')`.
   */
  function _safeMint(address to, uint256 quantity) internal {
    _safeMint(to, 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.
   *
   * Emits a {Transfer} event.
   */
  function _safeMint(
    address to,
    uint256 quantity,
    bytes memory _data
  ) internal {
    uint256 startTokenId = _currentIndex;
    if (to == address(0)) revert MintToZeroAddress();
    if (quantity == 0) revert MintZeroQuantity();

    _beforeTokenTransfers(address(0), to, startTokenId, quantity);

    // Overflows are incredibly unrealistic.
    // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
    // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
    unchecked {
      _addressData[to].balance += uint64(quantity);
      _addressData[to].numberMinted += uint64(quantity);

      _ownerships[startTokenId].addr = to;
      _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);

      uint256 updatedIndex = startTokenId;
      uint256 end = updatedIndex + quantity;

      if (to.isContract()) {
        do {
          emit Transfer(address(0), to, updatedIndex);
          if (
            !_checkContractOnERC721Received(
              address(0),
              to,
              updatedIndex++,
              _data
            )
          ) {
            revert TransferToNonERC721ReceiverImplementer();
          }
        } while (updatedIndex != end);
        // Reentrancy protection
        if (_currentIndex != startTokenId) revert();
      } else {
        do {
          emit Transfer(address(0), to, updatedIndex++);
        } while (updatedIndex != end);
      }
      _currentIndex = updatedIndex;
    }
    _afterTokenTransfers(address(0), to, startTokenId, quantity);
  }

  /**
   * @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.
   */
  function _mint(address to, uint256 quantity) internal {
    uint256 startTokenId = _currentIndex;
    if (to == address(0)) revert MintToZeroAddress();
    if (quantity == 0) revert MintZeroQuantity();

    _beforeTokenTransfers(address(0), to, startTokenId, quantity);

    // Overflows are incredibly unrealistic.
    // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
    // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
    unchecked {
      _addressData[to].balance += uint64(quantity);
      _addressData[to].numberMinted += uint64(quantity);

      _ownerships[startTokenId].addr = to;
      _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);

      uint256 updatedIndex = startTokenId;
      uint256 end = updatedIndex + quantity;

      do {
        emit Transfer(address(0), to, updatedIndex++);
      } while (updatedIndex != end);

      _currentIndex = updatedIndex;
    }
    _afterTokenTransfers(address(0), to, startTokenId, quantity);
  }

  /**
   * @dev Transfers `tokenId` from `from` to `to`.
   *
   * Requirements:
   *
   * - `to` cannot be the zero address.
   * - `tokenId` token must be owned by `from`.
   *
   * Emits a {Transfer} event.
   */
  function _transfer(
    address from,
    address to,
    uint256 tokenId
  ) private {
    TokenOwnership memory prevOwnership = _ownershipOf(tokenId);

    if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();

    bool isApprovedOrOwner = (_msgSender() == from ||
      isApprovedForAll(from, _msgSender()) ||
      getApproved(tokenId) == _msgSender());

    if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
    if (to == address(0)) revert TransferToZeroAddress();

    _beforeTokenTransfers(from, to, tokenId, 1);

    // Clear approvals from the previous owner
    _approve(address(0), tokenId, from);

    // 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 {
      _addressData[from].balance -= 1;
      _addressData[to].balance += 1;

      TokenOwnership storage currSlot = _ownerships[tokenId];
      currSlot.addr = to;
      currSlot.startTimestamp = uint64(block.timestamp);

      // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
      // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
      uint256 nextTokenId = tokenId + 1;
      TokenOwnership storage nextSlot = _ownerships[nextTokenId];
      if (nextSlot.addr == address(0)) {
        // This will suffice for checking _exists(nextTokenId),
        // as a burned slot cannot contain the zero address.
        if (nextTokenId != _currentIndex) {
          nextSlot.addr = from;
          nextSlot.startTimestamp = prevOwnership.startTimestamp;
        }
      }
    }

    emit Transfer(from, to, tokenId);
    _afterTokenTransfers(from, to, tokenId, 1);
  }

  /**
   * @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 {
    TokenOwnership memory prevOwnership = _ownershipOf(tokenId);

    address from = prevOwnership.addr;

    if (approvalCheck) {
      bool isApprovedOrOwner = (_msgSender() == from ||
        isApprovedForAll(from, _msgSender()) ||
        getApproved(tokenId) == _msgSender());

      if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
    }

    _beforeTokenTransfers(from, address(0), tokenId, 1);

    // Clear approvals from the previous owner
    _approve(address(0), tokenId, from);

    // 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 {
      AddressData storage addressData = _addressData[from];
      addressData.balance -= 1;
      addressData.numberBurned += 1;

      // Keep track of who burned the token, and the timestamp of burning.
      TokenOwnership storage currSlot = _ownerships[tokenId];
      currSlot.addr = from;
      currSlot.startTimestamp = uint64(block.timestamp);
      currSlot.burned = true;

      // If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.
      // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
      uint256 nextTokenId = tokenId + 1;
      TokenOwnership storage nextSlot = _ownerships[nextTokenId];
      if (nextSlot.addr == address(0)) {
        // This will suffice for checking _exists(nextTokenId),
        // as a burned slot cannot contain the zero address.
        if (nextTokenId != _currentIndex) {
          nextSlot.addr = from;
          nextSlot.startTimestamp = prevOwnership.startTimestamp;
        }
      }
    }

    emit Transfer(from, address(0), tokenId);
    _afterTokenTransfers(from, address(0), tokenId, 1);

    // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
    unchecked {
      _burnCounter++;
    }
  }

  /**
   * @dev Approve `to` to operate on `tokenId`
   *
   * Emits a {Approval} event.
   */
  function _approve(
    address to,
    uint256 tokenId,
    address owner
  ) private {
    _tokenApprovals[tokenId] = to;
    emit Approval(owner, to, tokenId);
  }

  /**
   * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.
   *
   * @param from address representing the previous owner of the given token ID
   * @param to target address that will receive the tokens
   * @param tokenId uint256 ID of the token to be transferred
   * @param _data bytes optional data to send along with the call
   * @return bool whether the call correctly returned the expected magic value
   */
  function _checkContractOnERC721Received(
    address from,
    address to,
    uint256 tokenId,
    bytes memory _data
  ) private returns (bool) {
    try
      IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data)
    returns (bytes4 retval) {
      return retval == IERC721Receiver(to).onERC721Received.selector;
    } catch (bytes memory reason) {
      if (reason.length == 0) {
        revert TransferToNonERC721ReceiverImplementer();
      } else {
        assembly {
          revert(add(32, reason), mload(reason))
        }
      }
    }
  }

  /**
   * @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 {}
}
                                                                                                                                                            

pragma solidity ^0.8.17;

contract Gateways is ERC721A, Ownable {
  using Strings for uint256;
  
  uint256 public cost = 0.003 ether;
  uint256 public maxSupply = 999;
  uint256 public freePerWallet = 0;
  uint256 public maxMint = 3;
  uint256 public requiredBalance = 0.003 ether;

  bool public status = false;

  string private baseTokenURI;

  mapping(address => uint256) public mintedByAddress;


  constructor() ERC721A("Gateways", "GTWY") {
  }

  // MINTING
  function mint(uint256 _count)
    external
    payable
  {
    uint256 _cost = getCost(msg.sender, _count);

    require(msg.sender == tx.origin, "No contracts!");
    require(status, "Not yet");
    require(totalSupply() + _count <= maxSupply, "Would excced supply");
    require(_count <= maxMint, "Too many");
    require(msg.value == _cost, "Wrong amount");

    mintedByAddress[msg.sender] += _count;
    _safeMint(msg.sender, _count);
  }

  function airdrop(
    address[] calldata _recipients,
    uint256[] calldata _mintAmounts
  ) external onlyOwner {
    for (uint256 i = 0; i < _recipients.length; i++) {
      require(totalSupply() + _mintAmounts[i] <= maxSupply, "Too many");
      _safeMint(_recipients[i], _mintAmounts[i]);
    }
  }

  // SETTERS

  function setCost(uint256 _newCost) public onlyOwner {
    cost = _newCost;
  }

  function setFreePerWallet(uint256 _newFreePerWallet) public onlyOwner {
    freePerWallet = _newFreePerWallet;
  }

  function setBaseURI(string memory baseURI) public onlyOwner {
    baseTokenURI = baseURI;
  }

  // modify qualifying collection
  function modifyWL(uint256 _requiredBalance)
    external
    onlyOwner
  {
    requiredBalance = _requiredBalance;
  }

  // GETTERS

  function getCost(
    address _address,
    uint256 _count
  ) public view returns (uint256) {
    uint256 _mintedByAddress = mintedByAddress[_address];
    bool _canClaim = canClaim(_address);

    if (_canClaim) {
      if (_count <= freePerWallet - _mintedByAddress) {
        return 0;
      } else {
        return cost * (_count - (freePerWallet - _mintedByAddress));
      }
    } else {
      return cost * _count;
    }
  }

  function canClaim(address _wallet)
    public
    view
    returns (bool)
  {
    if (
      (mintedByAddress[_wallet] < freePerWallet) && (_wallet.balance >= requiredBalance)
    ) {
      return true;
    } else {
      return false;
    }
  }

  function _startTokenId() internal view virtual override returns (uint256) {
    return 1;
  }

  function _baseURI() internal view virtual override returns (string memory) {
    return baseTokenURI;
  }

    function tokenURI(uint256 _tokenId) public view override returns (string memory) {
        require(_exists(_tokenId), "ERC721Metadata: URI query for nonexistent token");
        return string(abi.encodePacked(_baseURI(), _tokenId.toString(), ".json"));
    }

  // ADMIN

  //Open/close sale
  function flipSaleStatus() public onlyOwner {
    status = !status;
  }

  //Withdraw funds pro rata
  function withdrawAll() public payable onlyOwner {
  (bool success, ) = payable(msg.sender).call{value: address(this).balance}("");
  require(success);
  }

}