// File @openzeppelin/contracts/utils/introspection/IERC165.sol@v4.5.0

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
  /**
   * @dev Returns true if this contract implements the interface defined by
   * `interfaceId`. See the corresponding
   * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
   * to learn more about how these ids are created.
   *
   * This function call must use less than 30 000 gas.
   */
  function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File @openzeppelin/contracts/token/ERC721/IERC721.sol@v4.5.0

// 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;
}

// File @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol@v4.5.0

// 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);
}

// File @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol@v4.5.0

// 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);
}

// File @openzeppelin/contracts/utils/Address.sol@v4.5.0

// 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);
      }
    }
  }
}

// File @openzeppelin/contracts/utils/Context.sol@v4.5.0

// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
  function _msgSender() internal view virtual returns (address) {
    return msg.sender;
  }

  function _msgData() internal view virtual returns (bytes calldata) {
    return msg.data;
  }
}

// File @openzeppelin/contracts/utils/Strings.sol@v4.5.0

// 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);
  }
}

// File @openzeppelin/contracts/utils/introspection/ERC165.sol@v4.5.0

// 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;
  }
}

// File @openzeppelin/contracts/token/ERC721/ERC721.sol@v4.5.0

// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
  using Address for address;
  using Strings for uint256;

  // Token name
  string private _name;

  // Token symbol
  string private _symbol;

  // Mapping from token ID to owner address
  mapping(uint256 => address) private _owners;

  // Mapping owner address to token count
  mapping(address => uint256) private _balances;

  // Mapping from token ID to approved address
  mapping(uint256 => address) private _tokenApprovals;

  // Mapping from owner to operator approvals
  mapping(address => mapping(address => bool)) private _operatorApprovals;

  /**
   * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
   */
  constructor(string memory name_, string memory symbol_) {
    _name = name_;
    _symbol = symbol_;
  }

  /**
   * @dev See {IERC165-supportsInterface}.
   */
  function supportsInterface(bytes4 interfaceId)
    public
    view
    virtual
    override(ERC165, IERC165)
    returns (bool)
  {
    return
      interfaceId == type(IERC721).interfaceId ||
      interfaceId == type(IERC721Metadata).interfaceId ||
      super.supportsInterface(interfaceId);
  }

  /**
   * @dev See {IERC721-balanceOf}.
   */
  function balanceOf(address owner)
    public
    view
    virtual
    override
    returns (uint256)
  {
    require(owner != address(0), 'ERC721: balance query for the zero address');
    return _balances[owner];
  }

  /**
   * @dev See {IERC721-ownerOf}.
   */
  function ownerOf(uint256 tokenId)
    public
    view
    virtual
    override
    returns (address)
  {
    address owner = _owners[tokenId];
    require(owner != address(0), 'ERC721: owner query for nonexistent token');
    return owner;
  }

  /**
   * @dev See {IERC721Metadata-name}.
   */
  function name() public view virtual override returns (string memory) {
    return _name;
  }

  /**
   * @dev See {IERC721Metadata-symbol}.
   */
  function symbol() public view virtual override returns (string memory) {
    return _symbol;
  }

  /**
   * @dev See {IERC721Metadata-tokenURI}.
   */
  function tokenURI(uint256 tokenId)
    public
    view
    virtual
    override
    returns (string memory)
  {
    require(
      _exists(tokenId),
      'ERC721Metadata: URI query for nonexistent token'
    );

    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 virtual override {
    address owner = ERC721.ownerOf(tokenId);
    require(to != owner, 'ERC721: approval to current owner');

    require(
      _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
      'ERC721: approve caller is not owner nor approved for all'
    );

    _approve(to, tokenId);
  }

  /**
   * @dev See {IERC721-getApproved}.
   */
  function getApproved(uint256 tokenId)
    public
    view
    virtual
    override
    returns (address)
  {
    require(_exists(tokenId), 'ERC721: approved query for nonexistent token');

    return _tokenApprovals[tokenId];
  }

  /**
   * @dev See {IERC721-setApprovalForAll}.
   */
  function setApprovalForAll(address operator, bool approved)
    public
    virtual
    override
  {
    _setApprovalForAll(_msgSender(), operator, approved);
  }

  /**
   * @dev See {IERC721-isApprovedForAll}.
   */
  function isApprovedForAll(address owner, address operator)
    public
    view
    virtual
    override
    returns (bool)
  {
    return _operatorApprovals[owner][operator];
  }

  /**
   * @dev See {IERC721-transferFrom}.
   */
  function transferFrom(
    address from,
    address to,
    uint256 tokenId
  ) public virtual override {
    //solhint-disable-next-line max-line-length
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      'ERC721: transfer caller is not owner nor approved'
    );

    _transfer(from, to, tokenId);
  }

  /**
   * @dev See {IERC721-safeTransferFrom}.
   */
  function safeTransferFrom(
    address from,
    address to,
    uint256 tokenId
  ) public virtual override {
    safeTransferFrom(from, to, tokenId, '');
  }

  /**
   * @dev See {IERC721-safeTransferFrom}.
   */
  function safeTransferFrom(
    address from,
    address to,
    uint256 tokenId,
    bytes memory _data
  ) public virtual override {
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      'ERC721: transfer caller is not owner nor approved'
    );
    _safeTransfer(from, to, tokenId, _data);
  }

  /**
   * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
   * are aware of the ERC721 protocol to prevent tokens from being forever locked.
   *
   * `_data` is additional data, it has no specified format and it is sent in call to `to`.
   *
   * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
   * implement alternative mechanisms to perform token transfer, such as signature-based.
   *
   * Requirements:
   *
   * - `from` cannot be the zero address.
   * - `to` cannot be the zero address.
   * - `tokenId` token must exist and be owned by `from`.
   * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
   *
   * Emits a {Transfer} event.
   */
  function _safeTransfer(
    address from,
    address to,
    uint256 tokenId,
    bytes memory _data
  ) internal virtual {
    _transfer(from, to, tokenId);
    require(
      _checkOnERC721Received(from, to, tokenId, _data),
      'ERC721: transfer to non ERC721Receiver implementer'
    );
  }

  /**
   * @dev Returns whether `tokenId` exists.
   *
   * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
   *
   * Tokens start existing when they are minted (`_mint`),
   * and stop existing when they are burned (`_burn`).
   */
  function _exists(uint256 tokenId) internal view virtual returns (bool) {
    return _owners[tokenId] != address(0);
  }

  /**
   * @dev Returns whether `spender` is allowed to manage `tokenId`.
   *
   * Requirements:
   *
   * - `tokenId` must exist.
   */
  function _isApprovedOrOwner(address spender, uint256 tokenId)
    internal
    view
    virtual
    returns (bool)
  {
    require(_exists(tokenId), 'ERC721: operator query for nonexistent token');
    address owner = ERC721.ownerOf(tokenId);
    return (spender == owner ||
      getApproved(tokenId) == spender ||
      isApprovedForAll(owner, spender));
  }

  /**
   * @dev Safely mints `tokenId` and transfers it to `to`.
   *
   * Requirements:
   *
   * - `tokenId` must not exist.
   * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
   *
   * Emits a {Transfer} event.
   */
  function _safeMint(address to, uint256 tokenId) internal virtual {
    _safeMint(to, tokenId, '');
  }

  /**
   * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
   * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
   */
  function _safeMint(
    address to,
    uint256 tokenId,
    bytes memory _data
  ) internal virtual {
    _mint(to, tokenId);
    require(
      _checkOnERC721Received(address(0), to, tokenId, _data),
      'ERC721: transfer to non ERC721Receiver implementer'
    );
  }

  /**
   * @dev Mints `tokenId` and transfers it to `to`.
   *
   * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
   *
   * Requirements:
   *
   * - `tokenId` must not exist.
   * - `to` cannot be the zero address.
   *
   * Emits a {Transfer} event.
   */
  function _mint(address to, uint256 tokenId) internal virtual {
    require(to != address(0), 'ERC721: mint to the zero address');
    require(!_exists(tokenId), 'ERC721: token already minted');

    _beforeTokenTransfer(address(0), to, tokenId);

    _balances[to] += 1;
    _owners[tokenId] = to;

    emit Transfer(address(0), to, tokenId);

    _afterTokenTransfer(address(0), to, tokenId);
  }

  /**
   * @dev Destroys `tokenId`.
   * The approval is cleared when the token is burned.
   *
   * Requirements:
   *
   * - `tokenId` must exist.
   *
   * Emits a {Transfer} event.
   */
  function _burn(uint256 tokenId) internal virtual {
    address owner = ERC721.ownerOf(tokenId);

    _beforeTokenTransfer(owner, address(0), tokenId);

    // Clear approvals
    _approve(address(0), tokenId);

    _balances[owner] -= 1;
    delete _owners[tokenId];

    emit Transfer(owner, address(0), tokenId);

    _afterTokenTransfer(owner, address(0), tokenId);
  }

  /**
   * @dev Transfers `tokenId` from `from` to `to`.
   *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
   *
   * Requirements:
   *
   * - `to` cannot be the zero address.
   * - `tokenId` token must be owned by `from`.
   *
   * Emits a {Transfer} event.
   */
  function _transfer(
    address from,
    address to,
    uint256 tokenId
  ) internal virtual {
    require(
      ERC721.ownerOf(tokenId) == from,
      'ERC721: transfer from incorrect owner'
    );
    require(to != address(0), 'ERC721: transfer to the zero address');

    _beforeTokenTransfer(from, to, tokenId);

    // Clear approvals from the previous owner
    _approve(address(0), tokenId);

    _balances[from] -= 1;
    _balances[to] += 1;
    _owners[tokenId] = to;

    emit Transfer(from, to, tokenId);

    _afterTokenTransfer(from, to, tokenId);
  }

  /**
   * @dev Approve `to` to operate on `tokenId`
   *
   * Emits a {Approval} event.
   */
  function _approve(address to, uint256 tokenId) internal virtual {
    _tokenApprovals[tokenId] = to;
    emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
  }

  /**
   * @dev Approve `operator` to operate on all of `owner` tokens
   *
   * Emits a {ApprovalForAll} event.
   */
  function _setApprovalForAll(
    address owner,
    address operator,
    bool approved
  ) internal virtual {
    require(owner != operator, 'ERC721: approve to caller');
    _operatorApprovals[owner][operator] = approved;
    emit ApprovalForAll(owner, operator, approved);
  }

  /**
   * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
   * The call is not executed if the target address is not a contract.
   *
   * @param from address representing the previous owner of the given token ID
   * @param to target address that will receive the tokens
   * @param tokenId uint256 ID of the token to be transferred
   * @param _data bytes optional data to send along with the call
   * @return bool whether the call correctly returned the expected magic value
   */
  function _checkOnERC721Received(
    address from,
    address to,
    uint256 tokenId,
    bytes memory _data
  ) private returns (bool) {
    if (to.isContract()) {
      try
        IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data)
      returns (bytes4 retval) {
        return retval == IERC721Receiver.onERC721Received.selector;
      } catch (bytes memory reason) {
        if (reason.length == 0) {
          revert('ERC721: transfer to non ERC721Receiver implementer');
        } else {
          assembly {
            revert(add(32, reason), mload(reason))
          }
        }
      }
    } else {
      return true;
    }
  }

  /**
   * @dev Hook that is called before any token transfer. This includes minting
   * and burning.
   *
   * 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, ``from``'s `tokenId` will be burned.
   * - `from` and `to` are never both zero.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 tokenId
  ) internal virtual {}

  /**
   * @dev Hook that is called after any transfer of tokens. This includes
   * minting and burning.
   *
   * Calling conditions:
   *
   * - when `from` and `to` are both non-zero.
   * - `from` and `to` are never both zero.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _afterTokenTransfer(
    address from,
    address to,
    uint256 tokenId
  ) internal virtual {}
}

// File @openzeppelin/contracts/token/ERC721/extensions/ERC721Burnable.sol@v4.5.0

// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Burnable.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 Burnable Token
 * @dev ERC721 Token that can be irreversibly burned (destroyed).
 */
abstract contract ERC721Burnable is Context, ERC721 {
  /**
   * @dev Burns `tokenId`. See {ERC721-_burn}.
   *
   * Requirements:
   *
   * - The caller must own `tokenId` or be an approved operator.
   */
  function burn(uint256 tokenId) public virtual {
    //solhint-disable-next-line max-line-length
    require(
      _isApprovedOrOwner(_msgSender(), tokenId),
      'ERC721Burnable: caller is not owner nor approved'
    );
    _burn(tokenId);
  }
}

// File @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol@v4.5.0

// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
  /**
   * @dev Returns the total amount of tokens stored by the contract.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
   * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
   */
  function tokenOfOwnerByIndex(address owner, uint256 index)
    external
    view
    returns (uint256);

  /**
   * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
   * Use along with {totalSupply} to enumerate all tokens.
   */
  function tokenByIndex(uint256 index) external view returns (uint256);
}

// File @openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol@v4.5.0

// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Enumerable.sol)

pragma solidity ^0.8.0;

/**
 * @dev This implements an optional extension of {ERC721} defined in the EIP that adds
 * enumerability of all the token ids in the contract as well as all token ids owned by each
 * account.
 */
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
  // Mapping from owner to list of owned token IDs
  mapping(address => mapping(uint256 => uint256)) private _ownedTokens;

  // Mapping from token ID to index of the owner tokens list
  mapping(uint256 => uint256) private _ownedTokensIndex;

  // Array with all token ids, used for enumeration
  uint256[] private _allTokens;

  // Mapping from token id to position in the allTokens array
  mapping(uint256 => uint256) private _allTokensIndex;

  /**
   * @dev See {IERC165-supportsInterface}.
   */
  function supportsInterface(bytes4 interfaceId)
    public
    view
    virtual
    override(IERC165, ERC721)
    returns (bool)
  {
    return
      interfaceId == type(IERC721Enumerable).interfaceId ||
      super.supportsInterface(interfaceId);
  }

  /**
   * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
   */
  function tokenOfOwnerByIndex(address owner, uint256 index)
    public
    view
    virtual
    override
    returns (uint256)
  {
    require(
      index < ERC721.balanceOf(owner),
      'ERC721Enumerable: owner index out of bounds'
    );
    return _ownedTokens[owner][index];
  }

  /**
   * @dev See {IERC721Enumerable-totalSupply}.
   */
  function totalSupply() public view virtual override returns (uint256) {
    return _allTokens.length;
  }

  /**
   * @dev See {IERC721Enumerable-tokenByIndex}.
   */
  function tokenByIndex(uint256 index)
    public
    view
    virtual
    override
    returns (uint256)
  {
    require(
      index < ERC721Enumerable.totalSupply(),
      'ERC721Enumerable: global index out of bounds'
    );
    return _allTokens[index];
  }

  /**
   * @dev Hook that is called before any token transfer. This includes minting
   * and burning.
   *
   * 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, ``from``'s `tokenId` will be burned.
   * - `from` cannot be the zero address.
   * - `to` cannot be the zero address.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 tokenId
  ) internal virtual override {
    super._beforeTokenTransfer(from, to, tokenId);

    if (from == address(0)) {
      _addTokenToAllTokensEnumeration(tokenId);
    } else if (from != to) {
      _removeTokenFromOwnerEnumeration(from, tokenId);
    }
    if (to == address(0)) {
      _removeTokenFromAllTokensEnumeration(tokenId);
    } else if (to != from) {
      _addTokenToOwnerEnumeration(to, tokenId);
    }
  }

  /**
   * @dev Private function to add a token to this extension's ownership-tracking data structures.
   * @param to address representing the new owner of the given token ID
   * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
   */
  function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
    uint256 length = ERC721.balanceOf(to);
    _ownedTokens[to][length] = tokenId;
    _ownedTokensIndex[tokenId] = length;
  }

  /**
   * @dev Private function to add a token to this extension's token tracking data structures.
   * @param tokenId uint256 ID of the token to be added to the tokens list
   */
  function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
    _allTokensIndex[tokenId] = _allTokens.length;
    _allTokens.push(tokenId);
  }

  /**
   * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
   * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
   * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
   * This has O(1) time complexity, but alters the order of the _ownedTokens array.
   * @param from address representing the previous owner of the given token ID
   * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
   */
  function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId)
    private
  {
    // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
    // then delete the last slot (swap and pop).

    uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
    uint256 tokenIndex = _ownedTokensIndex[tokenId];

    // When the token to delete is the last token, the swap operation is unnecessary
    if (tokenIndex != lastTokenIndex) {
      uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

      _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
      _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
    }

    // This also deletes the contents at the last position of the array
    delete _ownedTokensIndex[tokenId];
    delete _ownedTokens[from][lastTokenIndex];
  }

  /**
   * @dev Private function to remove a token from this extension's token tracking data structures.
   * This has O(1) time complexity, but alters the order of the _allTokens array.
   * @param tokenId uint256 ID of the token to be removed from the tokens list
   */
  function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
    // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
    // then delete the last slot (swap and pop).

    uint256 lastTokenIndex = _allTokens.length - 1;
    uint256 tokenIndex = _allTokensIndex[tokenId];

    // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
    // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
    // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
    uint256 lastTokenId = _allTokens[lastTokenIndex];

    _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
    _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index

    // This also deletes the contents at the last position of the array
    delete _allTokensIndex[tokenId];
    _allTokens.pop();
  }
}

// File @openzeppelin/contracts/security/Pausable.sol@v4.5.0

// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
  /**
   * @dev Emitted when the pause is triggered by `account`.
   */
  event Paused(address account);

  /**
   * @dev Emitted when the pause is lifted by `account`.
   */
  event Unpaused(address account);

  bool private _paused;

  /**
   * @dev Initializes the contract in unpaused state.
   */
  constructor() {
    _paused = false;
  }

  /**
   * @dev Returns true if the contract is paused, and false otherwise.
   */
  function paused() public view virtual returns (bool) {
    return _paused;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   *
   * Requirements:
   *
   * - The contract must not be paused.
   */
  modifier whenNotPaused() {
    require(!paused(), 'Pausable: paused');
    _;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   *
   * Requirements:
   *
   * - The contract must be paused.
   */
  modifier whenPaused() {
    require(paused(), 'Pausable: not paused');
    _;
  }

  /**
   * @dev Triggers stopped state.
   *
   * Requirements:
   *
   * - The contract must not be paused.
   */
  function _pause() internal virtual whenNotPaused {
    _paused = true;
    emit Paused(_msgSender());
  }

  /**
   * @dev Returns to normal state.
   *
   * Requirements:
   *
   * - The contract must be paused.
   */
  function _unpause() internal virtual whenPaused {
    _paused = false;
    emit Unpaused(_msgSender());
  }
}

// File @openzeppelin/contracts/token/ERC721/extensions/ERC721Pausable.sol@v4.5.0

// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Pausable.sol)

pragma solidity ^0.8.0;

/**
 * @dev ERC721 token with pausable token transfers, minting and burning.
 *
 * Useful for scenarios such as preventing trades until the end of an evaluation
 * period, or having an emergency switch for freezing all token transfers in the
 * event of a large bug.
 */
abstract contract ERC721Pausable is ERC721, Pausable {
  /**
   * @dev See {ERC721-_beforeTokenTransfer}.
   *
   * Requirements:
   *
   * - the contract must not be paused.
   */
  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 tokenId
  ) internal virtual override {
    super._beforeTokenTransfer(from, to, tokenId);

    require(!paused(), 'ERC721Pausable: token transfer while paused');
  }
}

// File @openzeppelin/contracts/access/Ownable.sol@v4.5.0

// 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);
  }
}

// File @openzeppelin/contracts/utils/Counters.sol@v4.5.0

// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
  struct Counter {
    // This variable should never be directly accessed by users of the library: interactions must be restricted to
    // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
    // this feature: see https://github.com/ethereum/solidity/issues/4637
    uint256 _value; // default: 0
  }

  function current(Counter storage counter) internal view returns (uint256) {
    return counter._value;
  }

  function increment(Counter storage counter) internal {
    unchecked {
      counter._value += 1;
    }
  }

  function decrement(Counter storage counter) internal {
    uint256 value = counter._value;
    require(value > 0, 'Counter: decrement overflow');
    unchecked {
      counter._value = value - 1;
    }
  }

  function reset(Counter storage counter) internal {
    counter._value = 0;
  }
}

// File @openzeppelin/contracts/token/ERC20/IERC20.sol@v4.5.0

// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns the amount of tokens owned by `account`.
   */
  function balanceOf(address account) external view returns (uint256);

  /**
   * @dev Moves `amount` tokens from the caller's account to `to`.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transfer(address to, uint256 amount) external returns (bool);

  /**
   * @dev Returns the remaining number of tokens that `spender` will be
   * allowed to spend on behalf of `owner` through {transferFrom}. This is
   * zero by default.
   *
   * This value changes when {approve} or {transferFrom} are called.
   */
  function allowance(address owner, address spender)
    external
    view
    returns (uint256);

  /**
   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * IMPORTANT: Beware that changing an allowance with this method brings the risk
   * that someone may use both the old and the new allowance by unfortunate
   * transaction ordering. One possible solution to mitigate this race
   * condition is to first reduce the spender's allowance to 0 and set the
   * desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   *
   * Emits an {Approval} event.
   */
  function approve(address spender, uint256 amount) external returns (bool);

  /**
   * @dev Moves `amount` tokens from `from` to `to` using the
   * allowance mechanism. `amount` is then deducted from the caller's
   * allowance.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transferFrom(
    address from,
    address to,
    uint256 amount
  ) external returns (bool);

  /**
   * @dev Emitted when `value` tokens are moved from one account (`from`) to
   * another (`to`).
   *
   * Note that `value` may be zero.
   */
  event Transfer(address indexed from, address indexed to, uint256 value);

  /**
   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
   * a call to {approve}. `value` is the new allowance.
   */
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File @openzeppelin/contracts/interfaces/IERC20.sol@v4.5.0

// OpenZeppelin Contracts v4.4.1 (interfaces/IERC20.sol)

pragma solidity ^0.8.0;

// File contracts/interfaces/ISmoltingInu.sol

pragma solidity ^0.8.9;

/**
 * @dev SmoltingInu token interface
 */

interface ISmoltingInu is IERC20 {
  function gameMint(address _user, uint256 _amount) external;

  function gameBurn(address _user, uint256 _amount) external;

  function addPlayThrough(
    address _user,
    uint256 _amountWagered,
    uint8 _percentContribution
  ) external;

  function setCanSellWithoutElevation(address _wallet, bool _canSellWithoutElev)
    external;
}

// File contracts/interfaces/ISMOLNftRewards.sol

pragma solidity ^0.8.9;

interface ISMOLNftRewards {
  function claimReward() external;

  function depositRewards(uint256 _amount) external;

  function getShares(address wallet) external view returns (uint256);
}

// File contracts/SMOLNftRewards.sol

pragma solidity ^0.8.9;

contract SMOLNftRewards is ISMOLNftRewards, Ownable {
  struct Reward {
    uint256 totalExcluded; // excluded reward
    uint256 totalRealised;
    uint256 lastClaim; // used for boosting logic
  }

  struct Share {
    uint256 amount;
    uint256 stakedTime;
  }

  IERC721 shareholderNFT;
  ISmoltingInu smol = ISmoltingInu(0x553539d40AE81FD0d9C4b991B0b77bE6f6Bc030e);
  uint256 public totalStakedUsers;
  uint256 public totalSharesDeposited; // will only be actual deposited tokens without handling any reflections or otherwise

  // amount of shares a user has
  mapping(address => Share) shares;
  // reward information per user
  mapping(address => Reward) public rewards;

  uint256 public totalRewards;
  uint256 public totalDistributed;
  uint256 public rewardsPerShare;

  uint256 private constant ACC_FACTOR = 10**36;

  event ClaimReward(address user);
  event DistributeReward(address indexed user);
  event DepositRewards(address indexed user, uint256 amountTokens);

  modifier onlyToken() {
    require(msg.sender == address(shareholderNFT), 'must be token contract');
    _;
  }

  constructor(address _shareholderNFT) {
    shareholderNFT = IERC721(_shareholderNFT);
  }

  function setShare(address shareholder, uint256 newBalance)
    external
    onlyToken
  {
    // _addShares and _removeShares takes the amount to add or remove respectively,
    // so we should handle the diff from the new balance when passing in the amounts
    // to these functions
    if (shares[shareholder].amount > newBalance) {
      _removeShares(shareholder, shares[shareholder].amount - newBalance);
    } else if (shares[shareholder].amount < newBalance) {
      _addShares(shareholder, newBalance - shares[shareholder].amount);
    }
  }

  function _addShares(address shareholder, uint256 amount) private {
    if (shares[shareholder].amount > 0) {
      _distributeReward(shareholder);
    }

    uint256 sharesBefore = shares[shareholder].amount;

    totalSharesDeposited += amount;
    shares[shareholder].amount += amount;
    shares[shareholder].stakedTime = block.timestamp;
    if (sharesBefore == 0 && shares[shareholder].amount > 0) {
      totalStakedUsers++;
    }
    rewards[shareholder].totalExcluded = getCumulativeRewards(
      shares[shareholder].amount
    );
  }

  function _removeShares(address shareholder, uint256 amount) private {
    require(
      shares[shareholder].amount > 0 &&
        (amount == 0 || amount <= shares[shareholder].amount),
      'you can only unstake if you have some staked'
    );
    _distributeReward(shareholder);

    uint256 removeAmount = amount == 0 ? shares[shareholder].amount : amount;

    totalSharesDeposited -= removeAmount;
    shares[shareholder].amount -= removeAmount;
    rewards[shareholder].totalExcluded = getCumulativeRewards(
      shares[shareholder].amount
    );
  }

  function depositRewards(uint256 _amount) external override onlyOwner {
    require(
      totalSharesDeposited > 0,
      'must be shares deposited to be rewarded rewards'
    );

    totalRewards += _amount;
    rewardsPerShare += (ACC_FACTOR * _amount) / totalSharesDeposited;
    smol.gameMint(address(this), _amount);
    emit DepositRewards(msg.sender, _amount);
  }

  function _distributeReward(address shareholder) internal {
    if (shares[shareholder].amount == 0) {
      return;
    }

    uint256 amount = getUnpaid(shareholder);

    rewards[shareholder].totalRealised += amount;
    rewards[shareholder].totalExcluded = getCumulativeRewards(
      shares[shareholder].amount
    );
    rewards[shareholder].lastClaim = block.timestamp;

    if (amount > 0) {
      totalDistributed += amount;
      smol.transfer(shareholder, amount);
      emit DistributeReward(shareholder);
    }
  }

  function claimReward() external override {
    _distributeReward(msg.sender);
    emit ClaimReward(msg.sender);
  }

  // returns the unpaid rewards
  function getUnpaid(address shareholder) public view returns (uint256) {
    if (shares[shareholder].amount == 0) {
      return 0;
    }

    uint256 earnedRewards = getCumulativeRewards(shares[shareholder].amount);
    uint256 rewardsExcluded = rewards[shareholder].totalExcluded;
    if (earnedRewards <= rewardsExcluded) {
      return 0;
    }

    return earnedRewards - rewardsExcluded;
  }

  function getCumulativeRewards(uint256 share) internal view returns (uint256) {
    return (share * rewardsPerShare) / ACC_FACTOR;
  }

  function getShares(address user) external view override returns (uint256) {
    return shares[user].amount;
  }

  function getShareholderNFT() external view returns (address) {
    return address(shareholderNFT);
  }

  function getSmolToken() external view returns (address) {
    return address(smol);
  }

  function setShareholderNFT(address _nft) external onlyOwner {
    shareholderNFT = IERC721(_nft);
  }

  function setSmolToken(address _token) external onlyOwner {
    smol = ISmoltingInu(_token);
  }
}

// File contracts/SMOLNft.sol

pragma solidity ^0.8.9;

/**
 * SMOL yield bearing NFTs
 */
contract SMOLNft is Ownable, ERC721Burnable, ERC721Enumerable, ERC721Pausable {
  using Strings for uint256;
  using Counters for Counters.Counter;

  uint16 public constant PERCENT_DENOMENATOR = 1000;
  uint16 private constant FIVE_MINUTES = 60 * 5;

  Counters.Counter private _tokenIds;

  SMOLNftRewards private _rewards;
  mapping(address => bool) private _isRewardsExcluded;

  // user => timestamp of last mint
  // used for throttling wallets from minting too often
  mapping(address => uint256) public userLastMinted;

  // Base token uri
  string private baseTokenURI; // baseTokenURI can point to IPFS folder like https://ipfs.io/ipfs/{cid}/ while

  address public smol = 0x553539d40AE81FD0d9C4b991B0b77bE6f6Bc030e;
  uint256 public nativeCost = 9 ether / 100; // 0.09 ETH
  uint256 public smolCost = 100 * 10**18;
  uint8 public maxPerMint = 10;

  // Payment address
  address public paymentAddress = 0x98c574473313EAC3FC6af9740245949380ec166E;

  // Royalties address
  address public royaltyAddress = 0x98c574473313EAC3FC6af9740245949380ec166E;

  // Royalties basis points (percentage using 2 decimals - 1000 = 100, 500 = 50, 0 = 0)
  uint256 private royaltyBasisPoints = 50; // 5%

  // Token info
  string public constant TOKEN_NAME = 'yield bearing smolting';
  string public constant TOKEN_SYMBOL = 'ybSMOL'; // yield bearing SMOL
  uint256 public constant TOTAL_TOKENS = 4269;

  // Public sale params
  uint256 public publicSaleStartTime;
  bool public publicSaleActive;
  bool public isRevealing;

  mapping(address => bool) public canMintFreeNft;
  mapping(address => uint256) public mintedFreeNftTimestamp;

  mapping(uint256 => uint256) public tokenMintedAt;
  mapping(uint256 => uint256) public tokenLastTransferredAt;

  event PublicSaleStart(uint256 indexed _saleStartTime);
  event PublicSalePaused(uint256 indexed _timeElapsed);
  event PublicSaleActive(bool indexed _publicSaleActive);
  event RoyaltyBasisPoints(uint256 indexed _royaltyBasisPoints);

  // Public sale active modifier
  modifier whenPublicSaleActive() {
    require(publicSaleActive, 'Public sale is not active');
    _;
  }

  // Public sale not active modifier
  modifier whenPublicSaleNotActive() {
    require(
      !publicSaleActive && publicSaleStartTime == 0,
      'Public sale is already active'
    );
    _;
  }

  // Owner or public sale active modifier
  modifier whenOwnerOrPublicSaleActive() {
    require(
      owner() == _msgSender() || publicSaleActive,
      'Public sale is not active'
    );
    _;
  }

  // -- Constructor --//
  constructor(string memory _baseTokenURI) ERC721(TOKEN_NAME, TOKEN_SYMBOL) {
    baseTokenURI = _baseTokenURI;
    _rewards = new SMOLNftRewards(address(this));
    _rewards.transferOwnership(_msgSender());

    _isRewardsExcluded[address(this)] = true;
    _isRewardsExcluded[address(_rewards)] = true;
  }

  // -- External Functions -- //
  // Start public sale
  function startPublicSale() external onlyOwner whenPublicSaleNotActive {
    publicSaleStartTime = block.timestamp;
    publicSaleActive = true;
    emit PublicSaleStart(publicSaleStartTime);
  }

  // Set this value to the block.timestamp you'd like to reset to
  // Created as a way to fast foward in time for tier timing unit tests
  // Can also be used if needing to pause and restart public sale from original start time (returned in startPublicSale() above)
  function setPublicSaleStartTime(uint256 _publicSaleStartTime)
    external
    onlyOwner
  {
    publicSaleStartTime = _publicSaleStartTime;
    emit PublicSaleStart(publicSaleStartTime);
  }

  // Toggle public sale
  function togglePublicSaleActive() external onlyOwner {
    publicSaleActive = !publicSaleActive;
    emit PublicSaleActive(publicSaleActive);
  }

  // Pause public sale
  function pausePublicSale() external onlyOwner whenPublicSaleActive {
    publicSaleActive = false;
    emit PublicSalePaused(getElapsedSaleTime());
  }

  // Support royalty info - See {EIP-2981}: https://eips.ethereum.org/EIPS/eip-2981
  function royaltyInfo(uint256, uint256 _salePrice)
    external
    view
    returns (address receiver, uint256 royaltyAmount)
  {
    return (
      royaltyAddress,
      (_salePrice * royaltyBasisPoints) / PERCENT_DENOMENATOR
    );
  }

  function getElapsedSaleTime() public view returns (uint256) {
    return publicSaleStartTime > 0 ? block.timestamp - publicSaleStartTime : 0;
  }

  function getRewards() external view returns (address) {
    return address(_rewards);
  }

  // Get mints left
  function getMintsLeft() public view returns (uint256) {
    uint256 currentSupply = super.totalSupply();
    return TOTAL_TOKENS - currentSupply;
  }

  // Mint token - requires tier and amount
  function mint(uint256 _amount) public payable whenOwnerOrPublicSaleActive {
    bool _isOwner = owner() == _msgSender();
    require(_isOwner || getElapsedSaleTime() > 0, 'sale not active');
    require(
      _isOwner || block.timestamp > userLastMinted[_msgSender()] + FIVE_MINUTES,
      'can only mint once per 5 minutes'
    );
    require(
      _amount > 0 && (_isOwner || _amount <= maxPerMint),
      'must mint at least one and cannot exceed max amount'
    );
    // Check there enough NFTs left to mint
    require(_amount <= getMintsLeft(), 'minting would exceed max supply');

    userLastMinted[_msgSender()] = block.timestamp;

    // pay for NFTs & handle free NFT mint logic here as well
    if (
      canMintFreeNft[_msgSender()] && mintedFreeNftTimestamp[_msgSender()] == 0
    ) {
      mintedFreeNftTimestamp[_msgSender()] = block.timestamp;
      _payToMint(_amount - 1);
    } else {
      _payToMint(_amount);
    }

    for (uint256 i = 0; i < _amount; i++) {
      _tokenIds.increment();

      // Safe mint
      _safeMint(_msgSender(), _tokenIds.current());

      // Store minted at timestamp by token id
      tokenMintedAt[_tokenIds.current()] = block.timestamp;
    }
  }

  function _payToMint(uint256 _amount) internal whenOwnerOrPublicSaleActive {
    require(_amount > 0, 'must mint at least 1');
    bool isOwner = owner() == _msgSender();
    if (isOwner) {
      if (msg.value > 0) {
        Address.sendValue(payable(_msgSender()), msg.value);
      }
      return;
    }

    ISmoltingInu smolToken = ISmoltingInu(smol);
    uint256 totalNativeCost = nativeCost * _amount;
    uint256 totalSmolCost = smolCost * _amount;

    if (totalNativeCost > 0) {
      require(
        msg.value >= totalNativeCost,
        'not enough native token provided to mint'
      );
      uint256 balanceBefore = address(this).balance;
      Address.sendValue(payable(paymentAddress), totalNativeCost);
      // refund user for any extra native sent
      if (msg.value > totalNativeCost) {
        Address.sendValue(payable(_msgSender()), msg.value - totalNativeCost);
      }
      require(
        address(this).balance >= balanceBefore - msg.value,
        'too much native sent'
      );
    } else if (msg.value > 0) {
      Address.sendValue(payable(_msgSender()), msg.value);
    }

    if (totalSmolCost > 0) {
      require(
        smolToken.balanceOf(_msgSender()) >= totalSmolCost,
        'not enough SMOL balance to mint'
      );
      smolToken.gameBurn(_msgSender(), totalSmolCost);
    }
  }

  function setPaymentAddress(address _address) external onlyOwner {
    paymentAddress = _address;
  }

  // Set royalty wallet address
  function setRoyaltyAddress(address _address) external onlyOwner {
    royaltyAddress = _address;
  }

  function setSmolToken(address _smol) external onlyOwner {
    smol = _smol;
  }

  function setNativeCost(uint256 _wei) external onlyOwner {
    nativeCost = _wei;
  }

  function setSmolCost(uint256 _numTokens) external onlyOwner {
    smolCost = _numTokens;
  }

  // Set royalty basis points
  function setRoyaltyBasisPoints(uint256 _basisPoints) external onlyOwner {
    royaltyBasisPoints = _basisPoints;
    emit RoyaltyBasisPoints(_basisPoints);
  }

  // Set base URI
  function setBaseURI(string memory _uri) external onlyOwner {
    baseTokenURI = _uri;
  }

  function setRewards(address _contract) external onlyOwner {
    _rewards = SMOLNftRewards(_contract);
  }

  function setIsRewardsExcluded(address _wallet, bool _isExcluded)
    public
    onlyOwner
  {
    _isRewardsExcluded[_wallet] = _isExcluded;
    if (_isExcluded) {
      _rewards.setShare(_wallet, 0);
    } else {
      _rewards.setShare(_wallet, balanceOf(_wallet));
    }
  }

  function setMaxPerMint(uint8 _max) external onlyOwner {
    require(maxPerMint > 0, 'have to be able to mint at least 1 NFT');
    maxPerMint = _max;
  }

  function setCanMintFreeNft(address _wallet, bool _canMintFree)
    external
    onlyOwner
  {
    canMintFreeNft[_wallet] = _canMintFree;
  }

  function setCanMintFreeNftBulk(address[] memory _wallets, bool _canMintFree)
    external
    onlyOwner
  {
    for (uint256 i = 0; i < _wallets.length; i++) {
      canMintFreeNft[_wallets[i]] = _canMintFree;
    }
  }

  function isRewardsExcluded(address _wallet) external view returns (bool) {
    return _isRewardsExcluded[_wallet];
  }

  function tokenURI(uint256 _tokenId)
    public
    view
    virtual
    override
    returns (string memory)
  {
    require(_exists(_tokenId), 'Nonexistent token');

    return string(abi.encodePacked(_baseURI(), _tokenId.toString(), '.json'));
  }

  function isMinted(uint256 _tokenId) external view returns (bool) {
    return _exists(_tokenId);
  }

  // Contract metadata URI - Support for OpenSea: https://docs.opensea.io/docs/contract-level-metadata
  function contractURI() public view returns (string memory) {
    return string(abi.encodePacked(_baseURI(), 'contract.json'));
  }

  // Override supportsInterface - See {IERC165-supportsInterface}
  function supportsInterface(bytes4 _interfaceId)
    public
    view
    virtual
    override(ERC721, ERC721Enumerable)
    returns (bool)
  {
    return super.supportsInterface(_interfaceId);
  }

  // Pauses all token transfers - See {ERC721Pausable}
  function pause() public virtual onlyOwner {
    _pause();
  }

  // Unpauses all token transfers - See {ERC721Pausable}
  function unpause() public virtual onlyOwner {
    _unpause();
  }

  function reveal() external onlyOwner {
    require(!isRevealing, 'already revealing');
    isRevealing = true;
  }

  //-- Internal Functions --//

  function _setRewardsShares(address _from, address _to) internal {
    if (!_isRewardsExcluded[_from] && _from != address(0)) {
      _rewards.setShare(_from, balanceOf(_from));
    }
    if (!_isRewardsExcluded[_to] && _to != address(0)) {
      _rewards.setShare(_to, balanceOf(_to));
    }
  }

  // Get base URI
  function _baseURI() internal view override returns (string memory) {
    return baseTokenURI;
  }

  // before all token transfer
  function _beforeTokenTransfer(
    address _from,
    address _to,
    uint256 _tokenId
  ) internal virtual override(ERC721, ERC721Enumerable, ERC721Pausable) {
    // Store token last transfer timestamp by id
    tokenLastTransferredAt[_tokenId] = block.timestamp;

    super._beforeTokenTransfer(_from, _to, _tokenId);
  }

  // after all token transfer
  function _afterTokenTransfer(
    address _from,
    address _to,
    uint256 _tokenId
  ) internal virtual override(ERC721) {
    _setRewardsShares(_from, _to);

    super._afterTokenTransfer(_from, _to, _tokenId);
  }
}