// Sources flattened with hardhat v2.1.1 https://hardhat.org
// SPDX-License-Identifier: MIT
pragma solidity 0.8.0;

// File src/contracts/tokens/erc721.sol

/**
 * @dev ERC-721 non-fungible token standard.
 * See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md.
 */
interface ERC721 {
  /**
   * @dev Emits when ownership of any NFT changes by any mechanism. This event emits when NFTs are
   * created (`from` == 0) and destroyed (`to` == 0). Exception: during contract creation, any
   * number of NFTs may be created and assigned without emitting Transfer. At the time of any
   * transfer, the approved address for that NFT (if any) is reset to none.
   */
  event Transfer(address indexed _from, address indexed _to, uint256 indexed _tokenId);

  /**
   * @dev This emits when the approved address for an NFT is changed or reaffirmed. The zero
   * address indicates there is no approved address. When a Transfer event emits, this also
   * indicates that the approved address for that NFT (if any) is reset to none.
   */
  event Approval(address indexed _owner, address indexed _approved, uint256 indexed _tokenId);

  /**
   * @dev This emits when an operator is enabled or disabled for an owner. The operator can manage
   * all NFTs of the owner.
   */
  event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);

  /**
   * @dev Transfers the ownership of an NFT from one address to another address.
   * @notice Throws unless `msg.sender` is the current owner, an authorized operator, or the
   * approved address for this NFT. Throws if `_from` is not the current owner. Throws if `_to` is
   * the zero address. Throws if `_tokenId` is not a valid NFT. When transfer is complete, this
   * function checks if `_to` is a smart contract (code size > 0). If so, it calls
   * `onERC721Received` on `_to` and throws if the return value is not
   * `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`.
   * @param _from The current owner of the NFT.
   * @param _to The new owner.
   * @param _tokenId The NFT to transfer.
   * @param _data Additional data with no specified format, sent in call to `_to`.
   */
  function safeTransferFrom(
    address _from,
    address _to,
    uint256 _tokenId,
    bytes calldata _data
  ) external;

  /**
   * @dev Transfers the ownership of an NFT from one address to another address.
   * @notice This works identically to the other function with an extra data parameter, except this
   * function just sets data to ""
   * @param _from The current owner of the NFT.
   * @param _to The new owner.
   * @param _tokenId The NFT to transfer.
   */
  function safeTransferFrom(
    address _from,
    address _to,
    uint256 _tokenId
  ) external;

  /**
   * @dev Throws unless `msg.sender` is the current owner, an authorized operator, or the approved
   * address for this NFT. Throws if `_from` is not the current owner. Throws if `_to` is the zero
   * address. Throws if `_tokenId` is not a valid NFT.
   * @notice The caller is responsible to confirm that `_to` is capable of receiving NFTs or else
   * they mayb be permanently lost.
   * @param _from The current owner of the NFT.
   * @param _to The new owner.
   * @param _tokenId The NFT to transfer.
   */
  function transferFrom(
    address _from,
    address _to,
    uint256 _tokenId
  ) external;

  /**
   * @dev Set or reaffirm the approved address for an NFT.
   * @notice The zero address indicates there is no approved address. Throws unless `msg.sender` is
   * the current NFT owner, or an authorized operator of the current owner.
   * @param _approved The new approved NFT controller.
   * @param _tokenId The NFT to approve.
   */
  function approve(address _approved, uint256 _tokenId) external;

  /**
   * @dev Enables or disables approval for a third party ("operator") to manage all of
   * `msg.sender`'s assets. It also emits the ApprovalForAll event.
   * @notice The contract MUST allow multiple operators per owner.
   * @param _operator Address to add to the set of authorized operators.
   * @param _approved True if the operators is approved, false to revoke approval.
   */
  function setApprovalForAll(address _operator, bool _approved) external;

  /**
   * @dev Returns the number of NFTs owned by `_owner`. NFTs assigned to the zero address are
   * considered invalid, and this function throws for queries about the zero address.
   * @param _owner Address for whom to query the balance.
   * @return Balance of _owner.
   */
  function balanceOf(address _owner) external view returns (uint256);

  /**
   * @dev Returns the address of the owner of the NFT. NFTs assigned to zero address are considered
   * invalid, and queries about them do throw.
   * @param _tokenId The identifier for an NFT.
   * @return Address of _tokenId owner.
   */
  function ownerOf(uint256 _tokenId) external view returns (address);

  /**
   * @dev Get the approved address for a single NFT.
   * @notice Throws if `_tokenId` is not a valid NFT.
   * @param _tokenId The NFT to find the approved address for.
   * @return Address that _tokenId is approved for.
   */
  function getApproved(uint256 _tokenId) external view returns (address);

  /**
   * @dev Returns true if `_operator` is an approved operator for `_owner`, false otherwise.
   * @param _owner The address that owns the NFTs.
   * @param _operator The address that acts on behalf of the owner.
   * @return True if approved for all, false otherwise.
   */
  function isApprovedForAll(address _owner, address _operator) external view returns (bool);
}


// File src/contracts/tokens/erc721-token-receiver.sol

/**
 * @dev ERC-721 interface for accepting safe transfers.
 * See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md.
 */
interface ERC721TokenReceiver {
  /**
   * @dev Handle the receipt of a NFT. The ERC721 smart contract calls this function on the
   * recipient after a `transfer`. This function MAY throw to revert and reject the transfer. Return
   * of other than the magic value MUST result in the transaction being reverted.
   * Returns `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))` unless throwing.
   * @notice The contract address is always the message sender. A wallet/broker/auction application
   * MUST implement the wallet interface if it will accept safe transfers.
   * @param _operator The address which called `safeTransferFrom` function.
   * @param _from The address which previously owned the token.
   * @param _tokenId The NFT identifier which is being transferred.
   * @param _data Additional data with no specified format.
   * @return Returns `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`.
   */
  function onERC721Received(
    address _operator,
    address _from,
    uint256 _tokenId,
    bytes calldata _data
  ) external returns (bytes4);
}


// File src/contracts/utils/erc165.sol

/**
 * @dev A standard for detecting smart contract interfaces.
 * See: https://eips.ethereum.org/EIPS/eip-165.
 */
interface ERC165 {
  /**
   * @dev Checks if the smart contract includes a specific interface.
   * This function uses less than 30,000 gas.
   * @param _interfaceID The interface identifier, as specified in ERC-165.
   * @return True if _interfaceID is supported, false otherwise.
   */
  function supportsInterface(bytes4 _interfaceID) external view returns (bool);
}


// File src/contracts/utils/supports-interface.sol

/**
 * @dev Implementation of standard for detect smart contract interfaces.
 */
contract SupportsInterface is ERC165 {
  /**
   * @dev Mapping of supported intefraces. You must not set element 0xffffffff to true.
   */
  mapping(bytes4 => bool) internal supportedInterfaces;

  /**
   * @dev Contract constructor.
   */
  constructor() {
    supportedInterfaces[0x01ffc9a7] = true; // ERC165
  }

  /**
   * @dev Function to check which interfaces are suported by this contract.
   * @param _interfaceID Id of the interface.
   * @return True if _interfaceID is supported, false otherwise.
   */
  function supportsInterface(bytes4 _interfaceID) external view override returns (bool) {
    return supportedInterfaces[_interfaceID];
  }
}


// File src/contracts/utils/address-utils.sol

/**
 * @dev Utility library of inline functions on addresses.
 * @notice Based on:
 * https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Address.sol
 * Requires EIP-1052.
 */
library AddressUtils {
  /**
   * @dev Returns whether the target address is a contract.
   * @param _addr Address to check.
   * @return addressCheck True if _addr is a contract, false if not.
   */
  function isContract(address _addr) internal view returns (bool addressCheck) {
    // This method relies in extcodesize, which returns 0 for contracts in
    // construction, since the code is only stored at the end of the
    // constructor execution.

    // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
    // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
    // for accounts without code, i.e. `keccak256('')`
    bytes32 codehash;
    bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
    assembly {
      codehash := extcodehash(_addr)
    } // solhint-disable-line
    addressCheck = (codehash != 0x0 && codehash != accountHash);
  }
}


// File src/contracts/tokens/nf-token.sol

/**
 * @dev Implementation of ERC-721 non-fungible token standard.
 */
contract NFToken is ERC721, SupportsInterface {
  using AddressUtils for address;

  /**
   * @dev List of revert message codes. Implementing dApp should handle showing the correct message.
   * Based on 0xcert framework error codes.
   */
  string constant ZERO_ADDRESS = "003001";
  string constant NOT_VALID_NFT = "003002";
  string constant NOT_OWNER_OR_OPERATOR = "003003";
  string constant NOT_OWNER_APPROVED_OR_OPERATOR = "003004";
  string constant NOT_ABLE_TO_RECEIVE_NFT = "003005";
  string constant NFT_ALREADY_EXISTS = "003006";
  string constant NOT_OWNER = "003007";
  string constant IS_OWNER = "003008";

  /**
   * @dev Magic value of a smart contract that can recieve NFT.
   * Equal to: bytes4(keccak256("onERC721Received(address,address,uint256,bytes)")).
   */
  bytes4 internal constant MAGIC_ON_ERC721_RECEIVED = 0x150b7a02;

  /**
   * @dev A mapping from NFT ID to the address that owns it.
   */
  mapping(uint256 => address) internal idToOwner;

  /**
   * @dev Mapping from NFT ID to approved address.
   */
  mapping(uint256 => address) internal idToApproval;

  /**
   * @dev Mapping from owner address to count of his tokens.
   */
  mapping(address => uint256) private ownerToNFTokenCount;

  /**
   * @dev Mapping from owner address to mapping of operator addresses.
   */
  mapping(address => mapping(address => bool)) internal ownerToOperators;

  /**
   * @dev Guarantees that the msg.sender is an owner or operator of the given NFT.
   * @param _tokenId ID of the NFT to validate.
   */
  modifier canOperate(uint256 _tokenId) {
    address tokenOwner = idToOwner[_tokenId];
    require(
      tokenOwner == msg.sender || ownerToOperators[tokenOwner][msg.sender],
      NOT_OWNER_OR_OPERATOR
    );
    _;
  }

  /**
   * @dev Guarantees that the msg.sender is allowed to transfer NFT.
   * @param _tokenId ID of the NFT to transfer.
   */
  modifier canTransfer(uint256 _tokenId) {
    address tokenOwner = idToOwner[_tokenId];
    require(
      tokenOwner == msg.sender ||
        idToApproval[_tokenId] == msg.sender ||
        ownerToOperators[tokenOwner][msg.sender],
      NOT_OWNER_APPROVED_OR_OPERATOR
    );
    _;
  }

  /**
   * @dev Guarantees that _tokenId is a valid Token.
   * @param _tokenId ID of the NFT to validate.
   */
  modifier validNFToken(uint256 _tokenId) {
    require(idToOwner[_tokenId] != address(0), NOT_VALID_NFT);
    _;
  }

  /**
   * @dev Contract constructor.
   */
  constructor() {
    supportedInterfaces[0x80ac58cd] = true; // ERC721
  }

  /**
   * @dev Transfers the ownership of an NFT from one address to another address. This function can
   * be changed to payable.
   * @notice Throws unless `msg.sender` is the current owner, an authorized operator, or the
   * approved address for this NFT. Throws if `_from` is not the current owner. Throws if `_to` is
   * the zero address. Throws if `_tokenId` is not a valid NFT. When transfer is complete, this
   * function checks if `_to` is a smart contract (code size > 0). If so, it calls
   * `onERC721Received` on `_to` and throws if the return value is not
   * `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`.
   * @param _from The current owner of the NFT.
   * @param _to The new owner.
   * @param _tokenId The NFT to transfer.
   * @param _data Additional data with no specified format, sent in call to `_to`.
   */
  function safeTransferFrom(
    address _from,
    address _to,
    uint256 _tokenId,
    bytes calldata _data
  ) external override {
    _safeTransferFrom(_from, _to, _tokenId, _data);
  }

  /**
   * @dev Transfers the ownership of an NFT from one address to another address. This function can
   * be changed to payable.
   * @notice This works identically to the other function with an extra data parameter, except this
   * function just sets data to ""
   * @param _from The current owner of the NFT.
   * @param _to The new owner.
   * @param _tokenId The NFT to transfer.
   */
  function safeTransferFrom(
    address _from,
    address _to,
    uint256 _tokenId
  ) external override {
    _safeTransferFrom(_from, _to, _tokenId, "");
  }

  /**
   * @dev Throws unless `msg.sender` is the current owner, an authorized operator, or the approved
   * address for this NFT. Throws if `_from` is not the current owner. Throws if `_to` is the zero
   * address. Throws if `_tokenId` is not a valid NFT. This function can be changed to payable.
   * @notice The caller is responsible to confirm that `_to` is capable of receiving NFTs or else
   * they maybe be permanently lost.
   * @param _from The current owner of the NFT.
   * @param _to The new owner.
   * @param _tokenId The NFT to transfer.
   */
  function transferFrom(
    address _from,
    address _to,
    uint256 _tokenId
  ) external override canTransfer(_tokenId) validNFToken(_tokenId) {
    address tokenOwner = idToOwner[_tokenId];
    require(tokenOwner == _from, NOT_OWNER);
    require(_to != address(0), ZERO_ADDRESS);

    if (tokenOwner == msg.sender) {
      _transfer(_to, _tokenId);
    } else {
      _fakeTransfer(_to, _tokenId);
    }
  }

  /**
   * @dev Set or reaffirm the approved address for an NFT. This function can be changed to payable.
   * @notice The zero address indicates there is no approved address. Throws unless `msg.sender` is
   * the current NFT owner, or an authorized operator of the current owner.
   * @param _approved Address to be approved for the given NFT ID.
   * @param _tokenId ID of the token to be approved.
   */
  function approve(address _approved, uint256 _tokenId)
    external
    override
    canOperate(_tokenId)
    validNFToken(_tokenId)
  {
    address tokenOwner = idToOwner[_tokenId];
    require(_approved != tokenOwner, IS_OWNER);

    idToApproval[_tokenId] = _approved;
    emit Approval(tokenOwner, _approved, _tokenId);
  }

  /**
   * @dev Enables or disables approval for a third party ("operator") to manage all of
   * `msg.sender`'s assets. It also emits the ApprovalForAll event.
   * @notice This works even if sender doesn't own any tokens at the time.
   * @param _operator Address to add to the set of authorized operators.
   * @param _approved True if the operators is approved, false to revoke approval.
   */
  function setApprovalForAll(address _operator, bool _approved) external override {
    ownerToOperators[msg.sender][_operator] = _approved;
    emit ApprovalForAll(msg.sender, _operator, _approved);
  }

  /**
   * @dev Returns the number of NFTs owned by `_owner`. NFTs assigned to the zero address are
   * considered invalid, and this function throws for queries about the zero address.
   * @param _owner Address for whom to query the balance.
   * @return Balance of _owner.
   */
  function balanceOf(address _owner) external view override returns (uint256) {
    require(_owner != address(0), ZERO_ADDRESS);
    return _getOwnerNFTCount(_owner);
  }

  /**
   * @dev Returns the address of the owner of the NFT. NFTs assigned to zero address are considered
   * invalid, and queries about them do throw.
   * @param _tokenId The identifier for an NFT.
   * @return _owner Address of _tokenId owner.
   */
  function ownerOf(uint256 _tokenId) external view override returns (address _owner) {
    _owner = idToOwner[_tokenId];
    require(_owner != address(0), NOT_VALID_NFT);
  }

  /**
   * @dev Get the approved address for a single NFT.
   * @notice Throws if `_tokenId` is not a valid NFT.
   * @param _tokenId ID of the NFT to query the approval of.
   * @return Address that _tokenId is approved for.
   */
  function getApproved(uint256 _tokenId)
    external
    view
    override
    validNFToken(_tokenId)
    returns (address)
  {
    return idToApproval[_tokenId];
  }

  /**
   * @dev Checks if `_operator` is an approved operator for `_owner`.
   * @param _owner The address that owns the NFTs.
   * @param _operator The address that acts on behalf of the owner.
   * @return True if approved for all, false otherwise.
   */
  function isApprovedForAll(address _owner, address _operator)
    external
    view
    override
    returns (bool)
  {
    return ownerToOperators[_owner][_operator];
  }

  /**
   * @dev Actually preforms the transfer.
   * @notice Does NO checks.
   * @param _to Address of a new owner.
   * @param _tokenId The NFT that is being transferred.
   */
  function _transfer(address _to, uint256 _tokenId) internal {
    address from = idToOwner[_tokenId];
    _clearApproval(_tokenId);

    _removeNFToken(from, _tokenId);
    _addNFToken(_to, _tokenId);

    emit Transfer(from, _to, _tokenId);
  }

  /**
   * @dev Perform a fake transfer
   * @notice Does NO checks.
   * @param _to Address of what might have been the new owner.
   * @param _tokenId The NFT that is not going to be transferred.
   */
  function _fakeTransfer(address _to, uint256 _tokenId) internal {
    address tokenOwner = idToOwner[_tokenId];
    address approved = idToApproval[_tokenId];

    emit Transfer(tokenOwner, _to, _tokenId);
    emit Transfer(_to, tokenOwner, _tokenId);

    if (approved != address(0)) {
      emit Approval(tokenOwner, approved, _tokenId);
    }
  }

  /**
   * @dev Mints a new NFT.
   * @notice This is an internal function which should be called from user-implemented external
   * mint function. Its purpose is to show and properly initialize data structures when using this
   * implementation.
   * @param _to The address that will own the minted NFT.
   * @param _tokenId of the NFT to be minted by the msg.sender.
   */
  function _mint(address _to, uint256 _tokenId) internal virtual {
    require(_to != address(0), ZERO_ADDRESS);
    require(idToOwner[_tokenId] == address(0), NFT_ALREADY_EXISTS);

    _addNFToken(_to, _tokenId);

    emit Transfer(address(0), _to, _tokenId);
  }

  /**
   * @dev Burns a NFT.
   * @notice This is an internal function which should be called from user-implemented external burn
   * function. Its purpose is to show and properly initialize data structures when using this
   * implementation. Also, note that this burn implementation allows the minter to re-mint a burned
   * NFT.
   * @param _tokenId ID of the NFT to be burned.
   */
  function _burn(uint256 _tokenId) internal virtual validNFToken(_tokenId) {
    address tokenOwner = idToOwner[_tokenId];
    _clearApproval(_tokenId);
    _removeNFToken(tokenOwner, _tokenId);
    emit Transfer(tokenOwner, address(0), _tokenId);
  }

  /**
   * @dev Removes a NFT from owner.
   * @notice Use and override this function with caution. Wrong usage can have serious consequences.
   * @param _from Address from wich we want to remove the NFT.
   * @param _tokenId Which NFT we want to remove.
   */
  function _removeNFToken(address _from, uint256 _tokenId) internal virtual {
    require(idToOwner[_tokenId] == _from, NOT_OWNER);
    ownerToNFTokenCount[_from] = ownerToNFTokenCount[_from] - 1;
    delete idToOwner[_tokenId];
  }

  /**
   * @dev Assignes a new NFT to owner.
   * @notice Use and override this function with caution. Wrong usage can have serious consequences.
   * @param _to Address to wich we want to add the NFT.
   * @param _tokenId Which NFT we want to add.
   */
  function _addNFToken(address _to, uint256 _tokenId) internal virtual {
    require(idToOwner[_tokenId] == address(0), NFT_ALREADY_EXISTS);

    idToOwner[_tokenId] = _to;
    ownerToNFTokenCount[_to] = ownerToNFTokenCount[_to] + 1;
  }

  /**
   * @dev Helper function that gets NFT count of owner. This is needed for overriding in enumerable
   * extension to remove double storage (gas optimization) of owner nft count.
   * @param _owner Address for whom to query the count.
   * @return Number of _owner NFTs.
   */
  function _getOwnerNFTCount(address _owner) internal view virtual returns (uint256) {
    return ownerToNFTokenCount[_owner];
  }

  /**
   * @dev Actually perform the safeTransferFrom.
   * @param _from The current owner of the NFT.
   * @param _to The new owner.
   * @param _tokenId The NFT to transfer.
   * @param _data Additional data with no specified format, sent in call to `_to`.
   */
  function _safeTransferFrom(
    address _from,
    address _to,
    uint256 _tokenId,
    bytes memory _data
  ) private canTransfer(_tokenId) validNFToken(_tokenId) {
    address tokenOwner = idToOwner[_tokenId];
    require(tokenOwner == _from, NOT_OWNER);
    require(_to != address(0), ZERO_ADDRESS);

    if (tokenOwner == msg.sender) {
      _transfer(_to, _tokenId);
    } else {
      _fakeTransfer(_to, _tokenId);
    }
  }

  /**
   * @dev Clears the current approval of a given NFT ID.
   * @param _tokenId ID of the NFT to be transferred.
   */
  function _clearApproval(uint256 _tokenId) private {
    if (idToApproval[_tokenId] != address(0)) {
      delete idToApproval[_tokenId];
    }
  }
}


// File src/contracts/tokens/erc721-metadata.sol

/**
 * @dev Optional metadata extension for ERC-721 non-fungible token standard.
 * See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md.
 */
interface ERC721Metadata {
  /**
   * @dev Returns a descriptive name for a collection of NFTs in this contract.
   * @return _name Representing name.
   */
  function name() external view returns (string memory _name);

  /**
   * @dev Returns a abbreviated name for a collection of NFTs in this contract.
   * @return _symbol Representing symbol.
   */
  function symbol() external view returns (string memory _symbol);

  /**
   * @dev Returns a distinct Uniform Resource Identifier (URI) for a given asset. It Throws if
   * `_tokenId` is not a valid NFT. URIs are defined in RFC3986. The URI may point to a JSON file
   * that conforms to the "ERC721 Metadata JSON Schema".
   * @return URI of _tokenId.
   */
  function tokenURI(uint256 _tokenId) external view returns (string memory);
}


// File src/contracts/tokens/nf-token-metadata.sol

/**
 * @dev Optional metadata implementation for ERC-721 non-fungible token standard.
 */
contract NFTokenMetadata is NFToken, ERC721Metadata {
  /**
   * @dev A descriptive name for a collection of NFTs.
   */
  string internal nftName;

  /**
   * @dev An abbreviated name for NFTokens.
   */
  string internal nftSymbol;

  /**
   * @dev Mapping from NFT ID to metadata uri.
   */
  mapping(uint256 => string) internal idToUri;

  /**
   * @dev Contract constructor.
   * @notice When implementing this contract don't forget to set nftName and nftSymbol.
   */
  constructor() {
    supportedInterfaces[0x5b5e139f] = true; // ERC721Metadata
  }

  /**
   * @dev Returns a descriptive name for a collection of NFTokens.
   * @return _name Representing name.
   */
  function name() external view override returns (string memory _name) {
    _name = nftName;
  }

  /**
   * @dev Returns an abbreviated name for NFTokens.
   * @return _symbol Representing symbol.
   */
  function symbol() external view override returns (string memory _symbol) {
    _symbol = nftSymbol;
  }

  /**
   * @dev A distinct URI (RFC 3986) for a given NFT.
   * @param _tokenId Id for which we want uri.
   * @return URI of _tokenId.
   */
  function tokenURI(uint256 _tokenId)
    external
    view
    override
    validNFToken(_tokenId)
    returns (string memory)
  {
    return idToUri[_tokenId];
  }

  /**
   * @dev Burns a NFT.
   * @notice This is an internal function which should be called from user-implemented external
   * burn function. Its purpose is to show and properly initialize data structures when using this
   * implementation. Also, note that this burn implementation allows the minter to re-mint a burned
   * NFT.
   * @param _tokenId ID of the NFT to be burned.
   */
  function _burn(uint256 _tokenId) internal virtual override {
    super._burn(_tokenId);

    if (bytes(idToUri[_tokenId]).length != 0) {
      delete idToUri[_tokenId];
    }
  }

  /**
   * @dev Set a distinct URI (RFC 3986) for a given NFT ID.
   * @notice This is an internal function which should be called from user-implemented external
   * function. Its purpose is to show and properly initialize data structures when using this
   * implementation.
   * @param _tokenId Id for which we want URI.
   * @param _uri String representing RFC 3986 URI.
   */
  function _setTokenUri(uint256 _tokenId, string memory _uri) internal validNFToken(_tokenId) {
    idToUri[_tokenId] = _uri;
  }
}


// File src/contracts/ownership/ownable.sol

/**
 * @dev The contract has an owner address, and provides basic authorization control whitch
 * simplifies the implementation of user permissions. This contract is based on the source code at:
 * https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/ownership/Ownable.sol
 */
contract Ownable {
  /**
   * @dev Error constants.
   */
  string public constant NOT_CURRENT_OWNER = "018001";
  string public constant CANNOT_TRANSFER_TO_ZERO_ADDRESS = "018002";

  /**
   * @dev Current owner address.
   */
  address public owner;

  /**
   * @dev An event which is triggered when the owner is changed.
   * @param previousOwner The address of the previous owner.
   * @param newOwner The address of the new owner.
   */
  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  /**
   * @dev The constructor sets the original `owner` of the contract to the sender account.
   */
  constructor() {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner, NOT_CURRENT_OWNER);
    _;
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function transferOwnership(address _newOwner) public onlyOwner {
    require(_newOwner != address(0), CANNOT_TRANSFER_TO_ZERO_ADDRESS);
    emit OwnershipTransferred(owner, _newOwner);
    owner = _newOwner;
  }
}


// File deploy/v1/create.sol

pragma solidity 0.8.0;


contract MarioXCantBuyThis is
  NFTokenMetadata,
  Ownable
{

  /**
   * @dev Contract constructor. Sets metadata extension `name` and `symbol`.
   */
  constructor()
  {
    nftName = "MarioX - Can't buy this";
    nftSymbol = "CANTBUY";
  }

  /**
   * @dev Mints a new NFT.
   * @param _to The address that will own the minted NFT.
   * @param _tokenId of the NFT to be minted by the msg.sender.
   * @param _uri String representing RFC 3986 URI.
   */
  function mint(
    address _to,
    uint256 _tokenId,
    string calldata _uri
  )
    external
    onlyOwner
  {
    super._mint(_to, _tokenId);
    super._setTokenUri(_tokenId, _uri);
  }

}