// File: contracts/NANOHUB.sol



//SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

import '@openzeppelin/contracts/access/Ownable.sol';

interface INFT {
  function mintNEWELF(address to, uint tokenId) external;
  function exist(uint tokenId) external view returns (bool);
  function ownerOf(uint tokenId) external view returns (address);
  function transferFrom(address from, address to, uint id) external;
  function balanceOf(address owner) external view returns (uint256);
}

/// @author orion
contract NANOHUB is Ownable {
  INFT _ELFOOZ;
  INFT _NEWELF;

  constructor(address ELFOOZ, address NEWELF) {
    _ELFOOZ = INFT(ELFOOZ);
    _NEWELF = INFT(NEWELF);
  }

  function mintNEWELF(uint tokenId)
  public {
    require(!_NEWELF.exist(tokenId), "error NEWELF.exist");
    require(msg.sender == _ELFOOZ.ownerOf(tokenId), "error ELFOOZ.owner");
    _NEWELF.mintNEWELF(msg.sender, tokenId);
  }

  function batchMintNEWELF(uint256[] memory tokenIds)
  public {
    uint i = 0;
    uint balance = _ELFOOZ.balanceOf(msg.sender);
    require(balance == tokenIds.length, "error balance is invalid");
    while (i < balance) {
      uint tokenId = tokenIds[i];
      if (!_NEWELF.exist(tokenId)) {
        require(!_NEWELF.exist(tokenId), "error NEWELF.exist");
        require(msg.sender == _ELFOOZ.ownerOf(tokenId), "error ELFOOZ.owner");
        _NEWELF.mintNEWELF(msg.sender, tokenId);
      }
      i++;
    }
  }

  function recallNEWELF(uint tokenId)
  public {
    require(_NEWELF.exist(tokenId), "error NEWELF.exist");
    require(msg.sender != _NEWELF.ownerOf(tokenId), "error NEWELF.owner");
    require(msg.sender == _ELFOOZ.ownerOf(tokenId), "error ELFOOZ.owner");

    address newelfOwner = _NEWELF.ownerOf(tokenId);
    _NEWELF.transferFrom(newelfOwner, msg.sender, tokenId);
  }

  function batchRecallNEWELF(uint256[] memory tokenIds)
  public {
    uint i = 0;
    uint balance = _ELFOOZ.balanceOf(msg.sender);
    require(balance == tokenIds.length, "error balance is invalid");
    while (i < balance) {
      uint tokenId = tokenIds[i];
      require(msg.sender == _ELFOOZ.ownerOf(tokenId), "error ELFOOZ.owner");
      require(_NEWELF.exist(tokenId), "error NEWELF.exist");
      if (msg.sender != _NEWELF.ownerOf(tokenId)) {
        address newelfOwner = _NEWELF.ownerOf(tokenId);
        _NEWELF.transferFrom(newelfOwner, msg.sender, tokenId);
      }
      i++;
    }
  }

  function transferNEWELF(address to, uint tokenId)
  public {
    require(msg.sender == _NEWELF.ownerOf(tokenId), "error NEWELF.owner");
    require(_NEWELF.exist(tokenId), "error NEWELF.exist");

    _NEWELF.transferFrom(msg.sender, to, tokenId);
  }
}
// File: @openzeppelin/contracts/access/Ownable.sol



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

pragma solidity ^0.8.0;

import "../utils/Context.sol";

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

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

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

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

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

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

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions 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/Context.sol



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

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}