[ERC3589] NFTで複数の資産を管理・一括送付する仕組みを理解しよう！

pragma solidity ^0.8.0;

interface AssemblyNFTInterface {

  event AssemblyAsset(address indexed firstHolder,
                    uint256 indexed tokenId,
                    uint256 salt,
                    address[] addresses,
                    uint256[] numbers);

  /**
  * @dev hash function assigns the combination of assets with salt to bytes32 signature that is also the token id.
  * @param `_salt` prevents hash collision, can be chosen by user input or increasing nonce from contract.
  * @param `_addresses` concat assets addresses, e.g. [ERC-20_address1, ERC-20_address2, ERC-721_address_1, ERC-1155_address_1, ERC-1155_address_2]
  * @param `_numbers` describes how many eth, ERC-20 token addresses length, ERC-721 token addresses length, ERC-1155 token addresses length,
  * ERC-20 token amounts, ERC-721 token ids, ERC-1155 token ids and amounts.
  */
  function hash(uint256 _salt, address[] memory _addresses, uint256[] memory _numbers) external pure returns (uint256 tokenId);

  /// @dev to assemble lossless assets
  /// @param `_to` the receiver of the assembly token
  function mint(address _to, address[] memory _addresses, uint256[] memory _numbers) payable external returns(uint256 tokenId);

  /// @dev mint with additional logic that calculates the actual received value for tokens.
  function safeMint(address _to, address[] memory _addresses, uint256[] memory _numbers) payable external returns(uint256 tokenId);

  /// @dev burn this token and releases assembled assets
  /// @param `_to` to which address the assets is released
  function burn(address _to, uint256 _tokenId, uint256 _salt, address[] calldata _addresses, uint256[] calldata _numbers) external;

}

event AssemblyAsset(address indexed firstHolder, uint256 indexed tokenId, uint256 salt, address[] addresses, uint256[] numbers);

function hash(uint256 _salt, address[] memory _addresses, uint256[] memory _numbers) external pure returns (uint256 tokenId);

function mint(address _to, address[] memory _addresses, uint256[] memory _numbers) payable external returns(uint256 tokenId);

function safeMint(address _to, address[] memory _addresses, uint256[] memory _numbers) payable external returns(uint256 tokenId);

function burn(address _to, uint256 _tokenId, uint256 _salt, address[] calldata _addresses, uint256[] calldata _numbers) external;

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol";
import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
import "@openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol";
import "./AssemblyNFTInterface.sol";

abstract contract AssemblyNFT is ERC721, ERC721Holder, ERC1155Holder, AssemblyNFTInterface{
  using SafeERC20 for IERC20;

  function supportsInterface(bytes4 interfaceId) public view virtual override(ERC721, ERC1155Receiver) returns (bool) {
        return ERC721.supportsInterface(interfaceId) || ERC1155Receiver.supportsInterface(interfaceId);
  }

  uint256 nonce;

  /**
  * layout of _addresses:
  *     erc20 addresses | erc721 addresses | erc1155 addresses
  * layout of _numbers:
  *     eth | erc20.length | erc721.length | erc1155.length | erc20 amounts | erc721 ids | erc1155 ids | erc1155 amounts
   */

  function hash(uint256 _salt, address[] memory _addresses, uint256[] memory _numbers) public pure override returns (uint256 tokenId){
      bytes32 signature = keccak256(abi.encodePacked(_salt));
      for(uint256 i=0; i< _addresses.length; i++){
        signature = keccak256(abi.encodePacked(signature, _addresses[i]));
      }
      for(uint256 j=0; j<_numbers.length; j++){
        signature = keccak256(abi.encodePacked(signature, _numbers[j]));
      }
      assembly {
        tokenId := signature
      }
  }

  function mint(address _to, address[] memory _addresses, uint256[] memory _numbers) payable external override returns(uint256 tokenId){
      require(_to != address(0), "can't mint to address(0)");
      require(msg.value == _numbers[0], "value not match");
      require(_addresses.length == _numbers[1] + _numbers[2] + _numbers[3], "2 array length not match");
      require(_addresses.length == _numbers.length -4 - _numbers[3], "numbers length not match");
      uint256 pointerA; //points to first erc20 address, if there is any
      uint256 pointerB =4; //points to first erc20 amount, if there is any
      for(uint256 i = 0; i< _numbers[1]; i++){
        require(_numbers[pointerB] > 0, "transfer erc20 0 amount");
        IERC20(_addresses[pointerA++]).safeTransferFrom(_msgSender(), address(this), _numbers[pointerB++]);
      }
      for(uint256 j = 0; j< _numbers[2]; j++){
        IERC721(_addresses[pointerA++]).safeTransferFrom(_msgSender(), address(this), _numbers[pointerB++]);
      }
      for(uint256 k =0; k< _numbers[3]; k++){
        IERC1155(_addresses[pointerA++]).safeTransferFrom(_msgSender(), address(this), _numbers[pointerB], _numbers[_numbers[3] + pointerB++], "");
      }
      tokenId = hash(nonce, _addresses, _numbers);
      super._mint(_to, tokenId);
      emit AssemblyAsset(_to, tokenId, nonce, _addresses, _numbers);
      nonce ++;
  }

  function safeMint(address _to, address[] memory _addresses, uint256[] memory _numbers) payable external override returns(uint256 tokenId){
      require(_to != address(0), "can't mint to address(0)");
      require(msg.value == _numbers[0], "value not match");
      require(_addresses.length == _numbers[1] + _numbers[2] + _numbers[3], "2 array length not match");
      require(_addresses.length == _numbers.length -4 - _numbers[3], "numbers length not match");
      uint256 pointerA; //points to first erc20 address, if there is any
      uint256 pointerB =4; //points to first erc20 amount, if there is any
      for(uint256 i = 0; i< _numbers[1]; i++){
        require(_numbers[pointerB] > 0, "transfer erc20 0 amount");
        IERC20 token = IERC20(_addresses[pointerA++]);
        uint256 orgBalance = token.balanceOf(address(this));
        token.safeTransferFrom(_msgSender(), address(this), _numbers[pointerB]);
        _numbers[pointerB++] = token.balanceOf(address(this)) - orgBalance;
      }
      for(uint256 j = 0; j< _numbers[2]; j++){
        IERC721(_addresses[pointerA++]).safeTransferFrom(_msgSender(), address(this), _numbers[pointerB++]);
      }
      for(uint256 k =0; k< _numbers[3]; k++){
        IERC1155(_addresses[pointerA++]).safeTransferFrom(_msgSender(), address(this), _numbers[pointerB], _numbers[_numbers[3] + pointerB++], "");
      }
      tokenId = hash(nonce, _addresses, _numbers);
      super._mint(_to, tokenId);
      emit AssemblyAsset(_to, tokenId, nonce, _addresses, _numbers);
      nonce ++;
  }

  function burn(address _to, uint256 _tokenId, uint256 _salt, address[] calldata _addresses, uint256[] calldata _numbers) override external {
      require(_msgSender() == ownerOf(_tokenId), "not owned");
      require(_tokenId == hash(_salt, _addresses, _numbers));
      super._burn(_tokenId);
      payable(_to).transfer(_numbers[0]);
      uint256 pointerA; //points to first erc20 address, if there is any
      uint256 pointerB =4; //points to first erc20 amount, if there is any
      for(uint256 i = 0; i< _numbers[1]; i++){
        require(_numbers[pointerB] > 0, "transfer erc20 0 amount");
        IERC20(_addresses[pointerA++]).safeTransfer(_to, _numbers[pointerB++]);
      }
      for(uint256 j = 0; j< _numbers[2]; j++){
        IERC721(_addresses[pointerA++]).safeTransferFrom(address(this), _to, _numbers[pointerB++]);
      }
      for(uint256 k =0; k< _numbers[3]; k++){
        IERC1155(_addresses[pointerA++]).safeTransferFrom(address(this), _to, _numbers[pointerB], _numbers[_numbers[3] + pointerB++], "");
      }
  }

}