팀부문 Smart Contract

LoveChainSimple.sol

pragma solidity >=0.4.24 <=0.5.6;

contract LoveChainSimple {
    string public name = "LoveChain";
    string public symbol = "LC";

    mapping (uint256 => address) public tokenOwner;
    mapping (uint256 => string) public tokenCoupleName;
    mapping (uint256 => uint256) public tokenLevel;

    mapping (uint256 => string) private _tokenImageURIs;
    mapping (address => uint256[]) private _ownerTokens;

    bytes4 private constant _KIP17_RECEIVED = 0x6745782b;

    function mintWithImageURI(address to, uint256 tokenId, uint256 level, string memory imageURI) public returns (bool) {
        tokenOwner[tokenId] = address(to);
        _tokenImageURIs[tokenId] = imageURI;
        tokenLevel[tokenId] = level;

        _ownerTokens[address(to)].push(tokenId);

        return true;
    }

    function safeTransferFromLevelOneToken(address from, address to, uint256 tokenId, string memory name1, string memory name2, bytes memory _data) public {
        // 기본 (이름만 기록할 수 있는) 토큰(레벨 1) 전송 함수
        require(from == msg.sender, "from != msg.sender");
        require(from == tokenOwner[tokenId], "you are not the owner of the token");
        require(tokenLevel[tokenId] == 1, "you are not level 1 token's owner");
        
        _removeTokenFromList(from, tokenId);
        _ownerTokens[to].push(tokenId);

        tokenOwner[tokenId] = to;
        _lockingCoupleName(tokenId, name1, name2);

        require(
            _checkOnKIP17Received(from, to, tokenId, _data), "KIP17: transfer to non KIPReceiver implementer"
        );
    }

    function _checkOnKIP17Received(address from, address to, uint256 tokenId, bytes memory _data) internal returns (bool) {
        bool success;
        bytes memory returndata;

        if (!isContract(to)) {
            return true;
        }

        (success, returndata) = to.call(
            abi.encodeWithSelector(
                _KIP17_RECEIVED,
                msg.sender,
                from,
                tokenId,
                _data
            )
        );
        if (
            returndata.length != 0 &&
            abi.decode(returndata, (bytes4)) == _KIP17_RECEIVED
        ) {
            return true;
        }
        return false;
    }
    
    function isContract(address account) internal view returns (bool) {
        uint256 size;
        assembly { size := extcodesize(account)}
        return size > 0;
    }

    function _removeTokenFromList(address from, uint256 tokenId) private {
        for (uint256 i = 0; i < _ownerTokens[from].length; i++) {
            if (tokenId == _ownerTokens[from][i]) {
                _ownerTokens[from][i] = _ownerTokens[from][_ownerTokens[from].length - 1];
                break;
            }
        }
        _ownerTokens[from].length--;
    }

    function _lockingCoupleName(uint256 tokenId, string memory name1, string memory name2) private {
        tokenCoupleName[tokenId] = string(abi.encodePacked(name1, "&", name2));
    }

    function ownedTokens(address owner) public view returns (uint256[] memory) {
        return _ownerTokens[owner];
    }

    function coupleNamesOf(uint256 tokenId) public view returns (string memory) {
        // 토큰 소유 커플의 이름을 보여주는 함수
        return tokenCoupleName[tokenId];
    }

}

contract NSeoulTowerMarket {

    mapping (uint256 => address) public seller;

    function buyLevelOneLoveChain(uint256 tokenId, address NFTAddress, string memory name1, string memory name2) public payable returns (bool) {
        // 기본 (이름만 기록할 수 있는) 토큰(레벨 1) 구매 함수
        // name1, name2 를 입력받아서 스마트 컨트랙트 LoveChainSimple에 기록한다.

        address payable receiver = address(uint256(seller[tokenId]));

        receiver.transfer(10 ** 16);
        LoveChainSimple(NFTAddress).safeTransferFromLevelOneToken(address(this), msg.sender, tokenId, name1, name2, "0x00");

        return true;
    }

    function onKIP17Received(address operator, address from, uint256 tokenId, bytes memory data) public returns (bytes4) {
        require(tokenId <= 500, "This token is not placed in NSeoulTower"); // 마켓이 받은 NFT가 남산타워의 것이 맞는지?
        seller[tokenId] = from;

        return bytes4(keccak256("onKIP17Received(address,address,uint256,bytes)"));
    }
}