etc-contract.solidity

pragma solidity 0.5.1;


contract TrademarkRegistration {
    struct TradeMark {
        string phrase;
        string authorName;
        uint256 timestamp;
        bytes32 proof;
    }

    mapping (bytes32 => bool) private trademarkLookup;
    mapping (bytes32 => TradeMark) public trademarkRegistry;
    
    function checkTradeMark(string memory phrase) public view returns (bool) {
        bytes32 proof = phraseProof(phrase);
        return trademarkLookup[proof];
    }

    function registerTradeMark(string memory document, string memory author) public returns (bool){
        if (checkTradeMark(document) == false) {
            bytes32 proofHash = phraseProof(document);
            TradeMark memory trademark = TradeMark({
                phrase: document,
                authorName: author,
                timestamp: now,
                proof: proofHash
            });
            trademarkLookup[proofHash] = true;
            trademarkRegistry[proofHash] = trademark;
            return true;
        }
        return false;
    }

    function phraseProof(string memory phrase) public view returns (bytes32) {
        return sha256(abi.encode(phrase));
    }

    function getTradeMarkData(string memory phrase) 
        public view returns 
        (string memory document, 
         string memory authorName, 
         uint256 timestamp, 
         bytes32 proof) {
        TradeMark memory t = trademarkRegistry[phraseProof(phrase)];
        return (t.phrase, t.authorName, t.timestamp, t.proof);
    }
}