const Ethers = require('ethers');
const utils = require("./utils");

const TRX_MESSAGE_HEADER = '\x19TRON Signed Message:\n32';

module.exports.tronVerifyMessage = function (message = false, signature = false, address) {

  if(!utils.isHex(message))
    return false;

  if(message.substr(0, 2) == '0x')
    message = message.substring(2);

  if(signature.substr(0, 2) == '0x')
    signature = signature.substr(2);

  const messageBytes = [
    ...Ethers.utils.toUtf8Bytes(TRX_MESSAGE_HEADER),
    ...utils.code.hexStr2byteArray(message)
  ];

  const messageDigest = Ethers.utils.keccak256(messageBytes);
  const recovered = Ethers.utils.recoverAddress(messageDigest, {
    recoveryParam: signature.substring(128, 130) == '1c' ? 1 : 0,
    r: '0x' + signature.substring(0, 64),
    s: '0x' + signature.substring(64, 128)
  });

  const tronAddress = '41' + recovered.substr(2);
  const base58Address = fromHex(tronAddress);

  if (base58Address == fromHex(address))
    return true;

  return false;
};


function fromHex(address) {
  if(!utils.isHex(address))
    return address;

  return utils.crypto.getBase58CheckAddress(
      utils.code.hexStr2byteArray(address.replace(/^0x/,'41'))
  );
}