// Copyright © 2017-2020 Trust Wallet.

//

// This file is part of Trust. The full Trust copyright notice, including

// terms governing use, modification, and redistribution, is contained in the

// file LICENSE at the root of the source code distribution tree.

#include "Signer.h"

#include "Base64.h"

#include "../HexCoding.h"

using namespace TW;

using namespace TW::Nebulas;

Proto::SigningOutput Signer::sign(Proto::SigningInput &input) const noexcept {

Transaction tx(Address(input.from_address()),

load(input.nonce()),

load(input.gas_price()),

load(input.gas_limit()),

Address(input.to_address()),

load(input.amount()),

load(input.timestamp()),

input.payload()

);

auto privateKey = PrivateKey(Data(input.private_key().begin(), input.private_key().end()));

sign(privateKey, tx);

auto protoOutput = Proto::SigningOutput();

protoOutput.set_algorithm(tx.algorithm);

protoOutput.set_signature(reinterpret_cast<const char *>(tx.signature.data()), tx.signature.size());

protoOutput.set_raw(TW::Base64::encode(tx.raw));

return protoOutput;

}

void Signer::sign(const PrivateKey &privateKey, Transaction &transaction) const noexcept {

transaction.hash = this->hash(transaction);

transaction.chainID = chainID;

transaction.algorithm = 1;

transaction.signature = privateKey.sign(transaction.hash, TWCurveSECP256k1);

transaction.serializeToRaw();

}

Data Signer::hash(const Transaction &transaction) const noexcept {

auto encoded = Data();

auto payload = Data();

auto data = Transaction::newPayloadData(transaction.payload);

payload.resize(data->ByteSize());

data->SerializePartialToArray(payload.data(),(int)payload.size());

delete data;

encoded.insert(encoded.end(), transaction.from.bytes.begin(), transaction.from.bytes.end());

encoded.insert(encoded.end(), transaction.to.bytes.begin(), transaction.to.bytes.end());

encode256BE(encoded, transaction.amount, 128);

encode256BE(encoded, transaction.nonce, 64);

encode256BE(encoded, transaction.timestamp, 64);

encoded.insert(encoded.end(), payload.begin(), payload.end());

encode256BE(encoded, chainID, 32);

encode256BE(encoded, transaction.gasPrice, 128);

encode256BE(encoded, transaction.gasLimit, 128);

return Hash::sha3_256(encoded);

}