// 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 "Address.h"

#include "Protobuf/ZilliqaMessage.pb.h"

#include "../Hash.h"

#include "../HexCoding.h"

#include "../uint256.h"

#include <cassert>

using namespace TW;

using namespace TW::Zilliqa;

static inline Data prependZero(Data& data) {

if (data.size() < 16) {

Data zero = Data(16 - data.size(), 0);

zero.insert(zero.end(), data.begin(), data.end());

return zero;

}

return Data(data);

}

Data Signer::getPreImage(const Proto::SigningInput& input) noexcept {

auto internal = ZilliqaMessage::ProtoTransactionCoreInfo();

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

Address address;

if (!Address::decode(input.to_address(), address)) {

// invalid input

return Data(0);

}

const auto pubKey = key.getPublicKey(TWPublicKeyTypeSECP256k1);

internal.set_version(input.version());

internal.set_nonce(input.nonce());

internal.set_toaddr(address.getKeyHash().data(), address.getKeyHash().size());

auto sender = new ZilliqaMessage::ByteArray();

sender->set_data(pubKey.bytes.data(), pubKey.bytes.size());

internal.set_allocated_senderpubkey(sender);

auto amountArray = new ZilliqaMessage::ByteArray();

auto amount = Data(input.amount().begin(), input.amount().end());

amount = prependZero(amount);

amountArray->set_data(amount.data(), amount.size());

internal.set_allocated_amount(amountArray);

auto gasPriceArray = new ZilliqaMessage::ByteArray();

auto gasPrice = Data(input.gas_price().begin(), input.gas_price().end());

gasPrice = prependZero(gasPrice);

gasPriceArray->set_data(gasPrice.data(), gasPrice.size());

internal.set_allocated_gasprice(gasPriceArray);

internal.set_gaslimit(input.gas_limit());

const auto serialized = internal.SerializeAsString();

return Data(serialized.begin(), serialized.end());

}

Proto::SigningOutput Signer::sign(const Data& preImage, const PrivateKey& key) noexcept {

auto output = Proto::SigningOutput();

const auto signature = key.signSchnorr(preImage, TWCurveSECP256k1);

output.set_signature(signature.data(), signature.size());

return output;

}