// 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 "../Hash.h"

#include "../HexCoding.h"

#include "../PrivateKey.h"

#include "../uint256.h"

#include <boost/multiprecision/cpp_int.hpp>

#include <nlohmann/json.hpp>

#include <algorithm>

#include <iostream>

#include <sstream>

using namespace TW;

using namespace TW::Icon;

std::string to_hex(int64_t i) {

std::stringstream ss;

ss << "0x" << std::hex << i;

return ss.str();

}

std::string to_hex(const std::string& n) {

auto s = hex(n);

auto start = std::find_if(s.begin(), s.end(), [](auto c) { return c != '0'; });

if (start == s.end()) {

return "0x0";

}

return "0x" + std::string(start, s.end());

}

std::map<std::string, std::string> Signer::parameters() const noexcept {

auto params = std::map<std::string, std::string>();

params["from"] = input.from_address();

params["to"] = input.to_address();

params["timestamp"] = to_hex(input.timestamp());

params["nonce"] = to_hex(input.nonce());

params["stepLimit"] = to_hex(input.step_limit());

params["value"] = to_hex(input.value());

params["nid"] = to_hex(input.network_id());

params["version"] = "0x3";

return params;

}

std::string Signer::preImage() const noexcept {

std::string txHash = "icx_sendTransaction";

const auto params = parameters();

for (auto [key, value] : params) {

txHash += "." + key + "." + value;

}

return txHash;

}

std::string Signer::encode(const Data& signature) const noexcept {

auto json = nlohmann::json();

json["from"] = input.from_address();

json["to"] = input.to_address();

json["timestamp"] = to_hex(input.timestamp());

json["nonce"] = to_hex(input.nonce());

json["stepLimit"] = to_hex(input.step_limit());

json["value"] = to_hex(input.value());

json["nid"] = to_hex(input.network_id());

json["version"] = "0x3";

json["signature"] = Base64::encode(signature);

return json.dump();

}

Proto::SigningOutput Signer::sign() const noexcept {

const auto hash = Hash::sha3_256(Signer::preImage());

const auto key = PrivateKey(input.private_key());

const auto signature = key.sign(hash, TWCurveSECP256k1);

auto output = Proto::SigningOutput();

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

auto encoded = encode(Data(signature.begin(), signature.end()));

output.set_encoded(encoded.data(), encoded.size());

return output;

}