/*
    barrier -- mouse and keyboard sharing utility
    Copyright (C) Barrier contributors

    This package is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    found in the file LICENSE that should have accompanied this file.

    This package is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "base/String.h"
#include "FingerprintDatabase.h"
#include "io/filesystem.h"
#include <algorithm>
#include <fstream>

namespace barrier {

void FingerprintDatabase::read(const fs::path& path)
{
    std::ifstream file;
    open_utf8_path(file, path, std::ios_base::in);
    read_stream(file);
}

void FingerprintDatabase::write(const fs::path& path)
{
    std::ofstream file;
    open_utf8_path(file, path, std::ios_base::out);
    write_stream(file);
}

void FingerprintDatabase::read_stream(std::istream& stream)
{
    if (!stream.good()) {
        return;
    }

    std::string line;
    while (std::getline(stream, line)) {
        if (line.empty()) {
            continue;
        }

        auto fingerprint = parse_db_line(line);
        if (!fingerprint.valid()) {
            continue;
        }

        fingerprints_.push_back(fingerprint);
    }
}

void FingerprintDatabase::write_stream(std::ostream& stream)
{
    if (!stream.good()) {
        return;
    }

    for (const auto& fingerprint : fingerprints_) {
        stream << to_db_line(fingerprint) << "\n";
    }
}

void FingerprintDatabase::clear()
{
    fingerprints_.clear();
}

void FingerprintDatabase::add_trusted(const FingerprintData& fingerprint)
{
    if (is_trusted(fingerprint)) {
        return;
    }
    fingerprints_.push_back(fingerprint);
}

bool FingerprintDatabase::is_trusted(const FingerprintData& fingerprint)
{
    auto found_it = std::find(fingerprints_.begin(), fingerprints_.end(), fingerprint);
    return found_it != fingerprints_.end();
}

FingerprintData FingerprintDatabase::parse_db_line(const std::string& line)
{
    FingerprintData result;

    // legacy v1 certificate handling
    if (std::count(line.begin(), line.end(), ':') == 19 && line.size() == 40 + 19) {
        auto data = string::from_hex(line);
        if (data.empty()) {
            return result;
        }
        result.algorithm = fingerprint_type_to_string(FingerprintType::SHA1);
        result.data = data;
        return result;
    }

    auto version_end_pos = line.find(':');
    if (version_end_pos == std::string::npos) {
        return result;
    }
    if (line.substr(0, version_end_pos) != "v2") {
        return result;
    }
    auto algo_start_pos = version_end_pos + 1;
    auto algo_end_pos = line.find(':', algo_start_pos);
    if (algo_end_pos == std::string::npos) {
        return result;
    }
    auto algorithm = line.substr(algo_start_pos, algo_end_pos - algo_start_pos);
    auto data = string::from_hex(line.substr(algo_end_pos + 1));

    if (data.empty()) {
        return result;
    }

    result.algorithm = algorithm;
    result.data = data;
    return result;
}

std::string FingerprintDatabase::to_db_line(const FingerprintData& fingerprint)
{
    return "v2:" + fingerprint.algorithm + ":" + string::to_hex(fingerprint.data, 2);
}

} // namespace barrier