/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */
#include <fstream>

#include <boost/algorithm/string.hpp>

#include "katja/sbo.hpp"

namespace katja
{
    info_file::info_file(const std::string& program_name, const std::string& version,
            const std::string homepage, const std::string& email, const std::string& maintainer)
        : program_name(program_name), version(version), homepage(homepage), email(email), maintainer(maintainer)
    {
    }

    sbo_repository::sbo_repository(const std::filesystem::path& repository_path)
    {
        search_for_slackbuilds(this->info_paths, repository_path);
    }

    std::vector<package_identifier> sbo_repository::get_updates(const package_database& database)
    {
        std::vector<package_identifier> identifiers;

        for (const auto& [package_name, package] : database)
        {
            auto looked_up_info_path = this->info_paths.find(package_name);

            if (looked_up_info_path != this->info_paths.cend())
            {
                auto slackbuild_info = read_slackbuild_info(looked_up_info_path->second);

                if (slackbuild_info.has_value() && slackbuild_info.value().version != package.version)
                {
                    identifiers.push_back({
                        slackbuild_info->program_name, slackbuild_info->version, package.architecture, "SBo"
                    });
                }

            }
        }
        return identifiers;
    }

    bool trim_info_line(std::string& info_value)
    {
        if (boost::algorithm::ends_with(info_value, "\""))
        {
            info_value.pop_back();
            return false;
        }
        else if (boost::algorithm::ends_with(info_value, "\\"))
        {
            info_value.pop_back();
            return true;
        }
        return false;
    }

    std::optional<info_file> read_slackbuild_info(const std::filesystem::path& info_filepath)
    {
        std::ifstream info_stream{ info_filepath };
        std::string info_line, info_variable, info_value;
        std::string program_name, version, homepage, email, maintainer;
        std::vector<std::string> download, md5sum, download_x86_64, md5sum_x86_64, requires;
        bool continuation{ false };

        while (std::getline(info_stream, info_line))
        {
            if (info_line.empty())
            {
                continue;
            }
            else if (!continuation)
            {
                auto equals_position = std::find(info_line.cbegin(), info_line.cend(), '=');
                info_variable = std::string(info_line.cbegin(), equals_position);

                if (equals_position == info_line.cend()
                        || ++equals_position == info_line.cend() || *equals_position != '"')
                {
                    return std::nullopt;
                }
                info_value = std::string(std::next(equals_position), info_line.cend());
            }
            else
            {
                info_value += info_line;
            }
            continuation = trim_info_line(info_value);

            if (!continuation)
            {
                if (info_variable == "PRGNAM")
                {
                    std::swap(program_name, info_value);
                }
                else if (info_variable == "VERSION")
                {
                    std::swap(version, info_value);
                }
                else if (info_variable == "HOMEPAGE")
                {
                    std::swap(homepage, info_value);
                }
                else if (info_variable == "EMAIL")
                {
                    std::swap(email, info_value);
                }
                else if (info_variable == "MAINTAINER")
                {
                    std::swap(maintainer, info_value);
                }
                else if (info_variable == "DOWNLOAD")
                {
                    boost::split(download, info_value, boost::is_any_of(" "), boost::token_compress_on);
                }
                else if (info_variable == "MD5SUM")
                {
                    boost::split(md5sum, info_value, boost::is_any_of(" "), boost::token_compress_on);
                }
                else if (info_variable == "DOWNLOAD_x86_64")
                {
                    boost::split(download_x86_64, info_value, boost::is_any_of(" "), boost::token_compress_on);
                }
                else if (info_variable == "MD5SUM_x86_64")
                {
                    boost::split(md5sum_x86_64, info_value, boost::is_any_of(" "), boost::token_compress_on);
                }
                else if (info_variable == "REQUIRES")
                {
                    boost::split(requires, info_value, boost::is_any_of(" "), boost::token_compress_on);
                }
           }
        }
        return std::make_optional<info_file>(program_name, version, homepage, email, maintainer);
    }

    void search_for_slackbuilds(std::vector<info_file>& info_files, const std::filesystem::path& directory)
    {
        std::map<std::string, std::filesystem::path> info_paths;

        search_for_slackbuilds(info_paths, directory);
        for (const auto& [_, info_filepath] : info_paths)
        {
            auto slackbuild_info = read_slackbuild_info(info_filepath);

            if (slackbuild_info.has_value())
            {
                info_files.emplace_back(std::move(slackbuild_info.value()));
            }
        }
    }

    void search_for_slackbuilds(std::map<std::string, std::filesystem::path>& info_files,
            const std::filesystem::path& directory)
    {
        for (const auto& entry : std::filesystem::directory_iterator(directory))
        {
            std::filesystem::path entry_path = entry;
            std::filesystem::path info_filename = entry_path.filename();
            info_filename.replace_extension(".info");

            std::filesystem::path info_filepath = entry_path / info_filename;

            if (std::filesystem::exists(info_filepath))
            {
                info_files.emplace(entry_path.filename(), info_filepath);
            }
            else if (std::filesystem::is_directory(entry_path))
            {
                search_for_slackbuilds(info_files, entry_path);
            }
        }
    }
}