#include <filesystem>
#include <iostream>
#include <fstream>
#include <algorithm>
#include <optional>
#include <boost/algorithm/string.hpp>
#include "katja/database.hpp"

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;
}

struct info_file
{
    const std::string program_name;
    const std::string version;
    const std::string homepage;
    const std::string email;
    const std::string maintainer;

    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)
    {
    }
};

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)
{
    for (const auto& entry : std::filesystem::directory_iterator(directory))
    {
        std::filesystem::path entry_path = entry;
        std::filesystem::path info_filename = entry_path;
        info_filename.replace_extension(".info");

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

        if (std::filesystem::exists(info_filepath))
        {
            auto slackbuild_info = read_slackbuild_info(info_filepath);

            if (slackbuild_info.has_value())
            {
                info_files.emplace_back(std::move(slackbuild_info.value()));
            }
            else
            {
                std::cout << info_filepath << std::endl;
            }
        }
        else if (std::filesystem::is_directory(entry_path))
        {
            search_for_slackbuilds(info_files, entry_path);
        }
    }
}

int main(int argc, const char **argv)
{
    std::vector<info_file> info_files;

    if (argc > 1)
    {
        std::filesystem::path slackbuild_repository{ argv[1] };

        search_for_slackbuilds(info_files, slackbuild_repository);
        for (const auto& slackbuild_info : info_files)
        {
            std::cout << slackbuild_info.program_name << " " << slackbuild_info.version << " " << std::endl;
        }
    }
    else
    {
        for (const auto& entry : std::filesystem::directory_iterator(katja::database))
        {
            katja::database_package database_entry{ entry.path().filename() };

            std::cout << database_entry.to_string() << std::endl;
        }
    }
    return 0;
}