// Copyright (c) 2017 Egor Tensin <Egor.Tensin@gmail.com>
// This file is part of the "PDB repository" project.
// For details, see https://github.com/egor-tensin/pdb-repo.
// Distributed under the MIT License.

#pragma once

#pragma warning(push, 0)
#include <boost/filesystem.hpp>
#include <boost/program_options.hpp>
#pragma warning(pop)

#include <exception>
#include <iostream>
#include <ostream>
#include <string>

namespace
{
    class SettingsParser
    {
    public:
        explicit SettingsParser(const std::string& argv0)
            : prog_name{extract_filename(argv0)}
        {
            visible.add_options()
                ("help,h",
                    "show this message and exit");
        }

        virtual ~SettingsParser() = default;

        virtual const char* get_short_description() const
        {
            return "[--option VALUE]...";
        }

        virtual void parse(int argc, char* argv[])
        {
            boost::program_options::options_description all;
            all.add(hidden).add(visible);
            boost::program_options::variables_map vm;
            boost::program_options::store(
                boost::program_options::command_line_parser{argc, argv}
                    .options(all)
                    .positional(positional)
                    .run(),
                vm);
            if (vm.count("help"))
                exit_with_usage = true;
            else
                boost::program_options::notify(vm);
        }

        bool exit_with_usage = false;

        void usage() const
        {
            std::cout << *this;
        }

        void usage_error(const std::exception& e) const
        {
            std::cerr << "usage error: " << e.what() << '\n';
            std::cerr << *this;
        }

    protected:
        boost::program_options::options_description hidden;
        boost::program_options::options_description visible;
        boost::program_options::positional_options_description positional;

    private:
        static std::string extract_filename(const std::string& path)
        {
            return boost::filesystem::path{path}.filename().string();
        }

        const std::string prog_name;

        friend std::ostream& operator<<(std::ostream& os, const SettingsParser& parser)
        {
            const auto short_descr = parser.get_short_description();
            os << "usage: " << parser.prog_name << ' ' << short_descr << '\n';
            os << parser.visible;
            return os;
        }
    };
}