/*
 * 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/.
 */
module;

#include <variant>
#include <string>
#include <stdexcept>
#include <algorithm>
#include <cstring>

#include <boost/program_options.hpp>

export module katja.command_line;

namespace katja
{
    export enum class command
    {
        updates,
        search,
        help
    };

    export struct command_line
    {
        const command type;
        const std::vector<std::string> arguments;
    };

    export class invalid_command_error : public std::runtime_error
    {
        const std::string command;

    public:
        invalid_command_error()
            : std::runtime_error("Expecting the command line to begin with a command.")
        {
        }

        invalid_command_error(const std::string& invalid_command)
            : command{ invalid_command },
            std::runtime_error("Unknown command given on the command line.")
        {
        }
    };

    export command_line parse_command_line(int argc, const char **argv)
    {
        if (argc == 1)
        {
            throw invalid_command_error();
        }
        std::vector<std::string> arguments;
        std::copy(argv + 2, argv + argc, std::back_inserter(arguments));

        if (strcmp("updates", argv[1]) == 0)
        {
            return command_line{ command::updates, std::move(arguments) };
        }
        if (strcmp("search", argv[1]) == 0)
        {
            return command_line{ command::search, std::move(arguments) };
        }
        if (strcmp("help", argv[1]) == 0)
        {
            return command_line{ command::help, std::move(arguments) };
        }
        throw invalid_command_error(argv[1]);
    }
}