/**
 * @file script.hpp
 * Manages all Lua scripts.
 *
 * Copyright (C) 2019  Belle-Isle, Andrew <drumsetmonkey@gmail.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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/>.
 */

#ifndef SCRIPT_HPP_
#define SCRIPT_HPP_

#include <entityx/entityx.h>
#include <sol/sol.hpp>

struct EntitySpawnEvent {
    EntitySpawnEvent (sol::object ref)
        : ref(ref) {}

    sol::object ref;
};

/**
 * @class ScriptSystem
 * Handles all the game's scripting requests
 */
class ScriptSystem : public entityx::System<ScriptSystem>
                   , public entityx::Receiver<ScriptSystem>
{
    private:
        /**
         * The script systems internal lua state that handles all
         * interactions between C and Lua
         */
        sol::state lua;

        entityx::EventManager* events;
        entityx::EntityManager* manager;

    public:
        ScriptSystem(void)
        {}

        ~ScriptSystem(void)
        {}

        /**
         * Prepares the system for running.
         */
        void configure([[maybe_unused]]entityx::EntityManager& entities,
                       [[maybe_unused]]entityx::EventManager& events) final;
        
        /**
         * Updates the scripting system.
         */
        void update([[maybe_unused]] entityx::EntityManager& entites,
                    [[maybe_unused]] entityx::EventManager& events,
                    [[maybe_unused]] entityx::TimeDelta dt) final;

        /**
         * Receives all entity spawning events and manages the
         * script counterpart.
         */
        void receive (const EntitySpawnEvent &toSpawn);

        /**
         * Initializes the lua states and libraries.
         * @return Zero on success, non-zero on error
         */
        int init(void);

        /**
         * Run the initialization file.
         */
        void doFile(void);

        /**
         * The function called by lua scripts in order to spawn an entity.
         */
        sol::table spawn(sol::object param);

        /**
         * Contains all calls that export components/functions to lua.
         */
        void scriptExport();
};

#endif//SCRIPT_HPP_