/*
   core/gameinterface.h
   This file is part of the Osirion project and is distributed under
   the terms of the GNU General Public License version 2
*/

#ifndef __INCLUDED_CORE_GAMEINTERFACE_H__
#define __INCLUDED_CORE_GAMEINTERFACE_H__

#include "core/player.h"

namespace core
{

/// abstract interface from the core to the game-specific code
class GameInterface
{
public:
	/// create a new game
	GameInterface();

	/// destroy the game
	virtual ~GameInterface();

	/// type definition for the Players collection
	typedef std::list<Player *> Players;

/*----- inspectors ---------------------------------------------- */
	
	/// return the local player
	inline Player *localplayer() { return &game_localplayer; }

	/// return the server time of the last received server frame
	inline float serverframetime() const { return game_serverframetime; }

	/// return the server time of the previous received server frame
	inline float previousframetime() const { return game_previousframetime; }

	/// return the server time of the previous received server frame
	inline float clientframetime() const { return game_clientframetime; }

	/// client frame time between previousframetime and serverframetime, from 0 - 1
	float timeoffset();

	inline float timestep() const { return game_timestep; }

	inline Players & players() { return game_players; }
	
	/// show a list of connected players
	void list_players();

/*----- virtual inspectors --------------------------------------- */

	/// returns true if the game server can run a time frime
	virtual bool running() = 0;

	/// returns true if the game is running an interactive module
	virtual bool interactive() = 0;

/*-----  mutators ------------------------------------------------- */
	
	/// clear all game variables, game functions and entities
	void clear();

	/// reset the client state
	void reset_clientstate(float timestamp, float prevtimestamp);

	/// update the client state timers
	void update_clientstate(float seconds);

	void update_entity_clientstate(Entity *entity);

/*----- virtual mutators ------------------------------------------ */
	
	/// run one game time frame
	/// @param seconds time since the previous frame, in seconds
	virtual void frame(float seconds) = 0;

protected:
	/// the local player
	static Player 			game_localplayer;

	/// all the players
	Players				game_players;
	
	float				game_serverframetime;
	float				game_previousframetime;

	float				game_timestep;
	float				game_clientframetime;

	unsigned int			game_serverframelength;
};

/// global local player instance
Player *localplayer();

/// global local control instance
EntityControlable *localcontrol();

}

#endif // __INCLUDED_CORE_GAMEINTERFACE_H__