/*
   core/entity.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_ENTITY_H__
#define __INCLUDED_CORE_ENTITY_H__

#include <iostream>
#include <string>
#include <map>

#include "model/model.h"
#include "math/axis.h"
#include "math/mathlib.h"

namespace core
{

class Entity;
class EntityControlable;

}

#include "core/clientstate.h"
#include "core/player.h"

namespace core
{

/// The base world entity. All gameworld entities must derive from this class.
class Entity
{
public:
	/// Entity flags
	/**
 	 * entities with the Static flag set will not get client-side interpolation
	 */
	enum Flags {Static=1, Solid=2, Bright=4};

	/// Entity type constants
	enum Type {Default=0, Dynamic=1, Controlable=2, Globe=3};

	/// Entity shape constants
	enum Shape {Diamond=0, Sphere=1, Cube=2, Axis=3};

	/// create a new entity and add it to the registry
	Entity(unsigned int flags = 0);

	/// create an entity froms stream data
	Entity(std::istream & is);

	/// destroy an entity
	virtual ~Entity();

/*----- inspectors ------------------------------------------------ */
	
	/// entity id
	inline unsigned int id() const { return entity_id; }
	
	/// module type id
	inline unsigned int moduletype() const { return entity_moduletypeid; }

	///  core type id
	virtual inline unsigned int type() const { return Default; }

	/// entity flags
	inline unsigned int flags() const { return entity_flags; }

	/// entity name (can not contain double qoutes ")
	inline std::string const & name() { return entity_name; }

	/// entity model name
	inline std::string const & modelname() { return entity_modelname; }

	/// entity client render state
	inline ClientState * state() { return entity_clientstate; }

	/// pointer to the model, is used client-side
	inline model::Model * model() { return entity_model; }

	/// dirty flag
	inline bool dirty() const { return entity_dirty; }

	/// entity location
	inline math::Vector3f & location() { return entity_location; }

	/// local coordinate system of the entity
	inline math::Axis & axis() { return entity_axis; }
	
	/// base color of the entity
	inline math::Color const & color() const { return entity_color; }

	/// base shape of the entity
	inline Shape shape() const { return entity_shape; }

	/// base radius of the entity
	inline float radius() const { return entity_radius; }

	/// serialize the entity to a stream
	virtual void serialize(std::ostream & os) const;

	/// serialize a client-to-server update on a stream
	virtual void serialize_client_update(std::ostream & os) const;

	/// serialize a server-to-client update on a stream
	virtual void serialize_server_update(std::ostream & os) const;


/*----- mutators -------------------------------------------------- */

	/// receive a client-to-server update from a stream
	virtual void recieve_client_update(std::istream &is);

	/// receive a server-to-client update from a stream
	virtual void recieve_server_update(std::istream &is);

	/// mark the entity as destroyed
	inline void die() { entity_destroyed = true; }

	/// runs one game frame for the entity
	/**
	 * The default implementation does nothing
	 */
	virtual void frame(float seconds);

/*----- static ---------------------------------------------------- */
	
	/// the entity registry
 	static std::map<unsigned int, Entity*> registry;

	/// find an entity in the registry
	static Entity *find(unsigned int id);

	/// remove one entity from the registry and deletes it
	static void remove(unsigned int entity_id);

	/// list the entity registry
	static void list();

	/* entity_ variables can be set by the module */
	math::Vector3f 		entity_location;
	math::Axis		entity_axis;

	float 			entity_radius;
	std::string		entity_name;
	std::string		entity_modelname;
	model::Model		*entity_model;
	Shape 			entity_shape;	
	math::Color 		entity_color;
	unsigned int		entity_moduletypeid;
	unsigned int 		entity_flags;

	bool			entity_dirty;
	bool 			entity_created;
	bool			entity_destroyed;

	/// timestamp when entity data was received from the server
	float			entity_servertimestamp;

	ClientState		*entity_clientstate;

private:
	/// add an entity to the registry
	static void add(Entity *ent);

	/// add an entity with id to the registry
	void add(Entity *ent, unsigned int id);

	/// the id is set by add()
	unsigned int		entity_id;
};


/// an entity that can move around in the game world
class EntityDynamic : public Entity
{
public:
	/// create a dynamic entity
	EntityDynamic(unsigned int flags = 0);

	/// create a dynamic entity from stream data
	EntityDynamic(std::istream & is);

	virtual ~EntityDynamic();


/*----- inspectors ------------------------------------------------ */
	/// core type id
	virtual inline unsigned int type() const { return Entity::Dynamic; }

	/// current speed of the entity in game units per second
	inline float speed() const { return entity_speed; }

	/// serialize the entity to a stream
	virtual void serialize(std::ostream & os) const;

	/// serialize a client-to-server update on a stream
	virtual void serialize_client_update(std::ostream & os) const ;

	/// serialize a server-to-client update on a stream
	virtual void serialize_server_update(std::ostream & os) const;

/*----- mutators -------------------------------------------------- */

	/// receive a client-to-server update from a stream
	virtual void recieve_client_update(std::istream &is);

	/// receive a server-to-client update from a stream
	virtual void recieve_server_update(std::istream &is);

	/// runs one game frame for the entity
	/**
	 * The default implementation will update the position() of the entity,
	 * determined by its speed() and axis()
	 */
	virtual void frame(float seconds);

	/// speed of the entity
	float			entity_speed;	
};

/// an entity that can be controlled by a player
class EntityControlable : public EntityDynamic
{
public:
	/// create a controlable entity
	EntityControlable(Player *player, unsigned int flags = 0);

	/// create a controlable entity from stream data
	EntityControlable(std::istream & is);
	
	virtual ~EntityControlable();


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

	/// core type id
	virtual inline unsigned int type() const { return Entity::Controlable; }

	/// owner of this entity
	inline Player *owner() const { return entity_owner; }

	/// thrust
	inline float thrust() const { return entity_thrust; }

	/// serialize the entity to a stream
	virtual void serialize(std::ostream & os) const;

	/// serialize a client-to-server update on a stream
	virtual void serialize_client_update(std::ostream & os) const;

	/// serialize a server-to-client update on a stream
	virtual void serialize_server_update(std::ostream & os) const;


/*----- mutators -------------------------------------------------- */

	/// receive a client-to-server update from a stream
	virtual void recieve_client_update(std::istream &is);

	/// receive a server-to-client update from a stream
	virtual void recieve_server_update(std::istream &is);

	/// set the target thrust
	void set_thrust(float thrust);

	/// set the target direction
	void set_direction(float direction);

	/// set the target pitch
	void set_pitch(float pitch);

	/// set  target roll
	void set_roll(float roll);

	/// runs one game frame for the entity
	/**
	 * The default implementation will set direction() and thrust() to the desired targets
	 * and calls its parent frame() funcion.
	 */
	virtual void frame(float seconds);

	/* entity_ variables can be set by the module */
	/// owner of the entity
	Player			*entity_owner;
	/// current thrust
	float			entity_thrust;

	/* target_ variables can be set by the client */
	/// target thrust as set by the client
	float			target_thrust;
	/// target direction as set by the client
	/** target_direction must be in the [-1, 1] range
	 */
	float			target_direction;
	/// target pitch as set by the client
	/** target_pitch must be in the [-1, 1] range
	 */
	float 			target_pitch;
	/// target roll as set by the client
	/** target_roll must be in the [-1, 1] range
	 */
	float target_roll;
};

/// a Globe entity
class EntityGlobe : public Entity 
{
public:
	EntityGlobe(unsigned int flags = 0);
	EntityGlobe(std::istream & is);

	~EntityGlobe();

	virtual void serialize(std::ostream & os) const;

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

	/// core type id
	virtual inline unsigned int type() const { return Entity::Globe; }

	std::string		entity_texture;

	/// client side, texture id
	unsigned int		render_texture;
};

}

#endif // __INCLUDED_CORE_ENTITY_H__