/*
	Copyright (C) 2005-2006 Feeling Software Inc.
	MIT License: http://www.opensource.org/licenses/mit-license.php
*/
/*
	Based on the FS Import classes:
	Copyright (C) 2005-2006 Feeling Software Inc
	Copyright (C) 2005-2006 Autodesk Media Entertainment
	MIT License: http://www.opensource.org/licenses/mit-license.php
*/

/**
	@file FCDEntityInstance.h
	This file contains the FCDEntityInstance class.
*/

#ifndef _FCD_ENTITY_INSTANCE_H_
#define _FCD_ENTITY_INSTANCE_H_

class FCDocument;
class FCDEntity;

#include "FCDocument/FCDObject.h"
#include "FCDocument/FCDEntity.h"

/**
	A COLLADA entity instance.
	COLLADA allows for quite a bit of per-instance settings
	for entities. This information is held by the up-classes of this class.
	This base class is simply meant to hold the entity that is instantiated.

	@ingroup FCDocument
*/
class FCOLLADA_EXPORT FCDEntityInstance : public FCDObject
{
public:
	/** The class type of the entity instance class.
		Used this information to up-cast an entity instance. */
	enum Type
	{
		SIMPLE, /**< A simple entity instance that has no per-instance information.
					This is used for lights and cameras in the visual scene graph and there is no up-class. */
		EXTERNAL_REFERENCE, /**< An external reference(FCDExternalReference). */
		GEOMETRY, /**< A geometry entity(FCDGeometryInstance). */
		MATERIAL, /**< A material entity(FCDMaterialInstance). */
		PHYSICS_MODEL, /**< A physics model(FCDPhysicsModelInstance). */
		PHYSICS_RIGID_BODY, /**< A physics rigid body(FCDPhysicsRigidBodyInstance). */
		PHYSICS_RIGID_CONSTRAINT /**< A physics rigid constraint(FCDPhysicsRigidConstraintInstance). */
	};

private:
	DeclareObjectType;
	FCDEntity* entity;

public:
	/** Constructor: do not use directly.
		Instead, use the appropriate allocation function.
		For scene node instance: FCDSceneNode::AddInstance.
		@param document The COLLADA document that owns the entity instance.
		@param entity The entity to instantiate. This pointer will be NULL
			for some up-classes where the entity instantiate is more complex. */
	FCDEntityInstance(FCDocument* document, FCDEntity* entity = NULL);

	/** Destructor: do not use directly.
		Instead, use the appropriate release funciton.
		For scene node instances: FCDSceneNode::ReleaseInstance. */
	virtual ~FCDEntityInstance();

	/** Retrieves the entity instance class type.
		This is used to determine the up-class for the entity instance object.
		@return The class type: SIMPLE for entity instances with no up-class. */
	virtual Type GetType() const { return SIMPLE; }

	/** Retrieves the instantiated entity.
		@return The instantiated entity. */
	inline FCDEntity* GetEntity() { return entity; }
	inline const FCDEntity* GetEntity() const { return entity; } /**< See above. */

	/** [INTERNAL] Reads in the entity instance from a given COLLADA XML tree node.
		@param UNUSED The COLLADA XML tree node.
		@return The status of the import. If the status is not successful,
			it may be dangerous to extract information from the instance.*/
	virtual FUStatus LoadFromXML(xmlNode* UNUSED(instanceNode)) { return FUStatus(true); }

	/** [INTERNAL] Writes out the entity instance to the given COLLADA XML tree node.
		@param parentNode The COLLADA XML parent node in which to insert the node.
		@return The created XML tree node. */
	virtual xmlNode* WriteToXML(xmlNode* parentNode) const;

protected:
	/** Sets the instantiated entity.
		This is used in up-classes to support different instantiation schemes.
		@param _entity The instantiated entity. */
	inline void SetEntity(FCDEntity* _entity) { entity = _entity; }

	/** [INTERNAL] Retrieves the COLLADA name for the instantiation of a given entity type.
		@param type The entity class type.
		@return The COLLADA name to instantiate an entity of the given class type. */
	static const char* GetInstanceClassType(FCDEntity::Type type);
};

#endif // _FCD_ENTITY_INSTANCE_H_