//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: 
//
// $NoKeywords: $
//
//=============================================================================//

#ifndef ENTITYLIST_H
#define ENTITYLIST_H

#ifdef _WIN32
#pragma once
#endif

#include "baseentity.h"

class IEntityListener;

abstract_class CBaseEntityClassList
{
public:
	CBaseEntityClassList();
	~CBaseEntityClassList();
	virtual void LevelShutdownPostEntity() = 0;

	CBaseEntityClassList *m_pNextClassList;
};

template< class T >
class CEntityClassList : public CBaseEntityClassList
{
public:
	virtual void LevelShutdownPostEntity()  { m_pClassList = NULL; }

	void Insert( T *pEntity )
	{
		pEntity->m_pNext = m_pClassList;
		m_pClassList = pEntity;
	}

	void Remove( T *pEntity )
	{
		T **pPrev = &m_pClassList;
		T *pCur = *pPrev;
		while ( pCur )
		{
			if ( pCur == pEntity )
			{
				*pPrev = pCur->m_pNext;
				return;
			}
			pPrev = &pCur->m_pNext;
			pCur = *pPrev;
		}
	}

	static T *m_pClassList;
};

// Derive a class from this if you want to filter entity list searches
abstract_class IEntityFindFilter
{
public:
	virtual bool ShouldFindEntity( CBaseEntity *pEntity ) = 0;
	virtual CBaseEntity *GetFilterResult( void ) = 0;
};

//-----------------------------------------------------------------------------
// Purpose: a global list of all the entities in the game.  All iteration through
//			entities is done through this object.
//-----------------------------------------------------------------------------
class CGlobalEntityList : public CBaseEntityList
{
public:
private:
	int m_iHighestEnt; // the topmost used array index
	int m_iNumEnts;
	int m_iNumEdicts;

	bool m_bClearingEntities;
	CUtlVector<IEntityListener *>	m_entityListeners;

public:
	IServerNetworkable* GetServerNetworkable( CBaseHandle hEnt ) const;
	CBaseNetworkable* GetBaseNetworkable( CBaseHandle hEnt ) const;
	CBaseEntity* GetBaseEntity( CBaseHandle hEnt ) const;
	edict_t* GetEdict( CBaseHandle hEnt ) const;
	
	int NumberOfEntities( void );
	int NumberOfEdicts( void );

	// mark an entity as deleted
	void AddToDeleteList( IServerNetworkable *ent );
	// call this before and after each frame to delete all of the marked entities.
	void CleanupDeleteList( void );
	int ResetDeleteList( void );

	// frees all entities in the game
	void Clear( void );

	// Returns true while in the Clear() call.
	bool	IsClearingEntities()	{return m_bClearingEntities;}
	
	// add a class that gets notified of entity events
	void AddListenerEntity( IEntityListener *pListener );
	void RemoveListenerEntity( IEntityListener *pListener );

	void ReportEntityFlagsChanged( CBaseEntity *pEntity, unsigned int flagsOld, unsigned int flagsNow );

	// entity is about to be removed, notify the listeners
	void NotifyCreateEntity( CBaseEntity *pEnt );
	void NotifySpawn( CBaseEntity *pEnt );
	void NotifyRemoveEntity( CBaseHandle hEnt );
	// iteration functions

	// returns the next entity after pCurrentEnt;  if pCurrentEnt is NULL, return the first entity
	CBaseEntity *NextEnt( CBaseEntity *pCurrentEnt );
	CBaseEntity *FirstEnt() { return NextEnt(NULL); }

	// returns the next entity of the specified class, using RTTI
	template< class T >
	T *NextEntByClass( T *start )
	{
		for ( CBaseEntity *x = NextEnt( start ); x; x = NextEnt( x ) )
		{
			start = dynamic_cast<T*>( x );
			if ( start )
				return start;
		}
		return NULL;
	}

	// search functions
	bool		 IsEntityPtr( void *pTest );
	CBaseEntity *FindEntityByClassname( CBaseEntity *pStartEntity, const char *szName );
	CBaseEntity *FindEntityByName( CBaseEntity *pStartEntity, const char *szName, CBaseEntity *pSearchingEntity = NULL, CBaseEntity *pActivator = NULL, CBaseEntity *pCaller = NULL, IEntityFindFilter *pFilter = NULL );
	CBaseEntity *FindEntityByName( CBaseEntity *pStartEntity, string_t iszName, CBaseEntity *pSearchingEntity = NULL, CBaseEntity *pActivator = NULL, CBaseEntity *pCaller = NULL, IEntityFindFilter *pFilter = NULL )
	{
		return FindEntityByName( pStartEntity, STRING(iszName), pSearchingEntity, pActivator, pCaller, pFilter );
	}
	CBaseEntity *FindEntityInSphere( CBaseEntity *pStartEntity, const Vector &vecCenter, float flRadius );
	CBaseEntity *FindEntityByTarget( CBaseEntity *pStartEntity, const char *szName );
	CBaseEntity *FindEntityByModel( CBaseEntity *pStartEntity, const char *szModelName );

	CBaseEntity *FindEntityByNameNearest( const char *szName, const Vector &vecSrc, float flRadius, CBaseEntity *pSearchingEntity = NULL, CBaseEntity *pActivator = NULL, CBaseEntity *pCaller = NULL );
	CBaseEntity *FindEntityByNameWithin( CBaseEntity *pStartEntity, const char *szName, const Vector &vecSrc, float flRadius, CBaseEntity *pSearchingEntity = NULL, CBaseEntity *pActivator = NULL, CBaseEntity *pCaller = NULL );
	CBaseEntity *FindEntityByClassnameNearest( const char *szName, const Vector &vecSrc, float flRadius );
	CBaseEntity *FindEntityByClassnameWithin( CBaseEntity *pStartEntity , const char *szName, const Vector &vecSrc, float flRadius );
	CBaseEntity *FindEntityByClassnameWithin( CBaseEntity *pStartEntity , const char *szName, const Vector &vecMins, const Vector &vecMaxs );

	CBaseEntity *FindEntityGeneric( CBaseEntity *pStartEntity, const char *szName, CBaseEntity *pSearchingEntity = NULL, CBaseEntity *pActivator = NULL, CBaseEntity *pCaller = NULL );
	CBaseEntity *FindEntityGenericWithin( CBaseEntity *pStartEntity, const char *szName, const Vector &vecSrc, float flRadius, CBaseEntity *pSearchingEntity = NULL, CBaseEntity *pActivator = NULL, CBaseEntity *pCaller = NULL );
	CBaseEntity *FindEntityGenericNearest( const char *szName, const Vector &vecSrc, float flRadius, CBaseEntity *pSearchingEntity = NULL, CBaseEntity *pActivator = NULL, CBaseEntity *pCaller = NULL );
	
	CBaseEntity *FindEntityNearestFacing( const Vector &origin, const Vector &facing, float threshold);
	CBaseEntity *FindEntityClassNearestFacing( const Vector &origin, const Vector &facing, float threshold, char *classname);

	CBaseEntity *FindEntityProcedural( const char *szName, CBaseEntity *pSearchingEntity = NULL, CBaseEntity *pActivator = NULL, CBaseEntity *pCaller = NULL );
	
	CGlobalEntityList();

// CBaseEntityList overrides.
protected:

	virtual void OnAddEntity( IHandleEntity *pEnt, CBaseHandle handle );
	virtual void OnRemoveEntity( IHandleEntity *pEnt, CBaseHandle handle );

};

extern CGlobalEntityList gEntList;


//-----------------------------------------------------------------------------
// Inlines.
//-----------------------------------------------------------------------------
inline edict_t* CGlobalEntityList::GetEdict( CBaseHandle hEnt ) const
{
	IServerUnknown *pUnk = static_cast<IServerUnknown*>(LookupEntity( hEnt ));
	if ( pUnk )
		return pUnk->GetNetworkable()->GetEdict();
	else
		return NULL;
}

inline CBaseNetworkable* CGlobalEntityList::GetBaseNetworkable( CBaseHandle hEnt ) const
{
	IServerUnknown *pUnk = static_cast<IServerUnknown*>(LookupEntity( hEnt ));
	if ( pUnk )
		return pUnk->GetNetworkable()->GetBaseNetworkable();
	else
		return NULL;
}

inline IServerNetworkable* CGlobalEntityList::GetServerNetworkable( CBaseHandle hEnt ) const
{
	IServerUnknown *pUnk = static_cast<IServerUnknown*>(LookupEntity( hEnt ));
	if ( pUnk )
		return pUnk->GetNetworkable();
	else
		return NULL;
}

inline CBaseEntity* CGlobalEntityList::GetBaseEntity( CBaseHandle hEnt ) const
{
	IServerUnknown *pUnk = static_cast<IServerUnknown*>(LookupEntity( hEnt ));
	if ( pUnk )
		return pUnk->GetBaseEntity();
	else
		return NULL;
}


//-----------------------------------------------------------------------------
// Common finds
#if 0

template <class ENT_TYPE>
inline bool FindEntityByName( const char *pszName, ENT_TYPE **ppResult)
{
	CBaseEntity *pBaseEntity = gEntList.FindEntityByName( NULL, pszName );
	
	if ( pBaseEntity )
		*ppResult = dynamic_cast<ENT_TYPE *>( pBaseEntity );
	else
		*ppResult = NULL;

	return ( *ppResult != NULL );
}

template <>
inline bool FindEntityByName<CBaseEntity>( const char *pszName, CBaseEntity **ppResult)
{
	*ppResult = gEntList.FindEntityByName( NULL, pszName );
	return ( *ppResult != NULL );
}

template <>
inline bool FindEntityByName<CAI_BaseNPC>( const char *pszName, CAI_BaseNPC **ppResult)
{
	CBaseEntity *pBaseEntity = gEntList.FindEntityByName( NULL, pszName );
	
	if ( pBaseEntity )
		*ppResult = pBaseEntity->MyNPCPointer();
	else
		*ppResult = NULL;

	return ( *ppResult != NULL );
}
#endif
//-----------------------------------------------------------------------------
// Purpose: Simple object for storing a list of objects
//-----------------------------------------------------------------------------
struct entitem_t
{
	EHANDLE hEnt;
	struct entitem_t *pNext;

	// uses pool memory
	static void* operator new( size_t stAllocateBlock );
	static void *operator new( size_t stAllocateBlock, int nBlockUse, const char *pFileName, int nLine );
	static void operator delete( void *pMem );
	static void operator delete( void *pMem, int nBlockUse, const char *pFileName, int nLine ) { operator delete( pMem ); }
};

class CEntityList
{
public:
	CEntityList();
	~CEntityList();

	int m_iNumItems;
	entitem_t *m_pItemList;	// null terminated singly-linked list

	void AddEntity( CBaseEntity * );
	void DeleteEntity( CBaseEntity * );
};

enum notify_system_event_t
{
	NOTIFY_EVENT_TELEPORT = 0,
	NOTIFY_EVENT_DESTROY,
};

struct notify_teleport_params_t
{
	Vector prevOrigin;
	QAngle prevAngles;
	bool physicsRotate;
};

struct notify_destroy_params_t
{
};

struct notify_system_event_params_t
{
	union
	{
		const notify_teleport_params_t *pTeleport;
		const notify_destroy_params_t *pDestroy;
	};
	notify_system_event_params_t( const notify_teleport_params_t *pInTeleport ) { pTeleport = pInTeleport; }
	notify_system_event_params_t( const notify_destroy_params_t *pInDestroy ) { pDestroy = pInDestroy; }
};


abstract_class INotify
{
public:
	// Add notification for an entity
	virtual void AddEntity( CBaseEntity *pNotify, CBaseEntity *pWatched ) = 0;

	// Remove notification for an entity
	virtual void RemoveEntity( CBaseEntity *pNotify, CBaseEntity *pWatched ) = 0;

	// Call the named input in each entity who is watching pEvent's status
	virtual void ReportNamedEvent( CBaseEntity *pEntity, const char *pEventName ) = 0;

	// System events don't make sense as inputs, so are handled through a generic notify function
	virtual void ReportSystemEvent( CBaseEntity *pEntity, notify_system_event_t eventType, const notify_system_event_params_t &params ) = 0;

	inline void ReportDestroyEvent( CBaseEntity *pEntity )
	{
		notify_destroy_params_t destroy;
		ReportSystemEvent( pEntity, NOTIFY_EVENT_DESTROY, notify_system_event_params_t(&destroy) );
	}
	
	inline void ReportTeleportEvent( CBaseEntity *pEntity, const Vector &prevOrigin, const QAngle &prevAngles, bool physicsRotate )
	{
		notify_teleport_params_t teleport;
		teleport.prevOrigin = prevOrigin;
		teleport.prevAngles = prevAngles;
		teleport.physicsRotate = physicsRotate;
		ReportSystemEvent( pEntity, NOTIFY_EVENT_TELEPORT, notify_system_event_params_t(&teleport) );
	}
	
	// Remove this entity from the notify list
	virtual void ClearEntity( CBaseEntity *pNotify ) = 0;
};

// Implement this class and register with gEntList to receive entity create/delete notification
class IEntityListener
{
public:
	virtual void OnEntityCreated( CBaseEntity *pEntity ) {};
	virtual void OnEntitySpawned( CBaseEntity *pEntity ) {};
	virtual void OnEntityDeleted( CBaseEntity *pEntity ) {};
};

// singleton
extern INotify *g_pNotify;

void EntityTouch_Add( CBaseEntity *pEntity );
int AimTarget_ListCount();
int AimTarget_ListCopy( CBaseEntity *pList[], int listMax );
void AimTarget_ForceRepopulateList();

void SimThink_EntityChanged( CBaseEntity *pEntity );
int SimThink_ListCount();
int SimThink_ListCopy( CBaseEntity *pList[], int listMax );

#endif // ENTITYLIST_H