/** 
 * @file lllandmark.h
 * @brief Landmark asset class
 *
 * Copyright (c) 2002-$CurrentYear$, Linden Research, Inc.
 * $License$
 */


#ifndef LL_LLLANDMARK_H
#define LL_LLLANDMARK_H

#include <map>
#include "llframetimer.h"
#include "lluuid.h"
#include "v3dmath.h"

class LLMessageSystem;
class LLHost;

// virutal base class used for calling back interested parties when a
// region handle comes back.
class LLRegionHandleCallback
{
public:
	LLRegionHandleCallback() {}
	virtual ~LLRegionHandleCallback() {}
	virtual bool dataReady(
		const LLUUID& region_id,
		const U64& region_handle)
	{
		return true;
	}
};

class LLLandmark
{
public:
	~LLLandmark() {}

	// returns true if the position is known.
	bool getGlobalPos(LLVector3d& pos);

	// setter used in conjunction if more information needs to be
	// collected from the server.
	void setGlobalPos(const LLVector3d& pos);

	// return true if the region is known
	bool getRegionID(LLUUID& region_id);

	// return the local coordinates if known
	LLVector3 getRegionPos() const;

	// constructs a new LLLandmark from a string
	// return NULL if there's an error
	static LLLandmark* constructFromString(const char *buffer);

	// register callbacks that this class handles
	static void registerCallbacks(LLMessageSystem* msg);

	// request information about region_id to region_handle.Pass in a
	// callback pointer which will be erase but NOT deleted after the
	// callback is made. This function may call into the message
	// system to get the information.
	static void requestRegionHandle(
		LLMessageSystem* msg,
		const LLHost& upstream_host,
		const LLUUID& region_id,
		LLRegionHandleCallback* callback);

	// Call this method to create a lookup for this region. This
	// simplifies a lot of the code.
	static void setRegionHandle(const LLUUID& region_id, U64 region_handle);
		
private:
	LLLandmark();
	LLLandmark(const LLVector3d& pos);

	static void processRegionIDAndHandle(LLMessageSystem* msg, void**);
	static void expireOldEntries();

private:
	LLUUID mRegionID;
	LLVector3 mRegionPos;
	bool mGlobalPositionKnown;
	LLVector3d mGlobalPos;
	
	struct CacheInfo
	{
		U64 mRegionHandle;
		LLFrameTimer mTimer;
	};

	static std::pair<LLUUID, U64> mLocalRegion;
	typedef std::map<LLUUID, CacheInfo> region_map_t;
	static region_map_t mRegions;
	typedef std::multimap<LLUUID, LLRegionHandleCallback*> region_callback_t;
	static region_callback_t mRegionCallback;
};

#endif