/** 
 * @file lllandmark.h
 * @brief Landmark asset class
 *
 * $LicenseInfo:firstyear=2002&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */


#ifndef LL_LLLANDMARK_H
#define LL_LLLANDMARK_H

#include <map>
#include <boost/function.hpp>
#include "llframetimer.h"
#include "lluuid.h"
#include "v3dmath.h"

class LLMessageSystem;
class LLHost;

class LLLandmark
{
public:
	// for calling back interested parties when a region handle comes back.
	typedef boost::function<void(const LLUUID& region_id, const U64& region_handle)> region_handle_callback_t;

	~LLLandmark() = default;

	// 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,
		region_handle_callback_t 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, region_handle_callback_t> region_callback_map_t;
	static region_callback_map_t sRegionCallbackMap;
};

#endif
