/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
* Copyright 2008-2010 Pelican Mapping
* http://osgearth.org
*
* osgEarth 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 program.  If not, see <http://www.gnu.org/licenses/>
*/
#ifndef OSGEARTH_ENGINE_OSGTERRAIN_STREAMING_TERRAIN
#define OSGEARTH_ENGINE_OSGTERRAIN_STREAMING_TERRAIN 1

#include "Terrain"
#include "StreamingTile"
#include <osgEarth/TaskService>

using namespace osgEarth;

/**
 * Terrain implementation that supports the SEQUENTIAL and PREEMPTIVE loading policies.
 */
class StreamingTerrain : public Terrain
{
public:
    StreamingTerrain(
        const MapFrame& update_mapf,
        const MapFrame& cull_mapf,
        OSGTileFactory* factory,
        bool            quickReleaseGLObjects );

    virtual const char* libraryName() const { return "osgEarth"; }
    virtual const char* className() const { return "StreamingTerrain"; }
    
    //override
    virtual Tile* createTile(const TileKey& key, GeoLocator* locator) const;

public:

    TaskService* getImageryTaskService(int layerId);
    TaskService* getElevationTaskService();
    TaskService* getTileGenerationTaskService();

    /**
     * Updates the catalog of task service threads - this gets called by the OSGTerrainEngine
     * in response to a change in the Map's data model. The map frame is that of the terrain
     * engine.
     */
    void updateTaskServiceThreads( const MapFrame& mapf );

    const LoadingPolicy& getLoadingPolicy() const { return _loadingPolicy; }

protected:

	virtual ~StreamingTerrain();

    //override
    virtual unsigned getNumActiveTasks() const;

    //override
    virtual void updateTraversal( osg::NodeVisitor& nv );

private:

    TaskService* createTaskService( const std::string& name, int id, int numThreads );
    TaskService* getTaskService( int id );

    void refreshFamily( const MapInfo& info, const TileKey& key, StreamingTile::Relative* family, bool tileTableLocked );

    typedef std::map< int, osg::ref_ptr< TaskService > > TaskServiceMap;

    TaskServiceMap     _taskServices;
    OpenThreads::Mutex _taskServiceMutex;
    int                _numLoadingThreads;
    LoadingPolicy      _loadingPolicy;
    UID                _elevationTaskServiceUID;
};

#endif // OSGEARTH_ENGINE_OSGTERRAIN_STREAMING_TERRAIN
