/* -*-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_FEATURES_VIRTUAL_FEATURE_SOURCE
#define OSGEARTH_FEATURES_VIRTUAL_FEATURE_SOURCE

#include <osgEarthUtil/Common>
#include <osgEarthFeatures/FeatureSource>
#include <osgEarth/Layer>
#include <vector>

namespace osgEarth { namespace Features
{
    using namespace osgEarth;
    using namespace osgEarth::Features;
    using namespace osgEarth::Symbology;

    /**
     * Predicate that tells the multiplexer whether to accept or reject a 
     * feature for a given renderer.
     */
    struct OSGEARTHFEATURES_EXPORT FeaturePredicate : public osg::Referenced
    {
        virtual bool acceptFeature( Feature* f ) const =0;
    };

    // internal class
    struct FeatureSourceMapping
    {
        FeatureSourceMapping(FeatureSource* fs, FeaturePredicate* fp) : _source(fs), _predicate(fp) { }
        osg::ref_ptr<FeatureSource>      _source;
        osg::ref_ptr<FeaturePredicate>   _predicate;
    };
    typedef std::vector<FeatureSourceMapping> FeatureSourceMappingVector;


    class OSGEARTHFEATURES_EXPORT VirtualFeatureSource : public FeatureSource
    {
    public:
        /** Construct a new virtual feature source */
        VirtualFeatureSource() { }

        /**
         * Adds a feature source/predicate mapping. This FeatureSource will draw
         * from "source" and filter based on the predicate.
         */
        void add( FeatureSource* source, FeaturePredicate* predicate );

    public: // FeatureSource
        virtual FeatureCursor* createFeatureCursor( const Query& query );
		virtual void initialize( const std::string& referenceURI );
        virtual const FeatureProfile* createFeatureProfile();

    protected:
        FeatureSourceMappingVector _sources;
    };

} } // namespace osgEarth::Features

#endif // OSGEARTH_FEATURES_VIRTUAL_FEATURE_SOURCE
