/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
 * Copyright 2018 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_TRAVERSAL_DATA_H
#define OSGEARTH_TRAVERSAL_DATA_H 1

#include <osgEarth/Common>
#include <osgEarth/ThreadingUtils>
//#include <osgEarth/Horizon>
#include <osgEarth/Containers>
//#include <osg/Version>
#include <osg/NodeVisitor>
#include <osg/observer_ptr>
#include <map>

// osgEarth node masks for controlling traversals
#define OSGEARTH_MASK_TERRAIN_SURFACE    0x01
#define OSGEARTH_MASK_TERRAIN_LAND_COVER 0x02
#define OSGEARTH_MASK_TERRAIN            (OSGEARTH_MASK_TERRAIN_SURFACE | OSGEARTH_MASK_TERRAIN_LAND_COVER)
#define OSGEARTH_MASK_MAP_MODEL_GROUP    0x04


namespace osgEarth
{
    class MapNode;

    // internal utility class supporing VisitorData
    class OSGEARTH_EXPORT TransientUserDataStore
    {
    public:
        void store(osg::Referenced* owner, const std::string& key, osg::Referenced* data);

        osg::Referenced* fetch(osg::Referenced* owner, const std::string& key) const;

        bool exists(osg::Referenced* owner, const std::string& key) const;

        int size() const;

        void remove(osg::Referenced* owner, const std::string& key);
        
    protected:
        typedef fast_map<std::string, osg::ref_ptr<osg::Referenced> > StringTable;

        struct DataPair {
            osg::observer_ptr<osg::Referenced> _owner;
            StringTable                    _data;
        };

        typedef fast_map<void*, DataPair> Table;

        Table _table;

        mutable Threading::Mutex _mutex;

        static bool isObserverInvalid(const Table::entry_t&);

    public:
        static bool unitTest();
    };

    struct OSGEARTH_EXPORT VisitorData
    {
        static bool isSet(osg::NodeVisitor& nv, const std::string& key);

        struct Install : public osg::NodeCallback
        {
            osg::ref_ptr<osg::Referenced> _data;
            std::string _key;

            Install(const std::string& key) : _key(key) { }
            Install(const std::string& key, osg::Referenced* data) : _data(data), _key(key) { }

            void operator()(osg::Node* node, osg::NodeVisitor* nv)
            {
                VisitorData::store(*nv, _key, _data.get());
                traverse(node, nv);
                //VisitorData::clear(*nv, _key);
            }
        };

        static bool store(osg::NodeVisitor& nv, const std::string& key, osg::Referenced* object);

        template<typename T> static T* fetch(osg::NodeVisitor& nv, const std::string& key) {
            return dynamic_cast<T*>( _fetch(nv, key) ); }

        static void remove(osg::NodeVisitor& nv, const std::string& key);

        static osg::Referenced* _fetch(osg::NodeVisitor& nv, const std::string& key);
    };

} // namespace osgEarth

#endif // OSGEARTH_TRAVERSAL_DATA_H
