/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
 * Copyright 2015 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 OSGEARTHUTIL_UTM_GRATICLE
#define OSGEARTHUTIL_UTM_GRATICLE

#include <osgEarthUtil/Common>
#include <osgEarth/MapNode>
#include <osgEarth/MapNodeObserver>
#include <osgEarthSymbology/Style>
#include <osgEarthFeatures/Feature>
#include <osg/ClipPlane>
#include <vector>

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

    /**
     * Configuration options for the geodetic graticule.
     */
    class OSGEARTHUTIL_EXPORT UTMGraticuleOptions : public ConfigOptions
    {
    public:
        UTMGraticuleOptions( const Config& conf =Config() );

        /** dtor */
        virtual ~UTMGraticuleOptions() { }


    public:

        /** Default style for grid lines and text */
        optional<Style>& primaryStyle() { return _primaryStyle; }
        const optional<Style>& primaryStyle() const { return _primaryStyle; }

        /** Text scale factor (default = 1) */
        optional<float>& textScale() { return _textScale; }
        const optional<float>& textScale() const { return _textScale; }

    public:
        Config getConfig() const;

    protected:
        optional<Style>    _primaryStyle;
        optional<float>    _textScale;

        void mergeConfig( const Config& conf );
    };


    /**
     * Implements a UTM map graticule. 
     * 
     * NOTE: So far, this only works for geocentric maps.
     * TODO: Add projected support; add text label support
     */
    class OSGEARTHUTIL_EXPORT UTMGraticule : public osg::Group, public MapNodeObserver
    {
    public:

        /**
         * Constructs a new graticule for use with the specified map. The graticule
         * is created with several default levels. If you call addLevel(), the 
         * default levels are deleted.
         *
         * @param map
         *      Map with which you will use this graticule
         * @param options
         *      Optional "options" that configure the graticule. Defaults will be used
         *      if you don't specify this.
         */
        UTMGraticule( MapNode* mapNode );
        UTMGraticule( MapNode* mapNode, const UTMGraticuleOptions& options);

        /** dtor */
        virtual ~UTMGraticule() { }

        /** 
         * Applies a new set of options. The graticule will be rebuilt if necessary.
         */
        void setOptions( const UTMGraticuleOptions& options );

        /**
         * Gets the options with which the graticule was built.
         */
        const UTMGraticuleOptions& getOptions() const { return _options.value(); }

        /**
         * Sets the clip plane to use. If you don't set one, the object will
         * create both a ClipNode and ClipPlane for geocentric horizon clipping.
         * If you do set a clip plane, this object will update it automatically,
         * and we expect that you have the plane registered with an osg::ClipNode
         * elsewhere in the scene graph.
         */
        void setClipPlane(osg::ClipPlane* clipPlane);
        osg::ClipPlane* getClipPlane() const { return _clipPlane.get(); }

        
    public: // MapNodeObserver

        virtual void setMapNode( MapNode* mapNode );

        virtual MapNode* getMapNode() { return _mapNode.get(); }


    protected:
        osg::ref_ptr<const Profile>        _profile;
        osg::ref_ptr<const FeatureProfile> _featureProfile;

        unsigned int               _id;
        osg::observer_ptr<MapNode> _mapNode;
        osg::Group*                _root;

        optional<UTMGraticuleOptions> _options;

        typedef std::map<std::string, GeoExtent> SectorTable;
        SectorTable _gzd;

        osg::ref_ptr<osg::ClipPlane> _clipPlane;

    protected:
        unsigned int getID() const { return _id; }
        void init();
        void rebuild();
        osg::Node* buildGZDTile( const std::string& name, const GeoExtent& extent );

        virtual osg::Group* buildGZDChildren( osg::Group* node, const std::string& gzd ) {
            return node; }

    public:
        static Threading::Mutex s_graticuleMutex;
        typedef std::map<unsigned, osg::ref_ptr<UTMGraticule> > UTMGraticuleRegistry;
        static UTMGraticuleRegistry s_graticuleRegistry;
    };

} } // namespace osgEarth::Util

#endif // OSGEARTHUTIL_UTM_GRATICLE
