/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
 * Copyright 2020 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_DRIVER_SIMPLE_SKY_OPTIONS
#define OSGEARTH_DRIVER_SIMPLE_SKY_OPTIONS 1

#include <osgEarth/Sky>
#include <osgEarth/URI>

namespace osgEarth {
    namespace SimpleSky
    {
        using namespace osgEarth;

        /**
         * Options for creating a simple sky.
         */
        class SimpleSkyOptions : public SkyOptions
        {
        public:
            SimpleSkyOptions(const ConfigOptions& options = ConfigOptions()) :
                SkyOptions(options),
                _atmosphericLighting(true),
                _exposure(3.3f),
                _daytimeAmbientBoost(5.0f),
                _allowWireframe(false),
                _starSize(14.0f),
                _moonScale(2.0f),
                _maxAmbientIntensity(0.75f),
                _moonImageURI("moon_1024x512.jpg"),
                _sunVisible(true),
                _moonVisible(true),
                _starsVisible(true),
                _atmosphereVisible(true),
                _pbr(true),
                _eb(false)
            {
                setDriver("simple");
                fromConfig(_conf);
            }
            virtual ~SimpleSkyOptions() { }

        public: // properties

            /** Use advanced atmospheric lighting on the terrain (instead of simple shading) */
            optional<bool>& atmosphericLighting() { return _atmosphericLighting; }
            const optional<bool>& atmosphericLighting() const { return _atmosphericLighting; }

            /** Exposure factor for simulated HDR ground lighting. Default is in CTOR */
            optional<float>& exposure() { return _exposure; }
            const optional<float>& exposure() const { return _exposure; }

            /** Factor for boosting the ambient lighting of the sun during the daytime. Without
              * this, geometry like buildings or steep hillsides can be lit only based on their
              * normals and can appear too dark during the daytime.
              * 0=off, 2-10 are reasonable values. */
            optional<float>& daytimeAmbientBoost() { return _daytimeAmbientBoost; }
            const optional<float>& daytimeAmbientBoost() const { return _daytimeAmbientBoost; }

            //! Maximum ambient value at high noon. Default=0.75
            optional<float>& maxAmbientIntensity() { return _maxAmbientIntensity; }
            const optional<float>& maxAmbientIntensity() const { return _maxAmbientIntensity; }

            /** replacement star definition file */
            optional<std::string>& starFile() { return _starFile; }
            const optional<std::string>& starFile() const { return _starFile; }

            /** starfield image URI */
            optional<URI>& starImageURI() { return _starImageURI; }
            const optional<URI>& starImageURI() const { return _starImageURI; }

            //! Point size to use for stars (default=14)
            optional<float>& starSize() { return _starSize; }
            const optional<float>& starSize() const { return _starSize; }

            /** Whether to permit wireframe/point polygonmode rendering. Default is false. */
            optional<bool>& allowWireframe() { return _allowWireframe; }
            const optional<bool>& allowWireframe() const { return _allowWireframe; }

            /** Whether the Sun is visible. This has no effect on lighting. */
            optional<bool>& sunVisible() { return _sunVisible; }
            const optional<bool>& sunVisible() const { return _sunVisible; }

            /** Whether the Moon is visible */
            optional<bool>& moonVisible() { return _moonVisible; }
            const optional<bool>& moonVisible() const { return _moonVisible; }

            /** Whether the stars are visible */
            optional<bool>& starsVisible() { return _starsVisible; }
            const optional<bool>& starsVisible() const { return _starsVisible; }

            /** Whether the Earth's atmosphere is visible */
            optional<bool>& atmosphereVisible() { return _atmosphereVisible; }
            const optional<bool>& atmosphereVisible() const { return _atmosphereVisible; }

            /** Scale factor for the moon to compensate for apparent/expected size. Default=2.0 */
            optional<float>& moonScale() { return _moonScale; }
            const optional<float>& moonScale() const { return _moonScale; }

            /** URI of texture to load for moon */
            optional<URI>& moonImageURI() { return _moonImageURI; }
            const optional<URI>& moonImageURI() const { return _moonImageURI; }

            //! Whether to use PBR lighting calculations (instead of Phong)
            optional<bool>& usePBR() { return _pbr; }
            const optional<bool>& usePBR() const { return _pbr; }

            optional<bool>& useEB() { return _eb; }
            const optional<bool>& useEB() const { return _eb; }

        public:
            Config getConfig() const {
                Config conf = SkyOptions::getConfig();
                conf.set("atmospheric_lighting", _atmosphericLighting);
                conf.set("exposure", _exposure);
                conf.set("daytime_ambient_boost", _daytimeAmbientBoost);
                conf.set("max_ambient_intensity", _maxAmbientIntensity);
                conf.set("star_file", _starFile);
                conf.set("star_size", _starSize);
                conf.set("star_image", _starImageURI);
                conf.set("allow_wireframe", _allowWireframe);
                conf.set("sun_visible", _sunVisible);
                conf.set("moon_visible", _moonVisible);
                conf.set("stars_visible", _starsVisible);
                conf.set("atmosphere_visible", _atmosphereVisible);
                conf.set("moon_scale", _moonScale);
                conf.set("moon_image", _moonImageURI);
                conf.set("pbr", _pbr);
                conf.set("eb", _eb);
                return conf;
            }

        protected:
            void mergeConfig(const Config& conf) {
                SkyOptions::mergeConfig(conf);
                fromConfig(conf);
            }

        private:
            void fromConfig(const Config& conf) {
                conf.get("atmospheric_lighting", _atmosphericLighting);
                conf.get("exposure", _exposure);
                conf.get("daytime_ambient_boost", _daytimeAmbientBoost);
                conf.get("max_ambient_intensity", _maxAmbientIntensity);
                conf.get("star_file", _starFile);
                conf.get("star_size", _starSize);
                conf.get("star_image", _starImageURI);
                conf.get("allow_wireframe", _allowWireframe);
                conf.get("sun_visible", _sunVisible);
                conf.get("moon_visible", _moonVisible);
                conf.get("stars_visible", _starsVisible);
                conf.get("atmosphere_visible", _atmosphereVisible);
                conf.get("moon_scale", _moonScale);
                conf.get("moon_image", _moonImageURI);
                conf.get("pbr", _pbr);
                conf.get("eb", _eb);
            }

            optional<bool>        _atmosphericLighting;
            optional<float>       _exposure;
            optional<float>       _daytimeAmbientBoost;
            optional<float>       _maxAmbientIntensity;
            optional<std::string> _starFile;
            optional<float>       _starSize;
            optional<URI>         _starImageURI;
            optional<bool>        _allowWireframe;
            optional<bool>        _sunVisible;
            optional<bool>        _moonVisible;
            optional<bool>        _starsVisible;
            optional<bool>        _atmosphereVisible;
            optional<float>       _moonScale;
            optional<URI>         _moonImageURI;
            optional<bool>        _pbr;
            optional<bool> _eb;
        };

    }
} // namespace osgEarth::SimpleSky

#endif // OSGEARTH_DRIVER_SIMPLE_SKY_OPTIONS