#ifndef OPENMW_COMPONENTS_SCENEUTIL_LIGHTMANAGER_H
#define OPENMW_COMPONENTS_SCENEUTIL_LIGHTMANAGER_H

#include <osg/Light>

#include <osg/Group>
#include <osg/NodeVisitor>

namespace SceneUtil
{

    /// LightSource managed by a LightManager.
    class LightSource : public osg::Node
    {
        osg::ref_ptr<osg::Light> mLight;

        // The activation radius
        float mRadius;

    public:

        META_Node(SceneUtil, SceneUtil::LightSource)

        LightSource();

        LightSource(const LightSource& copy, const osg::CopyOp& copyop)
            : osg::Node(copy, copyop)
            , mLight(copy.mLight)
            , mRadius(copy.mRadius)
        {
        }

        float getRadius() const
        {
            return mRadius;
        }

        void setRadius(float radius)
        {
            mRadius = radius;
        }

        osg::Light* getLight()
        {
            return mLight;
        }

        void setLight(osg::Light* light)
        {
            mLight = light;
        }
    };

    /// All light sources must be a child of the LightManager node. The LightManager can be anywhere in the scene graph,
    /// but would be typically somewhere near the top.
    class LightManager : public osg::Group
    {
    public:

        META_Node(SceneUtil, SceneUtil::LightManager)

        LightManager();

        LightManager(const LightManager& copy, const osg::CopyOp& copyop);

        // Called automatically by the UpdateCallback
        void update();

        // Called automatically by the LightSource's UpdateCallback
        void addLight(LightSource* lightSource, osg::Matrix worldMat);

        void prepareForCamera(osg::Camera* cam);

        void decorateGeodes();

        struct LightSourceTransform
        {
            LightSource* mLightSource;
            osg::Matrix mWorldMatrix;
            osg::BoundingSphere mViewBound;
        };

        const std::vector<LightSourceTransform>& getLights() const;

        // Stores indices into the mLights vector
        typedef std::vector<int> LightList;

        osg::ref_ptr<osg::StateSet> getLightListStateSet(const LightList& lightList);

        /// Set the first light index that should be used by this manager, typically the number of directional lights in the scene.
        void setStartLight(int start);

        int getStartLight() const;

    private:
        // Lights collected from the scene graph. Only valid during the cull traversal.
        std::vector<LightSourceTransform> mLights;

        bool mLightsInViewSpace;

        // < Light list hash , StateSet >
        typedef std::map<size_t, osg::ref_ptr<osg::StateSet> > LightStateSetMap;
        LightStateSetMap mStateSetCache;

        bool mDecorated;

        int mStartLight;
    };

}

#endif