#ifndef OPENMW_COMPONENTS_NIFOSG_RIGGEOMETRY_H
#define OPENMW_COMPONENTS_NIFOSG_RIGGEOMETRY_H

#include <osg/Geometry>
#include <osg/Matrixf>

namespace SceneUtil
{
    class Skeleton;
    class Bone;

    // TODO: This class has a lot of issues.
    // - We require too many workarounds to ensure safety.
    // - mSourceGeometry should be const, but can not be const because of a use case in shadervisitor.cpp.
    // - We create useless mGeometry clones in template RigGeometries.
    // - We do not support compileGLObjects.
    // - We duplicate some code in MorphGeometry.

    /// @brief Mesh skinning implementation.
    /// @note A RigGeometry may be attached directly to a Skeleton, or somewhere below a Skeleton.
    /// Note though that the RigGeometry ignores any transforms below the Skeleton, so the attachment point is not that
    /// important.
    /// @note The internal Geometry used for rendering is double buffered, this allows updates to be done in a thread
    /// safe way while not compromising rendering performance. This is crucial when using osg's default threading model
    /// of DrawThreadPerContext.
    class RigGeometry : public osg::Drawable
    {
    public:
        RigGeometry();
        RigGeometry(const RigGeometry& copy, const osg::CopyOp& copyop);

        META_Object(SceneUtil, RigGeometry)

        // Currently empty as this is difficult to implement. Technically we would need to compile both internal
        // geometries in separate frames but this method is only called once. Alternatively we could compile just the
        // static parts of the model.
        void compileGLObjects(osg::RenderInfo& renderInfo) const override {}

        struct BoneInfluence
        {
            osg::Matrixf mInvBindMatrix;
            osg::BoundingSpheref mBoundSphere;
            // <vertex index, weight>
            std::vector<std::pair<unsigned short, float>> mWeights;
        };

        struct InfluenceMap : public osg::Referenced
        {
            std::vector<std::pair<std::string, BoneInfluence>> mData;
        };

        void setInfluenceMap(osg::ref_ptr<InfluenceMap> influenceMap);

        /// Initialize this geometry from the source geometry.
        /// @note The source geometry will not be modified.
        void setSourceGeometry(osg::ref_ptr<osg::Geometry> sourceGeom);

        osg::ref_ptr<osg::Geometry> getSourceGeometry() const;

        void accept(osg::NodeVisitor& nv) override;
        bool supports(const osg::PrimitiveFunctor&) const override { return true; }
        void accept(osg::PrimitiveFunctor&) const override;

        struct CopyBoundingBoxCallback : osg::Drawable::ComputeBoundingBoxCallback
        {
            osg::BoundingBox boundingBox;

            osg::BoundingBox computeBound(const osg::Drawable&) const override { return boundingBox; }
        };

        struct CopyBoundingSphereCallback : osg::Node::ComputeBoundingSphereCallback
        {
            osg::BoundingSphere boundingSphere;

            osg::BoundingSphere computeBound(const osg::Node&) const override { return boundingSphere; }
        };

    private:
        void cull(osg::NodeVisitor* nv);
        void updateBounds(osg::NodeVisitor* nv);

        osg::ref_ptr<osg::Geometry> mGeometry[2];
        osg::Geometry* getGeometry(unsigned int frame) const;

        osg::ref_ptr<osg::Geometry> mSourceGeometry;
        osg::ref_ptr<const osg::Vec4Array> mSourceTangents;
        Skeleton* mSkeleton;

        osg::ref_ptr<osg::RefMatrix> mGeomToSkelMatrix;

        osg::ref_ptr<InfluenceMap> mInfluenceMap;

        typedef std::pair<std::string, osg::Matrixf> BoneBindMatrixPair;

        typedef std::pair<BoneBindMatrixPair, float> BoneWeight;

        typedef std::vector<unsigned short> VertexList;

        typedef std::map<std::vector<BoneWeight>, VertexList> Bone2VertexMap;

        struct Bone2VertexVector : public osg::Referenced
        {
            std::vector<std::pair<std::vector<BoneWeight>, VertexList>> mData;
        };
        osg::ref_ptr<Bone2VertexVector> mBone2VertexVector;

        struct BoneSphereVector : public osg::Referenced
        {
            std::vector<std::pair<std::string, osg::BoundingSpheref>> mData;
        };
        osg::ref_ptr<BoneSphereVector> mBoneSphereVector;
        std::vector<Bone*> mBoneNodesVector;

        unsigned int mLastFrameNumber;
        bool mBoundsFirstFrame;

        bool initFromParentSkeleton(osg::NodeVisitor* nv);

        void updateGeomToSkelMatrix(const osg::NodePath& nodePath);
    };

}

#endif