/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version.  The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library 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
* OpenSceneGraph Public License for more details.
*/

#ifndef OSGVIEWER_VIEWEREVENTHANDLERS
#define OSGVIEWER_VIEWEREVENTHANDLERS 1

#include <osg/AnimationPath>
#include <osgText/Text>
#include <osgGA/GUIEventHandler>
#include <osgGA/AnimationPathManipulator>

#include <osgViewer/GraphicsWindow>
#include <osgViewer/Viewer>

#include <osgDB/fstream>

namespace osgViewer {

/** Event handler for adding on screen help to Viewers.*/
class OSGVIEWER_EXPORT HelpHandler : public osgGA::GUIEventHandler
{
    public:

        HelpHandler(osg::ApplicationUsage* au=0);

        void setApplicationUsage(osg::ApplicationUsage* au) { _applicationUsage = au; }
        osg::ApplicationUsage* getApplicationUsage() { return _applicationUsage.get(); }
        const osg::ApplicationUsage* getApplicationUsage() const { return _applicationUsage.get(); }

        void setKeyEventTogglesOnScreenHelp(int key) { _keyEventTogglesOnScreenHelp = key; }
        int getKeyEventTogglesOnScreenHelp() const { return _keyEventTogglesOnScreenHelp; }

        void reset();

        osg::Camera* getCamera() { return _camera.get(); }
        const osg::Camera* getCamera() const { return _camera.get(); }

        bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa);

        /** Get the keyboard and mouse usage of this manipulator.*/
        virtual void getUsage(osg::ApplicationUsage& usage) const;

    protected:

        void setUpHUDCamera(osgViewer::ViewerBase* viewer);

        void setUpScene(osgViewer::ViewerBase* viewer);

        osg::ref_ptr<osg::ApplicationUsage> _applicationUsage;

        int                                 _keyEventTogglesOnScreenHelp;

        bool                                _helpEnabled;

        bool                                _initialized;
        osg::ref_ptr<osg::Camera>           _camera;
        osg::ref_ptr<osg::Switch>           _switch;

};

/**
 * Event handler for adding on screen stats reporting to Viewers.
 */
class OSGVIEWER_EXPORT StatsHandler : public osgGA::GUIEventHandler
{
    public:

        StatsHandler();

        enum StatsType
        {
            NO_STATS = 0,
            FRAME_RATE = 1,
            VIEWER_STATS = 2,
            CAMERA_SCENE_STATS = 3,
            VIEWER_SCENE_STATS = 4,
            LAST = 5
        };

        void setKeyEventTogglesOnScreenStats(int key) { _keyEventTogglesOnScreenStats = key; }
        int getKeyEventTogglesOnScreenStats() const { return _keyEventTogglesOnScreenStats; }

        void setKeyEventPrintsOutStats(int key) { _keyEventPrintsOutStats = key; }
        int getKeyEventPrintsOutStats() const { return _keyEventPrintsOutStats; }

        void setKeyEventToggleVSync(int key) { _keyEventToggleVSync = key; }
        int getKeyEventToggleVSync() const { return _keyEventToggleVSync; }

        double getBlockMultiplier() const { return _blockMultiplier; }

        void reset();

        osg::Camera* getCamera() { return _camera.get(); }
        const osg::Camera* getCamera() const { return _camera.get(); }

        virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa);

        /** Get the keyboard and mouse usage of this manipulator.*/
        virtual void getUsage(osg::ApplicationUsage& usage) const;

    protected:

        void setUpHUDCamera(osgViewer::ViewerBase* viewer);

        osg::Geometry* createBackgroundRectangle(const osg::Vec3& pos, const float width, const float height, osg::Vec4& color);

        osg::Geometry* createGeometry(const osg::Vec3& pos, float height, const osg::Vec4& colour, unsigned int numBlocks);

        osg::Geometry* createFrameMarkers(const osg::Vec3& pos, float height, const osg::Vec4& colour, unsigned int numBlocks);

        osg::Geometry* createTick(const osg::Vec3& pos, float height, const osg::Vec4& colour, unsigned int numTicks);

        osg::Node* createCameraTimeStats(const std::string& font, osg::Vec3& pos, float startBlocks, bool acquireGPUStats, float characterSize, osg::Stats* viewerStats, osg::Camera* camera);

        void setUpScene(osgViewer::ViewerBase* viewer);

        void updateThreadingModelText();

        int                                 _keyEventTogglesOnScreenStats;
        int                                 _keyEventPrintsOutStats;
        int                                 _keyEventToggleVSync;

        int                                 _statsType;

        bool                                _initialized;
        osg::ref_ptr<osg::Camera>           _camera;

        osg::ref_ptr<osg::Switch>           _switch;

        ViewerBase::ThreadingModel          _threadingModel;
        osg::ref_ptr<osgText::Text>         _threadingModelText;

        unsigned int                        _frameRateChildNum;
        unsigned int                        _viewerChildNum;
        unsigned int                        _cameraSceneChildNum;
        unsigned int                        _viewerSceneChildNum;
        unsigned int                        _numBlocks;
        double                              _blockMultiplier;

        float                               _statsWidth;
        float                               _statsHeight;


};

/** Event handler allowing to change the screen resolution (in windowed mode) and toggle between fullscreen and windowed mode. */
class OSGVIEWER_EXPORT WindowSizeHandler : public osgGA::GUIEventHandler
{
public:

        WindowSizeHandler();

        /** Get the keyboard and mouse usage of this manipulator.*/
        virtual void getUsage(osg::ApplicationUsage &usage) const;

        void setKeyEventToggleFullscreen(int key) { _keyEventToggleFullscreen = key; }
        int getKeyEventToggleFullscreen() const { return _keyEventToggleFullscreen; }

        void setToggleFullscreen(bool flag) { _toggleFullscreen = flag; }
        bool getToggleFullscreen() const { return _toggleFullscreen; }

        void setKeyEventWindowedResolutionUp(int key) { _keyEventWindowedResolutionUp = key; }
        int getKeyEventWindowedResolutionUp() const { return _keyEventWindowedResolutionUp; }
        void setKeyEventWindowedResolutionDown(int key) { _keyEventWindowedResolutionDown = key; }
        int getKeyEventWindowedResolutionDown() const { return _keyEventWindowedResolutionUp; }

        void setChangeWindowedResolution(bool flag) { _changeWindowedResolution = flag; }
        bool getChangeWindowedResolution() const { return _changeWindowedResolution; }

        virtual bool handle(const osgGA::GUIEventAdapter &ea, osgGA::GUIActionAdapter &aa);

protected:

        void toggleFullscreen(osgViewer::GraphicsWindow *window);
        void changeWindowedResolution(osgViewer::GraphicsWindow *window, bool increase);

        unsigned int getNearestResolution(int screenWidth, int screenHeight, int width, int height) const;

        int                     _keyEventToggleFullscreen;
        bool                    _toggleFullscreen;

        int                     _keyEventWindowedResolutionUp;
        int                     _keyEventWindowedResolutionDown;
        bool                    _changeWindowedResolution;
        std::vector<osg::Vec2>  _resolutionList;
        int                     _currentResolutionIndex;
};

/** Event handler allowing to change the viewer threading model */
class OSGVIEWER_EXPORT ThreadingHandler : public osgGA::GUIEventHandler
{
public:

        ThreadingHandler();

        /** Get the keyboard and mouse usage of this manipulator.*/
        virtual void getUsage(osg::ApplicationUsage &usage) const;

        void setKeyEventChangeThreadingModel(int key) { _keyEventChangeThreadingModel = key; }
        int getKeyEventChangeThreadingModel() const { return _keyEventChangeThreadingModel; }

        void setChangeThreadingModel(bool flag) { _changeThreadingModel = flag; }
        bool getChangeThreadingModel() const { return _changeThreadingModel; }

        void setKeyEventChangeEndBarrierPosition(int key) { _keyEventChangeEndBarrierPosition = key; }
        int getKeyEventChangeEndBarrierPosition() const { return _keyEventChangeEndBarrierPosition; }

        void setChangeEndBarrierPosition(bool flag) { _changeEndBarrierPosition = flag; }
        bool getChangeEndBarrierPosition() const { return _changeEndBarrierPosition; }

        bool handle(const osgGA::GUIEventAdapter &ea, osgGA::GUIActionAdapter &aa);

protected:

        int             _keyEventChangeThreadingModel;
        bool            _changeThreadingModel;

        int             _keyEventChangeEndBarrierPosition;
        bool            _changeEndBarrierPosition;

        osg::Timer_t    _tickOrLastKeyPress;
        bool            _done;
};

/**
 * Event handler allowing the user to record the animation "path" of a camera. In it's current
 * implementation, this handler cannot guarantee the final view matrix is correct; it is
 * conceivable that the matrix may be one frame off. Eh--not a big deal! :)
 * TODO: Write the file as we go, not when it's all done.
 * TODO: Create an osgviewer on-screen indication that animation is taking place.
*/
class OSGVIEWER_EXPORT RecordCameraPathHandler : public osgGA::GUIEventHandler
{
public:

        RecordCameraPathHandler(const std::string &filename = "saved_animation.path", float fps = 25.0f);

        void setKeyEventToggleRecord(int key) { _keyEventToggleRecord = key; }
        int getKeyEventToggleRecord() const { return _keyEventToggleRecord; }

        void setKeyEventTogglePlayback(int key) { _keyEventTogglePlayback = key; }
        int getKeyEventTogglePlayback() const { return _keyEventTogglePlayback; }

        void setAutoIncrementFilename( bool autoinc = true ) { _autoinc = autoinc?0:-1; }

        virtual void getUsage(osg::ApplicationUsage &usage) const;

        bool handle(const osgGA::GUIEventAdapter &ea, osgGA::GUIActionAdapter &aa);

protected:

        std::string                                     _filename;
        int                                             _autoinc;
        osgDB::ofstream                                 _fout;

        int                                             _keyEventToggleRecord;
        int                                             _keyEventTogglePlayback;


        bool                                            _currentlyRecording;
        bool                                            _currentlyPlaying;
        double                                          _interval;
        double                                          _delta;
        osg::Timer_t                                    _animStartTime;
        osg::Timer_t                                    _lastFrameTime;
        osg::ref_ptr<osg::AnimationPath>                _animPath;
        osg::ref_ptr<osgGA::AnimationPathManipulator>   _animPathManipulator;
        osg::ref_ptr<osgGA::CameraManipulator>          _oldManipulator;
};

/** Event handler for increase/decreasing LODScale.*/
class OSGVIEWER_EXPORT LODScaleHandler : public osgGA::GUIEventHandler
{
    public:

        LODScaleHandler();

        void setKeyEventIncreaseLODScale(int key) { _keyEventIncreaseLODScale = key; }
        int getKeyEventIncreaseLODScale() const { return _keyEventIncreaseLODScale; }

        void setKeyEventDecreaseLODScale(int key) { _keyEventDecreaseLODScale = key; }
        int getKeyEventDecreaseLODScale() const { return _keyEventDecreaseLODScale; }

        bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa);

        /** Get the keyboard and mouse usage of this manipulator.*/
        virtual void getUsage(osg::ApplicationUsage& usage) const;

    protected:


        int _keyEventIncreaseLODScale;
        int _keyEventDecreaseLODScale;


};


/** Event handler that will capture the screen on key press. */
class OSGVIEWER_EXPORT ScreenCaptureHandler : public osgGA::GUIEventHandler
{
    public:

        /** Abstract base class for what to do when a screen capture happens. */
        class CaptureOperation : public osg::Referenced
        {
            public:
                virtual void operator()(const osg::Image& image, const unsigned int context_id) = 0;
        };

        /** Concrete implementation of a CaptureOperation that writes the screen capture to a file. */
        class OSGVIEWER_EXPORT WriteToFile : public CaptureOperation
        {
            public:
                enum SavePolicy
                {
                    OVERWRITE,
                    SEQUENTIAL_NUMBER
                    // ... any others?
                };

                WriteToFile(const std::string& filename, const std::string& extension, SavePolicy savePolicy = SEQUENTIAL_NUMBER);

                virtual void operator()(const osg::Image& image, const unsigned int context_id);

                void setSavePolicy(SavePolicy savePolicy) { _savePolicy = savePolicy; }
                SavePolicy getSavePolicy() const { return _savePolicy; }

            protected:

                WriteToFile& operator = (const WriteToFile&) { return *this; }

                const std::string _filename;
                const std::string _extension;

                SavePolicy _savePolicy;

                std::vector<unsigned int> _contextSaveCounter;
        };

        /** @param numFrames >0: capture that number of frames. <0: capture all frames, call stopCapture() to stop it. */
        ScreenCaptureHandler(CaptureOperation* defaultOperation = 0, int numFrames = 1);

        void setKeyEventTakeScreenShot(int key) { _keyEventTakeScreenShot = key; }
        int getKeyEventTakeScreenShot() const { return _keyEventTakeScreenShot; }

        void setKeyEventToggleContinuousCapture(int key) { _keyEventToggleContinuousCapture = key; }
        int getKeyEventToggleContinuousCapture() const { return _keyEventToggleContinuousCapture; }

        void setCaptureOperation(CaptureOperation* operation);
        CaptureOperation* getCaptureOperation() const;

        // aa will point to an osgViewer::View, so we will take a screenshot
        // of that view's graphics contexts.
        virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa);

        /** Capture the given viewer's views on the next frame. */
        virtual void captureNextFrame(osgViewer::ViewerBase& viewer);

        /** Set the number of frames to capture.
            @param numFrames >0: capture that number of frames. <0: capture all frames, call stopCapture() to stop it. */
        void setFramesToCapture(int numFrames);

        /** Get the number of frames to capture. */
        int getFramesToCapture() const;

        /** Start capturing any viewer(s) the handler is attached to at the
            end of the next frame. */
        void startCapture();

        /** Stop capturing. */
        void stopCapture();

        /** Get the keyboard and mouse usage of this manipulator.*/
        virtual void getUsage(osg::ApplicationUsage& usage) const;

    protected:
        bool _startCapture;
        bool _stopCapture;

        int _keyEventTakeScreenShot;
        int _keyEventToggleContinuousCapture;
        // there could be a key to start taking screenshots every new frame

        osg::ref_ptr<CaptureOperation>          _operation;
        osg::ref_ptr<osg::Camera::DrawCallback> _callback;

        void addCallbackToViewer(osgViewer::ViewerBase& viewer);
        void removeCallbackFromViewer(osgViewer::ViewerBase& viewer);
        osg::Camera* findAppropriateCameraForCallback(osgViewer::ViewerBase& viewer);
};

/** InteractiveImage is an event handler that computes the mouse coordinates in an images coordinate frame
  * and then passes keyboard and mouse events to it.  This event handler is useful for vnc or browser
  * surfaces in the 3D scene.*/
class OSGVIEWER_EXPORT InteractiveImageHandler : public osgGA::GUIEventHandler, public osg::Drawable::CullCallback
{
public:

    InteractiveImageHandler(osg::Image* image, osg::Camera* camera = 0):
        _image(image), _fullscreen(camera != 0), _camera(camera) {}

    META_Object(osgViewer, InteractiveImageHandler);

    virtual bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& aa, osg::Object*, osg::NodeVisitor* nv);

    virtual bool cull(osg::NodeVisitor* nv, osg::Drawable* drawable, osg::RenderInfo* renderInfo) const;

protected:

    virtual ~InteractiveImageHandler() {}

    InteractiveImageHandler() {}

    InteractiveImageHandler(const InteractiveImageHandler&,const osg::CopyOp& = osg::CopyOp::SHALLOW_COPY):
        osg::Object(), osgGA::GUIEventHandler(), osg::Drawable::CullCallback() {}

    bool mousePosition(osgViewer::View* view, osg::NodeVisitor* nv, const osgGA::GUIEventAdapter& ea, int& x, int &y) const;
    bool computeIntersections(osgViewer::View* view, float x,float y, const osg::NodePath& nodePath, osgUtil::LineSegmentIntersector::Intersections& intersections,osg::Node::NodeMask traversalMask = 0xffffffff) const;

    osg::observer_ptr<osg::Image>   _image;

    bool                            _fullscreen;
    osg::observer_ptr<osg::Camera>  _camera;

};

}

#endif