#ifndef Magnum_Platform_GlutApplication_h
#define Magnum_Platform_GlutApplication_h
/*
    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>

    This file is part of Magnum.

    Magnum is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License version 3
    only, as published by the Free Software Foundation.

    Magnum 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 version 3 for more details.
*/

/** @file
 * @brief Class Magnum::Platform::GlutApplication
 */

#include <string>

#include "Math/Vector2.h"
#include "Magnum.h"

#include <GL/freeglut.h>

namespace Magnum {

class Context;

namespace Platform {

/** @nosubgrouping
@brief GLUT application

Creates double-buffered RGBA window with depth and stencil buffers. Supports
keyboard handling for limited subset of keys, mouse handling with support for
changing cursor and mouse tracking and warping.

@section GlutApplication-usage Usage

You need to implement at least drawEvent() and viewportEvent() to be able to
draw on the screen. The subclass can be then used directly in `main()` -- see
convenience macro MAGNUM_GLUTAPPLICATION_MAIN().
@code
class MyApplication: public Magnum::Platform::GlutApplication {
    // implement required methods...
};
MAGNUM_GLUTAPPLICATION_MAIN(MyApplication)
@endcode
*/
class GlutApplication {
    public:
        class InputEvent;
        class KeyEvent;
        class MouseEvent;
        class MouseMoveEvent;

        /**
         * @brief Constructor
         * @param argc      Count of arguments of `main()` function
         * @param argv      Arguments of `main()` function
         * @param title     Window title
         * @param size      Window size
         */
        explicit GlutApplication(int& argc, char** argv, const std::string& title = "Magnum GLUT application", const Vector2i& size = Vector2i(800, 600));

        virtual ~GlutApplication();

        /**
         * @brief Execute main loop
         * @return Value for returning from `main()`.
         */
        inline int exec() {
            glutMainLoop();
            return 0;
        }

        /** @{ @name Drawing functions */

    protected:
        /**
         * @brief Viewport event
         *
         * Called when window size changes. You should pass the new size to
         * DefaultFramebuffer::setViewport() and possibly elsewhere (cameras,
         * other framebuffers...).
         */
        virtual void viewportEvent(const Vector2i& size) = 0;

        /**
         * @brief Draw event
         *
         * Called when the screen is redrawn. You should clean the framebuffer
         * using Framebuffer::clear() and then add your own drawing functions,
         * such as calling SceneGraph::AbstractCamera::draw(). After drawing
         * is finished, call swapBuffers(). If you want to draw immediately
         * again, call also redraw().
         */
        virtual void drawEvent() = 0;

        /**
         * @brief Swap buffers
         *
         * Paints currently rendered framebuffer on screen.
         */
        inline void swapBuffers() {
            glutSwapBuffers();
        }

        /**
         * @brief Redraw immediately
         *
         * Marks the window for redrawing, resulting in call to drawEvent()
         * in the next iteration.
         */
        virtual inline void redraw() {
            glutPostRedisplay();
        }

        /*@}*/

        /** @{ @name Keyboard handling */

        /**
         * @brief Key press event
         *
         * Called when an key is pressed. Default implementation does nothing.
         */
        virtual void keyPressEvent(KeyEvent& event);

        /*@}*/

        /** @{ @name Mouse handling */

    public:
        /**
         * @brief Mouse cursor
         *
         * @see setMouseCursor()
         */
        enum class MouseCursor: int {
            Default = GLUT_CURSOR_INHERIT,  /**< Default cursor provided by parent window */
            None = GLUT_CURSOR_NONE         /**< No cursor */
        };

        /**
         * @brief Enable or disable mouse tracking
         *
         * When mouse tracking is enabled, mouseMoveEvent() is called even
         * when no button is pressed. Mouse tracking is disabled by default.
         */
        inline void setMouseTracking(bool enabled) {
            glutPassiveMotionFunc(enabled ? staticMouseMoveEvent : nullptr);
        }

        /** @brief Set mouse cursor */
        inline void setMouseCursor(MouseCursor cursor) {
            glutSetCursor(static_cast<int>(cursor));
        }

        /** @brief Warp mouse cursor to given coordinates */
        inline void warpMouseCursor(const Vector2i& position) {
            glutWarpPointer(position.x(), position.y());
        }

    protected:
        /**
         * @brief Mouse press event
         *
         * Called when mouse button is pressed. Default implementation does
         * nothing.
         */
        virtual void mousePressEvent(MouseEvent& event);

        /**
         * @brief Mouse release event
         *
         * Called when mouse button is released. Default implementation does
         * nothing.
         */
        virtual void mouseReleaseEvent(MouseEvent& event);

        /**
         * @brief Mouse move event
         *
         * Called when any mouse button is pressed and mouse is moved. Default
         * implementation does nothing.
         * @see setMouseTracking()
         */
        virtual void mouseMoveEvent(MouseMoveEvent& event);

        /*@}*/

    private:
        inline static void staticViewportEvent(int x, int y) {
            instance->viewportEvent({x, y});
        }

        static void staticKeyEvent(int key, int x, int y);

        static void staticMouseEvent(int button, int state, int x, int y);

        static void staticMouseMoveEvent(int x, int y);

        inline static void staticDrawEvent() {
            instance->drawEvent();
        }

        static GlutApplication* instance;

        Context* c;
};

/**
@brief Base for input events

@see KeyEvent, MouseEvent, MouseMoveEvent, keyPressEvent(), mousePressEvent(),
    mouseReleaseEvent(), mouseMoveEvent()
*/
class GlutApplication::InputEvent {
    InputEvent(const InputEvent& other) = delete;
    InputEvent(InputEvent&& other) = delete;
    InputEvent& operator=(const InputEvent& other) = delete;
    InputEvent& operator=(InputEvent&& other) = delete;

    public:
        inline virtual ~InputEvent() {}

        /**
         * @brief Set event as accepted
         *
         * If the event is ignored (i.e., not set as accepted), it might be
         * propagated elsewhere. By default is each event ignored.
         */
        inline void setAccepted(bool accepted = true) { _accepted = accepted; }

        /** @brief Whether the event is accepted */
        inline bool isAccepted() { return _accepted; }

    #ifndef DOXYGEN_GENERATING_OUTPUT
    protected:
        inline InputEvent(): _accepted(false) {}
    #endif

    private:
        bool _accepted;
};

/**
@brief Key event

@see keyPressEvent()
*/
class GlutApplication::KeyEvent: public GlutApplication::InputEvent {
    friend class GlutApplication;

    public:
        /**
         * @brief Key
         *
         * @see key()
         */
        enum class Key: int {
            Up = GLUT_KEY_UP,               /**< Up arrow */
            Down = GLUT_KEY_DOWN,           /**< Down arrow */
            Left = GLUT_KEY_LEFT,           /**< Left arrow */
            Right = GLUT_KEY_RIGHT,         /**< Right arrow */
            F1 = GLUT_KEY_F1,               /**< F1 */
            F2 = GLUT_KEY_F2,               /**< F2 */
            F3 = GLUT_KEY_F3,               /**< F3 */
            F4 = GLUT_KEY_F4,               /**< F4 */
            F5 = GLUT_KEY_F5,               /**< F5 */
            F6 = GLUT_KEY_F6,               /**< F6 */
            F7 = GLUT_KEY_F7,               /**< F7 */
            F8 = GLUT_KEY_F8,               /**< F8 */
            F9 = GLUT_KEY_F9,               /**< F9 */
            F10 = GLUT_KEY_F10,             /**< F10 */
            F11 = GLUT_KEY_F11,             /**< F11 */
            F12 = GLUT_KEY_F12,             /**< F12 */
            Home = GLUT_KEY_HOME,           /**< Home */
            End = GLUT_KEY_END,             /**< End */
            PageUp = GLUT_KEY_PAGE_UP,      /**< Page up */
            PageDown = GLUT_KEY_PAGE_DOWN   /**< Page down */
        };

        /** @brief Key */
        inline Key key() const { return _key; }

        /** @brief Position */
        inline Vector2i position() const { return _position; }

    private:
        inline KeyEvent(Key key, const Vector2i& position): _key(key), _position(position) {}

        const Key _key;
        const Vector2i _position;
};

/**
@brief Mouse event

@see MouseMoveEvent, mousePressEvent(), mouseReleaseEvent()
*/
class GlutApplication::MouseEvent: public GlutApplication::InputEvent {
    friend class GlutApplication;

    public:
        /**
         * @brief Mouse button
         *
         * @see button()
         */
        enum class Button: int {
            Left = GLUT_LEFT_BUTTON,        /**< Left button */
            Middle = GLUT_MIDDLE_BUTTON,    /**< Middle button */
            Right = GLUT_RIGHT_BUTTON,      /**< Right button */
            WheelUp = 3,                    /**< Wheel up */
            WheelDown = 4                   /**< Wheel down */
        };

        /** @brief Button */
        inline Button button() const { return _button; }

        /** @brief Position */
        inline Vector2i position() const { return _position; }

    private:
        inline MouseEvent(Button button, const Vector2i& position): _button(button), _position(position) {}

        const Button _button;
        const Vector2i _position;
};

/**
@brief Mouse move event

@see MouseEvent, mouseMoveEvent()
*/
class GlutApplication::MouseMoveEvent: public GlutApplication::InputEvent {
    friend class GlutApplication;

    public:
        /** @brief Position */
        inline Vector2i position() const { return _position; }

    private:
        inline MouseMoveEvent(const Vector2i& position): _position(position) {}

        const Vector2i _position;
};

/** @hideinitializer
@brief Entry point for GLUT-based applications
@param className Class name

Can be with GlutApplication subclasses used as equivalent to the following
code to achieve better portability, see @ref portability-applications for more
information.
@code
int main(int argc, char** argv) {
    className app(argc, argv);
    return app.exec();
}
@endcode
When no other application header is included this macro is also aliased to
`MAGNUM_APPLICATION_MAIN()`.
*/
#define MAGNUM_GLUTAPPLICATION_MAIN(className)                              \
    int main(int argc, char** argv) {                                       \
        className app(argc, argv);                                          \
        return app.exec();                                                  \
    }

#ifndef DOXYGEN_GENERATING_OUTPUT
#ifndef MAGNUM_APPLICATION_MAIN
#define MAGNUM_APPLICATION_MAIN(className) MAGNUM_GLUTAPPLICATION_MAIN(className)
#else
#undef MAGNUM_APPLICATION_MAIN
#endif
#endif

/* Implementations for inline functions with unused parameters */
inline void GlutApplication::keyPressEvent(KeyEvent&) {}
inline void GlutApplication::mousePressEvent(MouseEvent&) {}
inline void GlutApplication::mouseReleaseEvent(MouseEvent&) {}
inline void GlutApplication::mouseMoveEvent(MouseMoveEvent&) {}

}}

#endif