/*
    This file is part of Mitsuba, a physically based rendering system.

    Copyright (c) 2007-2011 by Wenzel Jakob and others.

    Mitsuba is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License Version 3
    as published by the Free Software Foundation.

    Mitsuba 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

#if !defined(__HWDEVICE_H)
#define __HWDEVICE_H

#include <mitsuba/hw/session.h>
#include <list>

MTS_NAMESPACE_BEGIN

class Renderer;

/** \brief The device event structure encapsulates event
 * information such as mouse movement or key presses
 */
struct MTS_EXPORT_HW DeviceEvent {
public:
	/// Default constructor
	inline DeviceEvent() { }

	/// Type constructor
	inline DeviceEvent(unsigned short type) { m_type = type; }

	/// Return the event type
	inline unsigned short getType() const {  return m_type; }

	/// Set the event type
	inline void setType(int type) { m_type = type; }

	/// Get the mouse position vector
	inline void setMousePosition(const Point2i &position) { m_mouse.x = position.x; m_mouse.y = position.y; }

	/// Set the mouse position vector
	inline Point2i getMousePosition() const { return Point2i(m_mouse.x, m_mouse.y); }

	/// Get the relative mouse movement vector
	inline void setMouseRelative(const Vector2i &relative) { m_mouse.xrel = relative.x; m_mouse.yrel = relative.y; }

	/// Set the relative mouse movement vector
	inline Vector2i getMouseRelative() const { return Vector2i(m_mouse.xrel, m_mouse.yrel); }

	/// Set the enum of the pressed mouse button
	inline void setMouseButton(unsigned short button) { m_mouse.button = button; }

	/// Get the enum of the pressed mouse button
	inline unsigned short getMouseButton() const { return m_mouse.button; }

	/// Set the pressed keyboard key (latin1)
	inline void setKeyboardKey(char key) { m_keyboard.key = key; }

	/// Get the pressed keyboard key (latin1)
	inline char getKeyboardKey() const { return m_keyboard.key; }

	/// Set the pressed keyboard key special identifier enum (see Device::ESpecialKeys)
	inline void setKeyboardSpecial(unsigned short special) { m_keyboard.special = special; }

	/// Get the pressed keyboard key special identifier enum (see Device::ESpecialKeys)
	inline unsigned short getKeyboardSpecial() const { return m_keyboard.special; }

	/// Set the keyboard modifiers (see Device::EKeyboardModifiers)
	inline void setKeyboardModifiers(unsigned short modifiers) { m_keyboard.modifiers = modifiers; }

	/// Get the keyboard modifiers (see Device::EKeyboardModifiers)
	inline unsigned short getKeyboardModifiers() const { return m_keyboard.modifiers; }

	/// Get the interpreted keypress data
	inline const char* getKeyboardInterpreted() const { return m_keyboard.interpreted; }
	
	/// Get the interpreted keypress data
	inline char* getKeyboardInterpreted() { return m_keyboard.interpreted; }

	/// Set the event source
	inline void setActionSource(Object *source) { m_action.source = source; }

	/// Get the event source
	inline Object *getActionSource() { return m_action.source; }

	/// Return a string representation
	std::string toString() const;
private:
	unsigned short m_type;

	union {
		struct {
			unsigned short special, modifiers;
			char key, interpreted[16];
		} m_keyboard;

		struct {
			int x, y, xrel, yrel;
			unsigned short button;
		} m_mouse;

		struct {
			Object *source;
		} m_action;
	};
};

/** \brief Abstract device event callback
 */
class MTS_EXPORT_HW DeviceEventListener {
public:
	/** \brief Called when a device event occurs
	 * \param event The event data structure
	 * \return True if the result has been handled, false otherwise
	 */
	virtual bool deviceEventOccurred(const DeviceEvent &event) = 0;
protected:
	/// Virtual destructor
	virtual ~DeviceEventListener() { }
};

/** \brief An abstract drawing device
 */
class MTS_EXPORT_HW Device : public Object {
public:
	/// Device event types
	enum EEventType {
		ENoEvent = 0x0000,
		EQuitEvent = 0x0001,
		EKeyDownEvent = 0x0002,
		EKeyUpEvent = 0x0004,
		EMouseMotionEvent = 0x0008,
		EMouseDragEvent = 0x0010,
		EMouseButtonDownEvent = 0x0020,
		EMouseButtonUpEvent = 0x0040,
		EMouseEnterEvent = 0x0080,
		EMouseLeaveEvent = 0x0100,
		EMouseBeginDragEvent = 0x0200,
		EMouseEndDragEvent = 0x0400,
		EMouseDoubleClickEvent = 0x0800,
		EGainFocusEvent = 0x1000,
		ELoseFocusEvent = 0x2000,
		EResizeEvent = 0x4000
	};

	/// Device keyboard event modifiers
	enum EKeyboardModifiers {
		EShiftModifier = 0x01,
		EControlModifier = 0x02,
		EAltModifier = 0x04,
		EMetaModifier = 0x08
	};

	/// Device keyboard event modifiers
	enum EMouseButton {
		ENoButton = 0x0,
		ELeftButton = 0x01,
		EMiddleButton = 0x02,
		ERightButton = 0x04,
		EWheelUpButton = 0x08,
		EWheelDownButton = 0x10
	};

	/// Device special keys
	enum ESpecialKeys {
		ENoSpecial = 0,
		EKeyEscape,
		EKeyF1,
		EKeyF2,
		EKeyF3,
		EKeyF4,
		EKeyF5,
		EKeyF6,
		EKeyF7,
		EKeyF8,
		EKeyF9,
		EKeyF10,
		EKeyF11,
		EKeyF12,
		EKeyF13,
		EKeyF14,
		EKeyF15,
		EKeyBackspace,
		EKeyTab,
		EKeyClear,
		EKeyReturn,
		EKeyPause,
		EKeyInsert,
		EKeyDelete,
		EKeyUp,
		EKeyDown,
		EKeyLeft,
		EKeyRight,
		EKeyHome,
		EKeyEnd,
		EKeyPageUp,
		EKeyPageDown,
		EKeyNumLock,
		EKeyCapsLock,
		EKeyScrollLock,
		EKeyLShift,
		EKeyRShift,
		EKeyLAlt,
		EKeyRAlt,
		EKeyLMeta,
		EKeyRMeta,
		EKeyLControl,
		EKeyRControl,
		EKeyKeyPad0,
		EKeyKeyPad1,
		EKeyKeyPad2,
		EKeyKeyPad3,
		EKeyKeyPad4,
		EKeyKeyPad5,
		EKeyKeyPad6,
		EKeyKeyPad7,
		EKeyKeyPad8,
		EKeyKeyPad9,
		EKeyKeyPadPeriod,
		EKeyKeyPadDivide,
		EKeyKeyPadMultiply,
		EKeyKeyPadMinus,
		EKeyKeyPadPlus,
		EKeyKeyPadEnter,
		EKeyKeyPadEquals,
		EKeyLastSpecialKey
	};

	/// Construct a new device using the appropriate implementation
	static Device *create(Session *session);

	/// Return the dimension of the device
	inline Vector2i getSize() const { return m_size; }

	/// Set the dimension of the device
	void setSize(const Vector2i &dimension);

	/// Return the aspect ratio of the device
	inline Float getAspect() const { return (Float) m_size.x / (Float) m_size.y; }

	/// Return the position of the device
	inline Point2i getPosition() const { return m_position; }

	/// Set the position of the device
	virtual void setPosition(const Point2i &position);

	/// Set the FSAA sample count, do this before Init()
	void setFSAA(int fsaa);

	/// Return the FSAA sample count
	inline int getFSAA() const { return m_fsaa; }
	
	/// Only applies to devices, which are UI windows
	virtual void setVisible(bool visible) = 0;

	/** \brief A convenience method.
	 *
	 * Sets the amount of bits for the red, green and
	 * blue components
	 */
	void setColorBits(int colorBits);

	/// Set the amount of bits for the red component
	void setRedBits(int redBits);

	/// Return the amount of bits for the red component
	inline int getRedBits() const { return m_redBits; }

	/// Set the amount of bits for the green component
	void setGreenBits(int greenBits);

	/// Return the amount of bits for the green component
	inline int getGreenBits() const { return m_greenBits; }

	/// Set the amount of bits for the blue component
	void setBlueBits(int blueBits);

	/// Return the amount of bits for the blue component
	inline int getBlueBits() const { return m_blueBits; }

	/// Set the amount of bits for the alpha component
	void setAlphaBits(int alphaBits);

	/// Return the amount of bits for the alpha component
	inline int getAlphaBits() const { return m_alphaBits; }

	/// Set the amount of bits for the depth component
	void setDepthBits(int depthBits);

	/// Return the amount of bits for the depth component
	inline int getDepthBits() const { return m_depthBits; }

	/// Set the amount of bits for the stencil component
	void setStencilBits(int stencilBits);

	/// Return the amount of bits for the stencil component
	inline int getStencilBits() const { return m_stencilBits; }

	/// Define whether to enable double buffering
	void setDoubleBuffer(bool doubleBuffer);

	// Return whether double buffering is enabled
	inline bool getDoubleBuffer() const { return m_doubleBuffer; }

	// Define whether to enable full screen drawing
	void setFullscreen(bool fullscreen);

	/// Return whether full screen drawing is enabled
	inline bool getFullscreen() const { return m_fullscreen; }

	// Specify whether resizing the window is allowed
	void setResizeAllowed(bool resizeAllowed);

	/// Return whether it is possible to resize the window
	inline bool isResizeAllowed() const { return m_resizeAllowed; }

	/// Define whether to enable window centering
	void setCenter(bool center);

	/// Return whether window centering is enabled
	inline bool getCenter() const { return m_center; }

	/// Define whether to show the frames per second
	inline void setShowFPS(bool showFPS) { m_showFPS = showFPS; }

	/// Return whether to show the frames per second
	inline bool getShowFPS() const { return m_showFPS; }

	/// Return the frames per second (0 if no data is available)
	inline int getFPS() const { return m_fps; }

	/// Set the x window position
	void setXPos(int xpos);

	/// Set the window title
	virtual void setTitle(const std::string &title);

	/// Return the window title
	inline const std::string &getTitle() const { return m_title; }

	/// Get the session
	inline const Session *getSession() const { return m_session.get(); }

	/// Get the session
	inline Session *getSession() { return m_session; }

	/**
	 * Initialize the renderer. Optionally, an existing device instance 
	 * can be provided as a second argument -- this is primarily meant
	 * to create a device that will be able to support a shared context
	 * with another device.
	 */
	virtual void init(Device *other = NULL);

	/// Shut the device down
	virtual void shutdown();

	/// Add an event callback to the device
	void addCallback(DeviceEventListener *callback);

	/// Remove an event callback from the device
	void removeCallback(DeviceEventListener *callback);

	/// Associate the renderer with this device
	virtual void makeCurrent(Renderer *renderer) = 0;

	/// Flip the buffers (when using double buffering)
	virtual void flip();

	MTS_DECLARE_CLASS()
protected:
	/// Virtual destructor
	virtual ~Device();

	/// Create a new device
	Device(Session *session);

	/** \brief Send a device event using 
	 * the registered callbacks
	 */
	void fireDeviceEvent(const DeviceEvent &event);
protected:
	ref<Session> m_session;
	ref<Timer> m_timer;
	Vector2i m_size;
	Point2i m_position;
	int m_fsaa;
	int m_redBits, m_greenBits, m_blueBits;
	int m_alphaBits, m_depthBits, m_stencilBits;
	bool m_doubleBuffer, m_initialized, m_fullscreen;
	bool m_center, m_showFPS, m_resizeAllowed;
	int m_fpsCounter, m_fps, m_lastTime;
	std::string m_title;
	std::list<DeviceEventListener *> m_callbacks;
};

MTS_NAMESPACE_END

#endif /* __HWDEVICE_H */
