/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2012 Bolton Software Ltd.
 * Copyright (C) 2004 Chris Schoeneman
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file COPYING that should have accompanied this file.
 * 
 * This package 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/>.
 */

#pragma once

#include "synergy/IKeyState.h"
#include "synergy/KeyMap.h"

//! Core key state
/*!
This class provides key state services.  Subclasses must implement a few
platform specific methods.
*/
class KeyState : public IKeyState {
public:
	KeyState(IEventQueue* events);
	KeyState(IEventQueue* events, synergy::KeyMap& keyMap);
	virtual ~KeyState();

	//! @name manipulators
	//@{

	//! Handle key event
	/*!
	Sets the state of \p button to down or up and updates the current
	modifier state to \p newState.  This method should be called by
	primary screens only in response to local events.  For auto-repeat
	set \p down to \c true.  Overrides must forward to the superclass.
	*/
	virtual void		onKey(KeyButton button, bool down,
							KeyModifierMask newState);

	//! Post a key event
	/*!
	Posts a key event.  This may adjust the event or post additional
	events in some circumstances.  If this is overridden it must forward
	to the superclass.
	*/
	virtual void		sendKeyEvent(void* target,
							bool press, bool isAutoRepeat,
							KeyID key, KeyModifierMask mask,
							SInt32 count, KeyButton button);

	//@}
	//! @name accessors
	//@{

	//@}

	// IKeyState overrides
	virtual void		updateKeyMap();
	virtual void		updateKeyState();
	virtual void		setHalfDuplexMask(KeyModifierMask);
	virtual void		fakeKeyDown(KeyID id, KeyModifierMask mask,
							KeyButton button);
	virtual bool		fakeKeyRepeat(KeyID id, KeyModifierMask mask,
							SInt32 count, KeyButton button);
	virtual bool		fakeKeyUp(KeyButton button);
	virtual void		fakeAllKeysUp();
	virtual bool		fakeCtrlAltDel() = 0;
	virtual bool		isKeyDown(KeyButton) const;
	virtual KeyModifierMask
						getActiveModifiers() const;
	virtual KeyModifierMask
						pollActiveModifiers() const = 0;
	virtual SInt32		pollActiveGroup() const = 0;
	virtual void		pollPressedKeys(KeyButtonSet& pressedKeys) const = 0;

	SInt32 getKeyState(KeyButton keyButton) { return m_keys[keyButton]; }

protected:
	typedef synergy::KeyMap::Keystroke Keystroke;

	//! @name protected manipulators
	//@{

	//! Get the keyboard map
	/*!
	Fills \p keyMap with the current keyboard map.
	*/
	virtual void		getKeyMap(synergy::KeyMap& keyMap) = 0;

	//! Fake a key event
	/*!
	Synthesize an event for \p keystroke.
	*/
	virtual void		fakeKey(const Keystroke& keystroke) = 0;

	//! Get the active modifiers
	/*!
	Returns the modifiers that are currently active according to our
	shadowed state.  The state may be modified.
	*/
	virtual KeyModifierMask&
						getActiveModifiersRValue();

	//@}
	//! @name protected accessors
	//@{

	//! Compute a group number
	/*!
	Returns the number of the group \p offset groups after group \p group.
	*/
	SInt32				getEffectiveGroup(SInt32 group, SInt32 offset) const;

	//! Check if key is ignored
	/*!
	Returns \c true if and only if the key should always be ignored.
	The default returns \c true only for the toggle keys.
	*/
	virtual bool		isIgnoredKey(KeyID key, KeyModifierMask mask) const;

	//! Get button for a KeyID
	/*!
	Return the button mapped to key \p id in group \p group if any,
	otherwise returns 0.
	*/
	KeyButton			getButton(KeyID id, SInt32 group) const;

	//@}

private:
	typedef synergy::KeyMap::Keystrokes Keystrokes;
	typedef synergy::KeyMap::ModifierToKeys ModifierToKeys;
public:
	struct AddActiveModifierContext {
	public:
		AddActiveModifierContext(SInt32 group, KeyModifierMask mask,
							ModifierToKeys&	activeModifiers);

	public:
		SInt32			m_activeGroup;
		KeyModifierMask	m_mask;
		ModifierToKeys&	m_activeModifiers;

	private:
		// not implemented
		AddActiveModifierContext(const AddActiveModifierContext&);
		AddActiveModifierContext& operator=(const AddActiveModifierContext&);
	};
private:
	
	class ButtonToKeyLess {
	public:
		bool operator()(const synergy::KeyMap::ButtonToKeyMap::value_type& a,
						const synergy::KeyMap::ButtonToKeyMap::value_type b) const
		{
			return (a.first < b.first);
		}
	};

	// not implemented
	KeyState(const KeyState&);
	KeyState& operator=(const KeyState&);

	// called by all ctors.
	void				init();

	// adds alias key sequences.  these are sequences that are equivalent
	// to other sequences.
	void				addAliasEntries();

	// adds non-keypad key sequences for keypad KeyIDs
	void				addKeypadEntries();

	// adds key sequences for combination KeyIDs (those built using
	// dead keys)
	void				addCombinationEntries();

	// synthesize key events.  synthesize auto-repeat events count times.
	void				fakeKeys(const Keystrokes&, UInt32 count);

	// update key state to match changes to modifiers
	void				updateModifierKeyState(KeyButton button,
							const ModifierToKeys& oldModifiers,
							const ModifierToKeys& newModifiers);

	// active modifiers collection callback
	static void			addActiveModifierCB(KeyID id, SInt32 group,
							synergy::KeyMap::KeyItem& keyItem, void* vcontext);

private:
	// must be declared before m_keyMap. used when this class owns the key map.
	synergy::KeyMap*			m_keyMapPtr;

	// the keyboard map
	synergy::KeyMap&			m_keyMap;

	// current modifier state
	KeyModifierMask		m_mask;

	// the active modifiers and the buttons activating them
	ModifierToKeys		m_activeModifiers;

	// current keyboard state (> 0 if pressed, 0 otherwise).  this is
	// initialized to the keyboard state according to the system then
	// it tracks synthesized events.
	SInt32				m_keys[kNumButtons];

	// synthetic keyboard state (> 0 if pressed, 0 otherwise).  this
	// tracks the synthesized keyboard state.  if m_keys[n] > 0 but
	// m_syntheticKeys[n] == 0 then the key was pressed locally and
	// not synthesized yet.
	SInt32				m_syntheticKeys[kNumButtons];

	// client data for each pressed key
	UInt32				m_keyClientData[kNumButtons];

	// server keyboard state.  an entry is 0 if not the key isn't pressed
	// otherwise it's the local KeyButton synthesized for the server key.
	KeyButton			m_serverKeys[kNumButtons];

	IEventQueue*		m_events;
};