/*
 # Copyright (c) 2009 - OpenSLX Project, Computer Center University of Freiburg
 #
 # This program is free software distributed under the GPL version 2.
 # See http://openslx.org/COPYING
 #
 # If you have any feedback please consult http://openslx.org/feedback and
 # send your suggestions, praise, or complaints to feedback@openslx.org
 #
 # General information about OpenSLX can be found at http://openslx.org/
 # --------------------------------------------------------------------------
 # x11FakeKeyboardHandler.cpp:
 #  - Handle keyboard events on X11 - interface
 # --------------------------------------------------------------------------
 */

#include <map>
#include <set>
#include <cassert>
// Qt headers need to be included before X11 headers
#include <QApplication>
#include <QtCore>
#include "x11FakeKeyboardHandler.h"
// #include <multimap>
#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/keysym.h>
#include <X11/keysymdef.h>
#include <X11/extensions/XTest.h>
#ifdef HAVE_XINPUT2_H
# include <X11/extensions/XInput2.h>
#else
# include <X11/extensions/XInput.h>
#endif
#include <X11/XKBlib.h>
#include <src/util/consoleLogger.h>
#include "x11InputUtils.h"

// X11 supports 8 modifiers, so a bitmask of modifiers fits into a byte:
typedef unsigned char XModifiers;

// For debugging output, these are the names of modifier keys:
char modifiernames[][8] = {
		"SHIFT",
		"LOCK",
		"CONTROL",
		"MOD1",
		"MOD2",
		"MOD3",
		"MOD4",
		"MOD5"
};

QString modifiersToString(XModifiers mods)
{
	QString s;
	for(int i = 0; i < 8; i++)
	{
		if(mods & (1<<i))
		{
			s += modifiernames[i];
			s += ", ";
		}
	}
	s.chop(2);
	return s;
}

/////////////////////////////////////////////////////////////////////////
// Input event translation code
/////////////////////////////////////////////////////////////////////////

// We need to translate between Qt's keycodes and X11's keycodes.
// Unfortunately, there does not seem to be a direct correspondence
// between them, so we are stuck with storing a lookup table:
typedef std::map<quint32, KeySym> KeycodeLookupTable;
KeycodeLookupTable keysyms;

// The following code has been partially autogenerated by
// an insane sed(1) script and then hand-edited to make
// the errors go away.
void initializeKeycodeLookupTable() {
	keysyms[Qt::Key_Escape] = XK_Escape;
	keysyms[Qt::Key_Tab] = XK_Tab;
	keysyms[Qt::Key_Backspace] = XK_BackSpace;
	keysyms[Qt::Key_Return] = XK_Return;
	keysyms[Qt::Key_Enter] = XK_KP_Enter;
	keysyms[Qt::Key_Insert] = XK_Insert;
	keysyms[Qt::Key_Delete] = XK_Delete;
	keysyms[Qt::Key_Pause] = XK_Pause;
	keysyms[Qt::Key_Print] = XK_Print;
	keysyms[Qt::Key_SysReq] = XK_Sys_Req;
	keysyms[Qt::Key_Clear] = XK_Clear;
	keysyms[Qt::Key_Home] = XK_Home;
	keysyms[Qt::Key_End] = XK_End;
	keysyms[Qt::Key_Left] = XK_Left;
	keysyms[Qt::Key_Up] = XK_Up;
	keysyms[Qt::Key_Right] = XK_Right;
	keysyms[Qt::Key_Down] = XK_Down;
	keysyms[Qt::Key_PageUp] = XK_Page_Up;
	keysyms[Qt::Key_PageDown] = XK_Page_Down;
	keysyms[Qt::Key_Shift] = XK_Shift_L;
	keysyms[Qt::Key_Control] = XK_Control_L;
	keysyms[Qt::Key_Meta] = XK_Meta_L;
	keysyms[Qt::Key_Alt] = XK_Alt_L;
	keysyms[Qt::Key_CapsLock] = XK_Caps_Lock;
	keysyms[Qt::Key_NumLock] = XK_Num_Lock;
	keysyms[Qt::Key_ScrollLock] = XK_Scroll_Lock;
	keysyms[Qt::Key_F1] = XK_F1;
	keysyms[Qt::Key_F2] = XK_F2;
	keysyms[Qt::Key_F3] = XK_F3;
	keysyms[Qt::Key_F4] = XK_F4;
	keysyms[Qt::Key_F5] = XK_F5;
	keysyms[Qt::Key_F6] = XK_F6;
	keysyms[Qt::Key_F7] = XK_F7;
	keysyms[Qt::Key_F8] = XK_F8;
	keysyms[Qt::Key_F9] = XK_F9;
	keysyms[Qt::Key_F10] = XK_F10;
	keysyms[Qt::Key_F11] = XK_F11;
	keysyms[Qt::Key_F12] = XK_F12;
	keysyms[Qt::Key_F13] = XK_F13;
	keysyms[Qt::Key_F14] = XK_F14;
	keysyms[Qt::Key_F15] = XK_F15;
	keysyms[Qt::Key_F16] = XK_F16;
	keysyms[Qt::Key_F17] = XK_F17;
	keysyms[Qt::Key_F18] = XK_F18;
	keysyms[Qt::Key_F19] = XK_F19;
	keysyms[Qt::Key_F20] = XK_F20;
	keysyms[Qt::Key_F21] = XK_F21;
	keysyms[Qt::Key_F22] = XK_F22;
	keysyms[Qt::Key_F23] = XK_F23;
	keysyms[Qt::Key_F24] = XK_F24;
	keysyms[Qt::Key_F25] = XK_F25;
	keysyms[Qt::Key_F26] = XK_F26;
	keysyms[Qt::Key_F27] = XK_F27;
	keysyms[Qt::Key_F28] = XK_F28;
	keysyms[Qt::Key_F29] = XK_F29;
	keysyms[Qt::Key_F30] = XK_F30;
	keysyms[Qt::Key_F31] = XK_F31;
	keysyms[Qt::Key_F32] = XK_F32;
	keysyms[Qt::Key_F33] = XK_F33;
	keysyms[Qt::Key_F34] = XK_F34;
	keysyms[Qt::Key_F35] = XK_F35;
	keysyms[Qt::Key_Super_L] = XK_Super_L;
	keysyms[Qt::Key_Super_R] = XK_Super_R;
	keysyms[Qt::Key_Menu] = XK_Menu;
	keysyms[Qt::Key_Hyper_L] = XK_Hyper_L;
	keysyms[Qt::Key_Hyper_R] = XK_Hyper_R;
	keysyms[Qt::Key_Help] = XK_Help;
	keysyms[Qt::Key_Space] = XK_space;
	keysyms[Qt::Key_Exclam] = XK_exclam;
	keysyms[Qt::Key_QuoteDbl] = XK_quotedbl;
	keysyms[Qt::Key_NumberSign] = XK_numbersign;
	keysyms[Qt::Key_Dollar] = XK_dollar;
	keysyms[Qt::Key_Percent] = XK_percent;
	keysyms[Qt::Key_Ampersand] = XK_ampersand;
	keysyms[Qt::Key_Apostrophe] = XK_apostrophe;
	keysyms[Qt::Key_ParenLeft] = XK_parenleft;
	keysyms[Qt::Key_ParenRight] = XK_parenright;
	keysyms[Qt::Key_Asterisk] = XK_asterisk;
	keysyms[Qt::Key_Plus] = XK_plus;
	keysyms[Qt::Key_Comma] = XK_comma;
	keysyms[Qt::Key_Minus] = XK_minus;
	keysyms[Qt::Key_Period] = XK_period;
	keysyms[Qt::Key_Slash] = XK_slash;
	keysyms[Qt::Key_0] = XK_0;
	keysyms[Qt::Key_1] = XK_1;
	keysyms[Qt::Key_2] = XK_2;
	keysyms[Qt::Key_3] = XK_3;
	keysyms[Qt::Key_4] = XK_4;
	keysyms[Qt::Key_5] = XK_5;
	keysyms[Qt::Key_6] = XK_6;
	keysyms[Qt::Key_7] = XK_7;
	keysyms[Qt::Key_8] = XK_8;
	keysyms[Qt::Key_9] = XK_9;
	keysyms[Qt::Key_Colon] = XK_colon;
	keysyms[Qt::Key_Semicolon] = XK_semicolon;
	keysyms[Qt::Key_Less] = XK_less;
	keysyms[Qt::Key_Equal] = XK_equal;
	keysyms[Qt::Key_Greater] = XK_greater;
	keysyms[Qt::Key_Question] = XK_question;
	keysyms[Qt::Key_At] = XK_at;
	keysyms[Qt::Key_A] = XK_A;
	keysyms[Qt::Key_B] = XK_B;
	keysyms[Qt::Key_C] = XK_C;
	keysyms[Qt::Key_D] = XK_D;
	keysyms[Qt::Key_E] = XK_E;
	keysyms[Qt::Key_F] = XK_F;
	keysyms[Qt::Key_G] = XK_G;
	keysyms[Qt::Key_H] = XK_H;
	keysyms[Qt::Key_I] = XK_I;
	keysyms[Qt::Key_J] = XK_J;
	keysyms[Qt::Key_K] = XK_K;
	keysyms[Qt::Key_L] = XK_L;
	keysyms[Qt::Key_M] = XK_M;
	keysyms[Qt::Key_N] = XK_N;
	keysyms[Qt::Key_O] = XK_O;
	keysyms[Qt::Key_P] = XK_P;
	keysyms[Qt::Key_Q] = XK_Q;
	keysyms[Qt::Key_R] = XK_R;
	keysyms[Qt::Key_S] = XK_S;
	keysyms[Qt::Key_T] = XK_T;
	keysyms[Qt::Key_U] = XK_U;
	keysyms[Qt::Key_V] = XK_V;
	keysyms[Qt::Key_W] = XK_W;
	keysyms[Qt::Key_X] = XK_X;
	keysyms[Qt::Key_Y] = XK_Y;
	keysyms[Qt::Key_Z] = XK_Z;
	keysyms[Qt::Key_BracketLeft] = XK_bracketleft;
	keysyms[Qt::Key_Backslash] = XK_backslash;
	keysyms[Qt::Key_BracketRight] = XK_bracketright;
	keysyms[Qt::Key_AsciiCircum] = XK_asciicircum;
	keysyms[Qt::Key_Underscore] = XK_underscore;
	keysyms[Qt::Key_QuoteLeft] = XK_quoteleft;
	keysyms[Qt::Key_BraceLeft] = XK_braceleft;
	keysyms[Qt::Key_Bar] = XK_bar;
	keysyms[Qt::Key_BraceRight] = XK_braceright;
	keysyms[Qt::Key_AsciiTilde] = XK_asciitilde;
	keysyms[Qt::Key_nobreakspace] = XK_nobreakspace;
	keysyms[Qt::Key_exclamdown] = XK_exclamdown;
	keysyms[Qt::Key_cent] = XK_cent;
	keysyms[Qt::Key_sterling] = XK_sterling;
	keysyms[Qt::Key_currency] = XK_currency;
	keysyms[Qt::Key_yen] = XK_yen;
	keysyms[Qt::Key_brokenbar] = XK_brokenbar;
	keysyms[Qt::Key_section] = XK_section;
	keysyms[Qt::Key_diaeresis] = XK_diaeresis;
	keysyms[Qt::Key_copyright] = XK_copyright;
	keysyms[Qt::Key_ordfeminine] = XK_ordfeminine;
	keysyms[Qt::Key_guillemotleft] = XK_guillemotleft;
	keysyms[Qt::Key_notsign] = XK_notsign;
	keysyms[Qt::Key_hyphen] = XK_hyphen;
	keysyms[Qt::Key_registered] = XK_registered;
	keysyms[Qt::Key_macron] = XK_macron;
	keysyms[Qt::Key_degree] = XK_degree;
	keysyms[Qt::Key_plusminus] = XK_plusminus;
	keysyms[Qt::Key_twosuperior] = XK_twosuperior;
	keysyms[Qt::Key_threesuperior] = XK_threesuperior;
	keysyms[Qt::Key_acute] = XK_acute;
	keysyms[Qt::Key_mu] = XK_mu;
	keysyms[Qt::Key_paragraph] = XK_paragraph;
	keysyms[Qt::Key_periodcentered] = XK_periodcentered;
	keysyms[Qt::Key_cedilla] = XK_cedilla;
	keysyms[Qt::Key_onesuperior] = XK_onesuperior;
	keysyms[Qt::Key_masculine] = XK_masculine;
	keysyms[Qt::Key_guillemotright] = XK_guillemotright;
	keysyms[Qt::Key_onequarter] = XK_onequarter;
	keysyms[Qt::Key_onehalf] = XK_onehalf;
	keysyms[Qt::Key_threequarters] = XK_threequarters;
	keysyms[Qt::Key_questiondown] = XK_questiondown;
	keysyms[Qt::Key_Agrave] = XK_Agrave;
	keysyms[Qt::Key_Aacute] = XK_Aacute;
	keysyms[Qt::Key_Acircumflex] = XK_Acircumflex;
	keysyms[Qt::Key_Atilde] = XK_Atilde;
	keysyms[Qt::Key_Adiaeresis] = XK_Adiaeresis;
	keysyms[Qt::Key_Aring] = XK_Aring;
	keysyms[Qt::Key_AE] = XK_AE;
	keysyms[Qt::Key_Ccedilla] = XK_Ccedilla;
	keysyms[Qt::Key_Egrave] = XK_Egrave;
	keysyms[Qt::Key_Eacute] = XK_Eacute;
	keysyms[Qt::Key_Ecircumflex] = XK_Ecircumflex;
	keysyms[Qt::Key_Ediaeresis] = XK_Ediaeresis;
	keysyms[Qt::Key_Igrave] = XK_Igrave;
	keysyms[Qt::Key_Iacute] = XK_Iacute;
	keysyms[Qt::Key_Icircumflex] = XK_Icircumflex;
	keysyms[Qt::Key_Idiaeresis] = XK_Idiaeresis;
	keysyms[Qt::Key_ETH] = XK_ETH;
	keysyms[Qt::Key_Ntilde] = XK_Ntilde;
	keysyms[Qt::Key_Ograve] = XK_Ograve;
	keysyms[Qt::Key_Oacute] = XK_Oacute;
	keysyms[Qt::Key_Ocircumflex] = XK_Ocircumflex;
	keysyms[Qt::Key_Otilde] = XK_Otilde;
	keysyms[Qt::Key_Odiaeresis] = XK_Odiaeresis;
	keysyms[Qt::Key_multiply] = XK_multiply;
	keysyms[Qt::Key_Ooblique] = XK_Ooblique;
	keysyms[Qt::Key_Ugrave] = XK_Ugrave;
	keysyms[Qt::Key_Uacute] = XK_Uacute;
	keysyms[Qt::Key_Ucircumflex] = XK_Ucircumflex;
	keysyms[Qt::Key_Udiaeresis] = XK_Udiaeresis;
	keysyms[Qt::Key_Yacute] = XK_Yacute;
	keysyms[Qt::Key_THORN] = XK_THORN;
	keysyms[Qt::Key_ssharp] = XK_ssharp;
	keysyms[Qt::Key_Agrave] = XK_Agrave;
	keysyms[Qt::Key_Aacute] = XK_Aacute;
	keysyms[Qt::Key_Acircumflex] = XK_Acircumflex;
	keysyms[Qt::Key_Atilde] = XK_Atilde;
	keysyms[Qt::Key_Adiaeresis] = XK_Adiaeresis;
	keysyms[Qt::Key_Aring] = XK_Aring;
	keysyms[Qt::Key_AE] = XK_AE;
	keysyms[Qt::Key_Ccedilla] = XK_Ccedilla;
	keysyms[Qt::Key_Egrave] = XK_Egrave;
	keysyms[Qt::Key_Eacute] = XK_Eacute;
	keysyms[Qt::Key_Ecircumflex] = XK_Ecircumflex;
	keysyms[Qt::Key_Ediaeresis] = XK_Ediaeresis;
	keysyms[Qt::Key_Igrave] = XK_Igrave;
	keysyms[Qt::Key_Iacute] = XK_Iacute;
	keysyms[Qt::Key_Icircumflex] = XK_Icircumflex;
	keysyms[Qt::Key_Idiaeresis] = XK_Idiaeresis;
	keysyms[Qt::Key_ETH] = XK_ETH;
	keysyms[Qt::Key_Ntilde] = XK_Ntilde;
	keysyms[Qt::Key_Ograve] = XK_Ograve;
	keysyms[Qt::Key_Oacute] = XK_Oacute;
	keysyms[Qt::Key_Ocircumflex] = XK_Ocircumflex;
	keysyms[Qt::Key_Otilde] = XK_Otilde;
	keysyms[Qt::Key_Odiaeresis] = XK_Odiaeresis;
	keysyms[Qt::Key_division] = XK_division;
	keysyms[Qt::Key_Ooblique] = XK_Ooblique;
	keysyms[Qt::Key_Ugrave] = XK_Ugrave;
	keysyms[Qt::Key_Uacute] = XK_Uacute;
	keysyms[Qt::Key_Ucircumflex] = XK_Ucircumflex;
	keysyms[Qt::Key_Udiaeresis] = XK_Udiaeresis;
	keysyms[Qt::Key_Yacute] = XK_Yacute;
	keysyms[Qt::Key_THORN] = XK_THORN;
	keysyms[Qt::Key_ydiaeresis] = XK_ydiaeresis;
	keysyms[Qt::Key_AltGr] = XK_ISO_Level3_Shift;
	keysyms[Qt::Key_Multi_key] = XK_Multi_key;
	keysyms[Qt::Key_Codeinput] = XK_Codeinput;
	keysyms[Qt::Key_SingleCandidate] = XK_SingleCandidate;
	keysyms[Qt::Key_MultipleCandidate] = XK_MultipleCandidate;
	keysyms[Qt::Key_PreviousCandidate] = XK_PreviousCandidate;
	keysyms[Qt::Key_Mode_switch] = XK_Mode_switch;
	keysyms[Qt::Key_Kanji] = XK_Kanji;
	keysyms[Qt::Key_Muhenkan] = XK_Muhenkan;
	keysyms[Qt::Key_Henkan] = XK_Henkan;
	keysyms[Qt::Key_Romaji] = XK_Romaji;
	keysyms[Qt::Key_Hiragana] = XK_Hiragana;
	keysyms[Qt::Key_Katakana] = XK_Katakana;
	keysyms[Qt::Key_Hiragana_Katakana] = XK_Hiragana_Katakana;
	keysyms[Qt::Key_Zenkaku] = XK_Zenkaku;
	keysyms[Qt::Key_Hankaku] = XK_Hankaku;
	keysyms[Qt::Key_Zenkaku_Hankaku] = XK_Zenkaku_Hankaku;
	keysyms[Qt::Key_Touroku] = XK_Touroku;
	keysyms[Qt::Key_Massyo] = XK_Massyo;
	keysyms[Qt::Key_Kana_Lock] = XK_Kana_Lock;
	keysyms[Qt::Key_Kana_Shift] = XK_Kana_Shift;
	keysyms[Qt::Key_Eisu_Shift] = XK_Eisu_Shift;
	keysyms[Qt::Key_Eisu_toggle] = XK_Eisu_toggle;
	keysyms[Qt::Key_Hangul] = XK_Hangul;
	keysyms[Qt::Key_Hangul_Hanja] = XK_Hangul_Hanja;
	keysyms[Qt::Key_Hangul] = XK_Hangul;
	keysyms[Qt::Key_Hangul_Start] = XK_Hangul_Start;
	keysyms[Qt::Key_Hangul_End] = XK_Hangul_End;
	keysyms[Qt::Key_Hangul_Hanja] = XK_Hangul_Hanja;
	keysyms[Qt::Key_Hangul_Jamo] = XK_Hangul_Jamo;
	keysyms[Qt::Key_Hangul_Romaja] = XK_Hangul_Romaja;
	keysyms[Qt::Key_Hangul_Jeonja] = XK_Hangul_Jeonja;
	keysyms[Qt::Key_Hangul_Banja] = XK_Hangul_Banja;
	keysyms[Qt::Key_Hangul_PreHanja] = XK_Hangul_PreHanja;
	keysyms[Qt::Key_Hangul_PostHanja] = XK_Hangul_PostHanja;
	keysyms[Qt::Key_Hangul_Special] = XK_Hangul_Special;
	keysyms[Qt::Key_Dead_Grave] = XK_dead_grave;
	keysyms[Qt::Key_Dead_Acute] = XK_dead_acute;
	keysyms[Qt::Key_Dead_Circumflex] = XK_dead_circumflex;
	keysyms[Qt::Key_Dead_Tilde] = XK_dead_tilde;
	keysyms[Qt::Key_Dead_Macron] = XK_dead_macron;
	keysyms[Qt::Key_Dead_Breve] = XK_dead_breve;
	keysyms[Qt::Key_Dead_Abovedot] = XK_dead_abovedot;
	keysyms[Qt::Key_Dead_Diaeresis] = XK_dead_diaeresis;
	keysyms[Qt::Key_Dead_Abovering] = XK_dead_abovering;
	keysyms[Qt::Key_Dead_Doubleacute] = XK_dead_doubleacute;
	keysyms[Qt::Key_Dead_Caron] = XK_dead_caron;
	keysyms[Qt::Key_Dead_Cedilla] = XK_dead_cedilla;
	keysyms[Qt::Key_Dead_Ogonek] = XK_dead_ogonek;
	keysyms[Qt::Key_Dead_Iota] = XK_dead_iota;
	keysyms[Qt::Key_Dead_Voiced_Sound] = XK_dead_voiced_sound;
	keysyms[Qt::Key_Dead_Semivoiced_Sound] = XK_dead_semivoiced_sound;
	keysyms[Qt::Key_Dead_Belowdot] = XK_dead_belowdot;
	keysyms[Qt::Key_Dead_Hook] = XK_dead_hook;
	keysyms[Qt::Key_Dead_Horn] = XK_dead_horn;
	keysyms[Qt::Key_Select] = XK_Select;
	keysyms[Qt::Key_Cancel] = XK_Cancel;
	keysyms[Qt::Key_Execute] = XK_Execute;
	keysyms[Qt::Key_unknown] = XK_VoidSymbol;
}

// every keysym with a value under 256 corresponds
// directly to an ISO-Latin1 Character. We need
// to store how to generate those characters:
int basicKeycodes[0x100];	// What key do we need to press?
int basicModifiers[0x100]; // What modifiers are required?

// What keys do we need to press to generate the
// modifiers?
int modifierKeycodes[8];
// How do the X11 modifiers relate to Qt's KeyboardModifiers?
Qt::KeyboardModifier modifierMeaning[8];

// How do the X11 modifiers correspond to Qt's KeyboardModifiers?
typedef std::map<XModifiers, Qt::KeyboardModifier> XToQtModifierMap;
XToQtModifierMap XToQtModifier;

// And how do the modifiers relate to Keycodes?
typedef std::multimap<XModifiers, int> ModifierToKeycodeMap;
ModifierToKeycodeMap ModifierToKeycode;
typedef std::map<int, XModifiers> KeycodeToModifierMap;
KeycodeToModifierMap KeycodeToModifier;

// We need to query the input devices, preferrable through XInput2, but
// if that is not available we will contend ourselves with XInput1:
#ifndef HAVE_XINPUT2_H
#	define XIAllDevices 1 /* does not matter */
#	define XIDeviceInfo XDeviceInfo
#	define XIQueryDevice(dpy, which, ninfos) XListInputDevices(dpy, ninfos)
#	define XIFreeDeviceInfo(infos) XFreeDeviceList(infos)
#	define XIMasterKeyboard IsXKeyboard
#	define XISlaveKeyboard IsXExtensionKeyboard
	static inline Atom* getDeviceProperties(Display* dpy, XIDeviceInfo* devinfo, int* nprops)
	{
		if(devinfo->use == IsXKeyboard)
		{
			// According to XOpenDevice(3X11) you cannot open the Core Keyboard.
			*nprops = 0;
			return 0;
		}

		XDevice* dev = XOpenDevice(dpy, devinfo->id);
		Atom* props = XListDeviceProperties(dpy, dev, nprops);
		XCloseDevice(dpy, dev);
		return props;
	}
#else
	static inline Atom* getDeviceProperties(Display* dpy, XIDeviceInfo* devinfo, int* nprops)
	{
		return XIListProperties(dpy, devinfo->deviceid, nprops);
	}
#endif

// Initialize the above data structures:
void initializeBasicKeycodes()
{
	// Mark everything as unknown initially
	for(int i = 0; i < 8; i++) {
		modifierKeycodes[i] = -1;
	}
	for(int i = 0; i < 0x100; i++) {
		basicKeycodes[i] = -1;
	}

	Display* dpy = X11InputUtils::display();

	// Find out the valid range of keycodes
	int minKeycode, maxKeycode;
	XDisplayKeycodes(dpy, &minKeycode, &maxKeycode);

	// Initialize the XKB client-side code, and find out whether
	// the XKB extension is present in the server.
	int xkbOpcode, xkbEvent, xkbError, xkbMajor, xkbMinor;
	bool xkbPresent = XkbQueryExtension(dpy, &xkbOpcode, &xkbEvent, &xkbError, &xkbMajor, &xkbMinor);

	if(!xkbPresent) {
		// No XKB. This is probably not a very recent
		// system, but we will do the best we can.
		// Retrieve the keyboard mapping
		int keysymsPerCode;
		const int count = maxKeycode - minKeycode + 1;
		KeySym* mapping = XGetKeyboardMapping(dpy, minKeycode, count, &keysymsPerCode);

		// and traverse every entry
		for(int i = 0; i < count; i++)
		{
			for(int j = 0; j < keysymsPerCode; j++)
			{
				const int idx = i * keysymsPerCode + j;
				const KeySym ks = mapping[idx];
				const int keycode = minKeycode + i;

				// to find out if there is a Latin1 character there,
				if(ks >= ' ' && ks < 0x100)
				{
					// that we have not yet found,
					if(basicKeycodes[ks] != -1)
						continue; // already found

					// and record its keycode and needed modifiers.
					basicKeycodes[ks] = keycode;
					basicModifiers[ks] = j;
				}
			}
		}

		// We are finished, free the mapping structure.
		XFree(mapping);
	}
	else
	{
		// XKB is present.

		// As different input devices can have different keymaps,
		// we need to find out what device XTest will send events on:
		unsigned int xkbDeviceId = XkbUseCoreKbd;
		Atom xtestDeviceProp = XInternAtom(dpy, "XTEST Device", false);

		// Find the list of input devices:
		int ndevinfos;
		XIDeviceInfo* devinfos = XIQueryDevice(dpy, XIAllDevices, &ndevinfos);
		if(devinfos)
		{
#ifndef HAVE_XINPUT2_H
#	define deviceid	id
#endif
			for(int i = 0; i < ndevinfos && xkbDeviceId == XkbUseCoreKbd; i++)
			{
				XIDeviceInfo* devinfo = devinfos + i;
				qDebug("Found device %lu of type %d with name %s", (unsigned long)devinfo->deviceid, devinfo->use, devinfo->name);

				// We want it to be a keyboard.
				if(devinfo->use != XIMasterKeyboard && devinfo->use != XISlaveKeyboard)
					continue;

				int nprops;
				Atom* props = getDeviceProperties(dpy, devinfo, &nprops);
				if(props)
				{
					for(int j = 0; j < nprops && xkbDeviceId == XkbUseCoreKbd; j++)
					{
						Atom prop = props[j];
						if(prop == xtestDeviceProp)
						{
							// The device is the XTest Keyboard:
							xkbDeviceId = devinfo->deviceid;
						}
					}
					XFree(props);
				}
			}
			XIFreeDeviceInfo(devinfos);
#ifdef deviceid /* XInput1 */
#	undef deviceid
#endif
		}
		// at this point, xkbDeviceId contains the identifier
		// of the XTEST Device, or xkbUseCoreKbd if none was
		// found.

		// Okay, we know which device to query. Now get its keymap:
		XkbDescPtr keybDesc = XkbGetKeyboard(dpy, XkbAllComponentsMask, xkbDeviceId);
		if(!keybDesc)
		{
			qWarning("Unable to retrieve keyboard description for device %d. Falling back to unreliable global mapping", xkbDeviceId);
		}

		// This is basically the same loop as above, it just queries XKB
		// instead of the old core Xlib routines.
		for(int i = minKeycode; i <= maxKeycode; i++)
		{
			for(int j = 0; j <= 0xff; j++)
			{
				KeySym ks = 0;
				unsigned int unconsumed;
				if(keybDesc)
				{
					if(!XkbTranslateKeyCode(keybDesc, i, j, &unconsumed, &ks) || ks == NoSymbol)
						continue;
				}
				else
				{
					if(!XkbLookupKeySym(dpy, i, j, &unconsumed, &ks) || ks == NoSymbol)
						continue;
				}

				if(ks && (ks < 0x100))
				{
					if(basicKeycodes[ks] != -1)
						continue;

					basicKeycodes[ks] = i;
					basicModifiers[ks] = unconsumed & j;
				}
			}
		}

		// Free the keyboard description:
		if(keybDesc)
		{
			XkbFreeKeyboard(keybDesc, XkbAllComponentsMask, true);
		}
	}

	// find out which keycodes cause the modifier state bits:
	XModifierKeymap* modkm;
	modkm = XGetModifierMapping(dpy);

	const int shiftCode = XKeysymToKeycode(dpy, XK_Shift_L);
	const int controlCode = XKeysymToKeycode(dpy, XK_Control_L);
	const int altCode = XKeysymToKeycode(dpy, XK_Alt_L);
	const int metaCode = XKeysymToKeycode(dpy, XK_Meta_L);
	const int switchCode = XKeysymToKeycode(dpy, XK_Mode_switch);

	// and use this information to find out which
	// X11 modifiers correspond to Qt's modifiers:
	for(int i = 0; i < 8; i++) {
		for(int j = 0; j < modkm->max_keypermod; j++) {
			const int idx = i * modkm->max_keypermod + j;
			const int kc = modkm->modifiermap[idx];

			ModifierToKeycode.insert(std::make_pair((1<<i), kc));
			KeycodeToModifier[kc] = (1<<i);
			if(kc == shiftCode) {
				XToQtModifier[1<<i] = Qt::ShiftModifier;
			} else if(kc == controlCode) {
				XToQtModifier[1<<i] = Qt::ControlModifier;
			} else if(kc == altCode) {
				XToQtModifier[1<<i] = Qt::ShiftModifier;
			} else if(kc == metaCode) {
				XToQtModifier[1<<i] = Qt::MetaModifier;
			} else if(kc == switchCode) {
				XToQtModifier[1<<i] = Qt::GroupSwitchModifier;
			}

			// and record the keycode we need to press/release
			// to activate or deactivate a modifier:
			if(modifierKeycodes[i] != -1) {
				continue; // already found
			}

			// select one arbitrarily
			modifierKeycodes[i] = kc;
		}
	}

	XFreeModifiermap(modkm);
}

// Translate a Qt KeyboardModifiers flag to
// its corresponding X11 modifier bitmask
XModifiers translateModifiers(quint32 mods)
{
	XModifiers ret = 0;

	for(int j = 1; j < 8; j++) {
		XModifiers i = 1<<j;

		if(mods & XToQtModifier[i])
		{
			ret |= i;
		}
	}

	return ret;
}

// We need to keep track of which modifiers
// are currently active
typedef std::set<int> IntSet;
IntSet pressedModifierKeys;
XModifiers currentModifiers;

void trackModifiers(int keycode, bool down)
{
	// is this a modifier key?
	const bool isModifier = KeycodeToModifier.find(keycode) != KeycodeToModifier.end();

	if(!isModifier)
	{
		return;
	}

	if(down) {
		pressedModifierKeys.insert(keycode);
	} else {
		pressedModifierKeys.erase(keycode);
	}

	IntSet::iterator i, end = pressedModifierKeys.end();
	XModifiers modifs = 0;
	for(i = pressedModifierKeys.begin(); i != end; i++)
	{
		KeycodeToModifierMap::iterator foundCode = KeycodeToModifier.find(*i);
		if(foundCode != KeycodeToModifier.end())
		{
			modifs |= (*foundCode).second;
		}
	}
	currentModifiers = modifs;

	ConsoleLog writeLine(QString("[trackModifiers] current modifiers: %1").arg(modifiersToString(modifs)));
}

// And, if we need to tweak the modifiers to generate
// a particular keysym, we need to keep track of which
// ones we pressed or released.
typedef std::pair<int, bool> ModifierTweak;
typedef std::vector<ModifierTweak> TweakSequence;

// Tweak the modifiers to reach the neededState, from actualState
// and record tweaks in the tracker.
void tweakModifiers(Display* dpy, XModifiers neededState, XModifiers actualState, TweakSequence& tracker)
{
	ConsoleLog writeLine(QString("tweakModifiers: Trying to get to `%1' from `%2'").arg(modifiersToString(neededState)).arg(modifiersToString(actualState)));
	for(int j = 0; j < 8; j++)
	{
		XModifiers i = 1<<j;

		ConsoleLog writeLine(QString("Checking for %1...").arg(modifiersToString(i)));

		// Do we need to activate the modifier?
		if((i & neededState) && !(i & actualState))
		{
			ConsoleLog writeLine(QString("tweakModifiers: Modifier %1 needs to be pressed").arg(modifiernames[j]));

			//find the keycode
			ModifierToKeycodeMap::iterator iter = ModifierToKeycode.find(i);

			if((iter == ModifierToKeycode.end()) || ((*iter).first != i))
			{
				// we don't know a key that triggers this modifier
				continue;
			}

			ConsoleLog writeLine(QString("  pressing key %1").arg((*iter).second));
			XTestFakeKeyEvent(dpy, (*iter).second, 1, CurrentTime);

			// record the tweak
			tracker.push_back(std::make_pair((*iter).second, true));
		}
		// or do we need to deactivate it?
		else if((!(i & neededState)) && (i & actualState))
		{
			ConsoleLog writeLine(QString("tweakModifiers: Modifier %1 needs to be released").arg(modifiernames[j]));

			int kc = -1;

			// first, check whether any of the currently pressed keys has triggered this modifier:
			IntSet::iterator iter, end = pressedModifierKeys.end();
			for(iter = pressedModifierKeys.begin(); iter != end; iter++)
			{
				KeycodeToModifierMap::iterator modmapIter = KeycodeToModifier.find(*iter);
				if(modmapIter != KeycodeToModifier.end()) {
					if(modmapIter->second == i) {
						kc = *iter;

						// release this key:
						ConsoleLog writeLine(QString("  releasing key %1").arg(kc));
						XTestFakeKeyEvent(dpy, kc, 0, CurrentTime);
						tracker.push_back(std::make_pair(kc, false));
					}
				}
			}

			if(kc == -1) {
				// strange, but we need to release some other key:
				// we don't know which one, so we abort this and hope for the best
				continue;
			}
		}
	}
}

// Undo a recorded sequence of modifier tweaks
void untweakModifiers(Display* dpy, TweakSequence& tracker)
{
	TweakSequence::iterator i, end = tracker.end();
	for(i = tracker.begin(); i != end; i++) {
		ModifierTweak& t = *i;
		XTestFakeKeyEvent(dpy, t.first, !t.second, CurrentTime);
	}
}

// initialize the handler
void X11FakeKeyboardHandler::initialize()
{
	initializeKeycodeLookupTable();
	initializeBasicKeycodes();
	pressedModifierKeys.clear();
	currentModifiers = 0;
}

// actually try our best to generate the correct input sequence
// for the event
void X11FakeKeyboardHandler::doHandle(InputEvent const& evt, InputEventContext const*)
{
	Display* dpy = X11InputUtils::display();

	// find out which keysym caused this event:
	KeycodeLookupTable::const_iterator i = keysyms.find(evt.qtKeysym());
	if(i == keysyms.end()) {
		// Special cases. We don't know how to directly translate those, so we will try to emulate them.
		switch(evt.qtKeysym())
		{
		case Qt::Key_Backtab:
			doHandle(InputEvent(evt.type(), evt.code(), evt.qtModifiers() | Qt::ShiftModifier | Qt::Key_Tab));
			break;
		default:
			ConsoleLog writeLine(QString("Unknown keysym received: %1").arg(evt.qtKeysym(), 8, 16));
		}
	} else {
		KeySym ks = (*i).second;

		// is it a "normal" key?
		if(ks >= ' ' && ks < 0x100)
		{
			if(basicKeycodes[ks] != -1)
			{
				if(evt.isPress())
				{
					// Try the simple way first:
					// Does the keycode with current modifiers yield the requested symbol?
					KeySym unmodSym = XKeycodeToKeysym(dpy, basicKeycodes[ks], currentModifiers);
					ConsoleLog writeLine(QString("Pressing the key for %1 would yield %2 right now.").arg(XKeysymToString(ks)).arg(XKeysymToString(unmodSym)));

					if(ks == XKeycodeToKeysym(dpy, basicKeycodes[ks], currentModifiers))
					{
						XTestFakeKeyEvent(dpy, basicKeycodes[ks], 1, CurrentTime);
					}
					else
					{
						// what modifier keys do we need to press?
						XModifiers mods = translateModifiers(evt.qtModifiers());

						// we may need to press additional modifiers to generate this keysym:
						if(QChar(ks, 0).isLetter())
						{
							// but, since Qt does not differentiate upper and lower case,
							// we need to preserve Shift and Lock in their current state.
							mods |= basicModifiers[ks] & ~(1<<ShiftMapIndex) & ~(1<<LockMapIndex);
						}
						else
						{
							// Not a letter. We do need to respect Shift and Lock for those:
							mods |= basicModifiers[ks];
						}

						// now, tweak the modifiers
						TweakSequence tweaks;
						tweakModifiers(dpy, mods, currentModifiers, tweaks);

						// press the key:
						XTestFakeKeyEvent(dpy, basicKeycodes[ks], 1, CurrentTime);

						// and release the modifiers:
						untweakModifiers(dpy, tweaks);
					}
				}
				else
				{
					// just release the key.
					XTestFakeKeyEvent(dpy, basicKeycodes[ks], 0, CurrentTime);
				}
			}
			else
			{
				ConsoleLog writeLine(QString("No keycode is mapped to `%1'").arg(XKeysymToString(ks)));
			}
		}
		else
		{
			// It is some kind of "special" key, so we just fake that, then:
			KeyCode kc = XKeysymToKeycode(dpy, ks);
			if(kc != 0)
			{
				ConsoleLog writeLine(QString("%1 special keycode %2, hopefully giving keysym %3").arg(evt.isPress() ? "Pressed" : "Released").arg(kc).arg(XKeysymToString(ks)));
				XTestFakeKeyEvent(dpy, kc, evt.isPress(), CurrentTime);
				// and track it if it is a modifier key:
				trackModifiers(kc, evt.isPress());
			}
			else
			{
				ConsoleLog writeLine(QString("No keycode is mapped to %1").arg(XKeysymToString(ks)));
			}
		}
	}

	// Since there may not be a mainloop running, we need to manually flush the event queue
	XFlush(dpy);
}