/*
 * This file is part of libslab.
 *
 * Copyright (c) 2006 Novell, Inc.
 *
 * Libslab is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * Libslab 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 for
 * more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with libslab; if not, see <http://www.gnu.org/licenses/>.
 */

/* eggaccelerators.c
 * Copyright (C) 2002  Red Hat, Inc.; Copyright 1998, 2001 Tim Janik
 * Developed by Havoc Pennington, Tim Janik
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * 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 GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#include "eggaccelerators.h"

#include <string.h>
#include <gdk/gdkx.h>
#include <gdk/gdkkeysyms.h>

enum
{
	EGG_MODMAP_ENTRY_SHIFT = 0,
	EGG_MODMAP_ENTRY_LOCK = 1,
	EGG_MODMAP_ENTRY_CONTROL = 2,
	EGG_MODMAP_ENTRY_MOD1 = 3,
	EGG_MODMAP_ENTRY_MOD2 = 4,
	EGG_MODMAP_ENTRY_MOD3 = 5,
	EGG_MODMAP_ENTRY_MOD4 = 6,
	EGG_MODMAP_ENTRY_MOD5 = 7,
	EGG_MODMAP_ENTRY_LAST = 8
};

#define MODMAP_ENTRY_TO_MODIFIER(x) (1 << (x))

typedef struct
{
	EggVirtualModifierType mapping[EGG_MODMAP_ENTRY_LAST];

} EggModmap;

const EggModmap *egg_keymap_get_modmap (GdkKeymap * keymap);

static inline gboolean
is_alt (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 'a' || string[1] == 'A') && (string[2] == 'l'
			|| string[2] == 'L') && (string[3] == 't' || string[3] == 'T')
		&& (string[4] == '>'));
}

static inline gboolean
is_ctl (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 'c' || string[1] == 'C') && (string[2] == 't'
			|| string[2] == 'T') && (string[3] == 'l' || string[3] == 'L')
		&& (string[4] == '>'));
}

static inline gboolean
is_modx (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 'm' || string[1] == 'M') && (string[2] == 'o'
			|| string[2] == 'O') && (string[3] == 'd' || string[3] == 'D')
		&& (string[4] >= '1' && string[4] <= '5') && (string[5] == '>'));
}

static inline gboolean
is_ctrl (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 'c' || string[1] == 'C') && (string[2] == 't'
			|| string[2] == 'T') && (string[3] == 'r' || string[3] == 'R')
		&& (string[4] == 'l' || string[4] == 'L') && (string[5] == '>'));
}

static inline gboolean
is_shft (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 's' || string[1] == 'S') && (string[2] == 'h'
			|| string[2] == 'H') && (string[3] == 'f' || string[3] == 'F')
		&& (string[4] == 't' || string[4] == 'T') && (string[5] == '>'));
}

static inline gboolean
is_shift (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 's' || string[1] == 'S') && (string[2] == 'h'
			|| string[2] == 'H') && (string[3] == 'i' || string[3] == 'I')
		&& (string[4] == 'f' || string[4] == 'F') && (string[5] == 't' || string[5] == 'T')
		&& (string[6] == '>'));
}

static inline gboolean
is_control (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 'c' || string[1] == 'C') && (string[2] == 'o'
			|| string[2] == 'O') && (string[3] == 'n' || string[3] == 'N')
		&& (string[4] == 't' || string[4] == 'T') && (string[5] == 'r' || string[5] == 'R')
		&& (string[6] == 'o' || string[6] == 'O') && (string[7] == 'l' || string[7] == 'L')
		&& (string[8] == '>'));
}

static inline gboolean
is_release (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 'r' || string[1] == 'R') && (string[2] == 'e'
			|| string[2] == 'E') && (string[3] == 'l' || string[3] == 'L')
		&& (string[4] == 'e' || string[4] == 'E') && (string[5] == 'a' || string[5] == 'A')
		&& (string[6] == 's' || string[6] == 'S') && (string[7] == 'e' || string[7] == 'E')
		&& (string[8] == '>'));
}

static inline gboolean
is_meta (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 'm' || string[1] == 'M') && (string[2] == 'e'
			|| string[2] == 'E') && (string[3] == 't' || string[3] == 'T')
		&& (string[4] == 'a' || string[4] == 'A') && (string[5] == '>'));
}

static inline gboolean
is_super (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 's' || string[1] == 'S') && (string[2] == 'u'
			|| string[2] == 'U') && (string[3] == 'p' || string[3] == 'P')
		&& (string[4] == 'e' || string[4] == 'E') && (string[5] == 'r' || string[5] == 'R')
		&& (string[6] == '>'));
}

static inline gboolean
is_hyper (const gchar * string)
{
	return ((string[0] == '<') && (string[1] == 'h' || string[1] == 'H') && (string[2] == 'y'
			|| string[2] == 'Y') && (string[3] == 'p' || string[3] == 'P')
		&& (string[4] == 'e' || string[4] == 'E') && (string[5] == 'r' || string[5] == 'R')
		&& (string[6] == '>'));
}

/**
 * egg_accelerator_parse_virtual:
 * @accelerator:      string representing an accelerator
 * @accelerator_key:  return location for accelerator keyval
 * @accelerator_mods: return location for accelerator modifier mask
 *
 * Parses a string representing a virtual accelerator. The format
 * looks like "&lt;Control&gt;a" or "&lt;Shift&gt;&lt;Alt&gt;F1" or
 * "&lt;Release&gt;z" (the last one is for key release).  The parser
 * is fairly liberal and allows lower or upper case, and also
 * abbreviations such as "&lt;Ctl&gt;" and "&lt;Ctrl&gt;".
 *
 * If the parse fails, @accelerator_key and @accelerator_mods will
 * be set to 0 (zero) and %FALSE will be returned. If the string contains
 * only modifiers, @accelerator_key will be set to 0 but %TRUE will be
 * returned.
 *
 * The virtual vs. concrete accelerator distinction is a relic of
 * how the X Window System works; there are modifiers Mod2-Mod5 that
 * can represent various keyboard keys (numlock, meta, hyper, etc.),
 * the virtual modifier represents the keyboard key, the concrete
 * modifier the actual Mod2-Mod5 bits in the key press event.
 * 
 * Returns: %TRUE on success.
 */
gboolean
egg_accelerator_parse_virtual (const gchar * accelerator, guint * accelerator_key,
	EggVirtualModifierType * accelerator_mods)
{
	guint keyval;
	GdkModifierType mods;
	gint len;
	gboolean bad_keyval;

	if (accelerator_key)
		*accelerator_key = 0;
	if (accelerator_mods)
		*accelerator_mods = 0;

	g_return_val_if_fail (accelerator != NULL, FALSE);

	bad_keyval = FALSE;

	keyval = 0;
	mods = 0;
	len = strlen (accelerator);
	while (len)
	{
		if (*accelerator == '<')
		{
			if (len >= 9 && is_release (accelerator))
			{
				accelerator += 9;
				len -= 9;
				mods |= EGG_VIRTUAL_RELEASE_MASK;
			}
			else if (len >= 9 && is_control (accelerator))
			{
				accelerator += 9;
				len -= 9;
				mods |= EGG_VIRTUAL_CONTROL_MASK;
			}
			else if (len >= 7 && is_shift (accelerator))
			{
				accelerator += 7;
				len -= 7;
				mods |= EGG_VIRTUAL_SHIFT_MASK;
			}
			else if (len >= 6 && is_shft (accelerator))
			{
				accelerator += 6;
				len -= 6;
				mods |= EGG_VIRTUAL_SHIFT_MASK;
			}
			else if (len >= 6 && is_ctrl (accelerator))
			{
				accelerator += 6;
				len -= 6;
				mods |= EGG_VIRTUAL_CONTROL_MASK;
			}
			else if (len >= 6 && is_modx (accelerator))
			{
				static const guint mod_vals[] = {
					EGG_VIRTUAL_ALT_MASK, EGG_VIRTUAL_MOD2_MASK,
						EGG_VIRTUAL_MOD3_MASK,
					EGG_VIRTUAL_MOD4_MASK, EGG_VIRTUAL_MOD5_MASK
				};

				len -= 6;
				accelerator += 4;
				mods |= mod_vals[*accelerator - '1'];
				accelerator += 2;
			}
			else if (len >= 5 && is_ctl (accelerator))
			{
				accelerator += 5;
				len -= 5;
				mods |= EGG_VIRTUAL_CONTROL_MASK;
			}
			else if (len >= 5 && is_alt (accelerator))
			{
				accelerator += 5;
				len -= 5;
				mods |= EGG_VIRTUAL_ALT_MASK;
			}
			else if (len >= 6 && is_meta (accelerator))
			{
				accelerator += 6;
				len -= 6;
				mods |= EGG_VIRTUAL_META_MASK;
			}
			else if (len >= 7 && is_hyper (accelerator))
			{
				accelerator += 7;
				len -= 7;
				mods |= EGG_VIRTUAL_HYPER_MASK;
			}
			else if (len >= 7 && is_super (accelerator))
			{
				accelerator += 7;
				len -= 7;
				mods |= EGG_VIRTUAL_SUPER_MASK;
			}
			else
			{
				gchar last_ch;

				last_ch = *accelerator;
				while (last_ch && last_ch != '>')
				{
					last_ch = *accelerator;
					accelerator += 1;
					len -= 1;
				}
			}
		}
		else
		{
			keyval = gdk_keyval_from_name (accelerator);

			if (keyval == 0)
				bad_keyval = TRUE;

			accelerator += len;
			len -= len;
		}
	}

	if (accelerator_key)
		*accelerator_key = gdk_keyval_to_lower (keyval);
	if (accelerator_mods)
		*accelerator_mods = mods;

	return !bad_keyval;
}

/**
 * egg_virtual_accelerator_name:
 * @accelerator_key:  accelerator keyval
 * @accelerator_mods: accelerator modifier mask
 * @returns:          a newly-allocated accelerator name
 * 
 * Converts an accelerator keyval and modifier mask
 * into a string parseable by egg_accelerator_parse_virtual().
 * For example, if you pass in #GDK_q and #EGG_VIRTUAL_CONTROL_MASK,
 * this function returns "&lt;Control&gt;q".
 *
 * The caller of this function must free the returned string.
 */
gchar *
egg_virtual_accelerator_name (guint accelerator_key, EggVirtualModifierType accelerator_mods)
{
	static const gchar text_release[] = "<Release>";
	static const gchar text_shift[] = "<Shift>";
	static const gchar text_control[] = "<Control>";
	static const gchar text_mod1[] = "<Alt>";
	static const gchar text_mod2[] = "<Mod2>";
	static const gchar text_mod3[] = "<Mod3>";
	static const gchar text_mod4[] = "<Mod4>";
	static const gchar text_mod5[] = "<Mod5>";
	static const gchar text_meta[] = "<Meta>";
	static const gchar text_super[] = "<Super>";
	static const gchar text_hyper[] = "<Hyper>";
	guint l;
	gchar *keyval_name;
	gchar *accelerator;

	accelerator_mods &= EGG_VIRTUAL_MODIFIER_MASK;

	keyval_name = gdk_keyval_name (gdk_keyval_to_lower (accelerator_key));
	if (!keyval_name)
		keyval_name = "";

	l = 0;
	if (accelerator_mods & EGG_VIRTUAL_RELEASE_MASK)
		l += sizeof (text_release) - 1;
	if (accelerator_mods & EGG_VIRTUAL_SHIFT_MASK)
		l += sizeof (text_shift) - 1;
	if (accelerator_mods & EGG_VIRTUAL_CONTROL_MASK)
		l += sizeof (text_control) - 1;
	if (accelerator_mods & EGG_VIRTUAL_ALT_MASK)
		l += sizeof (text_mod1) - 1;
	if (accelerator_mods & EGG_VIRTUAL_MOD2_MASK)
		l += sizeof (text_mod2) - 1;
	if (accelerator_mods & EGG_VIRTUAL_MOD3_MASK)
		l += sizeof (text_mod3) - 1;
	if (accelerator_mods & EGG_VIRTUAL_MOD4_MASK)
		l += sizeof (text_mod4) - 1;
	if (accelerator_mods & EGG_VIRTUAL_MOD5_MASK)
		l += sizeof (text_mod5) - 1;
	if (accelerator_mods & EGG_VIRTUAL_META_MASK)
		l += sizeof (text_meta) - 1;
	if (accelerator_mods & EGG_VIRTUAL_HYPER_MASK)
		l += sizeof (text_hyper) - 1;
	if (accelerator_mods & EGG_VIRTUAL_SUPER_MASK)
		l += sizeof (text_super) - 1;
	l += strlen (keyval_name);

	accelerator = g_new (gchar, l + 1);

	l = 0;
	accelerator[l] = 0;
	if (accelerator_mods & EGG_VIRTUAL_RELEASE_MASK)
	{
		strcpy (accelerator + l, text_release);
		l += sizeof (text_release) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_SHIFT_MASK)
	{
		strcpy (accelerator + l, text_shift);
		l += sizeof (text_shift) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_CONTROL_MASK)
	{
		strcpy (accelerator + l, text_control);
		l += sizeof (text_control) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_ALT_MASK)
	{
		strcpy (accelerator + l, text_mod1);
		l += sizeof (text_mod1) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_MOD2_MASK)
	{
		strcpy (accelerator + l, text_mod2);
		l += sizeof (text_mod2) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_MOD3_MASK)
	{
		strcpy (accelerator + l, text_mod3);
		l += sizeof (text_mod3) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_MOD4_MASK)
	{
		strcpy (accelerator + l, text_mod4);
		l += sizeof (text_mod4) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_MOD5_MASK)
	{
		strcpy (accelerator + l, text_mod5);
		l += sizeof (text_mod5) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_META_MASK)
	{
		strcpy (accelerator + l, text_meta);
		l += sizeof (text_meta) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_HYPER_MASK)
	{
		strcpy (accelerator + l, text_hyper);
		l += sizeof (text_hyper) - 1;
	}
	if (accelerator_mods & EGG_VIRTUAL_SUPER_MASK)
	{
		strcpy (accelerator + l, text_super);
		l += sizeof (text_super) - 1;
	}

	strcpy (accelerator + l, keyval_name);

	return accelerator;
}

void
egg_keymap_resolve_virtual_modifiers (GdkKeymap * keymap, EggVirtualModifierType virtual_mods,
	GdkModifierType * concrete_mods)
{
	GdkModifierType concrete;
	int i;
	const EggModmap *modmap;

	g_return_if_fail (GDK_IS_KEYMAP (keymap));
	g_return_if_fail (concrete_mods != NULL);

	modmap = egg_keymap_get_modmap (keymap);

	/* Not so sure about this algorithm. */

	concrete = 0;
	i = 0;
	while (i < EGG_MODMAP_ENTRY_LAST)
	{
		if (modmap->mapping[i] & virtual_mods)
			concrete |= (1 << i);

		++i;
	}

	*concrete_mods = concrete;
}

void
egg_keymap_virtualize_modifiers (GdkKeymap * keymap, GdkModifierType concrete_mods,
	EggVirtualModifierType * virtual_mods)
{
	GdkModifierType virtual;
	int i;
	const EggModmap *modmap;

	g_return_if_fail (GDK_IS_KEYMAP (keymap));
	g_return_if_fail (virtual_mods != NULL);

	modmap = egg_keymap_get_modmap (keymap);

	/* Not so sure about this algorithm. */

	virtual = 0;
	i = 0;
	while (i < EGG_MODMAP_ENTRY_LAST)
	{
		if ((1 << i) & concrete_mods)
		{
			EggVirtualModifierType cleaned;

			cleaned =
				modmap->
				mapping[i] & ~(EGG_VIRTUAL_MOD2_MASK | EGG_VIRTUAL_MOD3_MASK |
				EGG_VIRTUAL_MOD4_MASK | EGG_VIRTUAL_MOD5_MASK);

			if (cleaned != 0)
			{
				virtual |= cleaned;
			}
			else
			{
				/* Rather than dropping mod2->mod5 if not bound,
				 * go ahead and use the concrete names
				 */
				virtual |= modmap->mapping[i];
			}
		}

		++i;
	}

	*virtual_mods = virtual;
}

static void
reload_modmap (GdkKeymap * keymap, EggModmap * modmap)
{
	XModifierKeymap *xmodmap;
	int map_size;
	int i;

	/* FIXME multihead */
	xmodmap = XGetModifierMapping (gdk_x11_get_default_xdisplay ());

	memset (modmap->mapping, 0, sizeof (modmap->mapping));

	/* there are 8 modifiers, and the first 3 are shift, shift lock,
	 * and control
	 */
	map_size = 8 * xmodmap->max_keypermod;
	i = 3 * xmodmap->max_keypermod;
	while (i < map_size)
	{
		/* get the key code at this point in the map,
		 * see if its keysym is one we're interested in
		 */
		int keycode = xmodmap->modifiermap[i];
		GdkKeymapKey *keys;
		guint *keyvals;
		int n_entries;
		int j;
		EggVirtualModifierType mask;

		keys = NULL;
		keyvals = NULL;
		n_entries = 0;

		gdk_keymap_get_entries_for_keycode (keymap, keycode, &keys, &keyvals, &n_entries);

		mask = 0;
		j = 0;
		while (j < n_entries)
		{
			if (keyvals[j] == GDK_Num_Lock)
				mask |= EGG_VIRTUAL_NUM_LOCK_MASK;
			else if (keyvals[j] == GDK_Scroll_Lock)
				mask |= EGG_VIRTUAL_SCROLL_LOCK_MASK;
			else if (keyvals[j] == GDK_Meta_L || keyvals[j] == GDK_Meta_R)
				mask |= EGG_VIRTUAL_META_MASK;
			else if (keyvals[j] == GDK_Hyper_L || keyvals[j] == GDK_Hyper_R)
				mask |= EGG_VIRTUAL_HYPER_MASK;
			else if (keyvals[j] == GDK_Super_L || keyvals[j] == GDK_Super_R)
				mask |= EGG_VIRTUAL_SUPER_MASK;
			else if (keyvals[j] == GDK_Mode_switch)
				mask |= EGG_VIRTUAL_MODE_SWITCH_MASK;

			++j;
		}

		/* Mod1Mask is 1 << 3 for example, i.e. the
		 * fourth modifier, i / keyspermod is the modifier
		 * index
		 */
		modmap->mapping[i / xmodmap->max_keypermod] |= mask;

		g_free (keyvals);
		g_free (keys);

		++i;
	}

	/* Add in the not-really-virtual fixed entries */
	modmap->mapping[EGG_MODMAP_ENTRY_SHIFT] |= EGG_VIRTUAL_SHIFT_MASK;
	modmap->mapping[EGG_MODMAP_ENTRY_CONTROL] |= EGG_VIRTUAL_CONTROL_MASK;
	modmap->mapping[EGG_MODMAP_ENTRY_LOCK] |= EGG_VIRTUAL_LOCK_MASK;
	modmap->mapping[EGG_MODMAP_ENTRY_MOD1] |= EGG_VIRTUAL_ALT_MASK;
	modmap->mapping[EGG_MODMAP_ENTRY_MOD2] |= EGG_VIRTUAL_MOD2_MASK;
	modmap->mapping[EGG_MODMAP_ENTRY_MOD3] |= EGG_VIRTUAL_MOD3_MASK;
	modmap->mapping[EGG_MODMAP_ENTRY_MOD4] |= EGG_VIRTUAL_MOD4_MASK;
	modmap->mapping[EGG_MODMAP_ENTRY_MOD5] |= EGG_VIRTUAL_MOD5_MASK;

	XFreeModifiermap (xmodmap);
}

const EggModmap *
egg_keymap_get_modmap (GdkKeymap * keymap)
{
	EggModmap *modmap;

	/* This is all a hack, much simpler when we can just
	 * modify GDK directly.
	 */

	modmap = g_object_get_data (G_OBJECT (keymap), "egg-modmap");

	if (modmap == NULL)
	{
		modmap = g_new0 (EggModmap, 1);

		/* FIXME modify keymap change events with an event filter
		 * and force a reload if we get one
		 */

		reload_modmap (keymap, modmap);

		g_object_set_data_full (G_OBJECT (keymap), "egg-modmap", modmap, g_free);
	}

	g_assert (modmap != NULL);

	return modmap;
}
