/* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-

   obt/keyboard.c for the Openbox window manager
   Copyright (c) 2007        Dana Jansens

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program 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.

   See the COPYING file for a copy of the GNU General Public License.
*/

#include "obt/display.h"
#include "obt/keyboard.h"

#include <X11/Xlib.h>
#include <X11/keysym.h>

/* These masks are constants and the modifier keys are bound to them as
   anyone sees fit:
        ShiftMask (1<<0), LockMask (1<<1), ControlMask (1<<2), Mod1Mask (1<<3),
        Mod2Mask (1<<4), Mod3Mask (1<<5), Mod4Mask (1<<6), Mod5Mask (1<<7)
*/
#define NUM_MASKS 8
#define ALL_MASKS 0xff /* an or'ing of all 8 keyboard masks */

/* Get the bitflag for the n'th modifier mask */
#define nth_mask(n) (1 << n)

static void set_modkey_mask(guchar mask, KeySym sym);
void obt_keyboard_shutdown();

static XModifierKeymap *modmap;
static KeySym *keymap;
static gint min_keycode, max_keycode, keysyms_per_keycode;
/* This is a bitmask of the different masks for each modifier key */
static guchar modkeys_keys[OBT_KEYBOARD_NUM_MODKEYS];

static gboolean alt_l = FALSE;
static gboolean meta_l = FALSE;
static gboolean super_l = FALSE;
static gboolean hyper_l = FALSE;

static gboolean started = FALSE;

void obt_keyboard_reload(void)
{
    gint i, j, k;

    if (started) obt_keyboard_shutdown(); /* free stuff */
    started = TRUE;

    /* reset the keys to not be bound to any masks */
    for (i = 0; i < OBT_KEYBOARD_NUM_MODKEYS; ++i)
        modkeys_keys[i] = 0;

    modmap = XGetModifierMapping(obt_display);
    g_assert(modmap->max_keypermod > 0);

    XDisplayKeycodes(obt_display, &min_keycode, &max_keycode);
    keymap = XGetKeyboardMapping(obt_display, min_keycode,
                                 max_keycode - min_keycode + 1,
                                 &keysyms_per_keycode);

    alt_l = meta_l = super_l = hyper_l = FALSE;

    /* go through each of the modifier masks (eg ShiftMask, CapsMask...) */
    for (i = 0; i < NUM_MASKS; ++i) {
        /* go through each keycode that is bound to the mask */
        for (j = 0; j < modmap->max_keypermod; ++j) {
            KeySym sym;
            /* get a keycode that is bound to the mask (i) */
            KeyCode keycode = modmap->modifiermap[i*modmap->max_keypermod + j];
            if (keycode) {
                /* go through each keysym bound to the given keycode */
                for (k = 0; k < keysyms_per_keycode; ++k) {
                    sym = keymap[(keycode-min_keycode) * keysyms_per_keycode +
                                 k];
                    if (sym != NoSymbol) {
                        /* bind the key to the mask (e.g. Alt_L => Mod1Mask) */
                        set_modkey_mask(nth_mask(i), sym);
                    }
                }
            }
        }
    }

    /* CapsLock, Shift, and Control are special and hard-coded */
    modkeys_keys[OBT_KEYBOARD_MODKEY_CAPSLOCK] = LockMask;
    modkeys_keys[OBT_KEYBOARD_MODKEY_SHIFT] = ShiftMask;
    modkeys_keys[OBT_KEYBOARD_MODKEY_CONTROL] = ControlMask;
}

void obt_keyboard_shutdown(void)
{
    XFreeModifiermap(modmap);
    modmap = NULL;
    XFree(keymap);
    keymap = NULL;
    started = FALSE;
}

guint obt_keyboard_keycode_to_modmask(guint keycode)
{
    gint i, j;
    guint mask = 0;

    if (keycode == NoSymbol) return 0;

    /* go through each of the modifier masks (eg ShiftMask, CapsMask...) */
    for (i = 0; i < NUM_MASKS; ++i) {
        /* go through each keycode that is bound to the mask */
        for (j = 0; j < modmap->max_keypermod; ++j) {
            /* compare with a keycode that is bound to the mask (i) */
            if (modmap->modifiermap[i*modmap->max_keypermod + j] == keycode)
                mask |= nth_mask(i);
        }
    }
    return mask;
}

guint obt_keyboard_only_modmasks(guint mask)
{
    mask &= ALL_MASKS;
    /* strip off these lock keys. they shouldn't affect key bindings */
    mask &= ~LockMask; /* use the LockMask, not what capslock is bound to,
                          because you could bind it to something else and it
                          should work as that modifier then. i think capslock
                          is weird in xkb. */
    mask &= ~obt_keyboard_modkey_to_modmask(OBT_KEYBOARD_MODKEY_NUMLOCK);
    mask &= ~obt_keyboard_modkey_to_modmask(OBT_KEYBOARD_MODKEY_SCROLLLOCK);
    return mask;
}

guint obt_keyboard_modkey_to_modmask(ObtModkeysKey key)
{
    return modkeys_keys[key];
}

static void set_modkey_mask(guchar mask, KeySym sym)
{
    /* find what key this is, and bind it to the mask */

    if (sym == XK_Num_Lock)
        modkeys_keys[OBT_KEYBOARD_MODKEY_NUMLOCK] |= mask;
    else if (sym == XK_Scroll_Lock)
        modkeys_keys[OBT_KEYBOARD_MODKEY_SCROLLLOCK] |= mask;

    else if (sym == XK_Super_L && super_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_SUPER] |= mask;
    else if (sym == XK_Super_L && !super_l)
        /* left takes precident over right, so erase any masks the right
           key may have set */
        modkeys_keys[OBT_KEYBOARD_MODKEY_SUPER] = mask, super_l = TRUE;
    else if (sym == XK_Super_R && !super_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_SUPER] |= mask;

    else if (sym == XK_Hyper_L && hyper_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_HYPER] |= mask;
    else if (sym == XK_Hyper_L && !hyper_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_HYPER] = mask, hyper_l = TRUE;
    else if (sym == XK_Hyper_R && !hyper_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_HYPER] |= mask;

    else if (sym == XK_Alt_L && alt_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_ALT] |= mask;
    else if (sym == XK_Alt_L && !alt_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_ALT] = mask, alt_l = TRUE;
    else if (sym == XK_Alt_R && !alt_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_ALT] |= mask;

    else if (sym == XK_Meta_L && meta_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_META] |= mask;
    else if (sym == XK_Meta_L && !meta_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_META] = mask, meta_l = TRUE;
    else if (sym == XK_Meta_R && !meta_l)
        modkeys_keys[OBT_KEYBOARD_MODKEY_META] |= mask;

    /* CapsLock, Shift, and Control are special and hard-coded */
}

KeyCode obt_keyboard_keysym_to_keycode(KeySym sym)
{
    gint i, j;

    /* go through each keycode and look for the keysym */
    for (i = min_keycode; i <= max_keycode; ++i)
        for (j = 0; j < keysyms_per_keycode; ++j)
            if (sym == keymap[(i-min_keycode) * keysyms_per_keycode + j])
                return i;
    return 0;
}

gchar *obt_keyboard_keycode_to_string(guint keycode)
{
    KeySym sym;

    if ((sym = XKeycodeToKeysym(obt_display, keycode, 0)) != NoSymbol)
        return g_locale_to_utf8(XKeysymToString(sym), -1, NULL, NULL, NULL);
    return NULL;
}

gunichar obt_keyboard_keycode_to_unichar(guint keycode)
{
    gunichar unikey = 0;
    char *key;

    if ((key = obt_keyboard_keycode_to_string(keycode)) != NULL &&
        /* don't accept keys that aren't a single letter, like "space" */
        key[1] == '\0')
    {
        unikey = g_utf8_get_char_validated(key, -1);
        if (unikey == (gunichar)-1 || unikey == (gunichar)-2 || unikey == 0)
            unikey = 0;
    }
    g_free(key);
    return unikey;
}