/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/*
 * Copyright (C) 2014 Red Hat
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * Written by:
 *     Jasper St. Pierre <jstpierre@mecheye.net>
 */

#include "config.h"

#include "meta-accel-parse.h"

#include <gtk/gtk.h>
#include <string.h>
#include <stdlib.h>

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_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] == '>'));
}

static inline gboolean
is_primary (const gchar *string)
{
  return ((string[0] == '<') &&
	  (string[1] == 'p' || string[1] == 'P') &&
	  (string[2] == 'r' || string[2] == 'R') &&
	  (string[3] == 'i' || string[3] == 'I') &&
	  (string[4] == 'm' || string[4] == 'M') &&
	  (string[5] == 'a' || string[5] == 'A') &&
	  (string[6] == 'r' || string[6] == 'R') &&
	  (string[7] == 'y' || string[7] == 'Y') &&
	  (string[8] == '>'));
}

static inline gboolean
is_keycode (const gchar *string)
{
  return (string[0] == '0' &&
          string[1] == 'x' &&
          g_ascii_isxdigit (string[2]) &&
          g_ascii_isxdigit (string[3]));
}

static void
accelerator_parse (const gchar         *accelerator,
                   guint               *accelerator_key,
                   guint               *accelerator_keycode,
                   MetaVirtualModifier *accelerator_mods)
{
  guint keyval, keycode;
  MetaVirtualModifier mods;
  gint len;
  gboolean error;

  if (accelerator_key)
    *accelerator_key = 0;
  if (accelerator_keycode)
    *accelerator_keycode = 0;
  if (accelerator_mods)
    *accelerator_mods = 0;
  g_return_if_fail (accelerator != NULL);

  error = FALSE;
  keyval = 0;
  mods = 0;
  len = strlen (accelerator);
  while (len)
    {
      if (*accelerator == '<')
        {
          if (len >= 9 && is_primary (accelerator))
            {
              /* Primary is treated the same as Control */
              accelerator += 9;
              len -= 9;
              mods |= META_VIRTUAL_CONTROL_MASK;
            }
          else if (len >= 9 && is_control (accelerator))
            {
              accelerator += 9;
              len -= 9;
              mods |= META_VIRTUAL_CONTROL_MASK;
            }
          else if (len >= 7 && is_shift (accelerator))
            {
              accelerator += 7;
              len -= 7;
              mods |= META_VIRTUAL_SHIFT_MASK;
            }
          else if (len >= 6 && is_shft (accelerator))
            {
              accelerator += 6;
              len -= 6;
              mods |= META_VIRTUAL_SHIFT_MASK;
            }
          else if (len >= 6 && is_ctrl (accelerator))
            {
              accelerator += 6;
              len -= 6;
              mods |= META_VIRTUAL_CONTROL_MASK;
            }
          else if (len >= 6 && is_modx (accelerator))
            {
              static const guint mod_vals[] = {
                META_VIRTUAL_ALT_MASK,
                META_VIRTUAL_MOD2_MASK,
                META_VIRTUAL_MOD3_MASK,
                META_VIRTUAL_MOD4_MASK,
                META_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 |= META_VIRTUAL_CONTROL_MASK;
            }
          else if (len >= 5 && is_alt (accelerator))
            {
              accelerator += 5;
              len -= 5;
              mods |= META_VIRTUAL_ALT_MASK;
            }
          else if (len >= 6 && is_meta (accelerator))
            {
              accelerator += 6;
              len -= 6;
              mods |= META_VIRTUAL_META_MASK;
            }
          else if (len >= 7 && is_hyper (accelerator))
            {
              accelerator += 7;
              len -= 7;
              mods |= META_VIRTUAL_HYPER_MASK;
            }
          else if (len >= 7 && is_super (accelerator))
            {
              accelerator += 7;
              len -= 7;
              mods |= META_VIRTUAL_SUPER_MASK;
            }
          else
            {
              gchar last_ch;

              last_ch = *accelerator;
              while (last_ch && last_ch != '>')
                {
                  last_ch = *accelerator;
                  accelerator += 1;
                  len -= 1;
                }
            }
        }
      else
        {
          if (len >= 4 && is_keycode (accelerator))
            {
              keycode = strtoul (accelerator, NULL, 16);
              goto out;
            }
	  else if (strcmp (accelerator, "Above_Tab") == 0)
            {
              keyval = META_KEY_ABOVE_TAB;
              goto out;
            }
          else
	    {
	      keyval = gdk_keyval_from_name (accelerator);
	      if (keyval == GDK_KEY_VoidSymbol)
	        {
	          error = TRUE;
	          goto out;
		}
	    }

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

out:
  if (error)
    keyval = keycode = mods = 0;

  if (accelerator_key)
    *accelerator_key = gdk_keyval_to_lower (keyval);
  if (accelerator_keycode)
    *accelerator_keycode = keycode;
  if (accelerator_mods)
    *accelerator_mods = mods;
}

gboolean
meta_parse_accelerator (const char          *accel,
                        unsigned int        *keysym,
                        unsigned int        *keycode,
                        MetaVirtualModifier *mask)
{
  MetaVirtualModifier gdk_mask = 0;
  guint gdk_sym = 0;
  guint gdk_code = 0;

  *keysym = 0;
  *keycode = 0;
  *mask = 0;

  if (!accel[0] || strcmp (accel, "disabled") == 0)
    return TRUE;
  
  accelerator_parse (accel, &gdk_sym, &gdk_code, &gdk_mask);
  if (gdk_mask == 0 && gdk_sym == 0 && gdk_code == 0)
    return FALSE;

  if (gdk_sym == None && gdk_code == 0)
    return FALSE;

  *keysym = gdk_sym;
  *keycode = gdk_code;
  *mask = gdk_mask;
  
  return TRUE;
}

gboolean
meta_parse_modifier (const char          *accel,
                     MetaVirtualModifier *mask)
{
  MetaVirtualModifier gdk_mask = 0;
  guint gdk_sym = 0;
  guint gdk_code = 0;
  
  *mask = 0;

  if (accel == NULL || !accel[0] || strcmp (accel, "disabled") == 0)
    return TRUE;

  accelerator_parse (accel, &gdk_sym, &gdk_code, &gdk_mask);
  if (gdk_mask == 0 && gdk_sym == 0 && gdk_code == 0)
    return FALSE;

  if (gdk_sym != None || gdk_code != 0)
    return FALSE;

  *mask = gdk_mask;

  return TRUE;
}