/*

 * Copyright © 2001 Red Hat, Inc.

 *

 * Permission to use, copy, modify, distribute, and sell this software and its

 * documentation for any purpose is hereby granted without fee, provided that

 * the above copyright notice appear in all copies and that both that

 * copyright notice and this permission notice appear in supporting

 * documentation, and that the name of Red Hat not be used in advertising or

 * publicity pertaining to distribution of the software without specific,

 * written prior permission.  Red Hat makes no representations about the

 * suitability of this software for any purpose.  It is provided "as is"

 * without express or implied warranty.

 *

 * RED HAT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL RED HAT

 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION

 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 

 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 *

 * Author:  Owen Taylor, Red Hat, Inc.

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <glib.h>

#include <X11/Xmd.h>		/* For CARD16 */

#include "xsettings-manager.h"

#define XSETTINGS_VARIANT_TYPE_COLOR  (G_VARIANT_TYPE ("(qqqq)"))

struct _XSettingsManager

{

  Display *display;

  int screen;

  Window window;

  Atom manager_atom;

  Atom selection_atom;

  Atom xsettings_atom;

  XSettingsTerminateFunc terminate;

  void *cb_data;

  GHashTable *settings;

  unsigned long serial;

  GVariant *overrides;

};

typedef struct 

{

  Window window;

  Atom timestamp_prop_atom;

} TimeStampInfo;

static Bool

timestamp_predicate (Display *display,

		     XEvent  *xevent,

		     XPointer arg)

{

  TimeStampInfo *info = (TimeStampInfo *)arg;

  if (xevent->type == PropertyNotify &&

      xevent->xproperty.window == info->window &&

      xevent->xproperty.atom == info->timestamp_prop_atom)

    return True;

  return False;

}

/**

 * get_server_time:

 * @display: display from which to get the time

 * @window: a #Window, used for communication with the server.

 *          The window must have PropertyChangeMask in its

 *          events mask or a hang will result.

 * 

 * Routine to get the current X server time stamp. 

 * 

 * Return value: the time stamp.

 **/

static Time

get_server_time (Display *display,

		 Window   window)

{

  unsigned char c = 'a';

  XEvent xevent;

  TimeStampInfo info;

  info.timestamp_prop_atom = XInternAtom  (display, "_TIMESTAMP_PROP", False);

  info.window = window;

  XChangeProperty (display, window,

		   info.timestamp_prop_atom, info.timestamp_prop_atom,

		   8, PropModeReplace, &c, 1);

  XIfEvent (display, &xevent,

	    timestamp_predicate, (XPointer)&info;;

  return xevent.xproperty.time;

}

Bool

xsettings_manager_check_running (Display *display,

				 int      screen)

{

  char buffer[256];

  Atom selection_atom;

  sprintf(buffer, "_XSETTINGS_S%d", screen);

  selection_atom = XInternAtom (display, buffer, False);

  if (XGetSelectionOwner (display, selection_atom))

    return True;

  else

    return False;

}

XSettingsManager *

xsettings_manager_new (Display                *display,

		       int                     screen,

		       XSettingsTerminateFunc  terminate,

		       void                   *cb_data)

{

  XSettingsManager *manager;

  Time timestamp;

  XClientMessageEvent xev;

  char buffer[256];

  manager = g_slice_new (XSettingsManager);

  manager->display = display;

  manager->screen = screen;

  sprintf(buffer, "_XSETTINGS_S%d", screen);

  manager->selection_atom = XInternAtom (display, buffer, False);

  manager->xsettings_atom = XInternAtom (display, "_XSETTINGS_SETTINGS", False);

  manager->manager_atom = XInternAtom (display, "MANAGER", False);

  manager->terminate = terminate;

  manager->cb_data = cb_data;

  manager->settings = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, (GDestroyNotify) xsettings_setting_free);

  manager->serial = 0;

  manager->overrides = NULL;

  manager->window = XCreateSimpleWindow (display,

					 RootWindow (display, screen),

					 0, 0, 10, 10, 0,

					 WhitePixel (display, screen),

					 WhitePixel (display, screen));

  XSelectInput (display, manager->window, PropertyChangeMask);

  timestamp = get_server_time (display, manager->window);

  XSetSelectionOwner (display, manager->selection_atom,

		      manager->window, timestamp);

  /* Check to see if we managed to claim the selection. If not,

   * we treat it as if we got it then immediately lost it

   */

  if (XGetSelectionOwner (display, manager->selection_atom) ==

      manager->window)

    {

      xev.type = ClientMessage;

      xev.window = RootWindow (display, screen);

      xev.message_type = manager->manager_atom;

      xev.format = 32;

      xev.data.l[0] = timestamp;

      xev.data.l[1] = manager->selection_atom;

      xev.data.l[2] = manager->window;

      xev.data.l[3] = 0;	/* manager specific data */

      xev.data.l[4] = 0;	/* manager specific data */

      XSendEvent (display, RootWindow (display, screen),

		  False, StructureNotifyMask, (XEvent *)&xev);

    }

  else

    {

      manager->terminate (manager->cb_data);

    }

  return manager;

}

void

xsettings_manager_destroy (XSettingsManager *manager)

{

  XDestroyWindow (manager->display, manager->window);

  g_hash_table_unref (manager->settings);

  g_slice_free (XSettingsManager, manager);

}

static void

xsettings_manager_set_setting (XSettingsManager *manager,

                               const gchar      *name,

                               gint              tier,

                               GVariant         *value)

{

  XSettingsSetting *setting;

  setting = g_hash_table_lookup (manager->settings, name);

  if (setting == NULL)

    {

      setting = xsettings_setting_new (name);

      setting->last_change_serial = manager->serial;

      g_hash_table_insert (manager->settings, setting->name, setting);

    }

  xsettings_setting_set (setting, tier, value, manager->serial);

  if (xsettings_setting_get (setting) == NULL)

    g_hash_table_remove (manager->settings, name);

}

void

xsettings_manager_set_int (XSettingsManager *manager,

			   const char       *name,

			   int               value)

{

  xsettings_manager_set_setting (manager, name, 0, g_variant_new_int32 (value));

}

void

xsettings_manager_set_string (XSettingsManager *manager,

			      const char       *name,

			      const char       *value)

{

  xsettings_manager_set_setting (manager, name, 0, g_variant_new_string (value));

}

void

xsettings_manager_set_color (XSettingsManager *manager,

			     const char       *name,

			     XSettingsColor   *value)

{

  GVariant *tmp;

  tmp = g_variant_new ("(qqqq)", value->red, value->green, value->blue, value->alpha);

  g_assert (g_variant_is_of_type (tmp, XSETTINGS_VARIANT_TYPE_COLOR)); /* paranoia... */

  xsettings_manager_set_setting (manager, name, 0, tmp);

}

void

xsettings_manager_delete_setting (XSettingsManager *manager,

                                  const char       *name)

{

  xsettings_manager_set_setting (manager, name, 0, NULL);

}

static gchar

xsettings_get_typecode (GVariant *value)

{

  switch (g_variant_classify (value))

    {

    case G_VARIANT_CLASS_INT32:

      return XSETTINGS_TYPE_INT;

    case G_VARIANT_CLASS_STRING:

      return XSETTINGS_TYPE_STRING;

    case G_VARIANT_CLASS_TUPLE:

      return XSETTINGS_TYPE_COLOR;

    default:

      g_assert_not_reached ();

    }

}

static void

align_string (GString *string,

              gint     alignment)

{

  /* Adds nul-bytes to the string until its length is an even multiple

   * of the specified alignment requirement.

   */

  while ((string->len % alignment) != 0)

    g_string_append_c (string, '\0');

}

static void

setting_store (XSettingsSetting *setting,

               GString          *buffer)

{

  XSettingsType type;

  GVariant *value;

  guint16 len16;

  value = xsettings_setting_get (setting);

  type = xsettings_get_typecode (value);

  g_string_append_c (buffer, type);

  g_string_append_c (buffer, 0);

  len16 = strlen (setting->name);

  g_string_append_len (buffer, (gchar *) &len16, 2);

  g_string_append (buffer, setting->name);

  align_string (buffer, 4);

  g_string_append_len (buffer, (gchar *) &setting->last_change_serial, 4);

  if (type == XSETTINGS_TYPE_STRING)

    {

      const gchar *string;

      gsize stringlen;

      guint32 len32;

      string = g_variant_get_string (value, &stringlen);

      len32 = stringlen;

      g_string_append_len (buffer, (gchar *) &len32, 4);

      g_string_append (buffer, string);

      align_string (buffer, 4);

    }

  else

    /* GVariant format is the same as XSETTINGS format for the non-string types */

    g_string_append_len (buffer, g_variant_get_data (value), g_variant_get_size (value));

}

void

xsettings_manager_notify (XSettingsManager *manager)

{

  GString *buffer;

  GHashTableIter iter;

  int n_settings;

  gpointer value;

  n_settings = g_hash_table_size (manager->settings);

  buffer = g_string_new (NULL);

  g_string_append_c (buffer, xsettings_byte_order ());

  g_string_append_c (buffer, '\0');

  g_string_append_c (buffer, '\0');

  g_string_append_c (buffer, '\0');

  g_string_append_len (buffer, (gchar *) &manager->serial, 4);

  g_string_append_len (buffer, (gchar *) &n_settings, 4);

  g_hash_table_iter_init (&iter, manager->settings);

  while (g_hash_table_iter_next (&iter, NULL, &value))

    setting_store (value, buffer);

  XChangeProperty (manager->display, manager->window,

                   manager->xsettings_atom, manager->xsettings_atom,

                   8, PropModeReplace, (guchar *) buffer->str, buffer->len);

  g_string_free (buffer, TRUE);

  manager->serial++;

}

void

xsettings_manager_set_overrides (XSettingsManager *manager,

                                 GVariant         *overrides)

{

  GVariantIter iter;

  const gchar *key;

  GVariant *value;

  g_return_if_fail (overrides != NULL && g_variant_is_of_type (overrides, G_VARIANT_TYPE_VARDICT));

  if (manager->overrides)

    {

      /* unset the existing overrides */

      g_variant_iter_init (&iter, manager->overrides);

      while (g_variant_iter_next (&iter, "{&sv}", &key, NULL))

        /* only unset it at this point if it's not in the new list */

        if (!g_variant_lookup (overrides, key, "*", NULL))

          xsettings_manager_set_setting (manager, key, 1, NULL);

      g_variant_unref (manager->overrides);

    }

  /* save this so we can do the unsets next time */

  manager->overrides = g_variant_ref_sink (overrides);

  /* set the new values */

  g_variant_iter_init (&iter, overrides);

  while (g_variant_iter_loop (&iter, "{&sv}", &key, &value))

    {

      /* only accept recognised types... */

      if (!g_variant_is_of_type (value, G_VARIANT_TYPE_STRING) &&

          !g_variant_is_of_type (value, G_VARIANT_TYPE_INT32) &&

          !g_variant_is_of_type (value, XSETTINGS_VARIANT_TYPE_COLOR))

        continue;

      xsettings_manager_set_setting (manager, key, 1, value);

    }

}