/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2004-2006 William Jon McCann <mccann@jhu.edu>
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Authors: William Jon McCann <mccann@jhu.edu>
 *
 */

#include "config.h"
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

#include <glib.h>
#include <glib-object.h>
#include <X11/Xlib.h>
#include <gdk/gdkx.h>

#include "gnome-screensaver.h"

#include "gs-manager.h"
#include "gs-watcher.h"
#include "gs-fade.h"
#include "gs-grab.h"

#include "gs-listener-dbus.h"
#include "gs-monitor.h"
#include "gs-prefs.h"
#include "gs-debug.h"

static void     gs_monitor_class_init (GSMonitorClass *klass);
static void     gs_monitor_init       (GSMonitor      *monitor);
static void     gs_monitor_finalize   (GObject        *object);

#define GS_MONITOR_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GS_TYPE_MONITOR, GSMonitorPrivate))

struct GSMonitorPrivate
{
	GSWatcher      *watcher;
	GSListener     *listener;
	GSManager      *manager;
	GSPrefs        *prefs;
	GSFade         *fade;
	GSGrab         *grab;
	guint           release_grab_id;
};

#define FADE_TIMEOUT 10000

G_DEFINE_TYPE (GSMonitor, gs_monitor, G_TYPE_OBJECT)

static void
gs_monitor_class_init (GSMonitorClass *klass)
{
	GObjectClass   *object_class = G_OBJECT_CLASS (klass);

	object_class->finalize = gs_monitor_finalize;

	g_type_class_add_private (klass, sizeof (GSMonitorPrivate));
}

static void
manager_activated_cb (GSManager *manager,
		      GSMonitor *monitor)
{
}

static void
manager_deactivated_cb (GSManager *manager,
			GSMonitor *monitor)
{
	gs_listener_set_active (monitor->priv->listener, FALSE);
}

static gboolean
watcher_idle_cb (GSWatcher *watcher,
		 gboolean   is_idle,
		 GSMonitor *monitor)
{
	gboolean res;

	gs_debug ("Idle signal detected: %d", is_idle);

	res = gs_listener_set_session_idle (monitor->priv->listener, is_idle);

	return res;
}

static gboolean
release_grab_timeout (GSMonitor *monitor)
{
	gboolean manager_active;

	manager_active = gs_manager_get_active (monitor->priv->manager);
	if (! manager_active) {
		gs_grab_release (monitor->priv->grab);
	}

	monitor->priv->release_grab_id = 0;
	return FALSE;
}

static gboolean
watcher_idle_notice_cb (GSWatcher *watcher,
			gboolean   in_effect,
			GSMonitor *monitor)
{
	gboolean activation_enabled;
	gboolean handled;

	gs_debug ("Idle notice signal detected: %d", in_effect);

	/* only fade if screensaver can activate */
	activation_enabled = gs_listener_get_activation_enabled (monitor->priv->listener);

	handled = FALSE;
	if (in_effect) {
		if (activation_enabled) {
			/* start slow fade */
			if (gs_grab_grab_offscreen (monitor->priv->grab, FALSE)) {
				gs_fade_async (monitor->priv->fade, FADE_TIMEOUT, NULL, NULL);
			} else {
				gs_debug ("Could not grab the keyboard so not performing idle warning fade-out");
			}

			handled = TRUE;
		}
	} else {
		gboolean manager_active;

		manager_active = gs_manager_get_active (monitor->priv->manager);
		/* cancel the fade unless manager was activated */
		if (! manager_active) {
			gs_debug ("manager not active, performing fade cancellation");
			gs_fade_reset (monitor->priv->fade);

			/* don't release the grab immediately to prevent typing passwords into windows */
			if (monitor->priv->release_grab_id != 0) {
				g_source_remove (monitor->priv->release_grab_id);
			}
			monitor->priv->release_grab_id = g_timeout_add_seconds (1, (GSourceFunc)release_grab_timeout, monitor);
		} else {
			gs_debug ("manager active, skipping fade cancellation");
		}

		handled = TRUE;
	}

	return handled;
}

static void
gs_monitor_lock_screen (GSMonitor *monitor)
{
	gboolean res;
	gboolean locked;
	gboolean active;

	/* set lock flag before trying to activate screensaver
	   in case something tries to react to the ActiveChanged signal */

	gs_manager_get_lock_active (monitor->priv->manager, &locked);
	gs_manager_set_lock_active (monitor->priv->manager, TRUE);
	active = gs_manager_get_active (monitor->priv->manager);

	if (! active) {
		res = gs_listener_set_active (monitor->priv->listener, TRUE);
		if (! res) {
			/* If we've failed then restore lock status */
			gs_manager_set_lock_active (monitor->priv->manager, locked);
			gs_debug ("Unable to lock the screen");
		}
	}

}

static void
gs_monitor_simulate_user_activity (GSMonitor *monitor)
{
	XResetScreenSaver (GDK_DISPLAY_XDISPLAY (gdk_display_get_default ()));

	/* request that the manager unlock -
	   will pop up a dialog if necessary */
	gs_manager_request_unlock (monitor->priv->manager);
}

static void
listener_lock_cb (GSListener *listener,
		  GSMonitor  *monitor)
{
	if (! monitor->priv->prefs->lock_disabled) {
		gs_monitor_lock_screen (monitor);
	} else {
		gs_debug ("Locking disabled by the administrator");
	}

}

static void
listener_config_lock_cb (GSListener *listener,
			 GSMonitor  *monitor)
{
	if (! monitor->priv->prefs->lock_disabled) {
		/* Unlike the Ubuntu implementation that uses a patched gsettings
		 * desktop schemas, we'll mandate that we lock on suspend */
		if (monitor->priv->prefs->lock_enabled) {
			gs_debug ("Locking the screen suspend");
			gs_monitor_lock_screen (monitor);
		}
	} else {
		gs_debug ("Locking disabled by the administrator");
	}

}

static void
listener_quit_cb (GSListener *listener,
		  GSMonitor  *monitor)
{
	gs_listener_set_active (monitor->priv->listener, FALSE);
	gnome_screensaver_quit ();
}

static void
listener_show_message_cb (GSListener *listener,
			  const char *summary,
			  const char *body,
			  const char *icon,
			  GSMonitor  *monitor)
{
	gs_manager_show_message (monitor->priv->manager,
				 summary,
				 body,
				 icon);
}

static gboolean
listener_active_changed_cb (GSListener *listener,
			    gboolean    active,
			    GSMonitor  *monitor)
{
	gboolean res;
	gboolean ret;
	gboolean idle_watch_enabled;

	res = gs_manager_set_active (monitor->priv->manager, active);
	if (! res) {
		gs_debug ("Unable to set manager active: %d", active);
		ret = FALSE;
		goto done;
	}

	ret = TRUE;

 done:

	idle_watch_enabled = gs_watcher_get_enabled (monitor->priv->watcher);
	if (ret && idle_watch_enabled) {
		res = gs_watcher_set_active (monitor->priv->watcher, !active);
		if (! res) {
			gs_debug ("Unable to set the idle watcher active: %d", !active);
		}
	}

	return ret;
}

static void
listener_simulate_user_activity_cb (GSListener *listener,
				    GSMonitor  *monitor)
{
	gs_monitor_simulate_user_activity (monitor);
}

static void
_gs_monitor_update_from_prefs (GSMonitor *monitor,
			       GSPrefs   *prefs)
{
	gboolean idle_detection_enabled;
	gboolean idle_detection_active;
	gboolean activate_watch;
	gboolean manager_active;
	gboolean lock_enabled;
	gboolean user_switch_enabled;

	lock_enabled = (monitor->priv->prefs->lock_enabled && !monitor->priv->prefs->lock_disabled);
	user_switch_enabled = (monitor->priv->prefs->user_switch_enabled && !monitor->priv->prefs->user_switch_disabled);

	gs_manager_set_lock_enabled (monitor->priv->manager, lock_enabled);
	gs_manager_set_lock_timeout (monitor->priv->manager, monitor->priv->prefs->lock_timeout);
	gs_manager_set_logout_enabled (monitor->priv->manager, monitor->priv->prefs->logout_enabled);
	gs_manager_set_user_switch_enabled (monitor->priv->manager, user_switch_enabled);
	gs_manager_set_keyboard_enabled (monitor->priv->manager, monitor->priv->prefs->keyboard_enabled);
	gs_manager_set_logout_timeout (monitor->priv->manager, monitor->priv->prefs->logout_timeout);
	gs_manager_set_logout_command (monitor->priv->manager, monitor->priv->prefs->logout_command);
	gs_manager_set_keyboard_command (monitor->priv->manager, monitor->priv->prefs->keyboard_command);

	/* enable activation when allowed */
	gs_listener_set_activation_enabled (monitor->priv->listener,
					    monitor->priv->prefs->idle_activation_enabled);

	/* idle detection always enabled */
	idle_detection_enabled = TRUE;

	gs_watcher_set_enabled (monitor->priv->watcher, idle_detection_enabled);

	/* in the case where idle detection is reenabled we may need to
	   activate the watcher too */

	manager_active = gs_manager_get_active (monitor->priv->manager);
	idle_detection_active = gs_watcher_get_active (monitor->priv->watcher);
	activate_watch = (! manager_active
			  && ! idle_detection_active
			  && idle_detection_enabled);
	if (activate_watch) {
		gs_watcher_set_active (monitor->priv->watcher, TRUE);
	}

	if (monitor->priv->prefs->status_message_enabled) {
		char *text;
		g_object_get (monitor->priv->watcher,
			      "status-message", &text,
			      NULL);
		gs_manager_set_status_message (monitor->priv->manager, text);
		g_free (text);
	} else {
		gs_manager_set_status_message (monitor->priv->manager, NULL);
	}
}

static void
disconnect_listener_signals (GSMonitor *monitor)
{
	g_signal_handlers_disconnect_by_func (monitor->priv->listener, listener_lock_cb, monitor);
	g_signal_handlers_disconnect_by_func (monitor->priv->listener, listener_config_lock_cb, monitor);
	g_signal_handlers_disconnect_by_func (monitor->priv->listener, listener_quit_cb, monitor);
	g_signal_handlers_disconnect_by_func (monitor->priv->listener, listener_active_changed_cb, monitor);
	g_signal_handlers_disconnect_by_func (monitor->priv->listener, listener_simulate_user_activity_cb, monitor);
	g_signal_handlers_disconnect_by_func (monitor->priv->listener, listener_show_message_cb, monitor);
}

static void
connect_listener_signals (GSMonitor *monitor)
{
	g_signal_connect (monitor->priv->listener, "lock",
			  G_CALLBACK (listener_lock_cb), monitor);
	g_signal_connect (monitor->priv->listener, "config-lock",
			  G_CALLBACK (listener_config_lock_cb), monitor);
	g_signal_connect (monitor->priv->listener, "quit",
			  G_CALLBACK (listener_quit_cb), monitor);
	g_signal_connect (monitor->priv->listener, "active-changed",
			  G_CALLBACK (listener_active_changed_cb), monitor);
	g_signal_connect (monitor->priv->listener, "simulate-user-activity",
			  G_CALLBACK (listener_simulate_user_activity_cb), monitor);
	g_signal_connect (monitor->priv->listener, "show-message",
			  G_CALLBACK (listener_show_message_cb), monitor);
}

static void
on_watcher_status_message_changed (GSWatcher  *watcher,
				   GParamSpec *pspec,
				   GSMonitor  *monitor)
{
	char *text;
	g_object_get (watcher, "status-message", &text, NULL);
	gs_manager_set_status_message (monitor->priv->manager, text);
	g_free (text);
}

static void
disconnect_watcher_signals (GSMonitor *monitor)
{
	g_signal_handlers_disconnect_by_func (monitor->priv->watcher, watcher_idle_cb, monitor);
	g_signal_handlers_disconnect_by_func (monitor->priv->watcher, watcher_idle_notice_cb, monitor);
	g_signal_handlers_disconnect_by_func (monitor->priv->watcher, on_watcher_status_message_changed, monitor);
}

static void
connect_watcher_signals (GSMonitor *monitor)
{
	g_signal_connect (monitor->priv->watcher, "idle-changed",
			  G_CALLBACK (watcher_idle_cb), monitor);
	g_signal_connect (monitor->priv->watcher, "idle-notice-changed",
			  G_CALLBACK (watcher_idle_notice_cb), monitor);
	g_signal_connect (monitor->priv->watcher, "notify::status-message",
			  G_CALLBACK (on_watcher_status_message_changed), monitor);

}

static void
disconnect_manager_signals (GSMonitor *monitor)
{
	g_signal_handlers_disconnect_by_func (monitor->priv->manager, manager_activated_cb, monitor);
	g_signal_handlers_disconnect_by_func (monitor->priv->manager, manager_deactivated_cb, monitor);
}

static void
connect_manager_signals (GSMonitor *monitor)
{
	g_signal_connect (monitor->priv->manager, "activated",
			  G_CALLBACK (manager_activated_cb), monitor);
	g_signal_connect (monitor->priv->manager, "deactivated",
			  G_CALLBACK (manager_deactivated_cb), monitor);
}

static void
disconnect_prefs_signals (GSMonitor *monitor)
{
	g_signal_handlers_disconnect_by_func (monitor->priv->prefs, _gs_monitor_update_from_prefs, monitor);
}

static void
connect_prefs_signals (GSMonitor *monitor)
{
	g_signal_connect_swapped (monitor->priv->prefs, "changed",
				  G_CALLBACK (_gs_monitor_update_from_prefs), monitor);
}

static void
gs_monitor_init (GSMonitor *monitor)
{

	monitor->priv = GS_MONITOR_GET_PRIVATE (monitor);

	monitor->priv->prefs = gs_prefs_new ();
	connect_prefs_signals (monitor);

	monitor->priv->listener = gs_listener_new ();
	connect_listener_signals (monitor);

	monitor->priv->fade = gs_fade_new ();
	monitor->priv->grab = gs_grab_new ();

	monitor->priv->watcher = gs_watcher_new ();
	connect_watcher_signals (monitor);

	monitor->priv->manager = gs_manager_new ();
	connect_manager_signals (monitor);

	_gs_monitor_update_from_prefs (monitor, monitor->priv->prefs);
}

static void
gs_monitor_finalize (GObject *object)
{
	GSMonitor *monitor;

	g_return_if_fail (object != NULL);
	g_return_if_fail (GS_IS_MONITOR (object));

	monitor = GS_MONITOR (object);

	g_return_if_fail (monitor->priv != NULL);

	disconnect_watcher_signals (monitor);
	disconnect_listener_signals (monitor);
	disconnect_manager_signals (monitor);
	disconnect_prefs_signals (monitor);

	g_object_unref (monitor->priv->fade);
	g_object_unref (monitor->priv->grab);
	g_object_unref (monitor->priv->watcher);
	g_object_unref (monitor->priv->listener);
	g_object_unref (monitor->priv->manager);
	g_object_unref (monitor->priv->prefs);

	G_OBJECT_CLASS (gs_monitor_parent_class)->finalize (object);
}

GSMonitor *
gs_monitor_new (void)
{
	GSMonitor *monitor;

	monitor = g_object_new (GS_TYPE_MONITOR, NULL);

	return GS_MONITOR (monitor);
}

gboolean
gs_monitor_start (GSMonitor *monitor,
		  GError   **error)
{
	g_return_val_if_fail (GS_IS_MONITOR (monitor), FALSE);

	if (! gs_listener_acquire (monitor->priv->listener, error)) {
		return FALSE;
	}

	return TRUE;
}
