/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2007 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 St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "config.h"

#include <stdlib.h>
#include <unistd.h>
#include <libintl.h>
#include <errno.h>
#include <locale.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/wait.h>

#include <glib/gi18n.h>
#include <glib/gstdio.h>
#include <gtk/gtk.h>

#include <dbus/dbus-glib.h>
#include <dbus/dbus-glib-lowlevel.h>

#ifdef HAVE_LIBNOTIFY
#include <libnotify/notify.h>
#endif /* HAVE_LIBNOTIFY */

#include "mate-settings-manager.h"
#include "mate-settings-profile.h"

#include <libmate-desktop/mate-gsettings.h>

#define MSD_DBUS_NAME         "org.mate.SettingsDaemon"

#define DEBUG_KEY             "mate-settings-daemon"
#define DEBUG_SCHEMA          "org.mate.debug"

#define MATE_SESSION_DBUS_NAME      "org.gnome.SessionManager"
#define MATE_SESSION_DBUS_OBJECT    "/org/gnome/SessionManager"
#define MATE_SESSION_DBUS_INTERFACE "org.gnome.SessionManager"
#define MATE_SESSION_PRIVATE_DBUS_INTERFACE "org.gnome.SessionManager.ClientPrivate"

/* this is kept only for compatibility with custom .desktop files */
static gboolean   no_daemon    = TRUE;
static gboolean   replace      = FALSE;
static gboolean   debug        = FALSE;
static gboolean   do_timed_exit = FALSE;
static int        term_signal_pipe_fds[2];

static GOptionEntry entries[] = {
        { "debug", 0, 0, G_OPTION_ARG_NONE, &debug, N_("Enable debugging code"), NULL },
        { "replace", 0, 0, G_OPTION_ARG_NONE, &replace, N_("Replace the current daemon"), NULL },
        { "no-daemon", 0, G_OPTION_FLAG_HIDDEN, G_OPTION_ARG_NONE, &no_daemon, N_("Don't become a daemon"), NULL },
        { "timed-exit", 0, 0, G_OPTION_ARG_NONE, &do_timed_exit, N_("Exit after a time (for debugging)"), NULL },
        { NULL }
};

static gboolean
timed_exit_cb (void)
{
        gtk_main_quit ();
        return FALSE;
}

static DBusGProxy *
get_bus_proxy (DBusGConnection *connection)
{
        DBusGProxy *bus_proxy;

        bus_proxy = dbus_g_proxy_new_for_name (connection,
                                               DBUS_SERVICE_DBUS,
                                               DBUS_PATH_DBUS,
                                               DBUS_INTERFACE_DBUS);

        return bus_proxy;
}

static gboolean
acquire_name_on_proxy (DBusGProxy *bus_proxy)
{
        GError     *error;
        guint       result;
        gboolean    res;
        gboolean    ret;
        guint32     flags;

        ret = FALSE;

        flags = DBUS_NAME_FLAG_DO_NOT_QUEUE|DBUS_NAME_FLAG_ALLOW_REPLACEMENT;
        if (replace)
            flags |= DBUS_NAME_FLAG_REPLACE_EXISTING;

        error = NULL;
        res = dbus_g_proxy_call (bus_proxy,
                                 "RequestName",
                                 &error,
                                 G_TYPE_STRING, MSD_DBUS_NAME,
                                 G_TYPE_UINT, flags,
                                 G_TYPE_INVALID,
                                 G_TYPE_UINT, &result,
                                 G_TYPE_INVALID);
        if (! res) {
                if (error != NULL) {
                        g_warning ("Failed to acquire %s: %s", MSD_DBUS_NAME, error->message);
                        g_error_free (error);
                } else {
                        g_warning ("Failed to acquire %s", MSD_DBUS_NAME);
                }
                goto out;
        }

        if (result != DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER) {
                if (error != NULL) {
                        g_warning ("Failed to acquire %s: %s", MSD_DBUS_NAME, error->message);
                        g_error_free (error);
                } else {
                        g_warning ("Failed to acquire %s", MSD_DBUS_NAME);
                }
                goto out;
        }

        ret = TRUE;

 out:
        return ret;
}

static DBusHandlerResult
bus_message_handler (DBusConnection *connection,
                     DBusMessage    *message,
                     void           *user_data)
{
        if (dbus_message_is_signal (message,
                                    DBUS_INTERFACE_LOCAL,
                                    "Disconnected")) {
                gtk_main_quit ();
                return DBUS_HANDLER_RESULT_HANDLED;
        }
        else if (dbus_message_is_signal (message,
                                         DBUS_INTERFACE_DBUS,
                                         "NameLost")) {
                g_warning ("D-Bus name lost, quitting");
                gtk_main_quit ();
                return DBUS_HANDLER_RESULT_HANDLED;
        }

        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}

static DBusGConnection *
get_session_bus (void)
{
        GError          *error;
        DBusGConnection *bus;
        DBusConnection  *connection;

        error = NULL;
        bus = dbus_g_bus_get (DBUS_BUS_SESSION, &error);
        if (bus == NULL) {
                g_warning ("Couldn't connect to session bus: %s",
                           error->message);
                g_error_free (error);
                goto out;
        }

        connection = dbus_g_connection_get_connection (bus);
        dbus_connection_add_filter (connection,
                                    (DBusHandleMessageFunction)
                                    bus_message_handler,
                                    NULL, NULL);

        dbus_connection_set_exit_on_disconnect (connection, FALSE);

 out:
        return bus;
}

static gboolean
bus_register (DBusGConnection *bus)
{
        DBusGProxy      *bus_proxy;
        gboolean         ret;

        mate_settings_profile_start (NULL);

        ret = FALSE;

        bus_proxy = get_bus_proxy (bus);

        if (bus_proxy == NULL) {
                g_warning ("Could not construct bus_proxy object");
                goto out;
        }

        ret = acquire_name_on_proxy (bus_proxy);
        g_object_unref (bus_proxy);

        if (!ret) {
                g_warning ("Could not acquire name");
                goto out;
        }

        g_debug ("Successfully connected to D-Bus");

 out:
        mate_settings_profile_end (NULL);

        return ret;
}

static void
on_session_over (DBusGProxy *proxy, MateSettingsManager *manager)
{
        /* not used, see on_session_end instead */
}

static void
on_session_query_end (DBusGProxy *proxy, guint flags, MateSettingsManager *manager)
{
        GError *error = NULL;
        gboolean ret = FALSE;

        /* send response */
        ret = dbus_g_proxy_call (proxy, "EndSessionResponse", &error,
                                 G_TYPE_BOOLEAN, TRUE /* ok */,
                                 G_TYPE_STRING, NULL /* reason */,
                                 G_TYPE_INVALID,
                                 G_TYPE_INVALID);
        if (!ret) {
                g_warning ("failed to send session response: %s", error->message);
                g_error_free (error);
        }
}

static void
on_session_end (DBusGProxy *proxy, guint flags, MateSettingsManager *manager)
{
        GError *error = NULL;
        gboolean ret = FALSE;

        /* send response */
        ret = dbus_g_proxy_call (proxy, "EndSessionResponse", &error,
                                 G_TYPE_BOOLEAN, TRUE /* ok */,
                                 G_TYPE_STRING, NULL /* reason */,
                                 G_TYPE_INVALID,
                                 G_TYPE_INVALID);
        if (!ret) {
                g_warning ("failed to send session response: %s", error->message);
                g_error_free (error);
        }

        mate_settings_manager_stop (manager);
        gtk_main_quit ();
}

static void
on_term_signal (int signal)
{
        /* Wake up main loop to tell it to shutdown */
        close (term_signal_pipe_fds[1]);
        term_signal_pipe_fds[1] = -1;
}

static gboolean
on_term_signal_pipe_closed (GIOChannel *source,
                            GIOCondition condition,
                            gpointer data)
{
        term_signal_pipe_fds[0] = -1;

        /* Got SIGTERM, time to clean up and get out
         */
        gtk_main_quit ();

        return FALSE;
}

static void
watch_for_term_signal (MateSettingsManager *manager)
{
        GIOChannel *channel;

        if (-1 == pipe (term_signal_pipe_fds) ||
            -1 == fcntl (term_signal_pipe_fds[0], F_SETFD, FD_CLOEXEC) ||
            -1 == fcntl (term_signal_pipe_fds[1], F_SETFD, FD_CLOEXEC)) {
                g_error ("Could not create pipe: %s", g_strerror (errno));
                exit (EXIT_FAILURE);
        }

        channel = g_io_channel_unix_new (term_signal_pipe_fds[0]);
        g_io_channel_set_encoding (channel, NULL, NULL);
        g_io_channel_set_buffered (channel, FALSE);
        g_io_add_watch (channel, G_IO_HUP, on_term_signal_pipe_closed, manager);
        g_io_channel_unref (channel);

        signal (SIGTERM, on_term_signal);

}

static void
set_session_over_handler (DBusGConnection *bus, MateSettingsManager *manager)
{
        DBusGProxy *session_proxy;
        DBusGProxy *private_proxy;
        gchar *client_id = NULL;
        const char *startup_id;
        GError *error = NULL;
        gboolean res;

        g_assert (bus != NULL);

        mate_settings_profile_start (NULL);

        session_proxy =
                 dbus_g_proxy_new_for_name (bus,
                                            MATE_SESSION_DBUS_NAME,
                                            MATE_SESSION_DBUS_OBJECT,
                                            MATE_SESSION_DBUS_INTERFACE);

        dbus_g_object_register_marshaller (
                g_cclosure_marshal_VOID__VOID,
                G_TYPE_NONE,
                G_TYPE_INVALID);

        dbus_g_proxy_add_signal (session_proxy,
                                 "SessionOver",
                                 G_TYPE_INVALID);

        dbus_g_proxy_connect_signal (session_proxy,
                                     "SessionOver",
                                     G_CALLBACK (on_session_over),
                                     manager,
                                     NULL);

        /* Register with mate-session */
        startup_id = g_getenv ("DESKTOP_AUTOSTART_ID");
        if (startup_id != NULL && *startup_id != '\0') {
                res = dbus_g_proxy_call (session_proxy,
                                         "RegisterClient",
                                         &error,
                                         G_TYPE_STRING, "mate-settings-daemon",
                                         G_TYPE_STRING, startup_id,
                                         G_TYPE_INVALID,
                                         DBUS_TYPE_G_OBJECT_PATH, &client_id,
                                         G_TYPE_INVALID);
                if (!res) {
                        g_warning ("failed to register client '%s': %s", startup_id, error->message);
                        g_error_free (error);
                }
                else {
                        /* get org.gnome.SessionManager.ClientPrivate interface */
                        private_proxy = dbus_g_proxy_new_for_name_owner (bus, MATE_SESSION_DBUS_NAME,
                                                                         client_id, MATE_SESSION_PRIVATE_DBUS_INTERFACE,
                                                                         &error);
                        if (private_proxy == NULL) {
                                g_warning ("DBUS error: %s", error->message);
                                g_error_free (error);
                        }
                        else {

                            /* get QueryEndSession */
                            dbus_g_proxy_add_signal (private_proxy, "QueryEndSession", G_TYPE_UINT, G_TYPE_INVALID);
                            dbus_g_proxy_connect_signal (private_proxy, "QueryEndSession",
                                                         G_CALLBACK (on_session_query_end),
                                                         manager, NULL);

                            /* get EndSession */
                            dbus_g_proxy_add_signal (private_proxy, "EndSession", G_TYPE_UINT, G_TYPE_INVALID);
                            dbus_g_proxy_connect_signal (private_proxy, "EndSession",
                                                         G_CALLBACK (on_session_end), manager, NULL);

                        }

                        g_free (client_id);
                }
        }

        watch_for_term_signal (manager);
        mate_settings_profile_end (NULL);
}

static void
msd_log_default_handler (const gchar   *log_domain,
                         GLogLevelFlags log_level,
                         const gchar   *message,
                         gpointer       unused_data)
{
        /* filter out DEBUG messages if debug isn't set */
        if ((log_level & G_LOG_LEVEL_MASK) == G_LOG_LEVEL_DEBUG
            && ! debug) {
                return;
        }

        g_log_default_handler (log_domain,
                               log_level,
                               message,
                               unused_data);
}

static void
parse_args (int *argc, char ***argv)
{
        GError *error;
        GOptionContext *context;

        mate_settings_profile_start (NULL);


        context = g_option_context_new (NULL);

        g_option_context_add_main_entries (context, entries, NULL);
        g_option_context_add_group (context, gtk_get_option_group (FALSE));

        error = NULL;
        if (!g_option_context_parse (context, argc, argv, &error)) {
                if (error != NULL) {
                        g_warning ("%s", error->message);
                        g_error_free (error);
                } else {
                        g_warning ("Unable to initialize GTK+");
                }
                exit (EXIT_FAILURE);
        }

        g_option_context_free (context);

        mate_settings_profile_end (NULL);

        if (debug)
            g_setenv ("G_MESSAGES_DEBUG", "all", FALSE);
}

static void debug_changed (GSettings *settings, gchar *key, gpointer user_data)
{
        debug = g_settings_get_boolean (settings, DEBUG_KEY);
        if (debug) {
            g_warning ("Enable DEBUG");
            g_setenv ("G_MESSAGES_DEBUG", "all", FALSE);
        } else {
            g_warning ("Disable DEBUG");
            g_unsetenv ("G_MESSAGES_DEBUG");
        }
}

int
main (int argc, char *argv[])
{
        MateSettingsManager *manager;
        DBusGConnection      *bus;
        gboolean              res;
        GError               *error;
        GSettings            *debug_settings = NULL;

        manager = NULL;

        mate_settings_profile_start (NULL);

        bindtextdomain (GETTEXT_PACKAGE, MATE_SETTINGS_LOCALEDIR);
        bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
        textdomain (GETTEXT_PACKAGE);
        setlocale (LC_ALL, "");

        parse_args (&argc, &argv);

        /* Allows to enable/disable debug from GSettings only if it is not set from argument */
        if (mate_gsettings_schema_exists (DEBUG_SCHEMA))
        {
                debug_settings = g_settings_new (DEBUG_SCHEMA);
                debug = g_settings_get_boolean (debug_settings, DEBUG_KEY);
                g_signal_connect (debug_settings, "changed::" DEBUG_KEY, G_CALLBACK (debug_changed), NULL);

		if (debug) {
		    g_setenv ("G_MESSAGES_DEBUG", "all", FALSE);
		}
        }

        mate_settings_profile_start ("opening gtk display");
        if (! gtk_init_check (NULL, NULL)) {
                g_warning ("Unable to initialize GTK+");
                exit (EXIT_FAILURE);
        }
        mate_settings_profile_end ("opening gtk display");

        g_log_set_default_handler (msd_log_default_handler, NULL);

        bus = get_session_bus ();
        if (bus == NULL) {
                g_warning ("Could not get a connection to the bus");
                goto out;
        }

        if (! bus_register (bus)) {
                goto out;
        }

#ifdef HAVE_LIBNOTIFY
        notify_init ("mate-settings-daemon");
#endif /* HAVE_LIBNOTIFY */

        mate_settings_profile_start ("mate_settings_manager_new");
        manager = mate_settings_manager_new ();
        mate_settings_profile_end ("mate_settings_manager_new");
        if (manager == NULL) {
                g_warning ("Unable to register object");
                goto out;
        }

        /* If we aren't started by dbus then load the plugins automatically during the
         * Initialization phase. Otherwise, wait for an Awake etc. */
        if (g_getenv ("DBUS_STARTER_BUS_TYPE") == NULL) {
                error = NULL;
                res = mate_settings_manager_start (manager, PLUGIN_LOAD_INIT, &error);
                if (! res) {
                        g_warning ("Unable to start: %s", error->message);
                        g_error_free (error);
                }
        }

        set_session_over_handler (bus, manager);

        /* If we aren't started by dbus then load the plugins automatically after
         * mate-settings-daemon has registered itself. Otherwise, wait for an Awake etc. */
        if (g_getenv ("DBUS_STARTER_BUS_TYPE") == NULL) {
                error = NULL;
                res = mate_settings_manager_start (manager, PLUGIN_LOAD_DEFER, &error);
                if (! res) {
                        g_warning ("Unable to start: %s", error->message);
                        g_error_free (error);
                        goto out;
                }
        }

        if (do_timed_exit) {
                g_timeout_add_seconds (30, (GSourceFunc) timed_exit_cb, NULL);
        }

        gtk_main ();

 out:

        if (bus != NULL) {
                dbus_g_connection_unref (bus);
        }

        if (manager != NULL) {
                g_object_unref (manager);
        }

        if (debug_settings != NULL) {
                g_object_unref (debug_settings);
        }

#ifdef HAVE_LIBNOTIFY
        if (notify_is_initted ())
            notify_uninit ();
#endif /* HAVE_LIBNOTIFY */

        g_debug ("SettingsDaemon finished");
        mate_settings_profile_end (NULL);

        return 0;
}