/*
An indicator to time and date related information in the menubar.

Copyright 2010 Canonical Ltd.

Authors:
    Ted Gould <ted@canonical.com>

This program is free software: you can redistribute it and/or modify it 
under the terms of the GNU General Public License version 3, as published 
by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranties of 
MERCHANTABILITY, SATISFACTORY QUALITY, 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, see <http://www.gnu.org/licenses/>.
*/

#include <config.h>
#include <libindicator/indicator-service.h>

#include <glib/gi18n.h>
#include <gio/gio.h>

#include <libdbusmenu-glib/server.h>
#include <libdbusmenu-glib/client.h>
#include <libdbusmenu-glib/menuitem.h>

#include "datetime-interface.h"
#include "dbus-shared.h"

static void setup_timer (void);

static IndicatorService * service = NULL;
static GMainLoop * mainloop = NULL;
static DbusmenuServer * server = NULL;
static DbusmenuMenuitem * root = NULL;
static DatetimeInterface * dbus = NULL;

/* Global Items */
static DbusmenuMenuitem * date = NULL;
static DbusmenuMenuitem * calendar = NULL;
static DbusmenuMenuitem * settings = NULL;

/* Updates the label in the date menuitem */
static gboolean
update_datetime (gpointer user_data)
{
	g_debug("Updating Date/Time");

	gchar longstr[128];
	time_t t;
	struct tm *ltime;

	t = time(NULL);
	ltime = localtime(&t);
	if (ltime == NULL) {
		g_warning("Error getting local time");
		dbusmenu_menuitem_property_set(date, DBUSMENU_MENUITEM_PROP_LABEL, _("Error getting time"));
		return FALSE;
	}

	/* Note: may require some localization tweaks */
	strftime(longstr, 128, "%A, %e %B %Y", ltime);
	
	gchar * utf8 = g_locale_to_utf8(longstr, -1, NULL, NULL, NULL);
	dbusmenu_menuitem_property_set(date, DBUSMENU_MENUITEM_PROP_LABEL, utf8);
	g_free(utf8);

	return FALSE;
}

/* Run a particular program based on an activation */
static void
activate_cb (DbusmenuMenuitem * menuitem, guint timestamp, const gchar *command)
{
	GError * error = NULL;

	g_debug("Issuing command '%s'", command);
	if (!g_spawn_command_line_async(command, &error)) {
		g_warning("Unable to start %s: %s", (char *)command, error->message);
		g_error_free(error);
	}
}

/* Looks for the calendar application and enables the item if
   we have one */
static gboolean
check_for_calendar (gpointer user_data)
{
	g_return_val_if_fail (calendar != NULL, FALSE);

	gchar *evo = g_find_program_in_path("evolution");
	if (evo != NULL) {
		g_debug("Found the calendar application: %s", evo);
		dbusmenu_menuitem_property_set_bool(calendar, DBUSMENU_MENUITEM_PROP_ENABLED, TRUE);
		dbusmenu_menuitem_property_set_bool(calendar, DBUSMENU_MENUITEM_PROP_VISIBLE, TRUE);
		g_free(evo);
	} else {
		g_debug("Unable to find calendar app.");
		dbusmenu_menuitem_property_set_bool(calendar, DBUSMENU_MENUITEM_PROP_VISIBLE, FALSE);
	}

	return FALSE;
}

/* Looks for the time and date admin application and enables the
   item we have one */
static gboolean
check_for_timeadmin (gpointer user_data)
{
	g_return_val_if_fail (settings != NULL, FALSE);

	gchar * timeadmin = g_find_program_in_path("time-admin");
	if (timeadmin != NULL) {
		g_debug("Found the time-admin application: %s", timeadmin);
		dbusmenu_menuitem_property_set_bool(settings, DBUSMENU_MENUITEM_PROP_ENABLED, TRUE);
		g_free(timeadmin);
	} else {
		g_debug("Unable to find time-admin app.");
		dbusmenu_menuitem_property_set_bool(settings, DBUSMENU_MENUITEM_PROP_ENABLED, FALSE);
	}

	return FALSE;
}

/* Does the work to build the default menu, really calls out
   to other functions but this is the core to clean up the
   main function. */
static void
build_menus (DbusmenuMenuitem * root)
{
	g_debug("Building Menus.");
	if (date == NULL) {
		date = dbusmenu_menuitem_new();
		dbusmenu_menuitem_property_set     (date, DBUSMENU_MENUITEM_PROP_LABEL, _("No date yet..."));
		dbusmenu_menuitem_property_set_bool(date, DBUSMENU_MENUITEM_PROP_ENABLED, FALSE);
		dbusmenu_menuitem_child_append(root, date);

		g_idle_add(update_datetime, NULL);
	}

	if (calendar == NULL) {
		calendar = dbusmenu_menuitem_new();
		dbusmenu_menuitem_property_set (calendar, DBUSMENU_MENUITEM_PROP_TYPE, DBUSMENU_CALENDAR_MENUITEM_TYPE);
		/* insensitive until we check for available apps */
		dbusmenu_menuitem_property_set_bool(calendar, DBUSMENU_MENUITEM_PROP_ENABLED, FALSE);
		g_signal_connect (G_OBJECT(calendar), DBUSMENU_MENUITEM_SIGNAL_ITEM_ACTIVATED,
						  G_CALLBACK (activate_cb), "evolution -c calendar");
		dbusmenu_menuitem_child_append(root, calendar);

		g_idle_add(check_for_calendar, NULL);
	}

	DbusmenuMenuitem * separator = dbusmenu_menuitem_new();
	dbusmenu_menuitem_property_set(separator, DBUSMENU_MENUITEM_PROP_TYPE, DBUSMENU_CLIENT_TYPES_SEPARATOR);
	dbusmenu_menuitem_child_append(root, separator);

	settings = dbusmenu_menuitem_new();
	dbusmenu_menuitem_property_set     (settings, DBUSMENU_MENUITEM_PROP_LABEL, _("Time & Date Settings..."));
	/* insensitive until we check for available apps */
	dbusmenu_menuitem_property_set_bool(settings, DBUSMENU_MENUITEM_PROP_ENABLED, FALSE);
	g_signal_connect(G_OBJECT(settings), DBUSMENU_MENUITEM_SIGNAL_ITEM_ACTIVATED, G_CALLBACK(activate_cb), "time-admin");
	dbusmenu_menuitem_child_append(root, settings);
	g_idle_add(check_for_timeadmin, NULL);

	return;
}

/* Run when the timezone file changes */
static void
timezone_changed (GFileMonitor * monitor, GFile * file, GFile * otherfile, GFileMonitorEvent event, gpointer user_data)
{
	datetime_interface_update(DATETIME_INTERFACE(user_data));
	update_datetime(NULL);
	setup_timer();
	return;
}

/* Set up monitoring the timezone file */
static void
build_timezone (DatetimeInterface * dbus)
{
	GFile * timezonefile = g_file_new_for_path(TIMEZONE_FILE);
	GFileMonitor * monitor = g_file_monitor_file(timezonefile, G_FILE_MONITOR_NONE, NULL, NULL);
	if (monitor != NULL) {
		g_signal_connect(G_OBJECT(monitor), "changed", G_CALLBACK(timezone_changed), dbus);
		g_debug("Monitoring timezone file: '" TIMEZONE_FILE "'");
	} else {
		g_warning("Unable to monitor timezone file: '" TIMEZONE_FILE "'");
	}
	return;
}

/* Source ID for the timer */
static guint timer = 0;

/* Execute at a given time, update and setup a new
   timer to go again.  */
static gboolean
timer_func (gpointer user_data)
{
	timer = 0;
	/* Reset up each time to reduce error */
	setup_timer();
	update_datetime(NULL);
	return FALSE;
}

/* Sets up the time to launch the timer to update the
   date in the datetime entry */
static void
setup_timer (void)
{
	if (timer != 0) {
		g_source_remove(timer);
		timer = 0;
	}

	time_t t;
	t = time(NULL);
	struct tm * ltime = localtime(&t);

	timer = g_timeout_add_seconds(((23 - ltime->tm_hour) * 60 * 60) +
	                              ((59 - ltime->tm_min) * 60) +
	                              ((60 - ltime->tm_sec)) + 60 /* one minute past */,
	                              timer_func, NULL);

	return;
}

/* Repsonds to the service object saying it's time to shutdown.
   It stops the mainloop. */
static void 
service_shutdown (IndicatorService * service, gpointer user_data)
{
	g_warning("Shutting down service!");
	g_main_loop_quit(mainloop);
	return;
}

/* Function to build everything up.  Entry point from asm. */
int
main (int argc, char ** argv)
{
	g_type_init();

	/* Acknowledging the service init and setting up the interface */
	service = indicator_service_new_version(SERVICE_NAME, SERVICE_VERSION);
	g_signal_connect(service, INDICATOR_SERVICE_SIGNAL_SHUTDOWN, G_CALLBACK(service_shutdown), NULL);

	/* Setting up i18n and gettext.  Apparently, we need
	   all of these. */
	setlocale (LC_ALL, "");
	bindtextdomain (GETTEXT_PACKAGE, GNOMELOCALEDIR);
	textdomain (GETTEXT_PACKAGE);

	/* Building the base menu */
	server = dbusmenu_server_new(MENU_OBJ);
	root = dbusmenu_menuitem_new();
	dbusmenu_server_set_root(server, root);
	build_menus(root);

	/* Setup dbus interface */
	dbus = g_object_new(DATETIME_INTERFACE_TYPE, NULL);

	/* Setup timezone watch */
	build_timezone(dbus);

	/* Setup the timer */
	setup_timer();

	mainloop = g_main_loop_new(NULL, FALSE);
	g_main_loop_run(mainloop);

	g_object_unref(G_OBJECT(dbus));
	g_object_unref(G_OBJECT(service));
	g_object_unref(G_OBJECT(server));
	g_object_unref(G_OBJECT(root));

	return 0;
}