Schedules notifications if neccesary

initNotifications.dart

  Future initNotifications(BuildContext context) async {
    bool updateNotifications;
    final SharedPreferences prefs = await SharedPreferences.getInstance();

    // Checks if is necessary to update scheduled notifications
    try {
      updateNotifications =
          prefs.getString('notifications.launches.upcoming') !=
              launch.launchDate.toIso8601String();
    } catch (e) {
      updateNotifications = true;
    }

    // Update notifications if necessary
    if (updateNotifications) {
      // T - 1 day notification
      await _scheduleNotification(
        id: 0,
        context: context,
        time: FlutterI18n.translate(
          context,
          'spacex.notifications.launches.time_tomorrow',
        ),
        subtract: Duration(days: 1),
      );

      // Update storaged launch date
      prefs.setString(
        'notifications.launches.upcoming',
        launch.launchDate.toIso8601String(),
      );
    }
  }