dart_handler.dart

class NotificationHandler {
  static const MethodChannel _channel = MethodChannel('com.helloinside.glucose/notification');

  final void Function(Object, bool isAppLaunch) onNotificationTap;

  NotificationHandler({required this.onNotificationTap});

  void initialize() {

    _channel.setMethodCallHandler(handleMethodCall);

    /// let the native side know that the channel is initialized, and it can start sending notifications
    _channel.invokeMethod("initializeChannel");

    /// check if there is a notification that was tapped while the app was in the background
    /// and handle it
    /// the tap would have been lost otherwise, since this handler is initialized after the tap
    _channel.invokeMethod("getLastNotificationData").then((Object? value) {
      if (value != null) {
        onNotificationTap(value, true);
      }
    });
  }

  Future<void> handleMethodCall(MethodCall call) {

    try {
      switch (call.method) {
        case 'onNotificationTap':
          _handleNotificationTap(call);
          break;
        default:
          log.warning('Unknown method: ${call.method}');
      }
    } catch (e, s) {
      log.error('Error in NotificationHandler: $e', e, s);
    }
    return Future.value();
  }

  void dispose() {
    _channel.setMethodCallHandler(null);
  }

  void _handleNotificationTap(MethodCall call) {
    log.debug('NotificationHandler: _handleNotificationTap: $call');

    final args = call.arguments as Map<Object?, Object?>;

    final payload = args['payload'];

    log.warning("_handleNotificationTap: args $args / $payload");

    onNotificationTap(payload ?? args, false);
  }
}