handleRequestNotification method

@visibleForTesting Future<void> handleRequestNotification(AtNotification notification)

Not part of API, but visibleForTesting. Receives 'request' notifications, and

• parses and validates
• sends an AtRpcRespType.nack response if deserialization or validation fails
• sends an AtRpcRespType.nack response otherwise
• calls AtRpcCallbacks.handleRequest
• calls sendResponse with the response from AtRpcCallbacks.handleRequest

Implementation

@visibleForTesting
Future<void> handleRequestNotification(AtNotification notification) async {
  if (!allowList.contains(notification.from)) {
    logger.info(
        'Ignoring notification from non-allowed atSign ${notification.from} : $notification');
    return;
  }

  // request key should be like:
  // @toAtSign:request.<id>.<domainNameSpace>.<rpcsNameSpace>.<baseNameSpace>@fromAtSign
  // strip off the prefix `@toAtSign:request.`
  String requestKey =
      notification.key.replaceFirst('${notification.to}:request.', '');
  // We should now have something like:
  // <id>.<domainNameSpace>.<rpcsNameSpace>.<baseNameSpace>@fromAtSign
  // We want to keep just the <id> and discard the rest
  requestKey = requestKey.replaceAll(
      '.$domainNameSpace.$rpcsNameSpace.$baseNameSpace${notification.from}',
      '');

  int requestId = -1;
  try {
    requestId = int.parse(requestKey);
  } catch (e) {
    logger.warning('Failed to get request ID from ${notification.key} - $e');
    return;
  }

  // print('Received request with id ${notification.key} and value ${chalk.brightGreen.bold(notification.value)}');
  late AtRpcReq request;

  try {
    request = AtRpcReq.fromJson(jsonDecode(notification.value!));
  } catch (e, st) {
    var message =
        'Failed to deserialize AtRpcReq from ${notification.value}: $e';
    logger.warning(message);
    logger.warning(st);
    // send NACK
    await sendResponse(notification, request,
        AtRpcResp.nack(request: request, message: message));
    return;
  }

  if (request.reqId != requestId) {
    var message =
        'Ignoring request: requestID from the notification key $requestId'
        ' does not match requestID from notification payload ${request.reqId}';
    logger.warning(message);
    // send NACK
    await sendResponse(notification, request,
        AtRpcResp.nack(request: request, message: message));
    return;
  }

  // send ACK
  await sendResponse(notification, request, AtRpcResp.ack(request: request));

  late AtRpcResp response;
  try {
    response = await callbacks.handleRequest(request, notification.from);
    await sendResponse(notification, request, response);
  } catch (e, st) {
    var message =
        'Exception $e from callbacks.handleRequest for request $request';
    logger.warning(message);
    logger.warning(st);
    await sendResponse(notification, request,
        AtRpcResp.nack(request: request, message: message));
  }
}