handle method

@override Future<IssueCredential?> handle(DidcommMessage message)

Actual handling method. variables can be expected to be non-null as configured

Implementation

@override
Future<IssueCredential?> handle(DidcommMessage message) async {
  message as DidcommPlaintextMessage;

  var request = RequestCredential.fromJson(message.toJson());
  var credential = request.detail!.first.credential;
  if (!credential.context.contains('https://schema.org')) {
    credential.context.add('https://schema.org');
  }

  // sign the requested credential
  // (normally we had to check before that,
  // that the data in it is the same we offered)
  // Hint: the REST API does some very basic check for that (see handler there)
  late String signed;
  try {
      signed = await signCredential(wallet!,
      credential,
      challenge: request.detail!.first.options.challenge);
  } on Exception catch (e) {
    throw DidcommServiceException("Could not sign the credential "
        "due to `${e.toString()}`",
        baseException: e,
        code: 3459340);
  }

  // issue the credential
  var issue = IssueCredential(
      threadId: message.threadId ?? message.id,
      from: getConversationDid(message, wallet!),
      to: [message.from!],
      replyTo: replyTo,
      pleaseAck: true,
      credentials: [VerifiableCredential.fromJson(signed)]);

  // patch ack as per didcomm spec (make sure the message contains
  // itself to be acked)
  issue.pleaseAck ??= [];

  if (!(issue.pleaseAck!.contains('') || issue.pleaseAck!.contains(issue.id))) {
    issue.pleaseAck!.add(issue.id);
  }
  return issue;
}