purifyForReceipt method

@override Map? purifyForReceipt(Envelope? head, Content? body)

Purifies message data for use in ReceiptCommand.

Extracts and cleans up metadata from the original message envelope/content to form the "origin" field in receipt commands (removes sensitive/redundant fields). Returns null if the envelope is null (invalid original message).

@param envelope - Optional envelope of the original message for receipt

@param content - Optional content of the original message for receipt

@return Normalized map containing core receipt origin metadata (null if envelope is null)

Implementation

@override
Map? purifyForReceipt(Envelope? head, Content? body) {
  if (head == null) {
    return null;
  }
  Map origin = head.copyMap();
  if (origin.containsKey('data')) {
    origin.remove('data');
    origin.remove('keys');
    origin.remove('meta');
    origin.remove('visa');
  }
  if (body != null) {
    origin['sn'] = body.sn;
  }
  return origin;
}