/// One decrypted direct message handed to the app.
class DirectMessage {
  const DirectMessage({
    required this.fromPubkey,
    required this.text,
    required this.at,
  });

  /// The authenticated sender (from the inner rumor). NOT the gift-wrap author,
  /// which is a throwaway ephemeral key — that's the metadata-privacy point.
  final String fromPubkey;
  final String text;
  final DateTime at;
}

/// The second interface over the shared `NostrConnection` (Q2): private 1:1
/// messaging. Deliberately SEPARATE from `OfferTransport` — its verbs (send a
/// private DM / read an inbox) don't fit publish/discover. Backed by NIP-17
/// gift-wrapped, NIP-44-encrypted events.
abstract interface class MessageTransport {
  /// Sends [text] privately to [toPubkey].
  Future<void> send({required String toPubkey, required String text});

  /// Streams decrypted messages addressed to this identity.
  Stream<DirectMessage> inbox();

  Future<void> close();
}