import '../security/secret_store.dart';

/// A durable "to publish when connected" queue of lot ids. When sharing is
/// attempted offline, the lot ids are parked here (keystore-backed, so no
/// plaintext at rest) and flushed once a relay is reachable — offline delivery
/// for the sender side.
///
/// We store lot ids, not serialized offers: on flush the offer is rebuilt from
/// the lot's current state, so an edit made while offline is respected and a
/// since-deleted lot simply drops out.
class OfferOutbox {
  OfferOutbox(this._store);

  final SecretStore _store;
  static const _key = 'tane.social.outbox';

  /// Lot ids waiting to be published.
  Future<Set<String>> pending() async {
    final raw = await _store.read(_key);
    if (raw == null || raw.isEmpty) return <String>{};
    return raw.split('\n').where((s) => s.isNotEmpty).toSet();
  }

  Future<void> enqueue(Iterable<String> lotIds) async {
    final next = await pending()..addAll(lotIds);
    await _write(next);
  }

  Future<void> remove(Iterable<String> lotIds) async {
    final next = await pending()..removeAll(lotIds.toSet());
    await _write(next);
  }

  Future<void> clear() => _store.write(_key, '');

  Future<void> _write(Set<String> ids) => _store.write(_key, ids.join('\n'));
}