clearChat method

  1. @override
Future<void> clearChat(
  1. ChatId id, [
  2. ChatItemId? untilId
])
override

Clears an existing Chat (hides all its ChatItems) for the authenticated MyUser until the specified ChatItem inclusively.

Clears all ChatItems in the specified Chat, if untilId if not provided.

Implementation

@override
Future<void> clearChat(ChatId id, [ChatItemId? untilId]) async {
  Log.debug('clearChat($id, $untilId)', '$runtimeType');

  if (id.isLocal) {
    await chats[id]?.clear();
    return;
  }

  final RxChatImpl? chat = chats[id];
  final ChatItem? lastItem = chat?.chat.value.lastItem;
  final ChatItemId? until = untilId ?? lastItem?.id;

  if (until == null) {
    // No-op, as there's nothing to clear until.
    return;
  }

  Iterable<Rx<ChatItem>>? items;

  if (chat != null) {
    final int index = chat.messages.indexWhere((c) => c.value.id == until);

    if (index != -1) {
      items = chat.messages.toList().getRange(0, index + 1);
      chat.messages.removeRange(0, index + 1);

      final ChatItem? last =
          chat.messages.isNotEmpty ? chat.messages.last.value : null;
      chat.chat.update((c) => c?.lastItem = last);
    }
  }

  try {
    await _graphQlProvider.clearChat(id, until);
  } catch (_) {
    if (chat != null) {
      chat.messages.insertAll(0, items ?? []);
      chat.chat.update((c) => c?.lastItem = lastItem);
    }
    rethrow;
  }
}