import 'dart:async';

/// App-wide pub/sub channel for cache invalidations. Producers (e.g. webdav
/// move/delete handlers) call [notifyListFiles] after they have dropped the
/// cached listing for a folder so that any [_FilesView] currently sitting on
/// that folder — possibly in the background, beneath a child route — can
/// refresh itself instead of showing the stale snapshot it loaded earlier.
class CacheInvalidationBus {
  CacheInvalidationBus._();

  static final StreamController<String> _listFiles = StreamController<String>.broadcast();

  /// Emits the invalidated `pathString` (in `FilesBloc` format: relative,
  /// no leading or trailing slash; root is '/').
  static Stream<String> get listFilesStream => _listFiles.stream;

  static void notifyListFiles(String pathString) {
    _listFiles.add(pathString);
  }
}