import 'store.dart';

/// A [Store] that has a [registerStores]
/// method which connects these child stores to this [RootStore],
/// initializes them and then disposes of the subscription.
abstract class RootStore extends Store {
  List<Store> _children = [];

  /// Register stores with this [RootStore].
  ///
  /// The root store will subscribe to all childrens
  /// [notifyListeners] calls, initialize them, and dispose
  /// of the subscription.
  void registerChildren(List<Store> children) {
    _children = children;
  }

  @override
  Future<void> initState() async {
    if (_children.isEmpty)
      print(
        "WARNING: $this has no _children. Typically a RootStore would have _children stores.",
      );

    /// Connect the root store's [notifyListeners] method to
    /// all child stores [notifyListeners] method.
    _children.forEach((e) => e.addListener(notifyListeners));

    /// Await all child store's [initState]
    await Future.wait(_children.map((e) => e.initState()));

    return super.initState();
  }

  @override
  void dispose() {
    /// Dispose all [notifyListeners] handlers.
    _children.forEach((e) {
      e.removeListener(notifyListeners);
      e.dispose();
    });

    super.dispose();
  }
}