import "package:flutter/foundation.dart";
import "package:flutter/widgets.dart";

class AppMenuNotifier extends ChangeNotifier {
  List<PlatformMenuItem> _menus = const [];

  List<PlatformMenuItem> get menus => _menus;

  void update(List<PlatformMenuItem> menus) {
    _menus = menus;
    notifyListeners();
  }
}

/// Keeps one native platform menu host above an application's provider tree.
class PlatformMenuHost extends StatefulWidget {
  const PlatformMenuHost({
    super.key,
    required this.notifier,
    required this.child,
  });

  final AppMenuNotifier notifier;
  final Widget child;

  @override
  State<PlatformMenuHost> createState() => _PlatformMenuHostState();
}

class _PlatformMenuHostState extends State<PlatformMenuHost> {
  List<PlatformMenuItem> _menus = const [];

  static bool get _supported =>
      !kIsWeb && defaultTargetPlatform == TargetPlatform.macOS;

  @override
  void initState() {
    super.initState();
    _menus = widget.notifier.menus;
    widget.notifier.addListener(_onMenusChanged);
  }

  @override
  void didUpdateWidget(PlatformMenuHost oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (widget.notifier == oldWidget.notifier) return;
    oldWidget.notifier.removeListener(_onMenusChanged);
    widget.notifier.addListener(_onMenusChanged);
    _menus = widget.notifier.menus;
  }

  @override
  void dispose() {
    widget.notifier.removeListener(_onMenusChanged);
    super.dispose();
  }

  void _onMenusChanged() {
    if (mounted) setState(() => _menus = widget.notifier.menus);
  }

  @override
  Widget build(BuildContext context) {
    if (!_supported) return widget.child;
    return PlatformMenuBar(menus: _menus, child: widget.child);
  }
}