import 'package:flutter/foundation.dart';
import 'package:go_router/go_router.dart';
import 'package:shuffle/core/routing/redirect_source.dart';

/// Steuerbare [RedirectSource]: `targets` bildet Pfad -> Weiterleitungsziel ab.
/// [notifyChanged] löst eine Neubewertung der Redirects aus.
class FakeRedirectSource implements RedirectSource {
  FakeRedirectSource([Map<String, String>? targets])
    : targets = targets ?? <String, String>{};

  final Map<String, String> targets;
  final _notifier = ValueNotifier<int>(0);

  void notifyChanged() => _notifier.value++;

  @override
  Listenable get changes => _notifier;

  @override
  String? redirect(GoRouterState state) => targets[state.uri.path];
}

/// Kleiner Test-Router mit eigenen [routes]. Für Screens, die ohne die
/// App-Routen geprüft werden. Der Aufrufer ruft am Ende `dispose` (z. B. per
/// `addTearDown(router.dispose)`).
GoRouter buildTestRouter({
  required List<RouteBase> routes,
  String initialLocation = '/',
  RedirectSource? redirectSource,
}) => GoRouter(
  initialLocation: initialLocation,
  routes: routes,
  refreshListenable: redirectSource?.changes,
  redirect: redirectSource == null
      ? null
      : (context, state) => redirectSource.redirect(state),
);

/// Aktueller Pfad des Routers (ohne Query).
String currentPath(GoRouter router) =>
    router.routerDelegate.currentConfiguration.uri.path;

/// Aktuelle URI inklusive Query, z. B. für `?from=`-Prüfungen.
Uri currentUri(GoRouter router) =>
    router.routerDelegate.currentConfiguration.uri;