import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:riverpod_annotation/riverpod_annotation.dart';
import 'package:tatlock_ui/core/auth/auth_provider.dart';
import 'package:tatlock_ui/features/control_room/router.dart';
import 'package:tatlock_ui/features/front_hall/presentation/pages/front_hall_page.dart';
import 'package:tatlock_ui/features/security/router.dart';
import 'package:tatlock_ui/features/settings/presentation/pages/settings_page.dart';
import 'package:tatlock_ui/shared/layouts/app_scaffold.dart';

part 'app_router.g.dart';

/// No-animation page builder for instant transitions
Page<void> noTransitionPage(BuildContext context, GoRouterState state, Widget child) {
  return NoTransitionPage<void>(
    key: state.pageKey,
    child: child,
  );
}

/// Route paths as constants.
abstract class AppRoutes {
  static const root = '/';
  static const frontHall = '/front-hall';
  static const parlor = '/parlor';
  static const settings = '/settings';
}

/// Maps defaultRoom preference value to route path.
String _routeForDefaultRoom(String? defaultRoom) {
  return switch (defaultRoom) {
    'control-room' => ControlRoomRoutes.containers,
    'security' => SecurityRoutes.users,
    'parlor' => AppRoutes.parlor,
    _ => AppRoutes.frontHall,
  };
}

/// Provides the GoRouter instance.
@riverpod
GoRouter appRouter(Ref ref) {
  final authState = ref.watch(authProvider);

  return GoRouter(
    initialLocation: AppRoutes.root,
    debugLogDiagnostics: true,
    redirect: (context, state) {
      // Redirect from root to user's default room preference
      if (state.matchedLocation == AppRoutes.root) {
        final defaultRoom = authState.value?.preferences?.defaultRoom;
        return _routeForDefaultRoom(defaultRoom);
      }
      return null;
    },
    routes: [
      // Root redirects to default room (handled by redirect callback above)
      GoRoute(
        path: AppRoutes.root,
        redirect: (context, state) => AppRoutes.frontHall,
      ),
      // Main app routes (inside shell with app scaffold)
      ShellRoute(
        builder: (context, state, child) => AppScaffold(child: child),
        routes: [
          GoRoute(
            path: AppRoutes.frontHall,
            name: 'frontHall',
            pageBuilder: (context, state) =>
                noTransitionPage(context, state, const FrontHallPage()),
          ),
          ...controlRoomRoutes(),
          ...securityRoutes(),
          GoRoute(
            path: AppRoutes.parlor,
            name: 'parlor',
            pageBuilder: (context, state) =>
                noTransitionPage(context, state, const _PlaceholderPage(title: 'Parlor')),
          ),
          GoRoute(
            path: AppRoutes.settings,
            name: 'settings',
            pageBuilder: (context, state) =>
                noTransitionPage(context, state, const SettingsPage()),
          ),
        ],
      ),
    ],
  );
}

/// Placeholder page for routes not yet implemented.
class _PlaceholderPage extends StatelessWidget {
  const _PlaceholderPage({required this.title});

  final String title;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(
            Icons.construction,
            size: 64,
            color: Theme.of(context).colorScheme.outline,
          ),
          const SizedBox(height: 16),
          Text(
            title,
            style: Theme.of(context).textTheme.headlineMedium,
          ),
          const SizedBox(height: 8),
          Text(
            'Coming soon',
            style: Theme.of(context).textTheme.bodyLarge?.copyWith(
                  color: Theme.of(context).colorScheme.outline,
                ),
          ),
        ],
      ),
    );
  }
}