import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:go_router/go_router.dart';
import 'package:hive_flutter/hive_flutter.dart';
import '../data/local/hive_boxes.dart';
import '../data/local/models/app_settings.dart';

import '../core/widgets/bottom_nav_bar.dart';
import '../features/dashboard/presentation/dashboard_screen.dart';
import '../features/imsakiyah/presentation/imsakiyah_screen.dart';
import '../features/checklist/presentation/checklist_screen.dart';
import '../features/laporan/presentation/laporan_screen.dart';
import '../features/tools/presentation/tools_screen.dart';
import '../features/dzikir/presentation/dzikir_screen.dart';
import '../features/doa/presentation/doa_screen.dart';
import '../features/hadits/presentation/hadits_screen.dart';
import '../features/qibla/presentation/qibla_screen.dart';
import '../features/quran/presentation/quran_screen.dart';
import '../features/quran/presentation/quran_reading_screen.dart';
import '../features/quran/presentation/quran_murattal_screen.dart';
import '../features/quran/presentation/quran_bookmarks_screen.dart';
import '../features/quran/presentation/quran_enrichment_screen.dart';
import '../features/notifications/presentation/notification_center_screen.dart';
import '../features/settings/presentation/settings_screen.dart';

/// Navigation key for the shell navigator (bottom-nav screens).
final _rootNavigatorKey = GlobalKey<NavigatorState>();
final _shellNavigatorKey = GlobalKey<NavigatorState>();

/// GoRouter configuration per PRD §5.2.
final GoRouter appRouter = GoRouter(
  navigatorKey: _rootNavigatorKey,
  initialLocation: '/',
  routes: [
    // ── Shell route (bottom nav persists) ──
    ShellRoute(
      navigatorKey: _shellNavigatorKey,
      pageBuilder: (context, state, child) => NoTransitionPage(
        key: ValueKey<String>('shell-${state.pageKey.value}'),
        child: _ScaffoldWithNav(child: child),
      ),
      routes: [
        GoRoute(
          path: '/',
          pageBuilder: (context, state) => NoTransitionPage(
            key: state.pageKey,
            child: const DashboardScreen(),
          ),
          routes: [
            GoRoute(
              path: 'qibla',
              parentNavigatorKey: _rootNavigatorKey,
              builder: (context, state) => const QiblaScreen(),
            ),
          ],
        ),
        GoRoute(
          path: '/imsakiyah',
          pageBuilder: (context, state) => NoTransitionPage(
            key: state.pageKey,
            child: const ImsakiyahScreen(),
          ),
        ),
        GoRoute(
          path: '/checklist',
          pageBuilder: (context, state) => NoTransitionPage(
            key: state.pageKey,
            child: const ChecklistScreen(),
          ),
        ),
        GoRoute(
          path: '/laporan',
          pageBuilder: (context, state) => NoTransitionPage(
            key: state.pageKey,
            child: const LaporanScreen(),
          ),
        ),
        GoRoute(
          path: '/tools',
          pageBuilder: (context, state) => NoTransitionPage(
            key: state.pageKey,
            child: const ToolsScreen(),
          ),
          routes: [
            GoRoute(
              path: 'dzikir',
              parentNavigatorKey: _rootNavigatorKey,
              builder: (context, state) => const DzikirScreen(),
            ),
            GoRoute(
              path: 'quran',
              parentNavigatorKey: _rootNavigatorKey,
              builder: (context, state) => const QuranScreen(),
              routes: [
                GoRoute(
                  path: 'enrichment',
                  parentNavigatorKey: _rootNavigatorKey,
                  builder: (context, state) => const QuranEnrichmentScreen(),
                ),
                GoRoute(
                  path: 'bookmarks',
                  parentNavigatorKey: _rootNavigatorKey,
                  builder: (context, state) => const QuranBookmarksScreen(),
                ),
                GoRoute(
                  path: ':surahId',
                  parentNavigatorKey: _rootNavigatorKey,
                  builder: (context, state) {
                    final surahId = state.pathParameters['surahId']!;
                    final startVerse = int.tryParse(
                        state.uri.queryParameters['startVerse'] ?? '');
                    return QuranReadingScreen(
                        surahId: surahId, initialVerse: startVerse);
                  },
                  routes: [
                    GoRoute(
                      path: 'murattal',
                      parentNavigatorKey: _rootNavigatorKey,
                      builder: (context, state) {
                        final surahId = state.pathParameters['surahId']!;
                        final qariId = state.uri.queryParameters['qariId'];
                        final autoplay =
                            state.uri.queryParameters['autoplay'] == 'true';
                        return QuranMurattalScreen(
                          surahId: surahId,
                          initialQariId: qariId,
                          autoPlay: autoplay,
                        );
                      },
                    ),
                  ],
                ),
              ],
            ),
            GoRoute(
              path: 'qibla',
              parentNavigatorKey: _rootNavigatorKey,
              builder: (context, state) => const QiblaScreen(),
            ),
            GoRoute(
              path: 'doa',
              parentNavigatorKey: _rootNavigatorKey,
              builder: (context, state) => const DoaScreen(),
            ),
            GoRoute(
              path: 'hadits',
              parentNavigatorKey: _rootNavigatorKey,
              builder: (context, state) => const HaditsScreen(),
            ),
          ],
        ),
        // Simple Mode Tab: Zikir
        GoRoute(
          path: '/dzikir',
          builder: (context, state) =>
              const DzikirScreen(isSimpleModeTab: true),
        ),
        // Simple Mode Tab: Tilawah
        GoRoute(
          path: '/quran',
          builder: (context, state) => const QuranScreen(isSimpleModeTab: true),
          routes: [
            GoRoute(
              path: 'enrichment',
              builder: (context, state) =>
                  const QuranEnrichmentScreen(isSimpleModeTab: true),
            ),
            GoRoute(
              path: 'bookmarks',
              builder: (context, state) =>
                  const QuranBookmarksScreen(isSimpleModeTab: true),
            ),
            GoRoute(
              path: ':surahId',
              builder: (context, state) {
                final surahId = state.pathParameters['surahId']!;
                final startVerse =
                    int.tryParse(state.uri.queryParameters['startVerse'] ?? '');
                return QuranReadingScreen(
                    surahId: surahId,
                    initialVerse: startVerse,
                    isSimpleModeTab: true);
              },
              routes: [
                GoRoute(
                  path: 'murattal',
                  parentNavigatorKey: _rootNavigatorKey,
                  builder: (context, state) {
                    final surahId = state.pathParameters['surahId']!;
                    final qariId = state.uri.queryParameters['qariId'];
                    final autoplay =
                        state.uri.queryParameters['autoplay'] == 'true';
                    return QuranMurattalScreen(
                      surahId: surahId,
                      initialQariId: qariId,
                      autoPlay: autoplay,
                      isSimpleModeTab: true,
                    );
                  },
                ),
              ],
            ),
          ],
        ),
        GoRoute(
          path: '/doa',
          builder: (context, state) => const DoaScreen(isSimpleModeTab: true),
        ),
        GoRoute(
          path: '/hadits',
          builder: (context, state) =>
              const HaditsScreen(isSimpleModeTab: true),
        ),
      ],
    ),
    // ── Settings (pushed, no bottom nav) ──
    GoRoute(
      path: '/notifications',
      parentNavigatorKey: _rootNavigatorKey,
      builder: (context, state) => const NotificationCenterScreen(),
    ),
    GoRoute(
      path: '/settings',
      parentNavigatorKey: _rootNavigatorKey,
      builder: (context, state) => const SettingsScreen(),
    ),
  ],
);

/// Scaffold wrapper that provides the persistent bottom nav bar.
class _ScaffoldWithNav extends StatefulWidget {
  const _ScaffoldWithNav({required this.child});

  final Widget child;

  @override
  State<_ScaffoldWithNav> createState() => _ScaffoldWithNavState();
}

class _ScaffoldWithNavState extends State<_ScaffoldWithNav> {
  DateTime? _lastBackPressedAt;

  bool _shouldHideBottomNav({
    required bool isSimpleMode,
    required String path,
  }) {
    if (!isSimpleMode) return false;
    if (path == '/dzikir') return true;
    if (!path.startsWith('/quran/')) return false;

    final tail = path.substring('/quran/'.length);
    if (tail == 'bookmarks' || tail == 'enrichment') return false;
    return !tail.contains('/');
  }

  /// Maps route locations to bottom nav indices.
  int _currentIndex(BuildContext context) {
    final location = GoRouterState.of(context).uri.toString();
    final box = Hive.box<AppSettings>(HiveBoxes.settings);
    final isSimpleMode = box.get('default')?.simpleMode ?? false;

    if (isSimpleMode) {
      if (location.startsWith('/imsakiyah')) return 1;
      if (location.startsWith('/quran')) return 2;
      if (location.startsWith('/dzikir')) return 3;
      if (location.startsWith('/tools') ||
          location.startsWith('/doa') ||
          location.startsWith('/hadits')) {
        return 4;
      }
      return 0;
    } else {
      if (location.startsWith('/imsakiyah')) return 1;
      if (location.startsWith('/checklist')) return 2;
      if (location.startsWith('/laporan')) return 3;
      if (location.startsWith('/tools')) return 4;
      return 0;
    }
  }

  void _onTap(BuildContext context, int index) {
    final box = Hive.box<AppSettings>(HiveBoxes.settings);
    final isSimpleMode = box.get('default')?.simpleMode ?? false;

    if (isSimpleMode) {
      switch (index) {
        case 0:
          context.go('/');
          break;
        case 1:
          context.go('/imsakiyah');
          break;
        case 2:
          context.go('/quran');
          break;
        case 3:
          context.go('/dzikir');
          break;
        case 4:
          context.go('/tools');
          break;
      }
    } else {
      switch (index) {
        case 0:
          context.go('/');
          break;
        case 1:
          context.go('/imsakiyah');
          break;
        case 2:
          context.go('/checklist');
          break;
        case 3:
          context.go('/laporan');
          break;
        case 4:
          context.go('/tools');
          break;
      }
    }
  }

  bool _isMainShellRoute({
    required bool isSimpleMode,
    required String path,
  }) {
    if (isSimpleMode) {
      return path == '/' ||
          path == '/imsakiyah' ||
          path == '/quran' ||
          path == '/dzikir' ||
          path == '/tools';
    }

    return path == '/' ||
        path == '/imsakiyah' ||
        path == '/checklist' ||
        path == '/laporan' ||
        path == '/tools';
  }

  Future<void> _handleMainRouteBack(
    BuildContext context, {
    required String path,
  }) async {
    if (path != '/') {
      context.go('/');
      return;
    }

    final now = DateTime.now();
    final pressedRecently = _lastBackPressedAt != null &&
        now.difference(_lastBackPressedAt!) <= const Duration(seconds: 2);

    if (pressedRecently) {
      await SystemNavigator.pop();
      return;
    }

    _lastBackPressedAt = now;
    final messenger = ScaffoldMessenger.maybeOf(context);
    messenger
      ?..hideCurrentSnackBar()
      ..showSnackBar(
        const SnackBar(
          content: Text('Tekan sekali lagi untuk keluar'),
          duration: Duration(seconds: 2),
        ),
      );
  }

  @override
  Widget build(BuildContext context) {
    return ValueListenableBuilder<Box<AppSettings>>(
      valueListenable: Hive.box<AppSettings>(HiveBoxes.settings).listenable(),
      builder: (context, box, _) {
        final isSimpleMode = box.get('default')?.simpleMode ?? false;
        final path = GoRouterState.of(context).uri.path;
        final hideBottomNav = _shouldHideBottomNav(
          isSimpleMode: isSimpleMode,
          path: path,
        );
        final modeScopedChild = KeyedSubtree(
          key: ValueKey(
            'shell:$path:${isSimpleMode ? 'simple' : 'full'}',
          ),
          child: widget.child,
        );
        final pageBody = hideBottomNav
            ? SafeArea(
                top: false,
                child: modeScopedChild,
              )
            : modeScopedChild;

        final handleBackInShell =
            defaultTargetPlatform == TargetPlatform.android &&
                _isMainShellRoute(isSimpleMode: isSimpleMode, path: path);

        return PopScope(
          canPop: !handleBackInShell,
          onPopInvokedWithResult: (didPop, _) async {
            if (didPop || !handleBackInShell) return;
            await _handleMainRouteBack(context, path: path);
          },
          child: Scaffold(
            body: pageBody,
            bottomNavigationBar: hideBottomNav
                ? null
                : AppBottomNavBar(
                    currentIndex: _currentIndex(context),
                    onTap: (i) => _onTap(context, i),
                  ),
          ),
        );
      },
    );
  }
}