import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'core/auth/auth_notifier.dart';
import 'features/splash/splash_screen.dart';
import 'features/auth/screens/account_inactive_screen.dart';
import 'features/auth/screens/login_screen.dart';
import 'features/auth/screens/otp_screen.dart';
import 'features/home/home_screen.dart';
import 'features/profile/profil_screen.dart';
import 'features/shell/shell_screen.dart';
import 'features/chat/screens/active_sessions_screen.dart';
import 'features/chat/screens/mitra_chat_screen.dart';
import 'features/chat/screens/chat_history_screen.dart';
import 'features/chat/screens/chat_transcript_screen.dart';
import 'features/chat/screens/request_history_screen.dart';
import 'features/chat/screens/request_history_detail_screen.dart';
import 'features/undangan/undangan_screen.dart';

class RouterNotifier extends ChangeNotifier {
  final Ref _ref;

  RouterNotifier(this._ref) {
    _ref.listen(mitraAuthProvider, (_, __) => notifyListeners());
  }
}

final routerProvider = Provider<GoRouter>((ref) => buildRouter(ref));

GoRouter buildRouter(Ref ref) {
  final notifier = RouterNotifier(ref);

  return GoRouter(
    initialLocation: '/splash',
    refreshListenable: notifier,
    redirect: (context, state) {
      final authState = ref.read(mitraAuthProvider);
      final isSplash = state.matchedLocation == '/splash';
      final isAuthRoute = state.matchedLocation.startsWith('/login') ||
          state.matchedLocation.startsWith('/otp') ||
          state.matchedLocation.startsWith('/auth');

      // Show splash only during initial load — don't redirect away from auth routes
      if (authState is AsyncLoading) {
        if (isSplash || isAuthRoute) return null;
        return '/splash';
      }

      final data = authState.valueOrNull;
      if (data == null) {
        // Error state — show login
        if (!isAuthRoute && !isSplash) return '/login';
        if (isSplash) return '/login';
        return null;
      }

      if (data is MitraAuthAuthenticatedData) {
        return (isSplash || isAuthRoute) ? '/home' : null;
      }
      if (!isAuthRoute && !isSplash) return '/login';
      if (isSplash) return '/login';
      return null;
    },
    routes: [
      // ── Standalone routes (no tab bar) ───────────────────────────────────
      GoRoute(path: '/splash', builder: (_, __) => const SplashScreen()),
      GoRoute(path: '/login', builder: (_, __) => const LoginScreen()),
      GoRoute(
        path: '/otp',
        builder: (context, state) => OtpScreen(phone: state.extra as String),
      ),
      GoRoute(path: '/auth/inactive', builder: (_, __) => const AccountInactiveScreen()),

      // Full-screen chat session / transcript / history routes — these live
      // outside the shell because BestieChatV5 is full-screen in the figma
      // (the tab bar is hidden during an active session or transcript view).
      GoRoute(path: '/sessions', builder: (_, __) => const ActiveSessionsScreen()),
      GoRoute(
        path: '/chat/session/:sessionId',
        builder: (context, state) {
          final extra = state.extra as Map<String, dynamic>?;
          return MitraChatScreen(
            sessionId: state.pathParameters['sessionId']!,
            customerName: extra?['customerName'] as String? ?? 'Customer',
          );
        },
      ),
      GoRoute(
        path: '/chat/history',
        builder: (_, __) => const MitraChatHistoryScreen(),
      ),
      GoRoute(
        path: '/chat/history/:sessionId',
        builder: (context, state) =>
            MitraChatTranscriptScreen(sessionId: state.pathParameters['sessionId']!),
      ),
      GoRoute(
        path: '/chat/requests/history',
        builder: (_, __) => const RequestHistoryScreen(),
      ),
      GoRoute(
        path: '/chat/requests/history/:notificationId',
        builder: (context, state) => RequestHistoryDetailScreen(
          notificationId: state.pathParameters['notificationId']!,
        ),
      ),

      // ── Tab-shell routes (3 branches behind a persistent BestieTabBar) ──
      StatefulShellRoute.indexedStack(
        builder: (context, state, navigationShell) =>
            ShellScreen(navigationShell: navigationShell),
        branches: [
          // Branch 0 — Home
          StatefulShellBranch(
            routes: [
              GoRoute(path: '/home', builder: (_, __) => const HomeScreen()),
            ],
          ),
          // Branch 1 — Chat (Undangan: Curhat Baru + Perpanjang Curhat tabs)
          StatefulShellBranch(
            routes: [
              GoRoute(
                path: '/chat',
                builder: (_, __) => const UndanganScreen(),
              ),
            ],
          ),
          // Branch 2 — Profil (BestieProfile, Stage 4)
          StatefulShellBranch(
            routes: [
              GoRoute(
                path: '/profil',
                builder: (_, __) => const ProfilScreen(),
              ),
            ],
          ),
        ],
      ),
    ],
  );
}