import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:outbag_app/backend/themes.dart';
import 'package:outbag_app/backend/user.dart';
import 'package:outbag_app/screens/room/edit.dart';
import 'package:outbag_app/screens/room/join.dart';
import 'package:outbag_app/screens/room/members.dart';
import 'package:outbag_app/screens/room/permissions.dart';
import 'package:outbag_app/screens/room/new.dart';
import 'package:outbag_app/screens/settings/main.dart';
import 'package:outbag_app/tools/fetch_wrapper.dart';
import 'package:provider/provider.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
import './screens/home.dart';
import './screens/welcome.dart';
import './screens/room/main.dart';
import './screens/auth.dart';
import './backend/request.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  runApp(const OutbagApp());
}

final GlobalKey<NavigatorState> _rootNavigatorKey =
    GlobalKey<NavigatorState>(debugLabel: 'root');
final GlobalKey<NavigatorState> _userShellNavigatorKey =
    GlobalKey<NavigatorState>(debugLabel: 'user');

class OutbagApp extends StatefulWidget {
  const OutbagApp({super.key});

  @override
  State<StatefulWidget> createState() => _OutbagAppState();
}

class _OutbagAppState extends State {
  // assume user is logged in
  // unless not userdata is found
  // or the userdata turns out to be wrong
  User? user;

  AppTheme theme = AppTheme.auto;

  void loadTheme() async {
    // load theme
    try {
      final theme = await AppTheme.fromDisk();
      setState(() {
        this.theme = theme;
      });
    } catch (_) {}
  }

  void loadUser() async {
    // load user
    try {
      final user = await User.fromDisk();
      setState(() {
        this.user = user;
      });
    } catch (_) {
      // user unavailable
      // invalid credentials
      // log out
      setState(() {
        user = null;
      });
    }
  }

  @override
  void initState() {
    super.initState();

    WidgetsBinding.instance.addPostFrameCallback((_) async {
      loadTheme();
      loadUser();
    });
  }

  Future<AccountMeta?> fetchInfo(User user) async {
    AccountMeta? info;
    // try to obtain user account information
    // with existing details
    // NOTE: also functions as a way to verify ther data
    await doNetworkRequest(null,
        req: () => postWithCreadentials(
            target: user.server,
            path: 'getMyAccount',
            credentials: user,
            body: {}),
        onOK: (body) async {
          final i = AccountMeta.fromJSON(body['data']);
          info = i;
        },
        onServerErr: (_) {
          info = null;

          setState(() {
            this.user = null;
          });
          return true;
        },
        onNetworkErr: () {
          info = null;
          // user is currently offline
          // approve login,
          // until user goes back offline
          // NOTE TODO: check user data once online
          return true;
        });

    return info;
  }

  @override
  Widget build(BuildContext context) {
    return MultiProvider(
        providers: [
          Provider<AppTheme>.value(value: theme),
        ],
        child: MaterialApp.router(
          title: "Outbag",
          localizationsDelegates: const [
            GlobalMaterialLocalizations.delegate,
            GlobalWidgetsLocalizations.delegate,
            GlobalCupertinoLocalizations.delegate,
            AppLocalizations.delegate
          ],
          supportedLocales: AppLocalizations.supportedLocales,
          themeMode: theme.mode,
          theme: ThemeData(useMaterial3: true, brightness: Brightness.light),
          darkTheme: ThemeData(useMaterial3: true, brightness: Brightness.dark),
          routerConfig: GoRouter(
              navigatorKey: _rootNavigatorKey,
              initialLocation: '/',
              redirect: (context, state) async {
                if (user == null) {
                  // prelogin
                  if (!state.subloc.startsWith('/welcome')) {
                    // prevent unauthorized user from accessing home
                    return '/welcome';
                  }
                } else {
                  // post login
                  if (state.subloc.startsWith('/welcome')) {
                    // prevent authorized user from accessing /welcome
                    return '/';
                  }
                }

                return null;
              },
              routes: <RouteBase>[
                // unauthorized routes
                GoRoute(
                    name: 'welcome',
                    path: '/welcome',
                    builder: (context, state) => const WelcomePage(),
                    routes: <RouteBase>[
                      GoRoute(
                        name: 'signin',
                        path: 'signin',
                        builder: (context, state) =>
                            AuthPage(mode: Mode.signin, refresh: loadUser),
                      ),
                      GoRoute(
                        name: 'signup',
                        path: 'signup',
                        builder: (context, state) =>
                            AuthPage(mode: Mode.signup, refresh: loadUser),
                      ),
                      GoRoute(
                        name: 'signup-ota',
                        path: 'signup-ota',
                        builder: (context, state) =>
                            AuthPage(mode: Mode.signupOTA, refresh: loadUser),
                      ),
                    ]),

                // authorized routes
                ShellRoute(
                    navigatorKey: _userShellNavigatorKey,
                    builder: (context, state, child) => Provider.value(
                        value: user!,
                        child: FutureProvider(
                          initialData: null,
                          child: child,
                          create: (context)=>fetchInfo(context.read<User>()),
                        )),
                    routes: <RouteBase>[
                      GoRoute(
                          path: '/',
                          name: 'home',
                          builder: (context, state) => const HomePage(),
                          routes: [
                            GoRoute(
                                name: 'settings',
                                path: 'settings',
                                builder: (context, state) =>
                                    SettingsPage(
                                      refreshTheme: loadTheme,
                                      refreshUser: loadUser
                                  )),
                            GoRoute(
                                path: 'join-room',
                                name: 'add-room',
                                builder: (context, state) =>
                                    const JoinRoomPage(),
                                routes: <RouteBase>[
                                  GoRoute(
                                      path: 'new',
                                      name: 'new-room',
                                      builder: (context, state) =>
                                          const NewRoomPage()),
                                ]),
                            GoRoute(
                                name: 'room',
                                path: 'r/:server/:id',
                                builder: (context, state) => RoomPage(
                                    state.params['server'] ?? '',
                                    state.params['id'] ?? ''),
                                routes: <RouteBase>[
                                  GoRoute(
                                      name: 'edit-room',
                                      path: 'edit',
                                      builder: (context, state) => EditRoomPage(
                                          state.params['server'] ?? '',
                                          state.params['id'] ?? '')),
                                  GoRoute(
                                      name: 'room-members',
                                      path: 'members',
                                      builder: (context, state) =>
                                          ManageRoomMembersPage(
                                              state.params['server'] ?? '',
                                              state.params['id'] ?? '')),
                                  GoRoute(
                                      name: 'room-permissions',
                                      path: 'roles',
                                      builder: (context, state) =>
                                          EditRoomPermissionSetPage(
                                              state.params['server'] ?? '',
                                              state.params['id'] ?? '')),
                                ])
                          ]),
                    ]),

                // routes that can be accessed
                // with and without an account
                // i.e the about screen
                GoRoute(
                    path: '/about',
                    name: 'about',
                    builder: (context, state) => const Text('About'))
              ]),
        ));
  }
}