8 user authentication (#14)

* Update README.md and dependencies

* Add basic app structure and assets

* Implement first models, viewmodels and api calls needed for user auth

* Implement TUM-SSO authentication and update README.md and

* Clean up auth_handler.dart and update routes

* Update userState and userViewModel to use riverpod and rxdart

* Refactor code to improve readability

* Remove unused import

* Clean up code, refactor models, update error-handling

README.md

@@ -1,3 +1,31 @@
 # The mobile client for [gocast](https://github.com/TUM-Dev/gocast)
 
 This mobile client for [gocast](https://github.com/TUM-Dev/gocast) is currently under development by the [iPraktikum Winter 23/24](https://ase.cit.tum.de/teaching/23w/ipraktikum/) on behalf of the TUM Developers. In order not to influence the grading of the students, we would ask you to refrain from code contributions until **March 2023**. Until then, we look forward to your contributions in our other repositories. Thank you for your understanding! 
+
+
+## Features
+
+- [x] Authentication using internal account
+- [x] Authentication using TUM SSO
+- [ ] Overview of own and publicly available Lectures
+- [ ] Ability to watch lectures (single, multi - view and split - view)
+- [ ] Bookmark lectures
+- [ ] Automatic notifications if lecture starts
+- [ ] Ability to search for lectures
+- [ ] Ability to download lectures in a data privacy conform manner (non - exportable and remotely deletable)
+- [ ] Ability to answer quizzes and feedback requests
+
+## Config
+
+1. Make sure to have a local [`gocast`](https://github.com/tum-dev/gocast) instance listening on port `8081`. 
+
+2. Run `$ flutter run` to start the app. 
+
+3. Run `dart fix --apply && dart format ./lib` before commiting new changes.
+
+## Development
+
+| Dependency                               | Usage                                    | Where to download it                         |
+|------------------------------------------|------------------------------------------|----------------------------------------------|
+| `Flutter` (includes the `Dart` compiler) | SDK to develop this app                  | https://docs.flutter.dev/get-started/install |
+| A local instance of [`gocast`](https://github.com/tum-dev/gocast) | API to fetch user data & streams                  | https://github.com/TUM-Dev/gocast#readme |

android/app/src/main/AndroidManifest.xml

@@ -22,6 +22,8 @@
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
                 <category android:name="android.intent.category.LAUNCHER"/>
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="de.tum.gocast_mobile" /> 
             </intent-filter>
         </activity>
         <!-- Don't delete the meta-data below.

ios/Runner/Info.plist

@@ -45,5 +45,15 @@
 		<string>UIInterfaceOrientationLandscapeLeft</string>
 		<string>UIInterfaceOrientationLandscapeRight</string>
 	</array>
+	<key>CFBundleURLTypes</key>
+	<array>
+		<dict>
+			<key>CFBundleURLSchemes</key>
+			<array>
+				<string>gocast</string>
+			</array>
+   	 </dict>
+	</array>
+
 </dict>
 </plist>

lib/base/helpers/model_generator.dart

@@ -0,0 +1,65 @@
+import 'dart:math';
+import 'package:gocast_mobile/model/course/bookmark_model.dart';
+import 'package:gocast_mobile/model/course/course_model.dart';
+import 'package:gocast_mobile/model/user/user_model.dart';
+import 'package:gocast_mobile/model/user/user_settings_model.dart';
+
+class ModelGenerator {
+  static User generateRandomUser() {
+    final random = Random();
+    final id = random.nextInt(1000);
+    final name = 'User$id';
+    final lastName = 'Last$id';
+    final email = '$name.$lastName@example.com';
+    final matriculationNumber = 'M$id';
+    final lrzId = 'L$id';
+    final role = random.nextInt(3) + 1;
+    final password = 'password$id';
+    final courses = List.generate(
+      random.nextInt(5) + 1,
+      (index) => Course(id: index, name: 'Course$index'),
+    );
+    final administeredCourses = List.generate(
+      random.nextInt(3) + 1,
+      (index) => Course(id: index, name: 'Administered Course$index'),
+    );
+    final pinnedCourses = List.generate(
+      random.nextInt(3) + 1,
+      (index) => Course(id: index, name: 'Pinned Course$index'),
+    );
+    final settings = List.generate(
+      random.nextInt(3) + 1,
+      (index) => UserSetting(
+        id: index,
+        userId: id,
+        type: UserSettingType.values[random.nextInt(3)],
+        value: 'Value$index',
+      ),
+    );
+    final bookmarks = List.generate(
+      random.nextInt(3) + 1,
+      (index) => Bookmark(
+        id: index,
+        userId: id,
+        title: 'Bookmark$index',
+        url: 'https://example.com/bookmark$index',
+      ),
+    );
+
+    return User(
+      id: id,
+      name: name,
+      lastName: lastName,
+      email: email,
+      matriculationNumber: matriculationNumber,
+      lrzId: lrzId,
+      role: role,
+      password: password,
+      courses: courses,
+      administeredCourses: administeredCourses,
+      pinnedCourses: pinnedCourses,
+      settings: settings,
+      bookmarks: bookmarks,
+    );
+  }
+}

lib/base/networking/apis/auth_handler.dart

@@ -0,0 +1,98 @@
+import 'package:cookie_jar/cookie_jar.dart';
+import 'package:dio/dio.dart';
+import 'package:dio_cookie_manager/dio_cookie_manager.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_inappwebview/flutter_inappwebview.dart' as webview;
+import 'package:gocast_mobile/base/helpers/model_generator.dart';
+import 'package:gocast_mobile/model/token_model.dart';
+import 'package:gocast_mobile/model/user/user_model.dart';
+import 'package:gocast_mobile/routes.dart';
+
+class AuthHandler {
+  static Future<void> basicAuth(
+    String username,
+    String password,
+  ) async {
+    const url = Routes.basicLogin;
+    final cookieJar = CookieJar();
+    final dio = Dio(
+      BaseOptions(
+        followRedirects: false,
+        validateStatus: (status) {
+          return status! < 500;
+        },
+      ),
+    );
+    dio.interceptors.add(CookieManager(cookieJar));
+
+    final formData = FormData.fromMap({
+      'username': username,
+      'password': password,
+    });
+
+    try {
+      await dio.post(
+        url,
+        data: formData,
+      );
+    } catch (e) {
+      // Throw the error so it can be caught and handled in the signIn method
+      throw Exception('Request error: $e');
+    }
+
+    List<Cookie> cookies = await cookieJar.loadForRequest(Uri.parse(url));
+
+    // Save jwt token
+    await Token.saveToken(cookies);
+  }
+
+  static Future<void> ssoAuth(BuildContext context) async {
+    debugPrint('ssoAuth started');
+    // Redirect the user to the Shibboleth login page
+    debugPrint('Login URL: $Routes.ssoLogin');
+
+    // Open the login page in a web view
+    await Navigator.push(
+      context,
+      MaterialPageRoute(
+        builder: (context) => webview.InAppWebView(
+          initialUrlRequest:
+              webview.URLRequest(url: Uri.parse(Routes.ssoLogin)),
+          onLoadStop:
+              (webview.InAppWebViewController controller, Uri? url) async {
+            debugPrint('Page load stopped: $url');
+
+            try {
+              final cookieManager = webview.CookieManager.instance();
+              List<webview.Cookie> cookies =
+                  await cookieManager.getCookies(url: url!);
+
+              // Save jwt token
+              await Token.saveToken(
+                cookies.map((c) => Cookie(c.name, c.value)).toList(),
+              );
+
+              // Redirect back to app
+              if (url.toString().startsWith(Routes.ssoRedirect)) {
+                debugPrint('Redirect URL detected: $url');
+
+                // Close the web view and go back to the app
+                debugPrint('Closing web view and returning to app');
+                Navigator.pop(context);
+              }
+            } catch (e) {
+              // Throw the error so it can be caught and handled by the caller of ssoAuth
+              throw Exception('Error in ssoAuth: $e');
+            }
+          },
+        ),
+      ),
+    );
+  }
+
+  // Generate user mock for testing the views until API/v2 is implemented
+  static Future<User> fetchUser() async {
+    // TODO: Add GET:/user endpoint in gocast API to fetch current user information
+    return ModelGenerator.generateRandomUser();
+  }
+}

lib/bootstrap.dart

@@ -0,0 +1,33 @@
+import 'dart:async';
+import 'dart:developer';
+
+import 'package:bloc/bloc.dart';
+import 'package:flutter/widgets.dart';
+
+class AppBlocObserver extends BlocObserver {
+  const AppBlocObserver();
+
+  @override
+  void onChange(BlocBase<dynamic> bloc, Change<dynamic> change) {
+    super.onChange(bloc, change);
+    log('onChange(${bloc.runtimeType}, $change)');
+  }
+
+  @override
+  void onError(BlocBase<dynamic> bloc, Object error, StackTrace stackTrace) {
+    log('onError(${bloc.runtimeType}, $error, $stackTrace)');
+    super.onError(bloc, error, stackTrace);
+  }
+}
+
+Future<void> bootstrap(FutureOr<Widget> Function() builder) async {
+  FlutterError.onError = (details) {
+    log(details.exceptionAsString(), stackTrace: details.stack);
+  };
+
+  Bloc.observer = const AppBlocObserver();
+
+  // Add cross-flavor configuration here
+
+  runApp(await builder());
+}

lib/main.dart

@@ -1,26 +1,64 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:gocast_mobile/model/user/user_state_model.dart';
+import 'package:gocast_mobile/viewModels/user_viewmodel.dart';
+import 'package:gocast_mobile/views/home_view.dart';
+import 'package:gocast_mobile/views/login_view.dart';
+import 'package:gocast_mobile/views/welcome_view.dart';
+
+final userViewModel = Provider((ref) => UserViewModel());
+
+final userStateProvider = StreamProvider<UserState>((ref) {
+  return ref.watch(userViewModel).current.stream;
+});
 
 void main() {
-  runApp(const MyApp());
+  runApp(
+    const ProviderScope(
+      child: App(),
+    ),
+  );
 }
 
-class MyApp extends StatelessWidget {
-  const MyApp({super.key});
+final scaffoldMessengerKey = GlobalKey<ScaffoldMessengerState>();
+
+class App extends ConsumerWidget {
+  const App({super.key});
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
+    final userState = ref.watch(userStateProvider);
+
+    if (userState.error != null) {
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        scaffoldMessengerKey.currentState!.showSnackBar(
+          SnackBar(content: Text('Error: ${userState.error}')),
+        );
+      });
+    }
+
     return MaterialApp(
+      scaffoldMessengerKey: scaffoldMessengerKey,
       title: 'gocast',
       debugShowCheckedModeBanner: false,
       theme: ThemeData(
         colorScheme: ColorScheme.fromSeed(seedColor: const Color(0xff0065bd)),
         useMaterial3: true,
-      ),
-      home: const Scaffold(
-        body: Center(
-          child: Text("Hello, iPraktikum! 👋"),
+        appBarTheme: AppBarTheme(
+          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
         ),
       ),
+      home: userState.value?.user == null
+          ? const LoginView(key: Key('loginView'))
+          : const HomeView(key: Key('homeView')),
+      routes: {
+        '/welcome': (context) => userState.value?.user == null
+            ? const LoginView(key: Key('loginView'))
+            : const WelcomeView(key: Key('welcomeView')),
+        '/home': (context) => userState.value?.user == null
+            ? const LoginView(key: Key('loginView'))
+            : const HomeView(key: Key('homeView')),
+      },
     );
   }
 }

lib/model/course/bookmark_model.dart

@@ -0,0 +1,13 @@
+class Bookmark {
+  Bookmark({
+    required this.id,
+    required this.userId,
+    required this.title,
+    required this.url,
+  });
+
+  int id;
+  int userId;
+  String title;
+  String url;
+}

lib/model/course/course_model.dart

@@ -0,0 +1,9 @@
+class Course {
+  Course({
+    required this.id,
+    required this.name,
+  });
+
+  int id;
+  String name;
+}

lib/model/token_model.dart

@@ -0,0 +1,23 @@
+import 'dart:io';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:flutter/foundation.dart';
+
+// This class will be extended once the API/v2 is implemented
+class Token {
+  static Future<void> saveToken(List<Cookie> cookies) async {
+    for (var cookie in cookies) {
+      if (cookie.name == 'jwt') {
+        SharedPreferences prefs = await SharedPreferences.getInstance();
+        await prefs.setString('jwt', cookie.value);
+
+        // DEBUG: Check cookie
+        String? jwt = prefs.getString('jwt');
+        debugPrint('Current jwt: $jwt');
+        return;
+      }
+    }
+
+    // Handle error when no jwt cookie is found
+    throw Exception('No JWT cookie found');
+  }
+}