feat: OIDC Login on same page

lib/pages/intro/intro_page_presenter.dart

@@ -0,0 +1,97 @@
+import 'dart:convert';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+import 'package:matrix/matrix_api_lite/utils/logs.dart';
+import 'package:matrix/msc_extensions/msc_2964_oidc_login_flow/msc_2964_oidc_login_flow.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:universal_html/universal_html.dart' as web;
+
+import 'package:fluffychat/pages/intro/intro_page.dart';
+import 'package:fluffychat/utils/localized_exception_extension.dart';
+import 'package:fluffychat/utils/matrix_sdk_extensions/oidc_session_json_extension.dart';
+import 'package:fluffychat/widgets/matrix.dart';
+
+class IntroPagePresenter extends StatefulWidget {
+  const IntroPagePresenter({super.key});
+
+  @override
+  State<IntroPagePresenter> createState() => _IntroPagePresenterState();
+}
+
+class _IntroPagePresenterState extends State<IntroPagePresenter> {
+  bool isLoading = kIsWeb;
+  String? loggingInToHomeserver;
+
+  @override
+  void initState() {
+    super.initState();
+
+    if (kIsWeb) _finishOidcLogin();
+  }
+
+  void _finishOidcLogin() async {
+    final store = await SharedPreferences.getInstance();
+    final storedHomeserverString = store.getString(
+      OidcSessionJsonExtension.homeserverStoreKey,
+    );
+    final homeserverUrl = storedHomeserverString == null
+        ? null
+        : Uri.tryParse(storedHomeserverString);
+
+    final oidcSessionString = store.getString(
+      OidcSessionJsonExtension.storeKey,
+    );
+    final session = oidcSessionString == null
+        ? null
+        : OidcSessionJsonExtension.fromJson(jsonDecode(oidcSessionString));
+
+    await store.remove(OidcSessionJsonExtension.storeKey);
+    await store.remove(OidcSessionJsonExtension.homeserverStoreKey);
+
+    if (homeserverUrl == null || session == null) {
+      setState(() {
+        isLoading = false;
+      });
+      return;
+    }
+    setState(() {
+      loggingInToHomeserver = homeserverUrl.origin;
+    });
+
+    try {
+      final returnUrl = Uri.parse(web.window.location.href);
+      final queryParameters = returnUrl.hasFragment
+          ? Uri.parse(returnUrl.fragment).queryParameters
+          : returnUrl.queryParameters;
+      final code = queryParameters['code'] as String;
+      final state = queryParameters['state'] as String;
+
+      final client = await Matrix.of(context).getLoginClient();
+      await client.checkHomeserver(homeserverUrl);
+      await client.oidcLogin(session: session, code: code, state: state);
+    } catch (e, s) {
+      Logs().w('Unable to login via OIDC', e, s);
+      if (mounted) {
+        ScaffoldMessenger.of(
+          context,
+        ).showSnackBar(SnackBar(content: Text(e.toLocalizedString(context))));
+      }
+    } finally {
+      if (mounted) {
+        setState(() {
+          isLoading = false;
+        });
+      }
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return IntroPage(
+      isLoading: isLoading,
+      loggingInToHomeserver: loggingInToHomeserver,
+    );
+  }
+}