feat: Implement new sign in flow

lib/pages/sign_in/view_model/flows/check_homeserver.dart

@@ -0,0 +1,72 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+import 'package:go_router/go_router.dart';
+import 'package:url_launcher/url_launcher_string.dart';
+
+import 'package:fluffychat/l10n/l10n.dart';
+import 'package:fluffychat/pages/sign_in/view_model/flows/sso_login.dart';
+import 'package:fluffychat/pages/sign_in/view_model/model/public_homeserver_data.dart';
+import 'package:fluffychat/utils/localized_exception_extension.dart';
+import 'package:fluffychat/utils/platform_infos.dart';
+import 'package:fluffychat/widgets/adaptive_dialogs/show_ok_cancel_alert_dialog.dart';
+import 'package:fluffychat/widgets/matrix.dart';
+
+void connectToHomeserverFlow(
+  PublicHomeserverData homeserverData,
+  BuildContext context,
+  void Function(AsyncSnapshot<bool>) setState,
+  bool signUp,
+) async {
+  setState(AsyncSnapshot.waiting());
+  try {
+    final homeserverInput = homeserverData.name!;
+    var homeserver = Uri.parse(homeserverInput);
+    if (homeserver.scheme.isEmpty) {
+      homeserver = Uri.https(homeserverInput, '');
+    }
+    final l10n = L10n.of(context);
+    final client = await Matrix.of(context).getLoginClient();
+    final (_, _, loginFlows, _) = await client.checkHomeserver(homeserver);
+
+    final supportsSso = loginFlows.any((flow) => flow.type == 'm.login.sso');
+
+    if (!supportsSso) {
+      final regLink = homeserverData.regLink;
+      if (signUp && regLink != null) {
+        await launchUrlString(regLink);
+      }
+
+      final pathSegments = List.of(
+        GoRouter.of(context).routeInformationProvider.value.uri.pathSegments,
+      );
+      pathSegments.removeLast();
+      pathSegments.add('login');
+      context.go('/${pathSegments.join('/')}', extra: client);
+      setState(AsyncSnapshot.withData(ConnectionState.done, true));
+      return;
+    }
+    if (kIsWeb || PlatformInfos.isLinux) {
+      final consent = await showOkCancelAlertDialog(
+        context: context,
+        title: l10n.appWantsToUseForLogin(homeserverInput),
+        message: l10n.appWantsToUseForLoginDescription,
+        okLabel: l10n.continueText,
+      );
+      if (consent != OkCancelResult.ok) return;
+    }
+    await ssoLoginFlow(client, context, signUp);
+
+    setState(AsyncSnapshot.withData(ConnectionState.done, true));
+  } catch (e, s) {
+    setState(AsyncSnapshot.withError(ConnectionState.done, e, s));
+    if (!context.mounted) return;
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: Text(
+          e.toLocalizedString(context, ExceptionContext.checkHomeserver),
+        ),
+      ),
+    );
+  }
+}

lib/pages/sign_in/view_model/flows/sort_homeservers.dart

@@ -0,0 +1,24 @@
+import 'package:fluffychat/pages/sign_in/view_model/model/public_homeserver_data.dart';
+
+int sortHomeservers(PublicHomeserverData a, PublicHomeserverData b) {
+  return _calcHomeserverScore(b).compareTo(_calcHomeserverScore(a));
+}
+
+int _calcHomeserverScore(PublicHomeserverData homeserver) {
+  var score = 0;
+  if (homeserver.description?.isNotEmpty == true) score++;
+  if (homeserver.homepage?.isNotEmpty == true) score++;
+  score += (homeserver.languages?.length ?? 0);
+  score += (homeserver.features?.length ?? 0);
+  score += (homeserver.onlineStatus ?? 0);
+  if (homeserver.ipv6 == true) score++;
+  if (homeserver.isp?.isNotEmpty == true) score++;
+  if (homeserver.privacy?.isNotEmpty == true) score++;
+  if (homeserver.rules?.isNotEmpty == true) score++;
+  if (homeserver.version?.isNotEmpty == true) score++;
+  if (homeserver.usingVanillaReg == true) score--;
+  if (homeserver.regLink != null) score--;
+  if (homeserver.regMethod != 'SSO') score--;
+  if (homeserver.regMethod == 'In-house Element') score--;
+  return score;
+}

lib/pages/sign_in/view_model/flows/sso_login.dart

@@ -0,0 +1,49 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+import 'package:flutter_web_auth_2/flutter_web_auth_2.dart';
+import 'package:matrix/matrix.dart';
+import 'package:universal_html/html.dart' as html;
+
+import 'package:fluffychat/config/app_config.dart';
+import 'package:fluffychat/utils/platform_infos.dart';
+
+Future<void> ssoLoginFlow(
+  Client client,
+  BuildContext context,
+  bool signUp,
+) async {
+  final redirectUrl = kIsWeb
+      ? Uri.parse(
+          html.window.location.href,
+        ).resolveUri(Uri(pathSegments: ['auth.html'])).toString()
+      : (PlatformInfos.isMobile || PlatformInfos.isWeb || PlatformInfos.isMacOS)
+      ? '${AppConfig.appOpenUrlScheme.toLowerCase()}://login'
+      : 'http://localhost:3001//login';
+
+  final url = client.homeserver!.replace(
+    path: '/_matrix/client/v3/login/sso/redirect',
+    queryParameters: {
+      'redirectUrl': redirectUrl,
+      'action': signUp ? 'register' : 'login',
+    },
+  );
+
+  final urlScheme =
+      (PlatformInfos.isMobile || PlatformInfos.isWeb || PlatformInfos.isMacOS)
+      ? Uri.parse(redirectUrl).scheme
+      : "http://localhost:3001";
+  final result = await FlutterWebAuth2.authenticate(
+    url: url.toString(),
+    callbackUrlScheme: urlScheme,
+    options: FlutterWebAuth2Options(useWebview: PlatformInfos.isMobile),
+  );
+  final token = Uri.parse(result).queryParameters['loginToken'];
+  if (token?.isEmpty ?? false) return;
+
+  await client.login(
+    LoginType.mLoginToken,
+    token: token,
+    initialDeviceDisplayName: PlatformInfos.clientName,
+  );
+}