store: Handle invalid API key on register-queue

assets/l10n/app_en.arb

@@ -186,8 +186,8 @@
       "url": {"type": "String", "example": "http://example.com/"}
     }
   },
-  "errorLoginCouldNotConnectTitle": "Could not connect",
-  "@errorLoginCouldNotConnectTitle": {
+  "errorCouldNotConnectTitle": "Could not connect",
+  "@errorCouldNotConnectTitle": {
     "description": "Error title when the app could not connect to the server."
   },
   "errorMessageDoesNotSeemToExist": "That message does not seem to exist.",
@@ -458,6 +458,13 @@
   "@topicValidationErrorMandatoryButEmpty": {
     "description": "Topic validation error when topic is required but was empty."
   },
+  "errorInvalidApiKeyMessage": "Your account at {url} could not be authenticated. Please try logging in again or use another account.",
+  "@errorInvalidApiKeyMessage": {
+    "description": "Error message in the dialog for invalid API key.",
+    "placeholders": {
+      "url": {"type": "String", "example": "http://chat.example.com/"}
+    }
+  },
   "errorInvalidResponse": "The server sent an invalid response",
   "@errorInvalidResponse": {
     "description": "Error message when an API call returned an invalid response."

lib/generated/l10n/zulip_localizations.dart

@@ -359,7 +359,7 @@ abstract class ZulipLocalizations {
   ///
   /// In en, this message translates to:
   /// **'Could not connect'**
-  String get errorLoginCouldNotConnectTitle;
+  String get errorCouldNotConnectTitle;
 
   /// Error message when loading a message that does not exist.
   ///
@@ -721,6 +721,12 @@ abstract class ZulipLocalizations {
   /// **'Topics are required in this organization.'**
   String get topicValidationErrorMandatoryButEmpty;
 
+  /// Error message in the dialog for invalid API key.
+  ///
+  /// In en, this message translates to:
+  /// **'Your account at {url} could not be authenticated. Please try logging in again or use another account.'**
+  String errorInvalidApiKeyMessage(String url);
+
   /// Error message when an API call returned an invalid response.
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -159,7 +159,7 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   }
 
   @override
-  String get errorLoginCouldNotConnectTitle => 'Could not connect';
+  String get errorCouldNotConnectTitle => 'Could not connect';
 
   @override
   String get errorMessageDoesNotSeemToExist => 'That message does not seem to exist.';
@@ -357,6 +357,11 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get topicValidationErrorMandatoryButEmpty => 'Topics are required in this organization.';
 
+  @override
+  String errorInvalidApiKeyMessage(String url) {
+    return 'Your account at $url could not be authenticated. Please try logging in again or use another account.';
+  }
+
   @override
   String get errorInvalidResponse => 'The server sent an invalid response';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -159,7 +159,7 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   }
 
   @override
-  String get errorLoginCouldNotConnectTitle => 'Could not connect';
+  String get errorCouldNotConnectTitle => 'Could not connect';
 
   @override
   String get errorMessageDoesNotSeemToExist => 'That message does not seem to exist.';
@@ -357,6 +357,11 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get topicValidationErrorMandatoryButEmpty => 'Topics are required in this organization.';
 
+  @override
+  String errorInvalidApiKeyMessage(String url) {
+    return 'Your account at $url could not be authenticated. Please try logging in again or use another account.';
+  }
+
   @override
   String get errorInvalidResponse => 'The server sent an invalid response';
 

lib/generated/l10n/zulip_localizations_fr.dart

@@ -159,7 +159,7 @@ class ZulipLocalizationsFr extends ZulipLocalizations {
   }
 
   @override
-  String get errorLoginCouldNotConnectTitle => 'Could not connect';
+  String get errorCouldNotConnectTitle => 'Could not connect';
 
   @override
   String get errorMessageDoesNotSeemToExist => 'That message does not seem to exist.';
@@ -357,6 +357,11 @@ class ZulipLocalizationsFr extends ZulipLocalizations {
   @override
   String get topicValidationErrorMandatoryButEmpty => 'Topics are required in this organization.';
 
+  @override
+  String errorInvalidApiKeyMessage(String url) {
+    return 'Your account at $url could not be authenticated. Please try logging in again or use another account.';
+  }
+
   @override
   String get errorInvalidResponse => 'The server sent an invalid response';
 

lib/generated/l10n/zulip_localizations_ja.dart

@@ -159,7 +159,7 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   }
 
   @override
-  String get errorLoginCouldNotConnectTitle => 'Could not connect';
+  String get errorCouldNotConnectTitle => 'Could not connect';
 
   @override
   String get errorMessageDoesNotSeemToExist => 'That message does not seem to exist.';
@@ -357,6 +357,11 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get topicValidationErrorMandatoryButEmpty => 'Topics are required in this organization.';
 
+  @override
+  String errorInvalidApiKeyMessage(String url) {
+    return 'Your account at $url could not be authenticated. Please try logging in again or use another account.';
+  }
+
   @override
   String get errorInvalidResponse => 'The server sent an invalid response';
 

lib/generated/l10n/zulip_localizations_pl.dart

@@ -159,7 +159,7 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   }
 
   @override
-  String get errorLoginCouldNotConnectTitle => 'Nie można połączyć';
+  String get errorCouldNotConnectTitle => 'Could not connect';
 
   @override
   String get errorMessageDoesNotSeemToExist => 'Taka wiadomość raczej nie istnieje.';
@@ -357,6 +357,11 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get topicValidationErrorMandatoryButEmpty => 'Wątki są wymagane przez tę organizację.';
 
+  @override
+  String errorInvalidApiKeyMessage(String url) {
+    return 'Your account at $url could not be authenticated. Please try logging in again or use another account.';
+  }
+
   @override
   String get errorInvalidResponse => 'Nieprawidłowa odpowiedź serwera';
 

lib/generated/l10n/zulip_localizations_ru.dart

@@ -159,7 +159,7 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
   }
 
   @override
-  String get errorLoginCouldNotConnectTitle => 'Could not connect';
+  String get errorCouldNotConnectTitle => 'Could not connect';
 
   @override
   String get errorMessageDoesNotSeemToExist => 'That message does not seem to exist.';
@@ -357,6 +357,11 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
   @override
   String get topicValidationErrorMandatoryButEmpty => 'Topics are required in this organization.';
 
+  @override
+  String errorInvalidApiKeyMessage(String url) {
+    return 'Your account at $url could not be authenticated. Please try logging in again or use another account.';
+  }
+
   @override
   String get errorInvalidResponse => 'The server sent an invalid response';
 

lib/log.dart

@@ -31,7 +31,8 @@ bool debugLog(String message) {
   return true;
 }
 
-typedef ReportErrorCallback = void Function(String? message, {String? details});
+typedef ReportErrorCancellablyCallback = void Function(String? message, {String? details});
+typedef ReportErrorCallback = void Function(String message, {String? details});
 
 /// Show the user an error message, without requiring them to interact with it.
 ///
@@ -48,9 +49,20 @@ typedef ReportErrorCallback = void Function(String? message, {String? details});
 // This gets set in [ZulipApp].  We need this indirection to keep `lib/log.dart`
 // from importing widget code, because the file is a dependency for the rest of
 // the app.
-ReportErrorCallback reportErrorToUserBriefly = defaultReportErrorToUserBriefly;
+ReportErrorCancellablyCallback reportErrorToUserBriefly = reportErrorToConsole;
 
-void defaultReportErrorToUserBriefly(String? message, {String? details}) {
+/// Show the user a dismissable error message in a modal popup.
+///
+/// Typically this shows a [AlertDialog] containing the message.
+/// If called before the app's widget tree is ready (see [ZulipApp.ready]),
+/// then we give up on showing the message to the user,
+/// and just log the message to the console.
+// This gets set in [ZulipApp].  We need this indirection to keep `lib/log.dart`
+// from importing widget code, because the file is a dependency for the rest of
+// the app.
+ReportErrorCallback reportErrorToUserModally = reportErrorToConsole;
+
+void reportErrorToConsole(String? message, {String? details}) {
   // Error dismissing is a no-op to the default handler.
   if (message == null) return;
   // If this callback is still in place, then the app's widget tree

lib/model/store.dart

@@ -19,6 +19,7 @@ import '../api/backoff.dart';
 import '../api/route/realm.dart';
 import '../log.dart';
 import '../notifications/receive.dart';
+import '../widgets/actions.dart';
 import 'autocomplete.dart';
 import 'database.dart';
 import 'emoji.dart';
@@ -149,13 +150,31 @@ abstract class GlobalStore extends ChangeNotifier {
   /// and/or [perAccountSync].
   Future<PerAccountStore> loadPerAccount(int accountId) async {
     assert(_accounts.containsKey(accountId));
-    final store = await doLoadPerAccount(accountId);
+    PerAccountStore? store;
+    try {
+      store = await doLoadPerAccount(accountId);
+    } catch (e) {
+      switch (e) {
+        case ZulipApiException(code: 'INVALID_API_KEY'):
+          // The API key is invalid and the store can never be loaded
+          // unless the user retries manually.
+          final zulipLocalizations = GlobalLocalizations.zulipLocalizations;
+          final account = getAccount(accountId)!;
+          reportErrorToUserModally(
+            zulipLocalizations.errorCouldNotConnectTitle,
+            details: zulipLocalizations.errorInvalidApiKeyMessage(
+              account.realmUrl.toString()));
+          await logOutAccount(this, accountId);
+        default:
+          rethrow;
+      }
+    }
     if (!_accounts.containsKey(accountId)) {
-      // [removeAccount] was called during [doLoadPerAccount].
-      store.dispose();
+      // [removeAccount] was called during or after [doLoadPerAccount].
+      store?.dispose();
       throw AccountNotFoundException();
     }
-    return store;
+    return store!;
   }
 
   /// Load per-account data for the given account, unconditionally.
@@ -912,7 +931,13 @@ class UpdateMachine {
         // at 1 kiB (at least on Android), and stack can be longer than that.
         assert(debugLog('Stack:\n$s'));
         assert(debugLog('Backing off, then will retry…'));
-        // TODO tell user if initial-fetch errors persist, or look non-transient
+        // TODO(#890): tell user if initial-fetch errors persist, or look non-transient
+        switch (e) {
+          case ZulipApiException(code: 'INVALID_API_KEY'):
+            // We cannot recover from this error through retrying.
+            // Leave it to [GlobalStore.loadPerAccount].
+            rethrow;
+        }
         await (backoffMachine ??= BackoffMachine()).wait();
         assert(debugLog('… Backoff wait complete, retrying initial fetch.'));
       }
@@ -1044,7 +1069,13 @@ class UpdateMachine {
       }
     } catch (e) {
       if (_disposed) return;
-      await _handlePollError(e);
+      try {
+        await _handlePollError(e);
+      } on AccountNotFoundException {
+        // Cannot recover by replacing the store because the account
+        // was logged out.
+        return;
+      }
       assert(_disposed);
       return;
     }

lib/widgets/actions.dart

@@ -20,9 +20,7 @@ import '../notifications/receive.dart';
 import 'dialog.dart';
 import 'store.dart';
 
-Future<void> logOutAccount(BuildContext context, int accountId) async {
-  final globalStore = GlobalStoreWidget.of(context);
-
+Future<void> logOutAccount(GlobalStore globalStore, int accountId) async {
   final account = globalStore.getAccount(accountId);
   if (account == null) return; // TODO(log)
 

lib/widgets/app.dart

@@ -84,7 +84,8 @@ class ZulipApp extends StatefulWidget {
   @visibleForTesting
   static void debugReset() {
     _snackBarCount = 0;
-    reportErrorToUserBriefly = defaultReportErrorToUserBriefly;
+    reportErrorToUserBriefly = reportErrorToConsole;
+    reportErrorToUserModally = reportErrorToConsole;
     _ready.dispose();
     _ready = ValueNotifier(false);
   }
@@ -128,10 +129,21 @@ class ZulipApp extends StatefulWidget {
     newSnackBar.closed.whenComplete(() => _snackBarCount--);
   }
 
+  /// The callback we normally use as [reportErrorToUserModally].
+  static void _reportErrorToUserModally(String message, {String? details}) {
+    assert(_ready.value);
+
+    showErrorDialog(
+      context: navigatorKey.currentContext!,
+      title: message,
+      message: details);
+  }
+
   void _declareReady() {
     assert(navigatorKey.currentContext != null);
     _ready.value = true;
     reportErrorToUserBriefly = _reportErrorToUserBriefly;
+    reportErrorToUserModally = _reportErrorToUserModally;
   }
 
   @override
@@ -177,6 +189,11 @@ class _ZulipAppState extends State<ZulipApp> with WidgetsBindingObserver {
     final themeData = zulipThemeData(context);
     return GlobalStoreWidget(
       child: Builder(builder: (context) {
+        final effectiveNavigatorObservers = [
+          _EmptyStackNavigatorObserver(),
+          if (widget.navigatorObservers != null)
+            ...widget.navigatorObservers!,
+        ];
         final globalStore = GlobalStoreWidget.of(context);
         // TODO(#524) choose initial account as last one used
         final initialAccountId = globalStore.accounts.firstOrNull?.id;
@@ -187,7 +204,7 @@ class _ZulipAppState extends State<ZulipApp> with WidgetsBindingObserver {
           theme: themeData,
 
           navigatorKey: ZulipApp.navigatorKey,
-          navigatorObservers: widget.navigatorObservers ?? const [],
+          navigatorObservers: effectiveNavigatorObservers,
           builder: (BuildContext context, Widget? child) {
             if (!ZulipApp.ready.value) {
               SchedulerBinding.instance.addPostFrameCallback(
@@ -218,6 +235,36 @@ class _ZulipAppState extends State<ZulipApp> with WidgetsBindingObserver {
   }
 }
 
+class _EmptyStackNavigatorObserver extends NavigatorObserver {
+  void _pushIfEmpty() async {
+    final navigator = await ZulipApp.navigator;
+    bool isEmptyStack = true;
+    // TODO: find a better way to inspect the navigator stack
+    navigator.popUntil((route) {
+      isEmptyStack = false;
+      return true; // never actually pops
+    });
+    if (isEmptyStack) {
+      unawaited(navigator.push(
+        MaterialWidgetRoute(page: const ChooseAccountPage())));
+    }
+  }
+
+  @override
+  void didRemove(Route<void> route, Route<void>? previousRoute) async {
+    if (previousRoute == null) {
+      _pushIfEmpty();
+    }
+  }
+
+  @override
+  void didPop(Route<void> route, Route<void>? previousRoute) async {
+    if (previousRoute == null) {
+      _pushIfEmpty();
+    }
+  }
+}
+
 class ChooseAccountPage extends StatelessWidget {
   const ChooseAccountPage({super.key});
 
@@ -249,7 +296,7 @@ class ChooseAccountPage extends StatelessWidget {
                   actionButtonText: zulipLocalizations.logOutConfirmationDialogConfirmButton,
                   onActionButtonPress: () {
                     // TODO error handling if db write fails?
-                    logOutAccount(context, accountId);
+                    logOutAccount(GlobalStoreWidget.of(context), accountId);
                   });
               },
               child: Text(zulipLocalizations.chooseAccountPageLogOutButton)),