Fix account settings and add seamless deletion and recovery

app/lib/auth/auth_api_client.dart

@@ -13,8 +13,15 @@ class AuthApiException implements Exception {
   final String message;
   final String? code;
   final Duration? retryAfter;
+  final AccountDeletionAuthorization? recoveryAuthorization;
 
-  const AuthApiException({required this.statusCode, required this.message, this.code, this.retryAfter});
+  const AuthApiException({
+    required this.statusCode,
+    required this.message,
+    this.code,
+    this.retryAfter,
+    this.recoveryAuthorization,
+  });
 
   @override
   String toString() => message;
@@ -129,6 +136,28 @@ class AuthApiClient {
     return PapyrusUser.fromJson(json);
   }
 
+  Future<DateTime> deleteAccount(String accessToken) async {
+    final json = await _postJson(config.endpoint('/account-deletion/current'), accessToken: accessToken);
+    return DateTime.parse(json['deletion_due_at'] as String);
+  }
+
+  Future<AuthTokens> recoverAccount(
+    AccountDeletionAuthorization authorization, {
+    required String clientType,
+    String? deviceLabel,
+  }) async {
+    final json = await _postJson(
+      config.endpoint('/account-deletion/cancel'),
+      body: {
+        'authorization_token': authorization.token,
+        'client_type': clientType,
+        'device_label': deviceLabel,
+      },
+    );
+
+    return AuthTokens.fromJson(json);
+  }
+
   Future<String> forgotPassword(String email) async {
     final json = await _postJson(config.endpoint('/auth/forgot-password'), body: {'email': email});
     return json['message'] as String? ?? 'If the email is registered, a reset link has been sent';
@@ -276,6 +305,9 @@ class AuthApiClient {
       throw AuthApiException(
         statusCode: response.statusCode,
         code: error['code'] as String?,
+        recoveryAuthorization: error['code'] == 'ACCOUNT_DELETION_PENDING'
+            ? AccountDeletionAuthorization.fromJson(error['details']['authorization'] as Map<String, dynamic>)
+            : null,
         message: error['message'] as String? ?? 'Authentication request failed',
       );
     }

app/lib/auth/auth_models.dart

@@ -8,6 +8,7 @@ class PapyrusUser {
   final bool emailVerified;
   final DateTime? createdAt;
   final DateTime? lastLoginAt;
+  final List<String> connectedProviders;
 
   const PapyrusUser({
     required this.userId,
@@ -17,6 +18,7 @@ class PapyrusUser {
     required this.emailVerified,
     required this.createdAt,
     required this.lastLoginAt,
+    this.connectedProviders = const [],
   });
 
   factory PapyrusUser.fromJson(Map<String, dynamic> json) {
@@ -28,6 +30,7 @@ class PapyrusUser {
       emailVerified: json['email_verified'] as bool? ?? false,
       createdAt: _parseDateTime(json['created_at']),
       lastLoginAt: _parseDateTime(json['last_login_at']),
+      connectedProviders: List<String>.unmodifiable(json['connected_providers'] as List),
     );
   }
 }
@@ -76,3 +79,32 @@ DateTime? _parseDateTime(Object? value) {
 
   return DateTime.tryParse(value);
 }
+
+class AccountDeletionAuthorization {
+  final String token;
+  final String userId;
+  final String? email;
+  final bool deletionPending;
+  final DateTime deletionDueAt;
+  final DateTime expiresAt;
+
+  const AccountDeletionAuthorization({
+    required this.token,
+    required this.userId,
+    required this.email,
+    required this.deletionPending,
+    required this.deletionDueAt,
+    required this.expiresAt,
+  });
+
+  factory AccountDeletionAuthorization.fromJson(Map<String, dynamic> json) {
+    return AccountDeletionAuthorization(
+      token: json['authorization_token'] as String,
+      userId: json['user_id'] as String,
+      email: json['email'] as String?,
+      deletionPending: json['deletion_pending'] as bool,
+      deletionDueAt: DateTime.parse(json['deletion_due_at'] as String),
+      expiresAt: DateTime.parse(json['expires_at'] as String),
+    );
+  }
+}

app/lib/auth/auth_repository.dart

@@ -16,6 +16,7 @@ class AuthRepository {
   final TokenStore tokenStore;
 
   Future<AuthTokens>? _refreshOperation;
+  int _tokenGeneration = 0;
 
   AuthRepository({required this.apiClient, required this.tokenStore});
 
@@ -79,6 +80,8 @@ class AuthRepository {
   }
 
   Future<AuthTokens> _refresh() async {
+    final generation = _tokenGeneration;
+
     try {
       final refreshToken = await tokenStore.readRefreshToken();
 
@@ -87,10 +90,18 @@ class AuthRepository {
       }
 
       final tokens = await apiClient.refresh(refreshToken);
+
+      if (generation != _tokenGeneration) {
+        throw const AuthApiException(statusCode: 401, message: 'Session has ended');
+      }
+
       await _save(tokens);
       return tokens;
     } catch (_) {
-      await tokenStore.clear();
+      if (generation == _tokenGeneration) {
+        await tokenStore.clear();
+      }
+
       rethrow;
     } finally {
       _refreshOperation = null;
@@ -141,6 +152,29 @@ class AuthRepository {
     return tokens;
   }
 
+  Future<DateTime> deleteAccount() => _withFreshAccessToken(apiClient.deleteAccount);
+
+  Future<AuthTokens> recoverAccount(
+    AccountDeletionAuthorization authorization, {
+    required String clientType,
+    String? deviceLabel,
+  }) async {
+    final generation = _tokenGeneration;
+
+    final tokens = await apiClient.recoverAccount(
+      authorization,
+      clientType: clientType,
+      deviceLabel: deviceLabel,
+    );
+
+    if (generation != _tokenGeneration) {
+      throw const AuthApiException(statusCode: 401, message: 'Session changed. Please sign in again.');
+    }
+
+    await _save(tokens);
+    return tokens;
+  }
+
   Future<void> logout() async {
     final accessToken = tokenStore.accessToken;
 
@@ -216,6 +250,7 @@ class AuthRepository {
   }
 
   Future<void> clearTokens() {
+    _tokenGeneration += 1;
     return tokenStore.clear();
   }
 

app/lib/pages/auth/oauth_callback_page.dart

@@ -1,6 +1,8 @@
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:papyrus/providers/auth_provider.dart';
+import 'package:papyrus/platform/web_redirect.dart';
+import 'package:papyrus/widgets/profile/account_deletion_dialog.dart';
 import 'package:papyrus/themes/design_tokens.dart';
 import 'package:provider/provider.dart';
 import 'package:papyrus/widgets/shared/app_progress_indicator.dart';
@@ -16,6 +18,7 @@ class OAuthCallbackPage extends StatefulWidget {
 
 class _OAuthCallbackPageState extends State<OAuthCallbackPage> {
   String? _errorMessage;
+  bool _showingConfirmation = false;
 
   @override
   void initState() {
@@ -25,6 +28,8 @@ class _OAuthCallbackPageState extends State<OAuthCallbackPage> {
 
   Future<void> _completeSignIn() async {
     final authProvider = context.read<AuthProvider>();
+    clearBrowserQuery();
+
     final success = await authProvider.completeGoogleSignIn(widget.callbackUri);
 
     if (!mounted) {
@@ -36,6 +41,19 @@ class _OAuthCallbackPageState extends State<OAuthCallbackPage> {
       return;
     }
 
+    final recovery = authProvider.takePendingRecovery();
+
+    if (recovery != null) {
+      setState(() => _showingConfirmation = true);
+      await showAccountDeletionDialog(context, authorization: recovery);
+
+      if (mounted && !authProvider.isSignedIn) {
+        context.go('/login');
+      }
+
+      return;
+    }
+
     setState(() {
       _errorMessage = authProvider.error ?? 'Google sign-in failed.';
     });
@@ -45,6 +63,18 @@ class _OAuthCallbackPageState extends State<OAuthCallbackPage> {
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
 
+    if (_showingConfirmation) {
+      return Scaffold(
+        body: SizedBox.expand(
+          child: Image.asset(
+            'assets/images/welcome-illustration.png',
+            fit: BoxFit.cover,
+            excludeFromSemantics: true,
+          ),
+        ),
+      );
+    }
+
     return Scaffold(
       body: Center(
         child: Padding(

app/lib/pages/login_page.dart

@@ -5,6 +5,7 @@ import 'package:papyrus/providers/auth_provider.dart';
 import 'package:papyrus/themes/design_tokens.dart';
 import 'package:papyrus/utils/responsive.dart';
 import 'package:papyrus/widgets/auth/auth_continue_button.dart';
+import 'package:papyrus/widgets/profile/account_deletion_dialog.dart';
 import 'package:papyrus/widgets/auth/auth_page_layouts.dart';
 import 'package:papyrus/widgets/auth/auth_switch_link.dart';
 import 'package:papyrus/widgets/buttons/google_sign_in.dart';
@@ -64,6 +65,15 @@ class _LoginPageState extends State<LoginPage> {
       }
 
       if (!success) {
+        final recovery = context.read<AuthProvider>().takePendingRecovery();
+
+        if (recovery != null) {
+          _passwordController.clear();
+          setState(() => _isLoading = false);
+          await showAccountDeletionDialog(context, authorization: recovery);
+          return;
+        }
+
         _showErrorSnackBar(context.read<AuthProvider>().error ?? 'Incorrect email or password.');
         return;
       }

app/lib/platform/web_redirect_stub.dart

@@ -1,3 +1,5 @@
 void redirectTo(String url) {
   throw UnsupportedError('Browser redirects are only available on web');
 }
+
+void clearBrowserQuery() {}

app/lib/platform/web_redirect_web.dart

@@ -3,3 +3,7 @@ import 'package:web/web.dart' as web;
 void redirectTo(String url) {
   web.window.location.assign(url);
 }
+
+void clearBrowserQuery() {
+  web.window.history.replaceState(null, '', web.window.location.pathname);
+}