fix: smooth social sign-in transitions

Author: jjoonleo

CONTEXT.md

@@ -41,6 +41,14 @@ _Avoid_: Tracking vendor, analytics SDK
 A Product Usage Event that marks completion or failure of a meaningful user workflow step.
 _Avoid_: Tap event, raw navigation log, interaction trace
 
+**Provider Authentication Completed**:
+The state where the external Apple or Google account prompt has returned credentials to OnTime.
+_Avoid_: Login completed, signed in, session ready
+
+**OnTime Session Established**:
+The state where OnTime has accepted provider credentials, created an app session, and can route the user into the signed-in app experience.
+_Avoid_: Provider login completed, credential received
+
 **Analytics Event Parameter**:
 An allowlisted non-content value attached to a Product Usage Event.
 _Avoid_: Event payload, arbitrary metadata, raw detail
@@ -102,6 +110,9 @@ _Avoid_: Notification, native alarm
 - A **Product Usage Event** may describe a schedule, preparation, notification, alarm, onboarding, or account action without storing the user's raw schedule names, notes, place names, credentials, tokens, or free text.
 - First-release **Product Usage Events** are **Workflow Milestone Events**, not every tap or raw navigation step.
 - First-release **Workflow Milestone Events** cover analytics preference, onboarding, authentication, schedule, notification permission, alarm, and schedule-finish outcomes.
+- **Provider Authentication Completed** precedes **OnTime Session Established** during Apple or Google sign-in.
+- **Provider Authentication Completed** does not mean the user is signed in to OnTime.
+- The signed-in app experience begins only after **OnTime Session Established**.
 - A **Product Usage Event** may include **Analytics Event Parameters** such as workflow, result, stable error category, coarse count, coarse duration, platform, or app version.
 - An **Analytics Event Parameter** must not contain user-authored text, direct identifiers, tokens, raw exception strings, request bodies, or response bodies.
 - A **Product Usage Event** uses a stable snake_case name and includes a schema version.
@@ -153,6 +164,7 @@ _Avoid_: Notification, native alarm
 - "Third party" was ambiguous for analytics; resolved: the canonical term is **Analytics Provider**.
 - "Event taxonomy" was broad; resolved: first-release analytics tracks **Workflow Milestone Events** only.
 - "Event payload" was too open-ended; resolved: events use allowlisted **Analytics Event Parameters** only.
+- "Login completed" was ambiguous for Apple and Google sign-in; resolved: external account prompt completion is **Provider Authentication Completed**, while usable OnTime sign-in is **OnTime Session Established**.
 - "Alarm permission" was ambiguous between **Exact Timing Permission** and notification permission; resolved: notification permission may enable a **Fallback Notification**, but does not mean **Exact Timing Permission** is granted.
 - "Pending" was ambiguous for notification status; resolved: the canonical state is **No Scheduled Notification** when notifications are enabled but no upcoming Schedule Notification is armed.
 - "Allowed" was ambiguous for permission requests; resolved: a request action is not the same as granted **Exact Timing Permission**.

lib/l10n/app_en.arb

@@ -123,6 +123,14 @@
     "@signInSlogan": {
         "description": "Slogan on the sign-in screen"
     },
+    "signInFailedTitle": "Sign-in failed",
+    "@signInFailedTitle": {
+        "description": "Dialog title shown when social sign-in fails after provider authentication"
+    },
+    "signInFailedDescription": "Please try again in a moment.",
+    "@signInFailedDescription": {
+        "description": "Dialog description shown when social sign-in fails after provider authentication"
+    },
     "welcome": "Welcome!",
     "@welcome": {
         "description": "Title on the onboarding start screen"

lib/l10n/app_ko.arb

@@ -30,6 +30,8 @@
     "finishPreparation": "준비 종료",
     "preparationReadyToGo": "출발 준비 완료",
     "signInSlogan": "당신의 잃어버린 여유를 찾아드립니다.",
+    "signInFailedTitle": "로그인에 실패했어요",
+    "signInFailedDescription": "잠시 후 다시 시도해 주세요.",
     "welcome": "반가워요!",
     "onboardingStartSubtitle": "Ontime과 함께 준비하기 위해서\n평소 본인의 준비 과정을 알려주세요",
     "start": "시작하기",

lib/l10n/app_localizations.dart

@@ -284,6 +284,18 @@ abstract class AppLocalizations {
   /// **'We\'ll find your lost leisure.'**
   String get signInSlogan;
 
+  /// Dialog title shown when social sign-in fails after provider authentication
+  ///
+  /// In en, this message translates to:
+  /// **'Sign-in failed'**
+  String get signInFailedTitle;
+
+  /// Dialog description shown when social sign-in fails after provider authentication
+  ///
+  /// In en, this message translates to:
+  /// **'Please try again in a moment.'**
+  String get signInFailedDescription;
+
   /// Title on the onboarding start screen
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_en.dart

@@ -107,6 +107,12 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get signInSlogan => 'We\'ll find your lost leisure.';
 
+  @override
+  String get signInFailedTitle => 'Sign-in failed';
+
+  @override
+  String get signInFailedDescription => 'Please try again in a moment.';
+
   @override
   String get welcome => 'Welcome!';
 

lib/l10n/app_localizations_ko.dart

@@ -105,6 +105,12 @@ class AppLocalizationsKo extends AppLocalizations {
   @override
   String get signInSlogan => '당신의 잃어버린 여유를 찾아드립니다.';
 
+  @override
+  String get signInFailedTitle => '로그인에 실패했어요';
+
+  @override
+  String get signInFailedDescription => '잠시 후 다시 시도해 주세요.';
+
   @override
   String get welcome => '반가워요!';
 

lib/presentation/login/components/google_sign_in_button/apple_sign_in_button_mobile.dart

@@ -1,67 +1,19 @@
 import 'package:flutter/material.dart' hide IconAlignment;
-import 'package:on_time_front/core/di/di_setup.dart';
-import 'package:on_time_front/core/dio/api_error_message.dart';
-import 'package:on_time_front/core/logging/app_logger.dart';
-import 'package:on_time_front/domain/repositories/user_repository.dart';
-import 'package:sign_in_with_apple/sign_in_with_apple.dart';
 
 class AppleSignInButton extends StatelessWidget {
-  const AppleSignInButton({super.key});
+  const AppleSignInButton({super.key, this.onPressed});
+
+  final VoidCallback? onPressed;
 
   @override
   Widget build(BuildContext context) {
-    final UserRepository userRepository = getIt.get<UserRepository>();
-
     return SizedBox(
       width: 358,
       height: 54,
       child: Material(
         color: Colors.transparent,
         child: InkWell(
-          onTap: () async {
-            try {
-              final credential = await SignInWithApple.getAppleIDCredential(
-                scopes: [
-                  AppleIDAuthorizationScopes.email,
-                  AppleIDAuthorizationScopes.fullName,
-                ],
-              );
-
-              final fullNameRaw =
-                  '${credential.givenName ?? ''} ${credential.familyName ?? ''}'
-                      .trim();
-              final fullName = fullNameRaw.isNotEmpty
-                  ? fullNameRaw
-                  : 'Apple User';
-
-              final identityToken = credential.identityToken;
-              final authorizationCode = credential.authorizationCode;
-              if (identityToken == null) {
-                throw Exception('Apple Sign In Failed: Missing credentials');
-              }
-
-              await userRepository.signInWithApple(
-                idToken: identityToken,
-                authCode: authorizationCode,
-                fullName: fullName,
-                email: credential.email,
-              );
-            } catch (error, stackTrace) {
-              AppLogger.debug(
-                'Apple Sign-In button failed errorType=${error.runtimeType} '
-                'message=$error stackTrace=$stackTrace',
-              );
-              if (!context.mounted) {
-                return;
-              }
-              final message =
-                  ApiErrorMessage.fromException(error) ??
-                  'Apple 로그인에 실패했습니다. 잠시 후 다시 시도해 주세요.';
-              ScaffoldMessenger.of(
-                context,
-              ).showSnackBar(SnackBar(content: Text(message)));
-            }
-          },
+          onTap: onPressed,
           borderRadius: BorderRadius.circular(14),
           child: Image.asset(
             'appleid_button.png',

lib/presentation/login/components/google_sign_in_button/google_sign_in_button_mobile.dart

@@ -1,61 +1,26 @@
 import 'package:flutter/material.dart';
-import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_svg/svg.dart';
-import 'package:on_time_front/core/di/di_setup.dart';
-import 'package:on_time_front/core/logging/app_logger.dart';
-import 'package:on_time_front/domain/repositories/user_repository.dart';
-import 'package:on_time_front/presentation/app/bloc/auth/auth_bloc.dart';
 
-class GoogleSignInButton extends StatefulWidget {
-  const GoogleSignInButton({super.key});
+class GoogleSignInButton extends StatelessWidget {
+  const GoogleSignInButton({super.key, this.onPressed});
 
-  @override
-  State<GoogleSignInButton> createState() => _GoogleSignInButtonState();
-}
-
-class _GoogleSignInButtonState extends State<GoogleSignInButton> {
-  bool _isSigningIn = false;
+  final VoidCallback? onPressed;
 
   @override
   Widget build(BuildContext context) {
-    final UserRepository authenticationRepository = getIt.get<UserRepository>();
-    final canSignIn = context.select<AuthBloc, bool>(
-      (bloc) => bloc.state.status == AuthStatus.unauthenticated,
-    );
-
     return SizedBox(
       width: 358,
       height: 54,
       child: ElevatedButton(
-        onPressed: !canSignIn || _isSigningIn
-            ? null
-            : () async {
-                setState(() {
-                  _isSigningIn = true;
-                });
-                try {
-                  final googleAccount = await authenticationRepository
-                      .authenticateWithGoogle();
-                  await authenticationRepository.signInWithGoogle(
-                    googleAccount,
-                  );
-                } catch (error) {
-                  AppLogger.debug(
-                    'Google Sign-In button failed errorType=${error.runtimeType}',
-                  );
-                } finally {
-                  if (mounted) {
-                    setState(() {
-                      _isSigningIn = false;
-                    });
-                  }
-                }
-              },
+        onPressed: onPressed,
         style: ElevatedButton.styleFrom(
           backgroundColor: Colors.white,
+          disabledBackgroundColor: Colors.white,
           foregroundColor: Colors.black,
+          disabledForegroundColor: Colors.black,
           elevation: 1,
           shadowColor: Colors.black26,
+          disabledMouseCursor: SystemMouseCursors.basic,
           shape: RoundedRectangleBorder(
             borderRadius: BorderRadius.circular(14),
             side: BorderSide(color: Color(0xFFDADCE0), width: 1),
@@ -74,15 +39,19 @@ class _GoogleSignInButtonState extends State<GoogleSignInButton> {
               height: 20,
             ),
             SizedBox(width: 10),
-            Text(
-              'Sign in with Google',
-              style: TextStyle(
-                fontFamily: 'Pretendard',
-                fontWeight: FontWeight.w600,
-                fontSize: 21,
-                height: 1.4,
-                letterSpacing: 0,
-                color: Colors.black87,
+            Flexible(
+              child: Text(
+                'Sign in with Google',
+                maxLines: 1,
+                overflow: TextOverflow.ellipsis,
+                style: TextStyle(
+                  fontFamily: 'Pretendard',
+                  fontWeight: FontWeight.w600,
+                  fontSize: 21,
+                  height: 1.4,
+                  letterSpacing: 0,
+                  color: Colors.black87,
+                ),
               ),
             ),
           ],

lib/presentation/login/components/google_sign_in_button/google_sign_in_button_web.dart

@@ -7,7 +7,9 @@ import 'package:on_time_front/core/di/di_setup.dart';
 import 'package:on_time_front/domain/repositories/user_repository.dart';
 
 class GoogleSignInButton extends StatefulWidget {
-  const GoogleSignInButton({super.key});
+  const GoogleSignInButton({super.key, this.onPressed});
+
+  final VoidCallback? onPressed;
 
   @override
   State<GoogleSignInButton> createState() => _GoogleSignInButtonState();

lib/presentation/login/components/google_sign_in_button/unsupported.dart

@@ -1,7 +1,9 @@
 import 'package:flutter/widgets.dart';
 
 class GoogleSignInButton extends StatelessWidget {
-  const GoogleSignInButton({super.key});
+  const GoogleSignInButton({super.key, this.onPressed});
+
+  final VoidCallback? onPressed;
 
   @override
   Widget build(BuildContext context) {