feat(preparation-edit): implement PreparationEditDraftCubit for managing draft state in preparation editing flow

Author: jjoonleo

lib/presentation/schedule_create/schedule_spare_and_preparing_time/preparation_form/cubit/preparation_edit_draft_cubit.dart

@@ -0,0 +1,18 @@
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:injectable/injectable.dart';
+import 'package:on_time_front/domain/entities/preparation_entity.dart';
+
+/// Shared draft state for the `/preparationEdit` flow.
+///
+/// The caller sets a draft before navigating. The editor overwrites it on Save.
+/// The caller reads it after pop and then clears it.
+@LazySingleton()
+class PreparationEditDraftCubit extends Cubit<PreparationEntity?> {
+  PreparationEditDraftCubit() : super(null);
+
+  void setDraft(PreparationEntity draft) => emit(draft);
+
+  void clear() => emit(null);
+}
+
+

lib/presentation/schedule_create/schedule_spare_and_preparing_time/preparation_form/screens/preparation_edit_form.dart

@@ -4,13 +4,12 @@ import 'package:go_router/go_router.dart';
 import 'package:on_time_front/core/di/di_setup.dart';
 import 'package:on_time_front/domain/entities/preparation_entity.dart';
 import 'package:on_time_front/presentation/schedule_create/schedule_spare_and_preparing_time/preparation_form/bloc/preparation_form_bloc.dart';
+import 'package:on_time_front/presentation/schedule_create/schedule_spare_and_preparing_time/preparation_form/cubit/preparation_edit_draft_cubit.dart';
 import 'package:on_time_front/presentation/schedule_create/components/top_bar.dart';
 import 'package:on_time_front/presentation/schedule_create/schedule_spare_and_preparing_time/preparation_form/components/preparation_form_create_list.dart';
 
 class PreparationEditForm extends StatefulWidget {
-  const PreparationEditForm({super.key, required this.preparationEntity});
-
-  final PreparationEntity preparationEntity;
+  const PreparationEditForm({super.key});
 
   @override
   State<PreparationEditForm> createState() => _PreparationEditFormState();
@@ -24,20 +23,25 @@ class _PreparationEditFormState extends State<PreparationEditForm> {
 
   @override
   Widget build(BuildContext context) {
+    final draft = getIt.get<PreparationEditDraftCubit>().state ??
+        const PreparationEntity(preparationStepList: []);
+
     return Scaffold(
       body: SafeArea(
         child: BlocProvider<PreparationFormBloc>(
           create: (context) => getIt.get<PreparationFormBloc>()
-            ..add(PreparationFormEditRequested(
-                preparationEntity: widget.preparationEntity)),
+            ..add(PreparationFormEditRequested(preparationEntity: draft)),
           child: BlocBuilder<PreparationFormBloc, PreparationFormState>(
             builder: (context, state) {
               return Column(
                 children: [
                   TopBar(
                     onNextPageButtonClicked: state.isValid
                         ? () {
-                            context.pop(state.toPreparationEntity());
+                            getIt
+                                .get<PreparationEditDraftCubit>()
+                                .setDraft(state.toPreparationEntity());
+                            context.pop();
                           }
                         : null,
                     onPreviousPageButtonClicked: context.pop,

lib/presentation/schedule_create/schedule_spare_and_preparing_time/screens/schedule_spare_and_preparing_time_form.dart

@@ -2,8 +2,10 @@ import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:go_router/go_router.dart';
 import 'package:on_time_front/domain/entities/preparation_entity.dart';
+import 'package:on_time_front/core/di/di_setup.dart';
 import 'package:on_time_front/presentation/app/bloc/auth/auth_bloc.dart';
 import 'package:on_time_front/presentation/schedule_create/schedule_spare_and_preparing_time/cubit/schedule_form_spare_time_cubit.dart';
+import 'package:on_time_front/presentation/schedule_create/schedule_spare_and_preparing_time/preparation_form/cubit/preparation_edit_draft_cubit.dart';
 import 'package:on_time_front/presentation/shared/components/cupertino_picker_modal.dart';
 import 'package:on_time_front/l10n/app_localizations.dart';
 import 'package:on_time_front/presentation/shared/utils/duration_format.dart';
@@ -46,15 +48,25 @@ class _ScheduleSpareAndPreparingTimeFormState
                     controller: TextEditingController(
                         text: formatDuration(
                             context, state.totalPreparationTime)),
-                    onTap: () async {
-                      final PreparationEntity? updatedPreparation =
-                          await context.push('/preparationEdit',
-                              extra: state.preparation);
-                      if (updatedPreparation != null) {
-                        context
-                            .read<ScheduleFormSpareTimeCubit>()
-                            .preparationChanged(updatedPreparation);
-                      }
+                    onTap: () {
+                      final draftCubit = getIt.get<PreparationEditDraftCubit>();
+                      final scheduleSpareTimeCubit =
+                          context.read<ScheduleFormSpareTimeCubit>();
+                      final before = state.preparation ??
+                          const PreparationEntity(preparationStepList: []);
+
+                      draftCubit.setDraft(before);
+                      context.push('/preparationEdit').then((_) {
+                        if (!mounted) return;
+
+                        final after = draftCubit.state;
+                        if (after != null && after != before) {
+                          scheduleSpareTimeCubit.preparationChanged(after);
+                        }
+
+                        // Avoid stale drafts leaking into the next edit session.
+                        draftCubit.clear();
+                      });
                     },
                   ),
                   onSaved: (value) {},

lib/presentation/shared/router/go_router.dart

@@ -5,8 +5,6 @@ import 'package:go_router/go_router.dart';
 import 'package:on_time_front/core/di/di_setup.dart';
 import 'package:on_time_front/core/services/navigation_service.dart';
 import 'package:on_time_front/core/services/notification_service.dart';
-import 'package:on_time_front/domain/entities/preparation_entity.dart';
-import 'package:on_time_front/domain/entities/schedule_entity.dart';
 import 'package:on_time_front/presentation/alarm/screens/alarm_screen.dart';
 import 'package:on_time_front/presentation/alarm/screens/schedule_start_screen.dart';
 import 'package:on_time_front/presentation/app/bloc/auth/auth_bloc.dart';
@@ -112,9 +110,7 @@ GoRouter goRouterConfig(AuthBloc authBloc, ScheduleBloc scheduleBloc) {
               scheduleId: state.pathParameters['scheduleId']!)),
       GoRoute(
           path: '/preparationEdit',
-          builder: (context, state) => PreparationEditForm(
-              preparationEntity: (state.extra as PreparationEntity?) ??
-                  const PreparationEntity(preparationStepList: []))),
+          builder: (context, state) => const PreparationEditForm()),
       GoRoute(
         path: '/scheduleStart',
         name: 'scheduleStart',