feat: implement idempotency key for critical API endpoints

lib/application/void/void_form/void_form_bloc.dart

@@ -3,6 +3,7 @@ import 'package:collection/collection.dart';
 import 'package:dartz/dartz.dart' hide Order;
 import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:injectable/injectable.dart' hide Order;
+import 'package:uuid/uuid.dart';
 
 import '../../../common/types/void_type.dart';
 import '../../../domain/order/order.dart';
@@ -105,13 +106,22 @@ class VoidFormBloc extends Bloc<VoidFormEvent, VoidFormState> {
           });
         }
 
-        emit(state.copyWith(isSubmitting: true, failureOrVoid: none()));
+        // Generate new idempotency key saat user intent (tap Void)
+        // Kalau sedang retry, pakai key yang sama
+        final idempotencyKey = state.idempotencyKey ?? const Uuid().v4();
+
+        emit(state.copyWith(
+          isSubmitting: true,
+          failureOrVoid: none(),
+          idempotencyKey: idempotencyKey,
+        ));
 
         failureOrVoid = await _repository.voidOrder(
           orderId: state.order.id,
           reason: state.voidReason ?? '',
           orderItems: voidItems,
           type: state.voidType.toStringType(),
+          idempotencyKey: idempotencyKey,
         );
 
         emit(
@@ -119,6 +129,8 @@ class VoidFormBloc extends Bloc<VoidFormEvent, VoidFormState> {
             isSubmitting: false,
             failureOrVoid: optionOf(failureOrVoid),
             voidItems: state.voidType.isItem ? voidItems : state.pendingItems,
+            // Clear key on success, keep on failure for retry
+            idempotencyKey: failureOrVoid.isRight() ? null : idempotencyKey,
           ),
         );
       },

lib/application/void/void_form/void_form_bloc.freezed.dart

@@ -1256,6 +1256,11 @@ mixin _$VoidFormState {
       throw _privateConstructorUsedError;
   bool get isSubmitting => throw _privateConstructorUsedError;
 
+  /// Idempotency key untuk void submission.
+  /// Di-generate saat user tap "Void", dipakai ulang saat retry,
+  /// di-clear setelah sukses atau clearState.
+  String? get idempotencyKey => throw _privateConstructorUsedError;
+
   /// Create a copy of VoidFormState
   /// with the given fields replaced by the non-null parameter values.
   @JsonKey(includeFromJson: false, includeToJson: false)
@@ -1280,6 +1285,7 @@ abstract class $VoidFormStateCopyWith<$Res> {
     int totalPriceVoid,
     Option<Either<OrderFailure, Unit>> failureOrVoid,
     bool isSubmitting,
+    String? idempotencyKey,
   });
 
   $OrderCopyWith<$Res> get order;
@@ -1309,6 +1315,7 @@ class _$VoidFormStateCopyWithImpl<$Res, $Val extends VoidFormState>
     Object? totalPriceVoid = null,
     Object? failureOrVoid = null,
     Object? isSubmitting = null,
+    Object? idempotencyKey = freezed,
   }) {
     return _then(
       _value.copyWith(
@@ -1348,6 +1355,10 @@ class _$VoidFormStateCopyWithImpl<$Res, $Val extends VoidFormState>
                 ? _value.isSubmitting
                 : isSubmitting // ignore: cast_nullable_to_non_nullable
                       as bool,
+            idempotencyKey: freezed == idempotencyKey
+                ? _value.idempotencyKey
+                : idempotencyKey // ignore: cast_nullable_to_non_nullable
+                      as String?,
           )
           as $Val,
     );
@@ -1383,6 +1394,7 @@ abstract class _$$VoidFormStateImplCopyWith<$Res>
     int totalPriceVoid,
     Option<Either<OrderFailure, Unit>> failureOrVoid,
     bool isSubmitting,
+    String? idempotencyKey,
   });
 
   @override
@@ -1412,6 +1424,7 @@ class __$$VoidFormStateImplCopyWithImpl<$Res>
     Object? totalPriceVoid = null,
     Object? failureOrVoid = null,
     Object? isSubmitting = null,
+    Object? idempotencyKey = freezed,
   }) {
     return _then(
       _$VoidFormStateImpl(
@@ -1451,6 +1464,10 @@ class __$$VoidFormStateImplCopyWithImpl<$Res>
             ? _value.isSubmitting
             : isSubmitting // ignore: cast_nullable_to_non_nullable
                   as bool,
+        idempotencyKey: freezed == idempotencyKey
+            ? _value.idempotencyKey
+            : idempotencyKey // ignore: cast_nullable_to_non_nullable
+                  as String?,
       ),
     );
   }
@@ -1469,6 +1486,7 @@ class _$VoidFormStateImpl implements _VoidFormState {
     required this.totalPriceVoid,
     required this.failureOrVoid,
     this.isSubmitting = false,
+    this.idempotencyKey,
   }) : _pendingItems = pendingItems,
        _voidItems = voidItems,
        _selectedItemQuantities = selectedItemQuantities;
@@ -1512,9 +1530,15 @@ class _$VoidFormStateImpl implements _VoidFormState {
   @JsonKey()
   final bool isSubmitting;
 
+  /// Idempotency key untuk void submission.
+  /// Di-generate saat user tap "Void", dipakai ulang saat retry,
+  /// di-clear setelah sukses atau clearState.
+  @override
+  final String? idempotencyKey;
+
   @override
   String toString() {
-    return 'VoidFormState(order: $order, pendingItems: $pendingItems, voidItems: $voidItems, voidType: $voidType, selectedItemQuantities: $selectedItemQuantities, voidReason: $voidReason, totalPriceVoid: $totalPriceVoid, failureOrVoid: $failureOrVoid, isSubmitting: $isSubmitting)';
+    return 'VoidFormState(order: $order, pendingItems: $pendingItems, voidItems: $voidItems, voidType: $voidType, selectedItemQuantities: $selectedItemQuantities, voidReason: $voidReason, totalPriceVoid: $totalPriceVoid, failureOrVoid: $failureOrVoid, isSubmitting: $isSubmitting, idempotencyKey: $idempotencyKey)';
   }
 
   @override
@@ -1544,7 +1568,9 @@ class _$VoidFormStateImpl implements _VoidFormState {
             (identical(other.failureOrVoid, failureOrVoid) ||
                 other.failureOrVoid == failureOrVoid) &&
             (identical(other.isSubmitting, isSubmitting) ||
-                other.isSubmitting == isSubmitting));
+                other.isSubmitting == isSubmitting) &&
+            (identical(other.idempotencyKey, idempotencyKey) ||
+                other.idempotencyKey == idempotencyKey));
   }
 
   @override
@@ -1559,6 +1585,7 @@ class _$VoidFormStateImpl implements _VoidFormState {
     totalPriceVoid,
     failureOrVoid,
     isSubmitting,
+    idempotencyKey,
   );
 
   /// Create a copy of VoidFormState
@@ -1581,6 +1608,7 @@ abstract class _VoidFormState implements VoidFormState {
     required final int totalPriceVoid,
     required final Option<Either<OrderFailure, Unit>> failureOrVoid,
     final bool isSubmitting,
+    final String? idempotencyKey,
   }) = _$VoidFormStateImpl;
 
   @override
@@ -1602,6 +1630,12 @@ abstract class _VoidFormState implements VoidFormState {
   @override
   bool get isSubmitting;
 
+  /// Idempotency key untuk void submission.
+  /// Di-generate saat user tap "Void", dipakai ulang saat retry,
+  /// di-clear setelah sukses atau clearState.
+  @override
+  String? get idempotencyKey;
+
   /// Create a copy of VoidFormState
   /// with the given fields replaced by the non-null parameter values.
   @override

lib/application/void/void_form/void_form_state.dart

@@ -12,6 +12,10 @@ class VoidFormState with _$VoidFormState {
     required int totalPriceVoid,
     required Option<Either<OrderFailure, Unit>> failureOrVoid,
     @Default(false) bool isSubmitting,
+    /// Idempotency key untuk void submission.
+    /// Di-generate saat user tap "Void", dipakai ulang saat retry,
+    /// di-clear setelah sukses atau clearState.
+    String? idempotencyKey,
   }) = _VoidFormState;
 
   factory VoidFormState.initial() => VoidFormState(