feat(buy/sell): explicit price provider (Aktionariat) message on outage

assets/languages/strings_de.arb

@@ -194,6 +194,8 @@
   "portfolio": "Bestand",
   "portfolioDevelopment": "Bestandsentwicklung",
   "postcodeAbr": "PLZ",
+  "priceProviderUnavailableDescription": "Der externe Kursanbieter Aktionariat liefert aktuell keine Kurse. Das Problem liegt bei Aktionariat – nicht bei RealUnit oder der App. Sobald Aktionariat wieder Kurse liefert, funktioniert alles automatisch. Bitte später erneut versuchen.",
+  "priceProviderUnavailableTitle": "Problem beim Kursanbieter (Aktionariat)",
   "proofDocument": "Nachweis-Dokument",
   "purposeOfPayment": "Verwendungszweck",
   "qrCode": "QR-Code",

assets/languages/strings_en.arb

@@ -194,6 +194,8 @@
   "portfolio": "Portfolio",
   "portfolioDevelopment": "Portfolio development",
   "postcodeAbr": "Post code",
+  "priceProviderUnavailableDescription": "The external price provider Aktionariat is currently not delivering prices. The problem is on Aktionariat's side, not with RealUnit or the app. Everything will work again automatically as soon as Aktionariat delivers prices. Please try again later.",
+  "priceProviderUnavailableTitle": "Problem with the price provider (Aktionariat)",
   "proofDocument": "Proof document",
   "purposeOfPayment": "Purpose of payment",
   "qrCode": "QR code",

lib/packages/service/dfx/models/payment/payment_info_error.dart

@@ -3,5 +3,6 @@ enum PaymentInfoError {
   kycRequired,
   minAmountNotMet,
   bitboxDisconnected,
+  priceSourceUnavailable,
   unknown,
 }

lib/screens/buy/cubits/buy_payment_info/buy_payment_info_cubit.dart

@@ -3,6 +3,7 @@ import 'dart:developer' as developer;
 import 'package:async/async.dart';
 import 'package:equatable/equatable.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:realunit_wallet/packages/service/dfx/exceptions/api_exception.dart';
 import 'package:realunit_wallet/packages/service/dfx/exceptions/bitbox_exception.dart';
 import 'package:realunit_wallet/packages/service/dfx/exceptions/payment/buy_exceptions.dart';
 import 'package:realunit_wallet/packages/service/dfx/models/payment/buy/buy_payment_info.dart';
@@ -80,6 +81,16 @@ class BuyPaymentInfoCubit extends Cubit<BuyPaymentInfoState> {
       );
     } on BitboxNotConnectedException {
       return const BuyPaymentInfoFailure(PaymentInfoError.bitboxDisconnected);
+    } on ApiException catch (e) {
+      // 503 / PRICE_SOURCE_UNAVAILABLE means the external price provider
+      // (Aktionariat) is down, so no quote can be built — surface that
+      // explicitly instead of a generic failure. Must stay below the
+      // KYC/Registration clauses (those are ApiException subclasses).
+      if (e.statusCode == 503 || e.code == 'PRICE_SOURCE_UNAVAILABLE') {
+        return const BuyPaymentInfoFailure(PaymentInfoError.priceSourceUnavailable);
+      }
+      developer.log(e.toString());
+      return const BuyPaymentInfoFailure(PaymentInfoError.unknown);
     } catch (e) {
       developer.log(e.toString());
       return const BuyPaymentInfoFailure(PaymentInfoError.unknown);

lib/screens/buy/widgets/payment_information.dart

@@ -43,6 +43,11 @@ class PaymentInformation extends StatelessWidget {
               title: S.of(context).bitboxDisconnectedTitle,
               description: S.of(context).bitboxDisconnectedDescription,
             );
+          } else if (error == PaymentInfoError.priceSourceUnavailable) {
+            return PaymentActionRequired(
+              title: S.of(context).priceProviderUnavailableTitle,
+              description: S.of(context).priceProviderUnavailableDescription,
+            );
           } else if (error == PaymentInfoError.unknown) {
             return PaymentActionRequired(
               title: S.of(context).paymentInformationFailed,

lib/screens/sell/cubits/sell_payment_info/sell_payment_info_cubit.dart

@@ -3,6 +3,7 @@ import 'dart:developer' as developer;
 import 'package:equatable/equatable.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:realunit_wallet/packages/service/app_store.dart';
+import 'package:realunit_wallet/packages/service/dfx/exceptions/api_exception.dart';
 import 'package:realunit_wallet/packages/service/dfx/exceptions/bitbox_exception.dart';
 import 'package:realunit_wallet/packages/service/dfx/exceptions/payment/buy_exceptions.dart';
 import 'package:realunit_wallet/packages/service/dfx/models/payment/payment_info_error.dart';
@@ -97,6 +98,27 @@ class SellPaymentInfoCubit extends Cubit<SellPaymentInfoState> {
           message: e.toString(),
         ),
       );
+    } on ApiException catch (e) {
+      // 503 / PRICE_SOURCE_UNAVAILABLE = external price provider (Aktionariat)
+      // down → no quote possible. Must stay below the KYC/Registration clauses
+      // (those are ApiException subclasses).
+      if (isClosed) return;
+      if (e.statusCode == 503 || e.code == 'PRICE_SOURCE_UNAVAILABLE') {
+        emit(
+          SellPaymentInfoFailure(
+            PaymentInfoError.priceSourceUnavailable,
+            message: e.message,
+          ),
+        );
+        return;
+      }
+      developer.log(e.toString());
+      emit(
+        SellPaymentInfoFailure(
+          PaymentInfoError.unknown,
+          message: e.toString(),
+        ),
+      );
     } catch (e) {
       developer.log(e.toString());
       if (isClosed) return;

lib/screens/sell/widgets/sell_button.dart

@@ -44,6 +44,17 @@ class SellButton extends StatelessWidget {
             }
             return;
           }
+          if (state.error == .priceSourceUnavailable) {
+            if (context.mounted) {
+              ScaffoldMessenger.of(context).showSnackBar(
+                SnackBar(
+                  content: Text(S.of(context).priceProviderUnavailableTitle),
+                  backgroundColor: RealUnitColors.status.red600,
+                ),
+              );
+            }
+            return;
+          }
           if (context.mounted) {
             ScaffoldMessenger.of(context).showSnackBar(
               SnackBar(

test/goldens/screens/buy/buy_golden_test.dart

@@ -227,5 +227,24 @@ void main() {
         return wrapForGolden(buildSubject());
       },
     );
+
+    goldenTest(
+      'price source (Aktionariat) unavailable failure',
+      fileName: 'buy_price_source_unavailable',
+      constraints: const BoxConstraints.tightFor(width: 390, height: 844),
+      builder: () {
+        when(() => paymentInfoCubit.state).thenReturn(
+          const BuyPaymentInfoFailure(PaymentInfoError.priceSourceUnavailable),
+        );
+        when(() => converterCubit.state).thenReturn(
+          const BuyConverterState(
+            fiatText: '100',
+            sharesText: '1.00',
+            currency: Currency.chf,
+          ),
+        );
+        return wrapForGolden(buildSubject());
+      },
+    );
   });
 }

test/packages/service/dfx/models/payment/buy_sell_dtos_test.dart

@@ -146,16 +146,17 @@ void main() {
   });
 
   group('$PaymentInfoError', () {
-    test('has the five documented variants', () {
+    test('has the six documented variants', () {
       // Pin the wire contract — any new variant has to be added intentionally.
-      expect(PaymentInfoError.values, hasLength(5));
+      expect(PaymentInfoError.values, hasLength(6));
       expect(
         PaymentInfoError.values.toSet(),
         {
           PaymentInfoError.registrationRequired,
           PaymentInfoError.kycRequired,
           PaymentInfoError.minAmountNotMet,
           PaymentInfoError.bitboxDisconnected,
+          PaymentInfoError.priceSourceUnavailable,
           PaymentInfoError.unknown,
         },
       );

test/screens/buy/cubits/buy_payment_info_cubit_test.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mocktail/mocktail.dart';
+import 'package:realunit_wallet/packages/service/dfx/exceptions/api_exception.dart';
 import 'package:realunit_wallet/packages/service/dfx/exceptions/bitbox_exception.dart';
 import 'package:realunit_wallet/packages/service/dfx/exceptions/payment/buy_exceptions.dart';
 import 'package:realunit_wallet/packages/service/dfx/models/payment/buy/buy_payment_info.dart';
@@ -230,6 +231,50 @@ void main() {
       expect(f.error, PaymentInfoError.bitboxDisconnected);
     });
 
+    test('ApiException 503 → Failure(priceSourceUnavailable)', () async {
+      when(() => service.getPaymentInfo(any(), currency: any(named: 'currency')))
+          .thenAnswer(
+        (_) async => throw const ApiException(
+          statusCode: 503,
+          code: 'PRICE_SOURCE_UNAVAILABLE',
+          message: 'RealUnit price source (Aktionariat) is currently unavailable',
+        ),
+      );
+
+      final cubit = build();
+      await cubit.getPaymentInfo(amount: '300');
+
+      expect((cubit.state as BuyPaymentInfoFailure).error, PaymentInfoError.priceSourceUnavailable);
+    });
+
+    test('ApiException with code PRICE_SOURCE_UNAVAILABLE (non-503) → priceSourceUnavailable', () async {
+      when(() => service.getPaymentInfo(any(), currency: any(named: 'currency')))
+          .thenAnswer(
+        (_) async => throw const ApiException(
+          statusCode: 500,
+          code: 'PRICE_SOURCE_UNAVAILABLE',
+          message: 'unavailable',
+        ),
+      );
+
+      final cubit = build();
+      await cubit.getPaymentInfo(amount: '300');
+
+      expect((cubit.state as BuyPaymentInfoFailure).error, PaymentInfoError.priceSourceUnavailable);
+    });
+
+    test('other ApiException (e.g. 400) → Failure(unknown)', () async {
+      when(() => service.getPaymentInfo(any(), currency: any(named: 'currency')))
+          .thenAnswer(
+        (_) async => throw const ApiException(statusCode: 400, code: 'BAD_REQUEST', message: 'bad'),
+      );
+
+      final cubit = build();
+      await cubit.getPaymentInfo(amount: '300');
+
+      expect((cubit.state as BuyPaymentInfoFailure).error, PaymentInfoError.unknown);
+    });
+
     test('does not emit after close', () async {
       final completer = Completer<BuyPaymentInfo>();
       when(() => service.getPaymentInfo(any(), currency: any(named: 'currency')))

test/screens/sell/cubits/sell_payment_info_cubit_test.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mocktail/mocktail.dart';
 import 'package:realunit_wallet/packages/service/app_store.dart';
+import 'package:realunit_wallet/packages/service/dfx/exceptions/api_exception.dart';
 import 'package:realunit_wallet/packages/service/dfx/exceptions/bitbox_exception.dart';
 import 'package:realunit_wallet/packages/service/dfx/exceptions/payment/buy_exceptions.dart';
 import 'package:realunit_wallet/packages/service/dfx/models/payment/payment_info_error.dart';
@@ -280,6 +281,32 @@ void main() {
       expect(f.message, contains('network'));
     });
 
+    test('ApiException 503 → Failure(priceSourceUnavailable)', () async {
+      when(() => service.getPaymentInfo(any(), any(), currency: any(named: 'currency'))).thenAnswer(
+        (_) async => throw const ApiException(
+          statusCode: 503,
+          code: 'PRICE_SOURCE_UNAVAILABLE',
+          message: 'RealUnit price source (Aktionariat) is currently unavailable',
+        ),
+      );
+
+      final cubit = build();
+      await cubit.getPaymentInfo(amount: '100', iban: 'CH56');
+
+      expect((cubit.state as SellPaymentInfoFailure).error, PaymentInfoError.priceSourceUnavailable);
+    });
+
+    test('other ApiException (e.g. 400) → Failure(unknown)', () async {
+      when(() => service.getPaymentInfo(any(), any(), currency: any(named: 'currency'))).thenAnswer(
+        (_) async => throw const ApiException(statusCode: 400, code: 'BAD_REQUEST', message: 'bad'),
+      );
+
+      final cubit = build();
+      await cubit.getPaymentInfo(amount: '100', iban: 'CH56');
+
+      expect((cubit.state as SellPaymentInfoFailure).error, PaymentInfoError.unknown);
+    });
+
     test(
       'negative amount is sent to service (UI prevents this via digitsOnly formatter)',
       () async {