fix(kyc): filter country pickers by allow-flag, harden load states

assets/languages/strings_de.arb

@@ -67,6 +67,7 @@
   "contactSupportDescription": "FAQ, Tickets & Chat",
   "continueAnyway": "Trotzdem fortfahren",
   "copyClipboard": "In die Zwischenablage kopiert",
+  "countriesLoadFailed": "Die Länderliste konnte nicht geladen werden. Bitte versuchen Sie es erneut.",
   "country": "Land",
   "createWallet": "Neue Wallet erstellen",
   "createWalletConfirm": "Ich habe es gesichert",
@@ -254,6 +255,7 @@
   "sellSuccess": "Verkauf erfolgreich",
   "sellSuccessDescription": "Der Betrag wird Ihnen auf das angegebene Bankkonto ausgezahlt.",
   "sending": "Wird gesendet",
+  "setNationalityFailed": "Ihre Staatsangehörigkeit konnte nicht gesetzt werden:\n${message}",
   "settings": "Einstellungen",
   "settingsAppVersion": "Version ${tag}",
   "settingsCurrency": "Währung",

assets/languages/strings_en.arb

@@ -67,6 +67,7 @@
   "contactSupportDescription": "FAQ, tickets & chat",
   "continueAnyway": "Continue anyway",
   "copyClipboard": "Copied to clipboard",
+  "countriesLoadFailed": "Could not load the country list. Please try again.",
   "country": "Country",
   "createWallet": "Create new Wallet",
   "createWalletConfirm": "I’ve written it down",
@@ -254,6 +255,7 @@
   "sellSuccess": "Sell successful",
   "sellSuccessDescription": "The amount will be paid into the bank account you have specified.",
   "sending": "Sending",
+  "setNationalityFailed": "Could not set your nationality:\n${message}",
   "settings": "Settings",
   "settingsAppVersion": "Version ${tag}",
   "settingsCurrency": "Currency",

lib/packages/service/dfx/models/country/country.dart

@@ -6,11 +6,16 @@ class Country extends Equatable {
   final String symbol;
   final String name;
   final String? foreignName;
+  // Whether the backend accepts this country as a KYC address/residence
+  // country (DTO alias `kycAllowed`, backed by `dfxEnable`). A non-allowed
+  // address country is rejected with HTTP 400 on registration submit.
+  final bool kycAllowed;
 
   const Country({
     required this.id,
     required this.symbol,
     required this.name,
+    required this.kycAllowed,
     this.foreignName,
   });
 
@@ -25,6 +30,7 @@ extension DfxCountryDtoMapper on DfxCountryDto {
       symbol: symbol,
       name: name,
       foreignName: foreignName,
+      kycAllowed: kycAllowed,
     );
   }
 }

lib/screens/kyc/steps/nationality/kyc_nationality_page.dart

@@ -51,7 +51,7 @@ class _KycNationalityViewState extends State<KycNationalityView> {
           if (state is KycNationalityFailure) {
             ScaffoldMessenger.of(context).showSnackBar(
               SnackBar(
-                content: Text('Set Nationality failed:\n${state.message}'),
+                content: Text(S.of(context).setNationalityFailed(state.message)),
                 backgroundColor: RealUnitColors.status.red600,
               ),
             );
@@ -70,11 +70,8 @@ class _KycNationalityViewState extends State<KycNationalityView> {
                   children: [
                     CountryField(
                       label: S.of(context).registerCitizenship,
+                      purpose: CountryFieldPurpose.nationality,
                       onChanged: (country) => nationalityCtrl.value = country,
-                      validator: (value) {
-                        if (value == null) return '';
-                        return null;
-                      },
                     ),
                     Padding(
                       padding: const EdgeInsets.symmetric(vertical: 16.0),

lib/screens/kyc/steps/registration/steps/kyc_registration_address_step.dart

@@ -104,11 +104,8 @@ class KycRegistrationAddressStep extends StatelessWidget {
                 ),
                 CountryField(
                   label: S.of(context).country,
+                  purpose: CountryFieldPurpose.residence,
                   onChanged: (country) => countryCtrl.value = country,
-                  validator: (value) {
-                    if (value == null) return '';
-                    return null;
-                  },
                 ),
                 Padding(
                   padding: const .symmetric(vertical: 16.0),

lib/screens/kyc/steps/registration/steps/kyc_registration_personal_step.dart

@@ -96,11 +96,8 @@ class KycRegistrationPersonalStep extends StatelessWidget {
                 ),
                 CountryField(
                   label: S.of(context).registerCitizenship,
+                  purpose: CountryFieldPurpose.nationality,
                   onChanged: (country) => nationalityCtrl.value = country,
-                  validator: (value) {
-                    if (value == null) return '';
-                    return null;
-                  },
                 ),
                 Padding(
                   padding: const .symmetric(vertical: 16.0),

lib/screens/settings_user_data/subpages/edit_address/settings_edit_address_page.dart

@@ -160,11 +160,8 @@ class _SettingsEditAddressViewState extends State<SettingsEditAddressView> {
                                 ),
                                 CountryField(
                                   label: S.of(context).country,
+                                  purpose: CountryFieldPurpose.residence,
                                   onChanged: (country) => _countryCtrl.value = country,
-                                  validator: (value) {
-                                    if (value == null) return '';
-                                    return null;
-                                  },
                                 ),
                                 FilePickerField(
                                   label: S.of(context).proofDocument,

lib/widgets/form/country_field.dart

@@ -1,19 +1,37 @@
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
+import 'package:realunit_wallet/generated/i18n.dart';
 import 'package:realunit_wallet/packages/service/dfx/dfx_country_service.dart';
 import 'package:realunit_wallet/packages/service/dfx/models/country/country.dart';
 import 'package:realunit_wallet/setup/di.dart';
+import 'package:realunit_wallet/styles/colors.dart';
 import 'package:realunit_wallet/widgets/form/dropdown_field.dart';
 
+/// Selects how a [CountryField] gates its country list.
+enum CountryFieldPurpose {
+  nationality,
+  residence
+  ;
+
+  bool allows(Country country) => switch (this) {
+    // Nationality is a fact, not a permission: the backend routes a
+    // disallowed nationality to manual review instead of rejecting it,
+    // so the picker must offer every country.
+    CountryFieldPurpose.nationality => true,
+    CountryFieldPurpose.residence => country.kycAllowed,
+  };
+}
+
 class CountryField extends StatefulWidget {
   final String label;
+  final CountryFieldPurpose purpose;
   final void Function(Country?)? onChanged;
-  final String? Function(Country?)? validator;
 
   const CountryField({
     super.key,
     required this.label,
+    required this.purpose,
     this.onChanged,
-    this.validator,
   });
 
   @override
@@ -23,7 +41,6 @@ class CountryField extends StatefulWidget {
 class _CountryFieldState extends State<CountryField> {
   final DfxCountryService countryService = getIt<DfxCountryService>();
   late Future<List<Country>> _countriesFuture;
-  bool _hasPreloaded = false;
 
   @override
   void initState() {
@@ -37,28 +54,56 @@ class _CountryFieldState extends State<CountryField> {
       future: _countriesFuture,
       builder: (context, snapshot) {
         if (snapshot.connectionState == ConnectionState.waiting) {
-          return const SizedBox.shrink();
+          return _StatusField(
+            label: widget.label,
+            child: const Center(
+              child: Padding(
+                padding: EdgeInsets.symmetric(vertical: 4),
+                child: CupertinoActivityIndicator(),
+              ),
+            ),
+          );
         }
         if (snapshot.hasError) {
-          return Text('Failed to load countries: ${snapshot.error}');
+          return _StatusField(
+            label: widget.label,
+            child: Row(
+              children: [
+                Expanded(
+                  child: Text(
+                    S.of(context).countriesLoadFailed,
+                    style: TextStyle(color: RealUnitColors.status.red600),
+                  ),
+                ),
+                TextButton(
+                  onPressed: _retry,
+                  child: Text(S.of(context).retry),
+                ),
+              ],
+            ),
+          );
         }
 
-        final countries = snapshot.data ?? [];
-        final initialCountry = countries.isNotEmpty ? countries.first : null;
-        _preloadCountry(initialCountry);
+        final countries = snapshot.data!.where(widget.purpose.allows).toList();
 
         return DropdownField<Country>(
           hintText: 'Schweiz',
           label: widget.label,
           items: countries.map((c) => DropdownMenuItem(value: c, child: Text(c.name))).toList(),
-          initialValue: initialCountry,
+          initialValue: null,
           onChanged: widget.onChanged,
-          validator: widget.validator,
+          validator: (value) => value == null ? '' : null,
         );
       },
     );
   }
 
+  void _retry() {
+    setState(() {
+      _countriesFuture = _loadCountries();
+    });
+  }
+
   Future<List<Country>> _loadCountries() async {
     final countries = await countryService.getAllCountries();
 
@@ -80,13 +125,51 @@ class _CountryFieldState extends State<CountryField> {
 
     return countries;
   }
+}
 
-  void _preloadCountry(Country? initialCountry) {
-    if (!_hasPreloaded && initialCountry != null) {
-      _hasPreloaded = true;
-      WidgetsBinding.instance.addPostFrameCallback((_) {
-        widget.onChanged?.call(initialCountry);
-      });
-    }
+/// A labeled container that always registers an *invalid* [FormField] while no
+/// country can be selected (loading or error). This guarantees that
+/// `Form.validate()` cannot return `true` before the user picks a country.
+class _StatusField extends StatelessWidget {
+  final String label;
+  final Widget child;
+
+  const _StatusField({required this.label, required this.child});
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Padding(
+          padding: const EdgeInsets.symmetric(horizontal: 12.0, vertical: 4.0),
+          child: Text(
+            label,
+            style: const TextStyle(
+              fontSize: 13,
+              fontWeight: FontWeight.bold,
+              height: 18 / 13,
+            ),
+          ),
+        ),
+        FormField<Country>(
+          // No country is available yet, so the field is always invalid and
+          // blocks the surrounding Form from validating.
+          validator: (_) => '',
+          builder: (state) {
+            return Container(
+              padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 12),
+              decoration: BoxDecoration(
+                borderRadius: BorderRadius.circular(8.0),
+                border: Border.all(
+                  color: state.hasError ? RealUnitColors.status.red600 : RealUnitColors.neutral300,
+                ),
+              ),
+              child: child,
+            );
+          },
+        ),
+      ],
+    );
   }
 }

test/packages/service/dfx/models/aggregate_dtos_test.dart

@@ -102,9 +102,24 @@ void main() {
 
   group('$Country', () {
     test('equality is by id only', () {
-      const a = Country(id: 41, symbol: 'CH', name: 'Switzerland');
-      const b = Country(id: 41, symbol: 'XX', name: 'Different');
-      const c = Country(id: 49, symbol: 'DE', name: 'Germany');
+      const a = Country(
+        id: 41,
+        symbol: 'CH',
+        name: 'Switzerland',
+        kycAllowed: true,
+      );
+      const b = Country(
+        id: 41,
+        symbol: 'XX',
+        name: 'Different',
+        kycAllowed: true,
+      );
+      const c = Country(
+        id: 49,
+        symbol: 'DE',
+        name: 'Germany',
+        kycAllowed: true,
+      );
 
       expect(a, b);
       expect(a, isNot(c));
@@ -208,29 +223,29 @@ void main() {
 }
 
 Map<String, dynamic> _userDataJson() => {
-      'email': 'a@b.com',
-      'name': 'Ada Lovelace',
-      'type': 'HUMAN',
-      'phoneNumber': '+41 79 000 00 00',
-      'birthday': '1815-12-10',
-      'nationality': 'CH',
-      'addressStreet': 'Bahnhofstrasse 1',
-      'addressPostalCode': '8000',
-      'addressCity': 'Zurich',
-      'addressCountry': 'CH',
-      'swissTaxResidence': true,
-      'lang': 'de',
-      'kycData': {
-        'accountType': 'Personal',
-        'firstName': 'Ada',
-        'lastName': 'Lovelace',
-        'phone': '+41 79 000 00 00',
-        'address': {
-          'street': 'Bahnhofstrasse',
-          'houseNumber': '1',
-          'zip': '8000',
-          'city': 'Zurich',
-          'country': {'id': 41},
-        },
-      },
-    };
+  'email': 'a@b.com',
+  'name': 'Ada Lovelace',
+  'type': 'HUMAN',
+  'phoneNumber': '+41 79 000 00 00',
+  'birthday': '1815-12-10',
+  'nationality': 'CH',
+  'addressStreet': 'Bahnhofstrasse 1',
+  'addressPostalCode': '8000',
+  'addressCity': 'Zurich',
+  'addressCountry': 'CH',
+  'swissTaxResidence': true,
+  'lang': 'de',
+  'kycData': {
+    'accountType': 'Personal',
+    'firstName': 'Ada',
+    'lastName': 'Lovelace',
+    'phone': '+41 79 000 00 00',
+    'address': {
+      'street': 'Bahnhofstrasse',
+      'houseNumber': '1',
+      'zip': '8000',
+      'city': 'Zurich',
+      'country': {'id': 41},
+    },
+  },
+};