feat: In-App-Update (Download + Installer öffnen)

Portiert von timemaster-mobile v0.1.7+8: UpdateCheckService prüft
kiosk-version.txt, LoginScreen zeigt Update-Banner mit Fortschrittsbalken +
"Jetzt aktualisieren"-Button, öffnet Android-Paketinstaller direkt
(open_filex + FileProvider). Banner sitzt im LoginScreen statt StampScreen,
da das der Idle-/Ruhezustand des Kiosks ist – Stempel-Sessions sind nur
900s aktiv. REQUEST_INSTALL_PACKAGES-Permission ergänzt.

v0.1.5+6. Diese Version selbst muss noch einmal manuell installiert werden
(Feature existiert ja erst danach), ab hier sollte der Update-Button reichen.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Dzdm3EWeNdYFUuXFRJryA1

android/app/src/main/AndroidManifest.xml

@@ -5,6 +5,7 @@
     <uses-permission android:name="android.permission.CAMERA"/>
     <uses-feature android:name="android.hardware.camera" android:required="false"/>
     <uses-feature android:name="android.hardware.camera.autofocus" android:required="false"/>
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES"/>
     <application
         android:label="timemaster_kiosk"
         android:name="${applicationName}"
@@ -36,6 +37,18 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
+
+        <!-- FileProvider für open_filex – Android 7+ verlangt content://
+             statt file:// beim Öffnen heruntergeladener APKs. -->
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.fileprovider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
     </application>
     <!-- Required to query activities that can process text, see:
          https://developer.android.com/training/package-visibility and

android/app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- Deckt getExternalFilesDir()/... ab, wo wir das APK zwischenspeichern -->
+    <external-files-path name="downloads" path="." />
+    <cache-path name="cache" path="." />
+</paths>

lib/app_version.dart

@@ -1,3 +1,3 @@
 /// Manuell mit pubspec.yaml synchron halten (siehe timemaster-mobile,
 /// gleiche Konvention – kein package_info_plus während aktiver Feldtests).
-const String kAppVersion = '0.1.4+5';
+const String kAppVersion = '0.1.5+6';

lib/screens/login_screen.dart

@@ -7,6 +7,7 @@ import '../app_version.dart';
 import '../models/kiosk_session.dart';
 import '../services/api_client.dart';
 import '../services/kiosk_service.dart';
+import '../services/update_check_service.dart';
 import 'enrollment_screen.dart';
 import 'stamp_screen.dart';
 
@@ -32,12 +33,49 @@ class _LoginScreenState extends State<LoginScreen> {
   String? _scannedUid;
   List<KioskEmployee>? _employees;
 
+  final _updateService = UpdateCheckService();
+  String? _newerVersion;
+  bool _updating = false;
+  double? _updateProgress;
+
+  @override
+  void initState() {
+    super.initState();
+    _updateService.checkForNewerVersion().then((v) {
+      if (mounted && v != null) setState(() => _newerVersion = v);
+    });
+  }
+
   @override
   void dispose() {
     if (_nfcScanning) NfcManager.instance.stopSession();
     super.dispose();
   }
 
+  Future<void> _installUpdate() async {
+    setState(() {
+      _updating = true;
+      _updateProgress = null;
+      _error = null;
+    });
+    try {
+      await _updateService.downloadAndInstall(
+        onProgress: (p) {
+          if (mounted) setState(() => _updateProgress = p);
+        },
+      );
+    } catch (e) {
+      if (mounted) setState(() => _error = 'Update fehlgeschlagen: $e');
+    } finally {
+      if (mounted) {
+        setState(() {
+          _updating = false;
+          _updateProgress = null;
+        });
+      }
+    }
+  }
+
   String _dioMessage(DioException e) {
     final detail = e.response?.data is Map ? e.response?.data['detail'] : null;
     if (detail is String) return detail;
@@ -223,6 +261,44 @@ class _LoginScreenState extends State<LoginScreen> {
             child: Column(
               mainAxisSize: MainAxisSize.min,
               children: [
+                if (_newerVersion != null) ...[
+                  Card(
+                    color: Colors.blue[50],
+                    child: Padding(
+                      padding: const EdgeInsets.all(12),
+                      child: Column(
+                        crossAxisAlignment: CrossAxisAlignment.start,
+                        children: [
+                          Row(
+                            children: [
+                              const Icon(Icons.system_update, color: Colors.blue),
+                              const SizedBox(width: 12),
+                              Expanded(
+                                child: Text(
+                                  'Neue Version $_newerVersion verfügbar (installiert: $kAppVersion).',
+                                  style: const TextStyle(color: Colors.blue),
+                                ),
+                              ),
+                            ],
+                          ),
+                          const SizedBox(height: 8),
+                          if (_updating)
+                            LinearProgressIndicator(value: _updateProgress)
+                          else
+                            SizedBox(
+                              width: double.infinity,
+                              child: OutlinedButton.icon(
+                                onPressed: _installUpdate,
+                                icon: const Icon(Icons.download),
+                                label: const Text('Jetzt aktualisieren'),
+                              ),
+                            ),
+                        ],
+                      ),
+                    ),
+                  ),
+                  const SizedBox(height: 16),
+                ],
                 SegmentedButton<_LoginMode>(
                   segments: const [
                     ButtonSegment(value: _LoginMode.pin, label: Text('PIN'), icon: Icon(Icons.pin)),

lib/services/update_check_service.dart

@@ -0,0 +1,56 @@
+import 'package:dio/dio.dart';
+import 'package:open_filex/open_filex.dart';
+import 'package:path_provider/path_provider.dart';
+import '../app_version.dart';
+import 'api_client.dart';
+
+/// Prüft `/static/downloads/kiosk-version.txt` auf dem konfigurierten Server
+/// gegen die eigene kAppVersion und kann das neue APK direkt herunterladen +
+/// den System-Installer öffnen (REQUEST_INSTALL_PACKAGES + FileProvider,
+/// siehe AndroidManifest.xml). Analog timemaster-mobile, eigene Dateinamen
+/// (kiosk-version.txt / timemaster-kiosk.apk – geteiltes Downloads-
+/// Verzeichnis mit der Employee-App auf dem Server, andere Dateien).
+class UpdateCheckService {
+  String get _origin {
+    final apiBase = ApiClient.instance.baseUrl; // endet auf .../api/v1
+    return apiBase.replaceFirst(RegExp(r'/api/v1/?$'), '');
+  }
+
+  Future<String?> checkForNewerVersion() async {
+    try {
+      final response = await Dio(BaseOptions(
+        baseUrl: _origin,
+        connectTimeout: const Duration(seconds: 5),
+        receiveTimeout: const Duration(seconds: 5),
+      )).get<String>('/static/downloads/kiosk-version.txt');
+
+      final remote = (response.data ?? '').trim();
+      if (remote.isEmpty || remote == kAppVersion) return null;
+      return remote;
+    } on DioException {
+      return null;
+    } catch (_) {
+      return null;
+    }
+  }
+
+  /// Lädt die APK herunter und öffnet den Android-Paketinstaller.
+  /// [onProgress] liefert 0.0–1.0, falls die Antwort ein Content-Length hat.
+  Future<void> downloadAndInstall({void Function(double)? onProgress}) async {
+    final dir = await getExternalStorageDirectory() ?? await getTemporaryDirectory();
+    final filePath = '${dir.path}/timemaster-kiosk-update.apk';
+
+    await Dio(BaseOptions(baseUrl: _origin)).download(
+      '/static/downloads/timemaster-kiosk.apk',
+      filePath,
+      onReceiveProgress: (received, total) {
+        if (total > 0 && onProgress != null) onProgress(received / total);
+      },
+    );
+
+    final result = await OpenFilex.open(filePath, type: 'application/vnd.android.package-archive');
+    if (result.type != ResultType.done) {
+      throw Exception('Installer konnte nicht geöffnet werden: ${result.message}');
+    }
+  }
+}

pubspec.yaml

@@ -1,7 +1,7 @@
 name: timemaster_kiosk
 description: TimeMaster Kiosk – Stempeluhr für Android-Tablets hinter VPN
 publish_to: 'none'
-version: 0.1.4+5
+version: 0.1.5+6
 
 environment:
   sdk: '>=3.3.0 <4.0.0'
@@ -15,6 +15,8 @@ dependencies:
   nfc_manager: ^4.2.1
   wakelock_plus: ^1.2.8
   mobile_scanner: ^6.0.2
+  open_filex: ^4.5.0
+  path_provider: ^2.1.4
 
 dev_dependencies:
   flutter_test: