feat: Introduce Wolf3dAppManager for managing audio shutdown and game data directory selection

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

packages/wolf_3d_flutter/lib/managers/wolf3d_app_manager.dart

@@ -0,0 +1,123 @@
+library;
+
+import 'dart:async';
+import 'dart:collection';
+
+import 'package:file_selector/file_selector.dart';
+import 'package:wolf_3d_flutter/wolf_3d_flutter.dart';
+
+/// Coordinates app-shell setup actions and shutdown behavior.
+class Wolf3dAppManager {
+  Wolf3dAppManager({required this.engine});
+
+  final Wolf3dFlutterEngine engine;
+
+  bool _isLoadingGameData = false;
+  String? _pickerError;
+  Future<void>? _shutdownFuture;
+
+  bool get isLoadingGameData => _isLoadingGameData;
+  String? get pickerError => _pickerError;
+
+  Future<void> ensureAudioShutdown() {
+    final existing = _shutdownFuture;
+    if (existing != null) {
+      return existing;
+    }
+
+    final shutdown = engine.shutdownAudio();
+    _shutdownFuture = shutdown;
+    return shutdown;
+  }
+
+  Future<void> pickGameDataDirectory({
+    required void Function() notifyChanged,
+  }) async {
+    _isLoadingGameData = true;
+    _pickerError = null;
+    notifyChanged();
+
+    try {
+      final String? directoryPath = await getDirectoryPath(
+        confirmButtonText: 'Use this folder',
+      );
+
+      if (directoryPath == null || directoryPath.trim().isEmpty) {
+        return;
+      }
+
+      await engine.init(directory: directoryPath.trim());
+    } catch (error) {
+      _pickerError = 'Unable to load selected directory: $error';
+    } finally {
+      _isLoadingGameData = false;
+      notifyChanged();
+    }
+  }
+
+  Future<void> pickGameDataFiles({
+    required void Function() notifyChanged,
+  }) async {
+    _isLoadingGameData = true;
+    _pickerError = null;
+    notifyChanged();
+
+    try {
+      final List<XFile> selectedFiles = await openFiles();
+
+      if (selectedFiles.isEmpty) {
+        return;
+      }
+
+      final LinkedHashSet<String> directories = LinkedHashSet<String>();
+      for (final XFile file in selectedFiles) {
+        final String directory = _directoryFromFilePath(file.path);
+        if (directory.isNotEmpty) {
+          directories.add(directory);
+        }
+      }
+
+      if (directories.isEmpty) {
+        _pickerError =
+            'Selected files do not expose local filesystem paths.';
+        return;
+      }
+
+      final List<String> orderedDirectories = directories.toList(
+        growable: false,
+      );
+      await engine.init(
+        directory: orderedDirectories.first,
+        additionalDirectories: orderedDirectories.skip(1),
+      );
+    } catch (error) {
+      _pickerError = 'Unable to load selected files: $error';
+    } finally {
+      _isLoadingGameData = false;
+      notifyChanged();
+    }
+  }
+
+  String _directoryFromFilePath(String path) {
+    final String trimmedPath = path.trim();
+    if (trimmedPath.isEmpty) {
+      return '';
+    }
+
+    final int slashIndex = trimmedPath.lastIndexOf('/');
+    final int backslashIndex = trimmedPath.lastIndexOf(r'\');
+    final int separatorIndex = slashIndex > backslashIndex
+        ? slashIndex
+        : backslashIndex;
+
+    if (separatorIndex < 0) {
+      return '';
+    }
+
+    if (separatorIndex == 0) {
+      return trimmedPath[0];
+    }
+
+    return trimmedPath.substring(0, separatorIndex);
+  }
+}

packages/wolf_3d_flutter/lib/widgets/wolf3d_app.dart

@@ -21,37 +21,47 @@ class Wolf3dApp extends StatefulWidget {
 }
 
 class _Wolf3dAppState extends State<Wolf3dApp> with WidgetsBindingObserver {
-  Future<void>? _shutdownFuture;
+  late final Wolf3dAppManager _manager;
 
   @override
   void initState() {
     super.initState();
+    _manager = Wolf3dAppManager(engine: widget.engine);
     WidgetsBinding.instance.addObserver(this);
   }
 
   @override
   void dispose() {
     WidgetsBinding.instance.removeObserver(this);
-    unawaited(_ensureAudioShutdown());
+    unawaited(_manager.ensureAudioShutdown());
     super.dispose();
   }
 
   @override
   void didChangeAppLifecycleState(AppLifecycleState state) {
     if (state == AppLifecycleState.detached) {
-      unawaited(_ensureAudioShutdown());
+      unawaited(_manager.ensureAudioShutdown());
     }
   }
 
-  Future<void> _ensureAudioShutdown() {
-    final Future<void>? existing = _shutdownFuture;
-    if (existing != null) {
-      return existing;
+  Future<void> _pickGameDataDirectory() {
+    return _manager.pickGameDataDirectory(
+      notifyChanged: () {
+        if (mounted) {
+          setState(() {});
+        }
+      },
+    );
   }
 
-    final Future<void> shutdown = widget.engine.shutdownAudio();
-    _shutdownFuture = shutdown;
-    return shutdown;
+  Future<void> _pickGameDataFiles() {
+    return _manager.pickGameDataFiles(
+      notifyChanged: () {
+        if (mounted) {
+          setState(() {});
+        }
+      },
+    );
   }
 
   @override
@@ -59,6 +69,10 @@ class _Wolf3dAppState extends State<Wolf3dApp> with WidgetsBindingObserver {
     return widget.engine.availableGames.isEmpty
         ? NoGameDataScreen(
             configuredDataDirectory: widget.engine.configuredDataDirectory,
+            onPickGameDataDirectory: _pickGameDataDirectory,
+            onPickGameDataFiles: _pickGameDataFiles,
+            isLoadingGameData: _manager.isLoadingGameData,
+            pickerError: _manager.pickerError,
           )
         : GameScreen(wolf3d: widget.engine);
   }

packages/wolf_3d_flutter/lib/wolf_3d_flutter.dart

@@ -30,6 +30,7 @@ export 'managers/game_screen_input_manager.dart'
         HostShortcutRegistry,
         GameScreenInputManager,
         isAltEnterShortcut;
+      export 'managers/wolf3d_app_manager.dart' show Wolf3dAppManager;
 export 'screens/audio_gallery.dart' show AudioGallery;
 export 'screens/debug_tools_screen.dart' show DebugToolsScreen;
 export 'screens/game_screen.dart' show GameScreen;