Initial commit

lib/library/library_service.dart

@@ -0,0 +1,83 @@
+import 'dart:io';
+
+import 'package:file_picker/file_picker.dart';
+import 'package:flutter/foundation.dart';
+import 'package:uuid/uuid.dart';
+
+import 'android_scan.dart';
+import 'database.dart';
+import 'permissions.dart';
+import 'scan_service.dart';
+
+/// Beschriftung des Hinzufügen-/Scan-Buttons je Plattform.
+String get addMusicLabel =>
+    Platform.isAndroid ? 'Musik scannen' : 'Musikordner hinzufügen';
+
+/// Koordiniert Ordnerwahl und Scans; hält den Scan-Fortschritt für die UI.
+/// Android scannt automatisch über MediaStore (Scoped Storage lässt keinen
+/// direkten Dateizugriff zu); Desktop scannt vom Nutzer gewählte Ordner.
+class LibraryService extends ChangeNotifier {
+  LibraryService(this.db);
+  final MeloDb db;
+  static const _uuid = Uuid();
+
+  bool scanning = false;
+  int scanDone = 0;
+  int scanTotal = 0;
+  bool permissionDenied = false;
+
+  /// Auf Android: automatischer Geräte-Scan. Auf Desktop: Ordner wählen + scannen.
+  Future<void> pickFolderAndScan() async {
+    if (!await _ensurePermission()) return;
+    if (Platform.isAndroid) {
+      await _scan();
+      return;
+    }
+    final path = await FilePicker.getDirectoryPath();
+    if (path == null) return;
+    await db.addFolder(FoldersCompanion.insert(
+      id: _uuid.v4(),
+      path: path,
+      updatedAtMs: DateTime.now().millisecondsSinceEpoch,
+    ));
+    await _scan();
+  }
+
+  /// Scannt erneut (Android: ganzes Gerät; Desktop: alle gemerkten Ordner).
+  Future<void> rescan() async {
+    if (!await _ensurePermission()) return;
+    await _scan();
+  }
+
+  Future<bool> _ensurePermission() async {
+    final granted = await ensureAudioPermission();
+    permissionDenied = !granted;
+    notifyListeners();
+    return granted;
+  }
+
+  Future<void> _scan() async {
+    if (scanning) return;
+    scanning = true;
+    scanDone = 0;
+    scanTotal = 0;
+    notifyListeners();
+    try {
+      if (Platform.isAndroid) {
+        await scanAndroidMediaStore(db, onProgress: _onProgress);
+      } else {
+        final folders = (await db.activeFolders()).map((f) => f.path).toList();
+        await scanFolders(db, folders, onProgress: _onProgress);
+      }
+    } finally {
+      scanning = false;
+      notifyListeners();
+    }
+  }
+
+  void _onProgress(int done, int total) {
+    scanDone = done;
+    scanTotal = total;
+    notifyListeners();
+  }
+}