Fix: Review-Findings korrigiert (Tag-Leiste, Profil, Singleton u.a.)

CRIT: - Tag-Leiste: Toggle-Kopf 'Tags & Filter' eingebaut (war unerreichbar) + TagStats - Profil: Cloud-Count vor Dialog aufloesen (kein 'Instance of Future' mehr) HIGH: - CloudEinstellungen: toten Sync-Timer entfernt (echter Timer im ViewModel) - StatistikCard + RecentWidget jetzt eingebaut (gesamtMB/gesamtMin endlich genutzt) - CloudService als Singleton (konsistenter Token-Zustand in allen Services) MED/LOW: - Playlist-Erkennung nur noch via list= Parameter - Player: fehlende Quelle wird geloggt statt still - song_tile: null-ID-Guard vor Tag-Dialog - Scanner-Log mit Exception-Objekt - FavoritenService: anzahlFavoriten() fuer StatistikCard
2026-07-31 15:42:54 +02:00
parent b3aedc53f9
commit 8b6a04ead8
18 changed files with 767 additions and 503 deletions
@@ -0,0 +1,91 @@
+import 'dart:io';
+
+/// Liest ID3-Tags (v1 + v2) und eingebettetes Cover aus MP3-Dateien
+class Id3Reader {
+  /// Gibt Metadaten zurück: titel, kuenstler, album, coverBytes
+  static Map<String, dynamic> lesen(String filepath) {
+    final result = <String, dynamic>{
+      'titel': '',
+      'kuenstler': '',
+      'album': '',
+      'cover': null,
+    };
+
+    try {
+      final file = File(filepath);
+      if (!file.existsSync()) return result;
+
+      final bytes = file.readAsBytesSync();
+      // ID3v1 (letzte 128 Bytes)
+      if (bytes.length > 128) {
+        final tag = bytes.sublist(bytes.length - 128);
+        if (String.fromCharCodes(tag.sublist(0, 3)) == 'TAG') {
+          result['titel'] = _trimNull(tag.sublist(3, 33)).trim();
+          result['kuenstler'] = _trimNull(tag.sublist(33, 63)).trim();
+          result['album'] = _trimNull(tag.sublist(63, 93)).trim();
+        }
+      }
+
+      // ID3v2 Header (Anfang der Datei) für Cover
+      if (bytes.length > 10 && String.fromCharCodes(bytes.sublist(0, 3)) == 'ID3') {
+        final size = _synchSafeInt(bytes, 6);
+        var pos = 10;
+        // Frame-Header lesen
+        while (pos < size && pos + 10 < bytes.length) {
+          final frameId = String.fromCharCodes(bytes.sublist(pos, pos + 4));
+          final frameSize = _frameSize(bytes, pos + 4);
+          pos += 10;
+          if (frameId == 'APIC' && pos + frameSize <= bytes.length) {
+            // APIC = Attached Picture
+            var p = pos;
+            // Encoding (1 Byte) + MIME-Type
+            final enc = bytes[p]; p += 1;
+            var mimeEnd = p;
+            while (mimeEnd < bytes.length && bytes[mimeEnd] != 0) mimeEnd++;
+            final mime = String.fromCharCodes(bytes.sublist(p, mimeEnd));
+            p = mimeEnd + 1;
+            // Picture Type (1 Byte)
+            p += 1;
+            // Description (null-terminated)
+            var descEnd = p;
+            while (descEnd < bytes.length) {
+              if (enc == 1 || enc == 2) {
+                if (descEnd + 1 < bytes.length && bytes[descEnd] == 0 && bytes[descEnd + 1] == 0) break;
+                descEnd += 2;
+              } else {
+                if (bytes[descEnd] == 0) break;
+                descEnd += 1;
+              }
+            }
+            p = descEnd + (enc == 1 || enc == 2 ? 2 : 1);
+            final remaining = pos + frameSize - p;
+            if (remaining > 0 && p + remaining <= bytes.length) {
+              result['cover'] = bytes.sublist(p, p + remaining);
+            }
+            break;
+          }
+          pos += frameSize;
+        }
+      }
+    } catch (_) {}
+
+    // Fallback: Dateiname als Titel
+    if (result['titel'].isEmpty) {
+      result['titel'] = filepath.split('/').last.replaceAll('.mp3', '').replaceAll('.m4a', '');
+    }
+    return result;
+  }
+
+  static String _trimNull(List<int> bytes) {
+    final end = bytes.indexWhere((b) => b == 0);
+    return String.fromCharCodes(end < 0 ? bytes : bytes.sublist(0, end));
+  }
+
+  static int _synchSafeInt(List<int> bytes, int offset) {
+    return (bytes[offset] << 21) | (bytes[offset + 1] << 14) | (bytes[offset + 2] << 7) | bytes[offset + 3];
+  }
+
+  static int _frameSize(List<int> bytes, int offset) {
+    return (bytes[offset] << 24) | (bytes[offset + 1] << 16) | (bytes[offset + 2] << 8) | bytes[offset + 3];
+  }
+}