refactor(reenrich): share the FFmpeg re-enrich apply flow

local_album and the queue batch action carried byte-identical ~110-line copies
of the FFmpeg re-enrich apply+SAF-writeback+temp-cleanup flow (differing only in
helper names). Extract one applyFfmpegReEnrichResult() so the SAF temp-file
cleanup — the class of bug fixed in fb7d101 — has a single source. The
track-detail copy stays: it drives snackbars and does not preserve metadata.

lib/screens/local_album_screen.dart

@@ -9,6 +9,7 @@ import 'package:spotiflac_android/providers/extension_provider.dart';
 import 'package:spotiflac_android/providers/settings_provider.dart';
 import 'package:spotiflac_android/utils/adaptive_layout.dart';
 import 'package:spotiflac_android/utils/confirm_and_delete_tracks.dart';
+import 'package:spotiflac_android/utils/ffmpeg_reenrich.dart';
 import 'package:spotiflac_android/utils/file_access.dart';
 import 'package:spotiflac_android/utils/image_cache_utils.dart';
 import 'package:spotiflac_android/utils/lyrics_metadata_helper.dart';
@@ -16,7 +17,6 @@ import 'package:spotiflac_android/utils/nav_bar_inset.dart';
 import 'package:spotiflac_android/services/library_database.dart';
 import 'package:spotiflac_android/services/batch_track_actions.dart';
 import 'package:spotiflac_android/models/unified_library_item.dart';
-import 'package:spotiflac_android/services/ffmpeg_service.dart';
 import 'package:spotiflac_android/services/local_track_redownload_service.dart';
 import 'package:spotiflac_android/widgets/batch_progress_dialog.dart';
 import 'package:spotiflac_android/widgets/re_enrich_field_dialog.dart';
@@ -425,140 +425,6 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen>
     );
   }
 
-  bool _hasValue(String? value) => value != null && value.trim().isNotEmpty;
-
-  Future<void> _safeDeleteFile(String path) async {
-    try {
-      final file = File(path);
-      if (await file.exists()) {
-        await file.delete();
-      }
-    } catch (_) {}
-  }
-
-  Future<void> _cleanupTempFileAndParent(String path) async {
-    await _safeDeleteFile(path);
-    try {
-      final parent = File(path).parent;
-      if (await parent.exists()) {
-        await parent.delete();
-      }
-    } catch (_) {}
-  }
-
-  Future<bool> _applyFfmpegReEnrichResult(
-    LocalLibraryItem item,
-    Map<String, dynamic> result,
-  ) async {
-    final tempPath = result['temp_path'] as String?;
-    final safUri = result['saf_uri'] as String?;
-    final ffmpegTarget = _hasValue(tempPath) ? tempPath! : item.filePath;
-    final downloadedCoverPath = result['cover_path'] as String?;
-    String? effectiveCoverPath = downloadedCoverPath;
-    String? extractedCoverPath;
-
-    if (!_hasValue(effectiveCoverPath)) {
-      try {
-        final tempDir = await Directory.systemTemp.createTemp(
-          'reenrich_cover_',
-        );
-        final coverOutput = '${tempDir.path}${Platform.pathSeparator}cover.jpg';
-        final extracted = await PlatformBridge.extractCoverToFile(
-          ffmpegTarget,
-          coverOutput,
-        );
-        if (extracted['error'] == null) {
-          effectiveCoverPath = coverOutput;
-          extractedCoverPath = coverOutput;
-        } else {
-          try {
-            await tempDir.delete(recursive: true);
-          } catch (_) {}
-        }
-      } catch (_) {}
-    }
-
-    final metadata = (result['metadata'] as Map<String, dynamic>?)?.map(
-      (k, v) => MapEntry(k, v.toString()),
-    );
-
-    final format = item.format?.toLowerCase();
-    final lowerPath = item.filePath.toLowerCase();
-    final isMp3 = format == 'mp3' || lowerPath.endsWith('.mp3');
-    final isM4A =
-        format == 'm4a' ||
-        format == 'aac' ||
-        lowerPath.endsWith('.m4a') ||
-        lowerPath.endsWith('.aac');
-    final isOpus =
-        format == 'opus' ||
-        format == 'ogg' ||
-        lowerPath.endsWith('.opus') ||
-        lowerPath.endsWith('.ogg');
-
-    final artistTagMode = ref.read(settingsProvider).artistTagMode;
-    String? ffmpegResult;
-    if (isMp3) {
-      ffmpegResult = await FFmpegService.embedMetadataToMp3(
-        mp3Path: ffmpegTarget,
-        coverPath: effectiveCoverPath,
-        metadata: metadata,
-        preserveMetadata: true,
-      );
-    } else if (isM4A) {
-      ffmpegResult = await FFmpegService.embedMetadataToM4a(
-        m4aPath: ffmpegTarget,
-        coverPath: effectiveCoverPath,
-        metadata: metadata,
-        preserveMetadata: true,
-      );
-    } else if (isOpus) {
-      ffmpegResult = await FFmpegService.embedMetadataToOpus(
-        opusPath: ffmpegTarget,
-        coverPath: effectiveCoverPath,
-        metadata: metadata,
-        artistTagMode: artistTagMode,
-        preserveMetadata: true,
-      );
-    }
-
-    if (ffmpegResult != null && _hasValue(tempPath) && _hasValue(safUri)) {
-      final ok = await PlatformBridge.writeTempToSaf(ffmpegResult, safUri!);
-      if (!ok) {
-        if (_hasValue(downloadedCoverPath)) {
-          await _safeDeleteFile(downloadedCoverPath!);
-        }
-        if (_hasValue(extractedCoverPath)) {
-          await _cleanupTempFileAndParent(extractedCoverPath!);
-        }
-        await _safeDeleteFile(tempPath!);
-        return false;
-      }
-      await writeReEnrichSafSidecarLrc(safUri: safUri, reEnrichResult: result);
-    }
-
-    if (_hasValue(downloadedCoverPath)) {
-      await _safeDeleteFile(downloadedCoverPath!);
-    }
-    if (_hasValue(extractedCoverPath)) {
-      await _cleanupTempFileAndParent(extractedCoverPath!);
-    }
-    if (_hasValue(tempPath)) {
-      await _safeDeleteFile(tempPath!);
-    }
-
-    if (ffmpegResult != null) {
-      // Filesystem .lrc sidecar. SAF sidecar is written only after
-      // writeTempToSaf succeeds.
-      await writeReEnrichSidecarLrc(
-        audioFilePath: item.filePath,
-        reEnrichResult: result,
-      );
-    }
-
-    return ffmpegResult != null;
-  }
-
   Future<bool> _reEnrichLocalTrack(
     LocalLibraryItem item, {
     List<String>? updateFields,
@@ -603,7 +469,11 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen>
       return true;
     }
     if (method == 'ffmpeg') {
-      return _applyFfmpegReEnrichResult(item, result);
+      return applyFfmpegReEnrichResult(
+        item: item,
+        result: result,
+        artistTagMode: ref.read(settingsProvider).artistTagMode,
+      );
     }
     return false;
   }

lib/screens/queue_tab.dart

@@ -5,13 +5,13 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:share_plus/share_plus.dart';
-import 'package:spotiflac_android/services/ffmpeg_service.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
 import 'package:spotiflac_android/utils/adaptive_layout.dart';
 import 'package:spotiflac_android/utils/app_bar_layout.dart';
 import 'package:spotiflac_android/utils/nav_bar_inset.dart';
 import 'package:spotiflac_android/widgets/settings_group.dart';
+import 'package:spotiflac_android/utils/ffmpeg_reenrich.dart';
 import 'package:spotiflac_android/utils/file_access.dart';
 import 'package:spotiflac_android/utils/lyrics_metadata_helper.dart';
 import 'package:spotiflac_android/models/download_item.dart';

lib/screens/queue_tab_batch_actions.dart

@@ -1,140 +1,6 @@
 part of 'queue_tab.dart';
 
 extension _QueueTabBatchActions on _QueueTabState {
-  Future<void> _safeDeleteTempFile(String path) async {
-    try {
-      final file = File(path);
-      if (await file.exists()) {
-        await file.delete();
-      }
-    } catch (_) {}
-  }
-
-  Future<void> _cleanupTempFileAndParentDir(String path) async {
-    await _safeDeleteTempFile(path);
-    try {
-      final parent = File(path).parent;
-      if (await parent.exists()) {
-        await parent.delete();
-      }
-    } catch (_) {}
-  }
-
-  Future<bool> _applyQueueFfmpegReEnrichResult(
-    LocalLibraryItem item,
-    Map<String, dynamic> result,
-  ) async {
-    final tempPath = result['temp_path'] as String?;
-    final safUri = result['saf_uri'] as String?;
-    final ffmpegTarget = _hasTextValue(tempPath) ? tempPath! : item.filePath;
-    final downloadedCoverPath = result['cover_path'] as String?;
-    String? effectiveCoverPath = downloadedCoverPath;
-    String? extractedCoverPath;
-
-    if (!_hasTextValue(effectiveCoverPath)) {
-      try {
-        final tempDir = await Directory.systemTemp.createTemp(
-          'reenrich_cover_',
-        );
-        final coverOutput = '${tempDir.path}${Platform.pathSeparator}cover.jpg';
-        final extracted = await PlatformBridge.extractCoverToFile(
-          ffmpegTarget,
-          coverOutput,
-        );
-        if (extracted['error'] == null) {
-          effectiveCoverPath = coverOutput;
-          extractedCoverPath = coverOutput;
-        } else {
-          try {
-            await tempDir.delete(recursive: true);
-          } catch (_) {}
-        }
-      } catch (_) {}
-    }
-
-    final metadata = (result['metadata'] as Map<String, dynamic>?)?.map(
-      (k, v) => MapEntry(k, v.toString()),
-    );
-
-    final format = item.format?.toLowerCase();
-    final lowerPath = item.filePath.toLowerCase();
-    final isMp3 = format == 'mp3' || lowerPath.endsWith('.mp3');
-    final isM4A =
-        format == 'm4a' ||
-        format == 'aac' ||
-        lowerPath.endsWith('.m4a') ||
-        lowerPath.endsWith('.aac');
-    final isOpus =
-        format == 'opus' ||
-        format == 'ogg' ||
-        lowerPath.endsWith('.opus') ||
-        lowerPath.endsWith('.ogg');
-
-    final artistTagMode = ref.read(settingsProvider).artistTagMode;
-    String? ffmpegResult;
-    if (isMp3) {
-      ffmpegResult = await FFmpegService.embedMetadataToMp3(
-        mp3Path: ffmpegTarget,
-        coverPath: effectiveCoverPath,
-        metadata: metadata,
-        preserveMetadata: true,
-      );
-    } else if (isM4A) {
-      ffmpegResult = await FFmpegService.embedMetadataToM4a(
-        m4aPath: ffmpegTarget,
-        coverPath: effectiveCoverPath,
-        metadata: metadata,
-        preserveMetadata: true,
-      );
-    } else if (isOpus) {
-      ffmpegResult = await FFmpegService.embedMetadataToOpus(
-        opusPath: ffmpegTarget,
-        coverPath: effectiveCoverPath,
-        metadata: metadata,
-        artistTagMode: artistTagMode,
-        preserveMetadata: true,
-      );
-    }
-
-    if (ffmpegResult != null &&
-        _hasTextValue(tempPath) &&
-        _hasTextValue(safUri)) {
-      final ok = await PlatformBridge.writeTempToSaf(ffmpegResult, safUri!);
-      if (!ok) {
-        if (_hasTextValue(downloadedCoverPath)) {
-          await _safeDeleteTempFile(downloadedCoverPath!);
-        }
-        if (_hasTextValue(extractedCoverPath)) {
-          await _cleanupTempFileAndParentDir(extractedCoverPath!);
-        }
-        await _safeDeleteTempFile(tempPath!);
-        return false;
-      }
-      await writeReEnrichSafSidecarLrc(safUri: safUri, reEnrichResult: result);
-    }
-
-    if (_hasTextValue(downloadedCoverPath)) {
-      await _safeDeleteTempFile(downloadedCoverPath!);
-    }
-    if (_hasTextValue(extractedCoverPath)) {
-      await _cleanupTempFileAndParentDir(extractedCoverPath!);
-    }
-    if (_hasTextValue(tempPath)) {
-      await _safeDeleteTempFile(tempPath!);
-    }
-
-    if (ffmpegResult != null) {
-      // Filesystem .lrc sidecar. SAF sidecar is written only after
-      // writeTempToSaf succeeds.
-      await writeReEnrichSidecarLrc(
-        audioFilePath: item.filePath,
-        reEnrichResult: result,
-      );
-    }
-
-    return ffmpegResult != null;
-  }
-
   Future<bool> _reEnrichQueueLocalTrack(
     LocalLibraryItem item, {
     List<String>? updateFields,
@@ -179,7 +45,11 @@ extension _QueueTabBatchActions on _QueueTabState {
       return true;
     }
     if (method == 'ffmpeg') {
-      return _applyQueueFfmpegReEnrichResult(item, result);
+      return applyFfmpegReEnrichResult(
+        item: item,
+        result: result,
+        artistTagMode: artistTagMode,
+      );
     }
     return false;
   }

lib/screens/queue_tab_filter_widgets.dart

@@ -952,8 +952,6 @@ extension _QueueTabFilterWidgets on _QueueTabState {
     );
   }
 
-  bool _hasTextValue(String? value) => value != null && value.trim().isNotEmpty;
-
   List<UnifiedLibraryItem> _selectedItemsFromAll(
     List<UnifiedLibraryItem> allItems,
   ) {

lib/utils/ffmpeg_reenrich.dart

@@ -0,0 +1,147 @@
+import 'dart:io';
+
+import 'package:spotiflac_android/services/ffmpeg_service.dart';
+import 'package:spotiflac_android/services/library_database.dart';
+import 'package:spotiflac_android/services/platform_bridge.dart';
+import 'package:spotiflac_android/utils/lyrics_metadata_helper.dart';
+
+bool _hasValue(String? value) => value != null && value.trim().isNotEmpty;
+
+Future<void> _safeDeleteFile(String path) async {
+  try {
+    final file = File(path);
+    if (await file.exists()) {
+      await file.delete();
+    }
+  } catch (_) {}
+}
+
+Future<void> _cleanupTempFileAndParent(String path) async {
+  await _safeDeleteFile(path);
+  try {
+    final parent = File(path).parent;
+    if (await parent.exists()) {
+      await parent.delete();
+    }
+  } catch (_) {}
+}
+
+/// Embeds [result]'s metadata/cover into [item] via FFmpeg while preserving
+/// existing tags, writes the output back through SAF when the source was staged
+/// to a temp file, drops the filesystem .lrc sidecar, and cleans up every temp
+/// artifact (including on the SAF-write failure path). Returns true when the
+/// FFmpeg step produced an output.
+///
+/// Shared by the local-album and queue batch re-enrich flows. The track-detail
+/// screen keeps its own copy because it drives snackbars and does not preserve
+/// existing metadata.
+Future<bool> applyFfmpegReEnrichResult({
+  required LocalLibraryItem item,
+  required Map<String, dynamic> result,
+  required String artistTagMode,
+}) async {
+  final tempPath = result['temp_path'] as String?;
+  final safUri = result['saf_uri'] as String?;
+  final ffmpegTarget = _hasValue(tempPath) ? tempPath! : item.filePath;
+  final downloadedCoverPath = result['cover_path'] as String?;
+  String? effectiveCoverPath = downloadedCoverPath;
+  String? extractedCoverPath;
+
+  if (!_hasValue(effectiveCoverPath)) {
+    try {
+      final tempDir = await Directory.systemTemp.createTemp('reenrich_cover_');
+      final coverOutput = '${tempDir.path}${Platform.pathSeparator}cover.jpg';
+      final extracted = await PlatformBridge.extractCoverToFile(
+        ffmpegTarget,
+        coverOutput,
+      );
+      if (extracted['error'] == null) {
+        effectiveCoverPath = coverOutput;
+        extractedCoverPath = coverOutput;
+      } else {
+        try {
+          await tempDir.delete(recursive: true);
+        } catch (_) {}
+      }
+    } catch (_) {}
+  }
+
+  final metadata = (result['metadata'] as Map<String, dynamic>?)?.map(
+    (k, v) => MapEntry(k, v.toString()),
+  );
+
+  final format = item.format?.toLowerCase();
+  final lowerPath = item.filePath.toLowerCase();
+  final isMp3 = format == 'mp3' || lowerPath.endsWith('.mp3');
+  final isM4A =
+      format == 'm4a' ||
+      format == 'aac' ||
+      lowerPath.endsWith('.m4a') ||
+      lowerPath.endsWith('.aac');
+  final isOpus =
+      format == 'opus' ||
+      format == 'ogg' ||
+      lowerPath.endsWith('.opus') ||
+      lowerPath.endsWith('.ogg');
+
+  String? ffmpegResult;
+  if (isMp3) {
+    ffmpegResult = await FFmpegService.embedMetadataToMp3(
+      mp3Path: ffmpegTarget,
+      coverPath: effectiveCoverPath,
+      metadata: metadata,
+      preserveMetadata: true,
+    );
+  } else if (isM4A) {
+    ffmpegResult = await FFmpegService.embedMetadataToM4a(
+      m4aPath: ffmpegTarget,
+      coverPath: effectiveCoverPath,
+      metadata: metadata,
+      preserveMetadata: true,
+    );
+  } else if (isOpus) {
+    ffmpegResult = await FFmpegService.embedMetadataToOpus(
+      opusPath: ffmpegTarget,
+      coverPath: effectiveCoverPath,
+      metadata: metadata,
+      artistTagMode: artistTagMode,
+      preserveMetadata: true,
+    );
+  }
+
+  if (ffmpegResult != null && _hasValue(tempPath) && _hasValue(safUri)) {
+    final ok = await PlatformBridge.writeTempToSaf(ffmpegResult, safUri!);
+    if (!ok) {
+      if (_hasValue(downloadedCoverPath)) {
+        await _safeDeleteFile(downloadedCoverPath!);
+      }
+      if (_hasValue(extractedCoverPath)) {
+        await _cleanupTempFileAndParent(extractedCoverPath!);
+      }
+      await _safeDeleteFile(tempPath!);
+      return false;
+    }
+    await writeReEnrichSafSidecarLrc(safUri: safUri, reEnrichResult: result);
+  }
+
+  if (_hasValue(downloadedCoverPath)) {
+    await _safeDeleteFile(downloadedCoverPath!);
+  }
+  if (_hasValue(extractedCoverPath)) {
+    await _cleanupTempFileAndParent(extractedCoverPath!);
+  }
+  if (_hasValue(tempPath)) {
+    await _safeDeleteFile(tempPath!);
+  }
+
+  if (ffmpegResult != null) {
+    // Filesystem .lrc sidecar. SAF sidecar is written only after
+    // writeTempToSaf succeeds.
+    await writeReEnrichSidecarLrc(
+      audioFilePath: item.filePath,
+      reEnrichResult: result,
+    );
+  }
+
+  return ffmpegResult != null;
+}