Added the import/cleanup functionality

src/indexer.rs

@@ -106,7 +106,7 @@ async fn process_file(
         bitrate: Set(meta.bitrate),
         file_size: Set(scanned.file_size),
         fingerprint: NotSet,
-        musicbrainz_id: NotSet,
+        musicbrainz_id: Set(meta.musicbrainz_recording_id),
         artist_id: Set(artist_id),
         album_id: Set(album_id),
         file_mtime: Set(Some(scanned.mtime)),

src/metadata.rs

@@ -22,6 +22,7 @@ pub struct MusicMetadata {
     pub duration: Option<f64>,
     pub codec: Option<String>,
     pub bitrate: Option<i32>,
+    pub musicbrainz_recording_id: Option<String>,
 }
 
 /// Map lofty FileType to a human-readable codec string.
@@ -74,6 +75,10 @@ pub fn extract_metadata(path: &Path) -> IndexResult<MusicMetadata> {
         meta.album_artist = tag
             .get_string(&lofty::tag::ItemKey::AlbumArtist)
             .map(|s| s.to_string());
+
+        meta.musicbrainz_recording_id = tag
+            .get_string(&lofty::tag::ItemKey::MusicBrainzRecordingId)
+            .map(|s| s.to_string());
     }
 
     Ok(meta)