feat(library): effective genre falls back to MusicBrainz enrichment (#949)

* feat(library): effective genre falls back to MusicBrainz enrichment Converted packs rarely carry a genres manifest key — on Byron's real library 1188/1190 songs had no genre, starving the genre facet and the career passport rack (2 usable genres) while song_enrichment already held MB genres for 636 matched songs. The effective-genre expression now resolves: per-song override → pack genre → json_extract(enrichment.genres, '$[0]') for MATCHED rows only (review/failed candidates could carry the wrong recording's genres). Same fast-path gating as before: the plain indexed column is used unless overrides or enrichment genres actually exist; stand-in DBs without the table degrade via the OperationalError guard. Career passports pick this up automatically through _effective_genre_expr(). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> * docs: changelog names manual rows in the enrichment fallback Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> --------- Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-11 03:09:57 +00:00 · 2026-07-13 16:53:06 +02:00
parent 5921157f35
commit 18d77d2d41
3 changed files with 94 additions and 9 deletions
@@ -1085,26 +1085,57 @@ class MetadataDB:
        vals["artist"], vals["title"] = self._romaji_display(filename, vals["artist"], vals["title"])
        return vals

-    # Effective genre = a per-song genre OVERRIDE (Fix-metadata popup) else the
-    # scanned pack genre. Applied at FILTER/FACET time (like the P4 artist alias)
-    # so a corrected genre is browsable — the correlated subquery is used ONLY
-    # when genre overrides actually exist; the common case stays on the plain
-    # indexed `genre` column. Genre stays a library-only overlay (it isn't a
-    # write-to-file field), so it never touches the pack.
-    _EFFECTIVE_GENRE_SQL = (
+    # Effective genre precedence: per-song OVERRIDE (Fix-metadata popup) →
+    # scanned pack genre → MusicBrainz enrichment primary genre (matched/manual rows
+    # only — a 'review'/'failed' candidate's genres could belong to the wrong
+    # recording). Applied at FILTER/FACET time (like the P4 artist alias) so a
+    # corrected or enriched genre is browsable. The vast majority of converted
+    # packs carry no `genres` manifest key, so without the enrichment leg the
+    # genre facet (and career passports) starve on real libraries. The
+    # correlated subqueries are used ONLY when overrides/enrichment genres
+    # actually exist; the common case stays on the plain indexed `genre`
+    # column. Genre stays a library-only overlay (it isn't a write-to-file
+    # field), so it never touches the pack.
+    _EFFECTIVE_GENRE_OVERRIDE_SQL = (
        "COALESCE((SELECT o.value FROM song_field_override o "
        "WHERE o.filename = songs.filename AND o.field = 'genre' "
        "AND o.value IS NOT NULL AND o.value != ''), genre)"
    )
+    _EFFECTIVE_GENRE_SQL = (
+        "COALESCE((SELECT o.value FROM song_field_override o "
+        "WHERE o.filename = songs.filename AND o.field = 'genre' "
+        "AND o.value IS NOT NULL AND o.value != ''), "
+        "NULLIF(genre, ''), "
+        "(SELECT json_extract(e.genres, '$[0]') FROM song_enrichment e "
+        "WHERE e.filename = songs.filename AND e.match_state IN ('matched', 'manual') "
+        "AND e.genres IS NOT NULL AND e.genres NOT IN ('', '[]')), "
+        "'')"
+    )

    def _has_genre_overrides(self) -> bool:
        return self.conn.execute(
            "SELECT 1 FROM song_field_override WHERE field = 'genre' "
            "AND value IS NOT NULL AND value != '' LIMIT 1").fetchone() is not None

+    def _has_enrichment_genres(self) -> bool:
+        try:
+            return self.conn.execute(
+                "SELECT 1 FROM song_enrichment WHERE match_state IN ('matched', 'manual') "
+                "AND genres IS NOT NULL AND genres NOT IN ('', '[]') "
+                "LIMIT 1").fetchone() is not None
+        except sqlite3.OperationalError:
+            return False  # stand-ins / DBs without the enrichment table
+
    def _effective_genre_expr(self) -> str:
-        """`genre` normally; the override-aware COALESCE only when overrides exist."""
-        return self._EFFECTIVE_GENRE_SQL if self._has_genre_overrides() else "genre"
+        """`genre` normally; the enrichment-aware COALESCE only when trusted
+        enrichment genres exist (which also proves the table exists — a
+        stand-in DB without song_enrichment must never receive SQL that
+        references it); the override-only form when just overrides exist."""
+        if self._has_enrichment_genres():
+            return self._EFFECTIVE_GENRE_SQL
+        if self._has_genre_overrides():
+            return self._EFFECTIVE_GENRE_OVERRIDE_SQL
+        return "genre"

    def set_song_tags(self, filename: str, tags) -> list:
        """Replace ALL of a song's tags with the given set (each normalized;