adding shazam, and LRClib support

core/metadata.py

@@ -0,0 +1,58 @@
+"""Read audio file tags via mutagen. Always safe — never raises."""
+from __future__ import annotations
+
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Optional
+
+
+@dataclass
+class TrackMetadata:
+    title: Optional[str] = None
+    artist: Optional[str] = None
+    album: Optional[str] = None
+    duration: Optional[float] = None
+    has_identity: bool = False
+
+
+def read_metadata(path: Path) -> TrackMetadata:
+    """Extract title/artist/album/duration from tags. Never raises."""
+    try:
+        from mutagen import File
+    except ImportError:
+        return TrackMetadata()
+
+    try:
+        audio = File(str(path), easy=True)
+    except Exception:
+        return TrackMetadata()
+
+    if audio is None:
+        return TrackMetadata()
+
+    def _first(key: str) -> Optional[str]:
+        v = audio.get(key)
+        if isinstance(v, list):
+            return v[0] if v else None
+        if isinstance(v, str):
+            return v
+        return None
+
+    title = _first("title")
+    artist = _first("artist")
+    album = _first("album")
+
+    duration: Optional[float] = None
+    try:
+        if audio.info is not None:
+            duration = float(audio.info.length)
+    except Exception:
+        pass
+
+    return TrackMetadata(
+        title=title,
+        artist=artist,
+        album=album,
+        duration=duration,
+        has_identity=bool(title and artist),
+    )