Support multiple discs and don't overwrite empty artists

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "discogs-tag"
-version = "0.1.3"
+version = "0.1.4"
 description = "A rudimentary audio tagger based on Discogs metadata."
 authors = ["infojunkie <[email protected]>"]
 readme = "README.md"

src/discogs_tag/cli.py

@@ -4,7 +4,7 @@
 import json
 import os
 from pprint import pprint
-from glob import glob
+import glob
 from discogs_tag import __NAME__, __VERSION__
 
 def tag(release, dir = './', dry = False):
@@ -14,15 +14,22 @@ def tag(release, dir = './', dry = False):
   })
   with urllib.request.urlopen(request) as response:
     data = json.load(response)
-    files = sorted(glob(os.path.join(dir, '*.flac')) + glob(os.path.join(dir, '*.mp3')))
+    files = sorted(
+      glob.glob(os.path.join(glob.escape(dir), '**', '*.flac'), recursive=True) +
+      glob.glob(os.path.join(glob.escape(dir), '**', '*.mp3'), recursive=True)
+    )
     tracks = list(filter(lambda t: t['type_'] == 'track', data['tracklist']))
     if (len(files) != len(tracks)):
       raise Exception(f'Expecting {len(tracks)} files but found {len(files)}. Aborting.')
     for n, track in enumerate(tracks):
       audio = mutagen.File(files[n], easy=True)
       audio['title'] = track['title']
-      audio['artist'] = ', '.join([artist_name(artist) for artist in track['artists']]) if 'artists' in track else ''
-      audio['tracknumber'] = track['position']
+      if 'artists' in track:
+        audio['artist'] = ', '.join([artist_name(artist) for artist in track['artists']])
+      positions = track['position'].split('-')
+      audio['tracknumber'] = positions[-1]
+      if (len(positions) > 1):
+        audio['discnumber'] = positions[0]
       composers = ', '.join([artist_name(composer) for composer in filter(lambda a: a['role'].casefold() == 'Written-By'.casefold(), track['extraartists'])]) if 'extraartists' in track else None
       if (composers):
         audio['composer'] = composers