Make gallery cover index variable

boop.py

@@ -24,13 +24,14 @@ def list_galleries_in(path):
             continue
 
         photos.sort(key=itemgetter("name"))
+        cover_index = (len(gallery_dir.name) + 42) % len(photos)
         gallery = {
             "name": gallery_dir.name,
             "path": gallery_dir.path,
             "url": gallery_dir.name,
             "num_photos": len(photos),
             "photos": photos,
-            "cover_photo": photos[0],
+            "cover_photo": photos[cover_index],
         }
         yield gallery