Handle "naked" CoverArtIDs (IDs of album, mediafiles and playlists)

model/artwork_id.go

@@ -34,6 +34,10 @@ func (id ArtworkID) String() string {
 	return fmt.Sprintf("%s-%s", id.Kind.prefix, id.ID)
 }
 
+func NewArtworkID(kind Kind, id string) ArtworkID {
+	return ArtworkID{kind, id}
+}
+
 func ParseArtworkID(id string) (ArtworkID, error) {
 	parts := strings.SplitN(id, "-", 2)
 	if len(parts) != 2 {

model/get_entity.go

@@ -0,0 +1,26 @@
+package model
+
+import (
+	"context"
+)
+
+// TODO: Should the type be encoded in the ID?
+func GetEntityByID(ctx context.Context, ds DataStore, id string) (interface{}, error) {
+	ar, err := ds.Artist(ctx).Get(id)
+	if err == nil {
+		return ar, nil
+	}
+	al, err := ds.Album(ctx).Get(id)
+	if err == nil {
+		return al, nil
+	}
+	pls, err := ds.Playlist(ctx).Get(id)
+	if err == nil {
+		return pls, nil
+	}
+	mf, err := ds.MediaFile(ctx).Get(id)
+	if err == nil {
+		return mf, nil
+	}
+	return nil, err
+}