feat(subsonic): expose all album genres in a list of subsonic api

expose album genres from getArtist

server/ctrlsubsonic/spec/construct_by_tags.go

@@ -15,7 +15,6 @@ func NewAlbumByTags(a *db.Album, artists []*db.Artist) *Album {
 		Name:          a.TagTitle,
 		Year:          a.TagYear,
 		TrackCount:    a.ChildCount,
-		Genre:         strings.Join(a.GenreStrings(), ", "),
 		Duration:      a.Duration,
 		AverageRating: formatRating(a.AverageRating),
 	}
@@ -41,6 +40,12 @@ func NewAlbumByTags(a *db.Album, artists []*db.Artist) *Album {
 			Name: a.Name,
 		})
 	}
+	if len(a.Genres) > 0 {
+		ret.Genre = a.Genres[0].Name
+	}
+	for _, g := range a.Genres {
+		ret.Genres = append(ret.Genres, g.Name)
+	}
 	return ret
 }
 

server/ctrlsubsonic/spec/spec.go

@@ -134,6 +134,7 @@ type Album struct {
 	TrackCount int           `xml:"songCount,attr"         json:"songCount"`
 	Duration   int           `xml:"duration,attr"          json:"duration"`
 	Genre      string        `xml:"genre,attr,omitempty"   json:"genre,omitempty"`
+	Genres     []string      `xml:"genres,omitempty"       json:"genres,omitempty"`
 	Year       int           `xml:"year,attr,omitempty"    json:"year,omitempty"`
 	Tracks     []*TrackChild `xml:"song,omitempty"         json:"song,omitempty"`
 	// star / rating