add support for disc subtitles from subsonic discTitles field (#1609)

src/shared/api/subsonic/subsonic-normalize.ts

@@ -134,6 +134,7 @@ const normalizeSong = (
     pathReplace?: string,
     pathReplaceWith?: string,
     playlistIndex?: number,
+    discTitleMap?: Map<number, string>,
 ): Song => {
     const participants = getParticipants(item);
 
@@ -156,7 +157,7 @@ const normalizeSong = (
         container: item.contentType,
         createdAt: item.created,
         discNumber: item.discNumber || 1,
-        discSubtitle: null,
+        discSubtitle: discTitleMap?.get(item.discNumber ?? 1) ?? null,
         duration: item.duration ? item.duration * 1000 : 0,
         explicitStatus:
             item.explicitStatus === 'explicit'
@@ -267,6 +268,12 @@ const normalizeAlbum = (
     pathReplace?: string,
     pathReplaceWith?: string,
 ): Album => {
+    const discTitleMap = new Map<number, string>();
+
+    (item as z.infer<typeof ssType._response.album>).discTitles?.forEach((discTitle) => {
+        discTitleMap.set(discTitle.disc, discTitle.title);
+    });
+
     const releaseDate =
         item.releaseDate &&
         typeof item.releaseDate.year === 'number' &&
@@ -312,7 +319,7 @@ const normalizeAlbum = (
         songCount: item.songCount,
         songs:
             (item as z.infer<typeof ssType._response.album>).song?.map((song) =>
-                normalizeSong(song, server, pathReplace, pathReplaceWith),
+                normalizeSong(song, server, pathReplace, pathReplaceWith, undefined, discTitleMap),
             ) || [],
         tags: null,
         updatedAt: item.created,