feat: add support for multi-disc albums

lib/utils/audio.ts

@@ -1,4 +1,5 @@
 import { parseFile } from 'music-metadata';
+import path from 'path';
 
 export interface AudioMetadata {
     format: {
@@ -39,6 +40,26 @@ export async function getFlacMetadata(filePath: string): Promise<AudioMetadata>
             //console.log(metadata.native.vorbis);
         }
 
+        const filename = path.basename(filePath);
+        let diskNo = metadata.common.disk?.no;
+        let trackNo = metadata.common.track?.no;
+
+        // Extract disc and track number from multi-disc filename prefix e.g. "1-03 - Title"
+        const multiDiscMatch = filename.match(/^(\d+)-(\d+)\b/);
+        if (multiDiscMatch) {
+            if (!diskNo) diskNo = parseInt(multiDiscMatch[1], 10);
+            if (!trackNo) trackNo = parseInt(multiDiscMatch[2], 10);
+        }
+
+        const trackObj = {
+            no: trackNo ?? metadata.common.track?.no ?? null,
+            of: metadata.common.track?.of ?? null
+        };
+        const diskObj = {
+            no: diskNo ?? metadata.common.disk?.no ?? null,
+            of: metadata.common.disk?.of ?? null
+        };
+
         return {
             format: {
                 sampleRate: metadata.format.sampleRate,
@@ -50,8 +71,8 @@ export async function getFlacMetadata(filePath: string): Promise<AudioMetadata>
                 title: metadata.common.title,
                 artist: metadata.common.artist,
                 album: metadata.common.album,
-                track: metadata.common.track,
-                disk: metadata.common.disk,
+                track: trackObj,
+                disk: diskObj,
                 year: metadata.common.year,
                 date: metadata.common.date,
                 copyright: metadata.common.copyright,