feat: add support for multi-disc albums

app/api/red-template/route.ts

@@ -34,6 +34,10 @@ export async function POST(request: Request) {
         // Sort tracks
         tracks.sort((a, b) => {
             if ('error' in a || 'error' in b) return 0;
+            const discA = a.common?.disk?.no ?? 1;
+            const discB = b.common?.disk?.no ?? 1;
+            if (discA !== discB) return discA - discB;
+
             const trackA = a.common?.track?.no ?? 0;
             const trackB = b.common?.track?.no ?? 0;
             if (trackA && trackB) return trackA - trackB;
@@ -58,13 +62,24 @@ export async function POST(request: Request) {
             if (!sr || sr < 48000 || !bd || bd < 24) isHiRes = false;
         });
 
+        const discNumbers = new Set(
+            tracks.map(t => ('error' in t ? 1 : (t.common?.disk?.no || 1)))
+        );
+        const isMultiDisc = discNumbers.size > 1 || Array.from(discNumbers).some(d => d > 1);
+
         if (sampleRates.size > 1 || bitDepths.size > 1) {
             mixed = true;
             qualityDetails = `\n\nNOTE: Mixed formats. Sample Rates: ${Array.from(sampleRates).join(', ')} Hz. Bit Depths: ${Array.from(bitDepths).join(', ')} bit.`;
 
             const mixedDetails = tracks.map(t => {
                 if ('error' in t) return `${t.filename}: Error`;
-                return `Track ${t.common?.track?.no || '?'}: ${t.format?.bitsPerSample}bit / ${t.format?.sampleRate}Hz`;
+                const discNo = t.common?.disk?.no || 1;
+                const trackNo = t.common?.track?.no;
+                let trackStr = trackNo !== undefined && trackNo !== null ? String(trackNo).padStart(2, '0') : '?';
+                if (isMultiDisc) {
+                    trackStr = `${discNo}-${trackStr}`;
+                }
+                return `Track ${trackStr}: ${t.format?.bitsPerSample}bit / ${t.format?.sampleRate}Hz`;
             }).join('\n');
 
             qualityDetails += '\n' + mixedDetails;
@@ -155,10 +170,32 @@ export async function POST(request: Request) {
         }
 
         // Tracklist
-        const tracklist = tracks.map(t => {
-            if ('error' in t) return `${t.filename} (Error)`;
-            return `${t.common?.track?.no || '00'}. ${t.common?.title || t.filename}`;
-        }).join('\n');
+
+        let currentDisc: number | null = null;
+        const tracklistLines: string[] = [];
+
+        tracks.forEach(t => {
+            if ('error' in t) {
+                tracklistLines.push(`${t.filename} (Error)`);
+                return;
+            }
+
+            const discNo = t.common?.disk?.no || 1;
+            const trackNo = t.common?.track?.no
+                ? String(t.common.track.no).padStart(2, '0')
+                : '00';
+
+            if (isMultiDisc && discNo !== currentDisc) {
+                if (currentDisc !== null) tracklistLines.push('');
+                tracklistLines.push(`[b]Disc ${discNo}[/b]`);
+                currentDisc = discNo;
+            }
+
+            const trackLabel = isMultiDisc ? `${discNo}-${trackNo}` : trackNo;
+            tracklistLines.push(`${trackLabel}. ${t.common?.title || t.filename}`);
+        });
+
+        const tracklist = tracklistLines.join('\n');
 
         // Description
         let description = "Sourced from TIDAL";