feat(F-056): completed feature

project/apps/admin/src/app/api/upload/route.ts

@@ -14,6 +14,9 @@ const PEER_UPLOAD_DIRS = [
   path.join(process.cwd(), '..', '..', 'storefront', 'public', 'uploads'),
 ];
 
+/** Thumbnail widths pre-generated for lists (40px) and previews (200px). */
+const THUMBNAIL_WIDTHS = [40, 200];
+
 async function mirrorToPeers(filePath: string): Promise<void> {
   await Promise.allSettled(
     PEER_UPLOAD_DIRS.map(async (dir) => {
@@ -23,6 +26,34 @@ async function mirrorToPeers(filePath: string): Promise<void> {
   );
 }
 
+/**
+ * Generate the 40px/200px thumbnails for every upload directory right after
+ * the file lands on disk, so list and preview URLs (`/uploads/40/<file>` and
+ * `/uploads/200/<file>`) resolve without waiting for the batch script.
+ * Failures are non-fatal: the dynamic `/uploads/[...path]` handler regenerates
+ * missing thumbnails on demand.
+ */
+async function generateThumbnails(buffer: Buffer, filename: string): Promise<void> {
+  let sharp: (input: Buffer) => import('sharp').Sharp;
+  try {
+    ({ default: sharp } = await import('sharp'));
+  } catch {
+    return;
+  }
+
+  const targets = [path.join(process.cwd(), 'public', 'uploads'), ...PEER_UPLOAD_DIRS];
+  await Promise.allSettled(
+    targets.flatMap((dir) =>
+      THUMBNAIL_WIDTHS.map(async (width) => {
+        const thumbDir = path.join(dir, String(width));
+        await mkdir(thumbDir, { recursive: true });
+        const resized = await sharp(buffer).resize({ width, withoutEnlargement: true }).toBuffer();
+        await writeFile(path.join(thumbDir, filename), resized);
+      }),
+    ),
+  );
+}
+
 const API = process.env.NEXT_PUBLIC_API_URL ?? 'http://127.0.0.1:3000';
 const MAX_SIZE = 10 * 1024 * 1024;
 const EXTENSION_BY_TYPE: Readonly<Record<string, string>> = {
@@ -70,6 +101,7 @@ export async function POST(request: NextRequest) {
     await mkdir(uploadDir, { recursive: true });
     await writeFile(filePath, buffer, { flag: 'wx' });
     await mirrorToPeers(filePath);
+    await generateThumbnails(buffer, filename);
 
     return NextResponse.json({
       url: `/uploads/${filename}`,