Fix Persian user-product URL redirect loop.

Compare decoded/NFC slugs and stop percent-encoding path segments so detail pages no longer 307 themselves into a white screen.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/app/user-products/[id]/[slug]/page.tsx

@@ -13,6 +13,7 @@ import {
   getUserProductByIdOrNull,
   getUserProductTechnicalInfoById,
   listUserProducts,
+  normalizePathSlug,
   productCategory,
   productTitle,
   userProductHref,
@@ -51,7 +52,7 @@ export default async function UserProductDetailPage({ params }: PageProps) {
   if (!product) notFound();
 
   const canonicalSlug = userProductPathSlug(product);
-  if (slug !== canonicalSlug) {
+  if (normalizePathSlug(slug) !== canonicalSlug) {
     redirect(userProductHref(product));
   }
 

src/lib/api/user-products.ts

@@ -77,22 +77,36 @@ export function slugifyForUrl(value: string, fallback = "user-product") {
   return slug || fallback;
 }
 
+/** Decode + NFC so route params and API pathSlug compare safely. */
+export function normalizePathSlug(value: string) {
+  let decoded = value.trim();
+  try {
+    decoded = decodeURIComponent(decoded);
+  } catch {
+    /* already decoded or malformed — keep as-is */
+  }
+  return decoded.normalize("NFC").trim();
+}
+
 export function userProductPathSlug(
   product: Pick<UserProductListItem, "pathSlug" | "titleFa" | "titleEn">,
 ) {
   const fromApi = product.pathSlug?.trim();
-  if (fromApi) return fromApi;
+  if (fromApi) return normalizePathSlug(fromApi);
   return slugifyForUrl(
     product.titleFa?.trim() || product.titleEn?.trim() || "",
     "user-product",
   );
 }
 
-/** Canonical storefront path: `/user-products/{id}/{pathSlug}`. */
+/**
+ * Canonical storefront path: `/user-products/{id}/{pathSlug}`.
+ * Leave Unicode unencoded — encoding + Next param decoding caused redirect loops.
+ */
 export function userProductHref(
   product: Pick<UserProductListItem, "id" | "pathSlug" | "titleFa" | "titleEn">,
 ) {
-  return `/user-products/${encodeURIComponent(product.id)}/${encodeURIComponent(userProductPathSlug(product))}`;
+  return `/user-products/${product.id}/${userProductPathSlug(product)}`;
 }
 
 export async function listUserProducts(params: ListUserProductsParams = {}) {