fix: og image generation

lib/og.ts

@@ -6,6 +6,7 @@
  */
 
 import { BOOK_NAMES, CC_LILAS } from "@/lib/constants";
+import { decodeTextFragment } from "@/lib/text-highlight";
 
 const SITE_URL =
   process.env.NEXT_PUBLIC_SITE_URL || "https://prabhupadasays.org";
@@ -297,6 +298,43 @@ export function ogForLettersByLocation(location: string, count: number) {
   });
 }
 
+// ---------------------------------------------------------------------------
+// hl= query param → OG quote extraction
+// ---------------------------------------------------------------------------
+
+/**
+ * Extract a display quote from the `?hl=` search param.
+ *
+ * The `hl` param encodes `prefix,suffix,length`. We reconstruct a readable
+ * snippet from the prefix + suffix: "first few words ... last few words"
+ *
+ * Returns null if hl is missing or invalid.
+ */
+export function extractQuoteFromHl(
+  searchParams: Record<string, string | string[] | undefined> | URLSearchParams,
+): string | null {
+  const raw =
+    searchParams instanceof URLSearchParams
+      ? searchParams.get("hl")
+      : typeof searchParams.hl === "string"
+        ? searchParams.hl
+        : null;
+
+  if (!raw) return null;
+
+  const fragment = decodeTextFragment(raw);
+  if (!fragment) return null;
+
+  const { prefix, suffix } = fragment;
+  if (!prefix) return null;
+
+  if (suffix && suffix !== prefix) {
+    return `${prefix} ... ${suffix}`;
+  }
+
+  return prefix;
+}
+
 /** Default OG metadata for the site. */
 export function ogDefault() {
   return buildOgMeta({