quiz seo image and authguard

lib/og.ts

@@ -318,6 +318,68 @@ export function ogForLettersByLocation(location: string, count: number) {
   });
 }
 
+// ---------------------------------------------------------------------------
+// Quizzes
+// ---------------------------------------------------------------------------
+
+const QUIZ_DESCRIPTION =
+  "Test your understanding of Śrīla Prabhupāda's books, lectures and conversations.";
+
+const QUIZ_KIND_LABEL: Record<string, string> = {
+  chapter: "Book chapter",
+  lecture: "Lecture",
+  conversation: "Conversation",
+};
+
+/**
+ * Admin text carries light formatting markers (*bold*, _italic_, links…).
+ * A preview card wants the words only.
+ */
+function stripRichMarkers(text: string): string {
+  return text
+    .replace(/\[([^\]\n]+)\]\((https?:\/\/[^\s)]+)\)/g, "$1")
+    .replace(/__([^_\n]+?)__/g, "$1")
+    .replace(/\*([^*\n]+?)\*/g, "$1")
+    .replace(/~([^~\n]+?)~/g, "$1")
+    .replace(/(^|\W)_([^_\n]+?)_(?=\W|$)/g, "$1$2")
+    .replace(/\s+/g, " ")
+    .trim();
+}
+
+/** OG metadata for a single quiz. */
+export function ogForQuiz(quiz: {
+  title: string;
+  description?: string;
+  target_kind: string;
+  target_title?: string;
+  question_count: number;
+}) {
+  const kind = QUIZ_KIND_LABEL[quiz.target_kind];
+  const count = `${quiz.question_count} question${quiz.question_count === 1 ? "" : "s"}`;
+  const detail = [
+    "Quiz",
+    kind && quiz.target_title ? `${kind}: ${quiz.target_title}` : null,
+    count,
+  ]
+    .filter(Boolean)
+    .join(" · ");
+  const about = stripRichMarkers(quiz.description ?? "");
+  return buildOgMeta({
+    title: quiz.title,
+    detail,
+    quote: about || QUIZ_DESCRIPTION,
+  });
+}
+
+/** OG metadata for the /quizzes index. */
+export function ogForQuizzes() {
+  return buildOgMeta({
+    title: "Quizzes",
+    detail: "Prabhupāda Says",
+    quote: QUIZ_DESCRIPTION,
+  });
+}
+
 // ---------------------------------------------------------------------------
 // hl= query param → OG quote extraction
 // ---------------------------------------------------------------------------