search: cache results

server/src/search-cache.ts

@@ -0,0 +1,29 @@
+export const SEARCH_QUERY_CACHE_TTL_MS = 24 * 60 * 60 * 1000;
+
+export function normalizeSearchQuery(value: string | null | undefined) {
+  const normalized = value?.trim().toLowerCase() ?? "";
+  return normalized || null;
+}
+
+export function hasReusableSearchPayload(candidate: { resultCount: number; answerText?: string | null }) {
+  return candidate.resultCount > 0 || Boolean(candidate.answerText?.trim());
+}
+
+export function isFreshSearchCacheHit(
+  candidate: {
+    updatedAt: Date | string;
+    resultCount: number;
+    answerText?: string | null;
+    isActive?: boolean;
+  },
+  now = new Date(),
+  ttlMs = SEARCH_QUERY_CACHE_TTL_MS
+) {
+  if (candidate.isActive) return false;
+  if (!hasReusableSearchPayload(candidate)) return false;
+
+  const updatedAtMs = new Date(candidate.updatedAt).getTime();
+  if (!Number.isFinite(updatedAtMs)) return false;
+
+  return now.getTime() - updatedAtMs <= ttlMs;
+}