Genarrative/packages/shared/src/utils/signedReadUrlCache.ts

export const SIGNED_READ_URL_CACHE_SAFETY_WINDOW_MS = 30 * 1000;

export type SignedReadUrlCacheEntry = {
  signedUrl: string;
  expiresAtMs: number;
};

export function parseSignedReadUrlExpiresAtMs(expiresAt: string) {
  if (!expiresAt) {
    return 0;
  }

  const parsed = Date.parse(expiresAt);
  return Number.isFinite(parsed) ? parsed : 0;
}

export function shouldReuseSignedReadUrlCacheEntry(
  entry: SignedReadUrlCacheEntry | undefined,
  nowMs = Date.now(),
) {
  if (!entry) {
    return false;
  }

  return entry.expiresAtMs - SIGNED_READ_URL_CACHE_SAFETY_WINDOW_MS > nowMs;
}