import { createHash, timingSafeEqual } from "crypto";

export function isAuthorized(header: string | null): boolean {
  const expected = process.env.SYNC_TOKEN;
  if (!expected || !header) return false;
  const match = /^Bearer (\S+)$/.exec(header);
  if (!match) return false;
  const presented = createHash("sha256").update(match[1]).digest();
  const actual = createHash("sha256").update(expected).digest();
  return timingSafeEqual(presented, actual);
}