import { randomBytes, scryptSync, timingSafeEqual } from "crypto";

const KEY_LENGTH = 64;

export const hashPassword = (password: string): string => {
  const salt = randomBytes(16).toString("hex");
  const hash = scryptSync(password, salt, KEY_LENGTH).toString("hex");
  return `scrypt:${salt}:${hash}`;
};

export const verifyPassword = (
  password: string,
  stored: string,
): boolean => {
  const [scheme, salt, hash] = stored.split(":");
  if (scheme !== "scrypt" || !salt || !hash) return false;

  const candidate = scryptSync(password, salt, KEY_LENGTH);
  const expected = Buffer.from(hash, "hex");

  return (
    candidate.length === expected.length && timingSafeEqual(candidate, expected)
  );
};
