async function getCachedUser(id: string) {
  const cached = await redis.get(`user:${id}`);
  if (cached) return JSON.parse(cached);

  const user = await db.user.findUnique({ where: { id } });
  await redis.setex(`user:${id}`, 3600, JSON.stringify(user));
  return user;
}

async function rateLimit(ip: string, limit = 100, window = 60) {
  const key = `ratelimit:${ip}`;
  const count = await redis.incr(key);
  if (count === 1) await redis.expire(key, window);
  return count <= limit;
}