const jitter = Math.random() * 100;
const delay = baseDelay * 2 ** attempt + jitter;

async function fetchWithRetry(url, options = {}, maxRetries = 5, baseDelay = 500) {
  for (let attempt = 0; attempt <= maxRetries; attempt++) {
    try {
      const response = await fetch(url, options);
      if (!response.ok && response.status >= 500) {
        throw new Error(`Server error: ${response.status}`);
      }
      return response;
    } catch (error) {
      if (attempt === maxRetries) {
        throw new Error(`Failed after ${maxRetries + 1} attempts: ${error.message}`);
      }
      const backoff = baseDelay * 2 ** attempt;
      const jitter = Math.random() * 100;
      const delay = backoff + jitter;
      console.warn(`Attempt ${attempt + 1} failed. Retrying in ${delay.toFixed(0)}ms...`);
      await new Promise((r) => setTimeout(r, delay));
    }
  }
}

// Pseudo-code lưu thông tin retry trong Redis
const retryKey = `retry:${jobId}`;
const attempt = await redis.get(retryKey) || 0;
if (attempt > maxRetries) throw new Error('Too many retries');
await redis.set(retryKey, attempt + 1, 'EX', retryExpirySeconds);