Exponential Backoff Retry for API Calls

async function fetchWithExponentialBackoff(url, options = {}, retries = 3, delay = 1000) {
  try {
    const response = await fetch(url, options);
    if (!response.ok) {
      if (response.status >= 500 && retries > 0) { // Retry for server errors
        console.warn(`Attempt failed for ${url}. Retrying in ${delay / 1000}s... (${retries} retries left)`);
        await new Promise(res => setTimeout(res, delay));
        return fetchWithExponentialBackoff(url, options, retries - 1, delay * 2); // Exponentially increase delay
      }
      throw new Error(`HTTP error! status: ${response.status} for ${url}`);
    }
    return await response.json();
  } catch (error) {
    if (retries > 0 && error.name === 'TypeError') { // Network errors like 'Failed to fetch'
        console.warn(`Network error for ${url}. Retrying in ${delay / 1000}s... (${retries} retries left)`);
        await new Promise(res => setTimeout(res, delay));
        return fetchWithExponentialBackoff(url, options, retries - 1, delay * 2);
    }
    console.error(`Final attempt failed for ${url}:`, error);
    throw error;
  }
}

// Example Usage:
// fetchWithExponentialBackoff('https://api.example.com/unreliable-service', {}, 5, 500) // 5 retries, starting with 0.5s delay
//   .then(data => console.log('Successfully fetched:', data))
//   .catch(error => console.error('Failed after multiple retries:', error));

// // To test network error, you can make it call a non-existent domain:
// // fetchWithExponentialBackoff('https://nonexistent-domain-test.com/data', {}, 3, 200)
// //   .then(data => console.log('Successfully fetched:', data))
// //   .catch(error => console.error('Failed after multiple retries:', error));