/**
 * Simple retry wrapper with exponential backoff.
 * Usage: await withRetry(() => someAsyncCall(), { retries: 3 })
 */

async function withRetry(fn, options = {}) {
  const {
    retries = 3,
    initialDelayMs = 500,
    maxDelayMs = 5000,
    factor = 2,
    onRetry = null,
  } = options;

  let attempt = 0;
  let delay = initialDelayMs;

  while (true) {
    try {
      return await fn();
    } catch (err) {
      attempt++;

      if (attempt > retries) {
        throw err;
      }

      if (onRetry) {
        onRetry(err, attempt);
      }

      await new Promise(resolve => setTimeout(resolve, delay));
      delay = Math.min(delay * factor, maxDelayMs);
    }
  }
}

module.exports = { withRetry };