/**
 * Retry utility with exponential backoff
 */

export interface RetryOptions {
  maxRetries?: number
  initialDelay?: number
  maxDelay?: number
  backoffMultiplier?: number
  retryable?: (error: Error) => boolean
}

const DEFAULT_OPTIONS: Required<RetryOptions> = {
  maxRetries: 3,
  initialDelay: 1000,
  maxDelay: 10000,
  backoffMultiplier: 2,
  retryable: () => true,
}

/**
 * Retry a function with exponential backoff
 */
export async function retryWithBackoff<T>(
  fn: () => Promise<T>,
  options: RetryOptions = {}
): Promise<T> {
  const opts = { ...DEFAULT_OPTIONS, ...options }
  let lastError: Error | null = null

  for (let attempt = 0; attempt <= opts.maxRetries; attempt++) {
    try {
      return await fn()
    } catch (error) {
      lastError = error instanceof Error ? error : new Error(String(error))

      // Check if error is retryable
      if (!opts.retryable(lastError)) {
        throw lastError
      }

      // Don't retry on last attempt
      if (attempt === opts.maxRetries) {
        throw lastError
      }

      // Calculate delay with exponential backoff
      const delay = Math.min(
        opts.initialDelay * Math.pow(opts.backoffMultiplier, attempt),
        opts.maxDelay
      )

      // Wait before retrying
      await new Promise((resolve) => setTimeout(resolve, delay))
    }
  }

  throw lastError || new Error('Retry failed')
}

/**
 * Check if an error is a network error that should be retried
 */
export function isRetryableNetworkError(error: Error): boolean {
  // Network errors
  if (error.message.includes('network') || error.message.includes('fetch')) {
    return true
  }

  // Timeout errors
  if (error.message.includes('timeout') || error.message.includes('timed out')) {
    return true
  }

  // Connection errors
  if (error.message.includes('ECONNRESET') || error.message.includes('ECONNREFUSED')) {
    return true
  }

  // Rate limiting (429)
  if (error.message.includes('429') || error.message.includes('rate limit')) {
    return true
  }

  // Server errors (5xx)
  if (error.message.includes('50')) {
    return true
  }

  return false
}