import { Func } from '../types.ts';
/**
 * Error thrown when the maximum number of retries is reached.
 */
export declare class RetryError extends Error {
    constructor(message: string);
}
export declare const isRetryError: (error: unknown) => error is RetryError;
export interface RetryOptions {
    /**
     * Number of retries
     *
     * @default 3
     */
    retries?: number;
    /**
     * Delay between retries
     *
     * @default 0
     */
    delay?: number;
    /**
     * Multiplier for the delay between retries
     *
     * @default 1
     */
    backoff?: number;
    /**
     * Jitter factor for the delay between retries
     *
     * @default 0
     */
    jitterFactor?: number;
    /**
     * Function to determine if the function should be retried
     *
     * @param error error to check
     * @returns true if the function should be retried
     */
    shouldRetry?: (error: Error) => boolean;
    /**
     * Abort signal to cancel the retry
     */
    signal?: AbortSignal;
    /**
     * Throw the last error encountered if all retries fail
     *
     * @default false
     */
    throwLastError?: boolean;
    /**
     * Callback invoked before each retry attempt
     *
     * @param error last error encountered
     * @param attempt current attempt number
     */
    onRetry?: (error: Error, attempt: number) => void | Promise<void>;
    /**
     * Callback invoked after all retry attempts have been exhausted.
     * Use to take over error handling and return a fallback value.
     *
     * @param error last error encountered
     * @param args original function arguments
     * @returns fallback value
     */
    onRetryExhausted?: (error: Error) => ReturnType<Func> | Promise<ReturnType<Func>>;
}
/**
 * Retries a function until it succeeds or the number of retries is reached.
 * @param fn function to retry
 * @param opts options
 * @returns
 *
 * @example
 *
 * const fetchData = retry(
 *     async () => {
 *         const response = await fetch('https://api.example.com/data');
 *         return response.json();
 *     },
 *     {
 *         retries: 3,
 *         delay: 1000,
 *         backoff: 2,
 *         shouldRetry: (error) => error.message.includes('500')
 *     }
 * );
 *
 * const data = await fetchData();
 *
 */
export declare const retry: <T extends Func>(fn: T, opts: RetryOptions) => Promise<ReturnType<T>>;
/**
 * Makes a function retryable.
 * @param fn function to make retryable
 * @param opts options
 * @returns retryable function
 */
export declare const makeRetryable: <T extends Func>(fn: T, opts: RetryOptions) => T;