import { CsrfRequestInit } from './finCsrfFetch';
import { FetchMethod } from './fetchVal';
/**
 * A general authentication error.
 */
export declare class AuthenticationError extends Error {
    /**
     * Used for a type guard check.
     */
    readonly _isAuthenticationError = true;
    /**
     * Error that caused this authentication error to occur
     */
    readonly cause: Error | undefined;
    constructor(cause?: Error, message?: string);
}
/**
 * A type guard for an authentication error.
 *
 * @param value The value to check.
 * @returns The result of the type guard check.
 */
export declare function isAuthenticationError(value: unknown): value is AuthenticationError;
/**
 * An enhanced fetch API for a pluggable authentication mechanism.
 *
 * Transparently handles pre-authentication, authentication fault detection, authentication, and
 * will replay the requested resource upon successful authentication.
 *
 * By default, this fetch function will utilize the finCsrfFetch function internally to execute the request.
 *
 * For example...
 *
 * ```typescript
 * const result = finAuthFetch(request, {
 * 		authenticator: {
 * 			isAuthenticated: (response: Response) => response.status !== 401,
 *			preauthenticate: async (request: RequestInfo) => new Request(request, {headers: {auth_header: '12345'}}),
 *			authenticate: (response: Response) => return execute_authentication(username, password),
 *			maxTries: 3
 * 	}
 * })
 * ```
 *
 * @link https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch
 *
 * @param resource The resource to request.
 * @param options Optional object containing custom settings and the authenticator.
 * @returns A promise that resolves to a response object.
 * @throws Exception on failed authentication
 */
export declare function finAuthFetch(resource: RequestInfo, options?: RequestInit | RequestInitAuth): Promise<Response>;
/**
 * Request Init with Authenticator
 */
export interface RequestInitAuth extends CsrfRequestInit {
    /**
     * Request Authenticator
     */
    authenticator?: RequestAuthenticator;
    /**
     * Pluggable fetch API function
     *
     * @link https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch
     *
     * @param resource The resource to request.
     * @param options Optional object containing any custom settings.
     * @returns A promise that resolves to a response object.
     */
    fetch?: FetchMethod;
}
/**
 * Request Authenticator
 * @interface
 */
export interface RequestAuthenticator {
    /**
     * Is Authenticated
     *
     * This function checkes the response and should determine if the response is returning an authentication fault
     *
     * @param response Response that authentication test should be ran against
     * @retuns true if the response is already authenticated
     */
    isAuthenticated: (response: Response) => Promise<boolean>;
    /**
     * Pre-Authenticate
     *
     * This optional function is used to pre authenticate a request. For example in the case the request
     * is authenticated via a token.
     *
     * @param request to pre authenticate
     * @returns Pre authenticated Request Object
     */
    preAuthenticate?: (request: RequestInfo, options?: RequestInit) => Promise<Request>;
    /**
     * Authenticate
     *
     * This function is used to request authentication. This is where the authentication mechanism is handled.
     *
     * @param Response to authenticate
     * @returns true if authentication was successful
     */
    authenticate: (request: RequestInfo, response?: Response, options?: RequestInit) => Promise<boolean>;
    /**
     * Maximum Tries
     *
     * Number of failed authentication attempts before giving up.
     * @default 3
     */
    maxTries?: number;
}