import { URL } from '@gjsify/url';
import type Request from '../request.js';
/**
 * @external URL
 * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/URL URL}
 */
/**
 * @module utils/referrer
 * @private
 */
/**
 * @see {@link https://w3c.github.io/webappsec-referrer-policy/#strip-url Referrer Policy §8.4. Strip url for use as a referrer}
 * @param url
 * @param originOnly
 */
export declare function stripURLForUseAsAReferrer(url: null | URL | 'no-referrer', originOnly?: boolean): "no-referrer" | (URL & {
    username: string;
    password: string;
    hash: string;
    pathname: string;
    search: string;
});
/**
 * @see {@link https://w3c.github.io/webappsec-referrer-policy/#enumdef-referrerpolicy enum ReferrerPolicy}
 */
export declare const ReferrerPolicy: Set<string>;
/**
 * @see {@link https://w3c.github.io/webappsec-referrer-policy/#default-referrer-policy default referrer policy}
 */
export declare const DEFAULT_REFERRER_POLICY = "strict-origin-when-cross-origin";
/**
 * @see {@link https://w3c.github.io/webappsec-referrer-policy/#referrer-policies Referrer Policy §3. Referrer Policies}
 * @param referrerPolicy
 * @returns referrerPolicy
 */
export declare function validateReferrerPolicy(referrerPolicy: ReferrerPolicy): ReferrerPolicy;
/**
 * @see {@link https://w3c.github.io/webappsec-secure-contexts/#is-origin-trustworthy Referrer Policy §3.2. Is origin potentially trustworthy?}
 * @param url
 * @returns `true`: "Potentially Trustworthy", `false`: "Not Trustworthy"
 */
export declare function isOriginPotentiallyTrustworthy(url: URL): boolean;
/**
 * @see {@link https://w3c.github.io/webappsec-secure-contexts/#is-url-trustworthy Referrer Policy §3.3. Is url potentially trustworthy?}
 * @param url
 * @returns `true`: "Potentially Trustworthy", `false`: "Not Trustworthy"
 */
export declare function isUrlPotentiallyTrustworthy(url: URL | 'no-referrer'): boolean;
/**
 * Modifies the referrerURL to enforce any extra security policy considerations.
 * @see {@link https://w3c.github.io/webappsec-referrer-policy/#determine-requests-referrer Referrer Policy §8.3. Determine request's Referrer}, step 7
 * @callback module:utils/referrer~referrerURLCallback
 * @param {external:URL} referrerURL
 * @returns {external:URL} modified referrerURL
 */
/**
 * Modifies the referrerOrigin to enforce any extra security policy considerations.
 * @see {@link https://w3c.github.io/webappsec-referrer-policy/#determine-requests-referrer Referrer Policy §8.3. Determine request's Referrer}, step 7
 * @callback module:utils/referrer~referrerOriginCallback
 * @param {external:URL} referrerOrigin
 * @returns {external:URL} modified referrerOrigin
 */
/**
 * @see {@link https://w3c.github.io/webappsec-referrer-policy/#determine-requests-referrer Referrer Policy §8.3. Determine request's Referrer}
 * @param request
 * @param {object} o
 * @param {module:utils/referrer~referrerURLCallback} o.referrerURLCallback
 * @param {module:utils/referrer~referrerOriginCallback} o.referrerOriginCallback
 * @returns {external:URL} Request's referrer
 */
export declare function determineRequestsReferrer(request: Request, obj?: {
    referrerURLCallback?: (url: URL | 'no-referrer') => URL;
    referrerOriginCallback?: (url: URL | 'no-referrer') => URL;
}): URL | string;
/**
 * @see {@link https://w3c.github.io/webappsec-referrer-policy/#parse-referrer-policy-from-header|Referrer Policy §8.1. Parse a referrer policy from a Referrer-Policy header}
 * @param {Headers} headers Response headers
 * @returns {string} policy
 */
export declare function parseReferrerPolicyFromHeader(headers: {
    get(name: string): string | null;
}): ReferrerPolicy;