import { SiteInfo } from '@sitecore-jss/sitecore-jss/site';
import { NextRequest, NextResponse } from 'next/server';
export type MiddlewareBaseConfig = {
    /**
     * function, determines if middleware should be turned off, based on cookie, header, or other considerations
     * @param {NextRequest} [req] request object from middleware handler
     * @param {NextResponse} [res] response object from middleware handler
     */
    disabled?: (req?: NextRequest, res?: NextResponse) => boolean;
    /**
     * Function used to determine if route should be excluded.
     * By default, files (pathname.includes('.')), Next.js API routes (pathname.startsWith('/api/')), and Sitecore API routes (pathname.startsWith('/sitecore/')) are ignored.
     * This is an important performance consideration since Next.js Edge middleware runs on every request.
     * @param {string} pathname The pathname
     * @returns {boolean} Whether to exclude the route
     */
    excludeRoute?: (pathname: string) => boolean;
    /**
     * Fallback hostname in case `host` header is not present
     * @default localhost
     */
    defaultHostname?: string;
    /**
     * Site resolution implementation by name/hostname
     */
    siteResolver: any;
};
export declare abstract class MiddlewareBase {
    protected config: MiddlewareBaseConfig;
    protected SITE_SYMBOL: string;
    protected defaultHostname: string;
    constructor(config: MiddlewareBaseConfig);
    /**
     * Determines if mode is preview
     * @param {NextRequest} req request
     * @returns {boolean} is preview
     */
    protected isPreview(req: NextRequest): boolean;
    protected excludeRoute(pathname: string): boolean | undefined;
    /**
     * Safely extract all headers for debug logging
     * Necessary to avoid middleware issue https://github.com/vercel/next.js/issues/39765
     * @param {Headers} incomingHeaders Incoming headers
     * @returns Object with headers as key/value pairs
     */
    protected extractDebugHeaders(incomingHeaders: Headers): {
        [key: string]: string;
    };
    /**
     * Provides used language
     * @param {NextRequest} req request
     * @returns {string} language
     */
    protected getLanguage(req: NextRequest): string;
    /**
     * Extract 'host' header
     * @param {NextRequest} req request
     */
    protected getHostHeader(req: NextRequest): string | undefined;
    /**
     * Get site information.
     * Can not be used in **Preview** mode, since site will not be resolved
     * @param {NextRequest} req request
     * @param {NextResponse} [res] response
     * @returns {SiteInfo} site information
     */
    protected getSite(req: NextRequest, res?: NextResponse): SiteInfo;
}