import { SearchBackendInterface } from './search-backend-interface';
import type { SearchParams } from '../search-params';
import type { Result } from '@internetarchive/result-type';
import { SearchServiceError } from '../search-service-error';
import type { SearchBackendOptionsInterface } from './search-backend-options';
/**
 * An abstract base class for search backends.
 */
export declare abstract class BaseSearchBackend implements SearchBackendInterface {
    /**
     * The base URL / host this backend should use for its requests.
     * Defaults to 'archive.org'.
     */
    protected baseUrl: string;
    protected includeCredentials: boolean;
    protected requestScope?: string;
    protected cachingFlags?: string;
    protected verbose?: boolean;
    protected debuggingEnabled?: boolean;
    constructor(options?: SearchBackendOptionsInterface);
    /** @inheritdoc */
    abstract performSearch(params: SearchParams): Promise<Result<any, SearchServiceError>>;
    /**
     * Fires a request to the URL (with this backend's options applied) and
     * asynchronously returns a Result object containing either the raw response
     * JSON or a SearchServiceError.
     */
    protected fetchUrl(url: string, options?: {
        requestOptions?: RequestInit;
    }): Promise<Result<any, SearchServiceError>>;
    private getErrorResult;
    /**
     * Logs a full response to the console, with truncated hits.
     */
    private printResponse;
    /**
     * Logs PPS debugging info to the console if it is present on the response object
     */
    private printDebuggingInfo;
}