import type { ApiDocument } from '@opra/common';
import { Observable } from 'rxjs';
import type { HttpEvent } from './interfaces/http-event.js';
import type { HttpHandler } from './interfaces/http-handler.js';
import type { HttpInterceptor } from './interfaces/http-interceptor.js';
/**
 * Base class for HTTP backends.
 *
 * @class HttpBackend
 */
export declare abstract class HttpBackend implements HttpHandler {
    /** The API document associated with this backend */
    document?: ApiDocument;
    /** The base URL of the service */
    readonly serviceUrl: string;
    /** List of HTTP interceptors */
    interceptors?: HttpInterceptor<any>[];
    /**
     * Creates a new instance of HttpBackend.
     *
     * @param serviceUrl The base URL of the service.
     * @param options Configuration options.
     * @protected
     */
    protected constructor(serviceUrl: string, options?: HttpBackend.Options);
    /**
     * Handles the request and returns an observable of {@link HttpEvent}.
     *
     * @param init The request initialization parameters.
     * @returns An observable of HttpEvent.
     */
    abstract handle(init: HttpBackend.RequestInit): Observable<HttpEvent>;
}
/**
 * Namespace for {@link HttpBackend} related types and interfaces.
 *
 * @namespace HttpBackend
 */
export declare namespace HttpBackend {
    /** Configuration options for HttpBackend */
    interface Options {
        /** The API document associated with this backend */
        document?: ApiDocument;
    }
    /** Request initialization parameters for HttpBackend */
    interface RequestInit {
        /** HTTP method (GET, POST, etc.) */
        method: string;
        /** The target URL */
        url: string | URL;
        /** HTTP headers */
        headers?: Headers;
        /** Request body */
        body?: any;
    }
}