import { HttpParams, HttpClient, HttpHeaders } from '@angular/common/http';
import { Observable } from 'rxjs';
/**
 * Http service to interact with backend api
 * Injectable - will be available in overall the application scope
 */
export declare class HttpService {
    private http;
    /**
     * Creates an instance of http service.
     * @param http Http backend handler to by pass interceptors
     */
    constructor(http: HttpClient);
    /**
     * Gets headers
     * @param token Auth token
     * @returns Http headers
     */
    private getHeaders;
    /**
     * Formats errors
     * @param error Error received in api response
     * @returns Throw error after some processing
     */
    private handleErrors;
    /**
     * Gets http service
     * @template T Generic type template
     * @param token Auth token
     * @param path Api end point
     * @param [params] Http parameters
     * @param headers Http headers
     * @returns Api response with status codes
     */
    get<T>(token: string, path: string, params?: HttpParams, headers?: HttpHeaders): Observable<T>;
    /**
     * Posts http service
     * @template T Generic type template
     * @param token Auth token
     * @param path Api end point
     * @param [body] Post data
     * @param headers Http headers
     * @returns api Response with status codes
     */
    post<T>(token: string, path: string, body?: Object, headers?: HttpHeaders): Observable<T>;
    /**
     * Puts http service
     * @template T Generic type template
     * @param token Auth token
     * @param path Api end point
     * @param [body] Post data
     * @param headers Http headers
     * @returns Api response with status codes
     */
    put<T>(token: string, path: string, body?: object, headers?: HttpHeaders): Observable<T>;
    /**
     * Patch http service
     * @template T Generic type template
     * @param token Auth token
     * @param path Api end point
     * @param [body] Post data
     * @param headers Http headers
     * @returns Api response with status codes
     */
    patch<T>(token: string, path: string, body?: object, headers?: HttpHeaders): Observable<T>;
    /**
     * Deletes http service
     * @template T Generic type template
     * @param token Auth token
     * @param path Api end point
     * @param headers Http headers
     * @returns Api response with status codes
     */
    delete<T>(token: string, path: string, headers?: HttpHeaders): Observable<T>;
}