import { AxiosRequestConfig, AxiosResponse } from "../api";
import IApiService from '../../domain/contracts/api/IApiService';
/**
 * Class {@link ApiService} is a concrete implementation of the {@link IApiService} interface.
 * It encapsulates the logic to make API calls to the {@link https://localhost:3000/api/v1|API server} and handles token retrieval and refresh.
 *
 * @see https://github.com/axios/axios
 * @see https://github.com/nodejs/node/blob/master/doc/api/https.md#httpsrequesturl-options-callback
 * @see https://github.com/nodejs/node/blob/master/doc/api/http.md#httprequesturl-options-callback
 */
declare class ApiService implements IApiService {
    private static instance;
    private authBaseUrl;
    private axiosInstance;
    private authToken;
    private tokenExpiration;
    /**
     * Constructor for the ApiService class.
     * It initializes the API base URL and if specified, the keep-alive agent configuration.
     * It also creates an instance of the axios client and sets up the request and response interceptors.
     * The request interceptor adds the authorization header to the request if the token is available.
     * The response interceptor handles 401 responses by refreshing the token and retrying the original request.
     * If the token refresh fails, it rejects the promise with the original error.
     * @param {string} clientId - The client ID to use for token refresh.
     * @param {string} sharedSecret - The shared secret to use for token refresh.
     * @param {string} apiBaseUrl - The base URL of the API server.
     * @param {string} authBaseUrl - The base URL of the authorization server.
     */
    private constructor();
    /**
     * Returns an instance of the ApiService class, creating a new one if it doesn't exist already.
     * @param {string} clientId - The client ID to use for authentication.
     * @param {string} sharedSecret - The shared secret to use for authentication.
     * @param {string} apiBaseUrl - The base URL of the API endpoints.
     * @param {string} authBaseUrl - The base URL of the authentication endpoints.
     * @returns {ApiService} The instance of the ApiService class.
     */
    static getInstance(clientId: string, sharedSecret: string, apiBaseUrl: string, authBaseUrl: string): ApiService;
    /**
     * Sets the authentication token for the API service.
     *
     * @param {string} token - The authentication token to be set.
     * @returns {Promise<void>} A promise that resolves when the token is set.
     */
    setAuthToken(token: string): Promise<void>;
    /**
     * Retrieves the authentication token for the API service.
     * If the token does not exist or is expired, it refreshes the token.
     *
     * @returns {Promise<string | null>} A promise that resolves to the current authentication token or null if unavailable.
     */
    getAuthToken(): Promise<string | null>;
    /**
     * Sends a GET request to the specified URL using the provided Axios request configuration.
     *
     * @template T - The expected response data type.
     * @param {string} url - The URL to send the GET request to.
     * @param {AxiosRequestConfig} [config] - Optional Axios request configuration.
     * @returns {Promise<AxiosResponse<any>>} A promise that resolves to the Axios response.
     */
    get<T>(url: string, config?: AxiosRequestConfig): Promise<AxiosResponse<any>>;
    /**
     * Sends a POST request to the specified URL using the provided Axios request configuration.
     *
     * @template T - The expected response data type.
     * @param {string} url - The URL to send the POST request to.
     * @param {any} [data] - The data to be sent as the request body.
     * @param {AxiosRequestConfig} [config] - Optional Axios request configuration.
     * @returns {Promise<AxiosResponse<T>>} A promise that resolves to the Axios response.
     */
    post<T>(url: string, data?: any, config?: AxiosRequestConfig): Promise<AxiosResponse<T>>;
    /**
     * Sends a PUT request to the specified URL using the provided Axios request configuration.
     *
     * @template T - The expected response data type.
     * @param {string} url - The URL to send the PUT request to.
     * @param {any} [data] - The data to be sent as the request body.
     * @param {AxiosRequestConfig} [config] - Optional Axios request configuration.
     * @returns {Promise<AxiosResponse<T>>} A promise that resolves to the Axios response.
     */
    put<T>(url: string, data?: any, config?: AxiosRequestConfig): Promise<AxiosResponse<T>>;
    /**
     * Sends a PATCH request to the specified URL using the provided Axios request configuration.
     *
     * @template T - The expected response data type.
     * @param {string} url - The URL to send the PATCH request to.
     * @param {any} [data] - The data to be sent as the request body.
     * @param {AxiosRequestConfig} [config] - Optional Axios request configuration.
     * @returns {Promise<AxiosResponse<T>>} A promise that resolves to the Axios response.
     */
    patch<T>(url: string, data?: any, config?: AxiosRequestConfig): Promise<AxiosResponse<T>>;
    /**
     * Sends a DELETE request to the specified URL using the provided Axios request configuration.
     *
     * @template T - The expected response data type.
     * @param {string} url - The URL to send the DELETE request to.
     * @param {AxiosRequestConfig} [config] - Optional Axios request configuration.
     * @returns {Promise<AxiosResponse<T>>} A promise that resolves to the Axios response.
     */
    delete<T>(url: string, config?: AxiosRequestConfig): Promise<AxiosResponse<T>>;
    /**
     * Checks if the authentication token has expired.
     * @returns {boolean} True if the token has expired, false otherwise.
     */
    private isTokenExpired;
    /**
     * Refreshes the authentication token by making an API call to the /auth/refresh endpoint.
     * The new token is then stored in the AuthService instance.
     * @private
     * @returns {Promise<void>} A promise that resolves when the token has been refreshed.
     */
    private refreshToken;
}
export default ApiService;