import * as http from "http";
import * as https from "https";
import type { FetchRequest, IConfigCatConfigFetcher } from "../ConfigFetcher.js";
import { fetchInternalAsyncMethodName, FetchResponse } from "../ConfigFetcher.js";
export interface INodeHttpConfigFetcherOptions {
    /**
     * The {@link https://nodejs.org/api/http.html#class-httpagent | http.Agent} instance to use for non-secure HTTP communication.
     * For example, this option allows you to configure the SDK to route `http://...` requests through an HTTP, HTTPS or SOCKS proxy.
     *
     * If not set, an internally managed agent with the same options as {@link https://nodejs.org/api/http.html#httpglobalagent | http.globalAgent}
     * will be used.
     *
     * This option applies when the SDK connects to a custom `http://...` URL you specified via `baseUrl`.
     *
     * @remarks If this and `httpAgentFactory` options are both specified, this option is ignored.
     *
     * @deprecated This option is kept for backward compatibility but will be removed in a future major version.
     * Please use the `httpAgentFactory` option instead.
     */
    httpAgent?: http.Agent | null;
    /**
     * An optional callback to override the creation of {@link https://nodejs.org/api/http.html#class-httpagent | http.Agent}
     * instances for non-secure HTTP communication. For example, this option allows you to configure the SDK to route
     * `http://...` requests through an HTTP, HTTPS or SOCKS proxy.
     *
     * If not set, an internally managed agent with the same options as {@link https://nodejs.org/api/http.html#httpglobalagent | http.globalAgent}
     * will be used.
     *
     * This option applies when the SDK connects to a custom `http://...` URL you specified via `baseUrl`.
     *
     * @remarks The callback must always return a new `http.Agent` instance and leave lifetime management of that instance to the SDK.
     *
     * @param recommendedOptions Default options for the agent to create. This object can be modified as needed.
     * @returns The `http.Agent` instance to use for making requests.
     */
    httpAgentFactory?: ((recommendedOptions: http.AgentOptions) => http.Agent) | null;
    /**
     * The {@link https://nodejs.org/api/https.html#class-httpsagent | https.Agent} instance to use for secure HTTP communication.
     * For example, this option allows you to configure the SDK to route `https://...` requests through an HTTP, HTTPS or SOCKS proxy.
     *
     * If not set, an internally managed agent with the same options as {@link https://nodejs.org/api/https.html#httpsglobalagent | https.globalAgent}
     * will be used.
     *
     * This option applies when the SDK connects to the ConfigCat CDN or a custom `https://...` URL you specified via `baseUrl`.
     *
     * @remarks If this and `httpsAgentFactory` options are both specified, this option is ignored.
     *
     * @deprecated This option is kept for backward compatibility but will be removed in a future major version.
     * Please use the `httpsAgentFactory` option instead.
    */
    httpsAgent?: https.Agent | null;
    /**
     * An optional callback to override the creation of {@link https://nodejs.org/api/https.html#class-httpsagent | https.Agent}
     * instances for secure HTTP communication. For example, this option allows you to configure the SDK to route
     * `https://...` requests through an HTTP, HTTPS or SOCKS proxy.
     *
     * If not set, an internally managed agent with the same options as {@link https://nodejs.org/api/https.html#httpsglobalagent | https.globalAgent}
     * will be used.
     *
     * This option applies when the SDK connects to the ConfigCat CDN or a custom `https://...` URL you specified via `baseUrl`.
     *
     * @remarks The callback must always return a new `https.Agent` instance and leave lifetime management of that instance to the SDK.
     *
     * @param recommendedOptions Default options for the agent to create. This object can be modified as needed.
     * @returns The `https.Agent` instance to use for making requests.
     */
    httpsAgentFactory?: ((recommendedOptions: https.AgentOptions) => https.Agent) | null;
}
export declare class NodeHttpConfigFetcher implements IConfigCatConfigFetcher {
    private static getFactory;
    private httpAgentState;
    private httpsAgentState;
    private agentRenewalThresholdMs;
    private requestRetryDelayMs;
    private readonly disposeToken;
    constructor(options?: INodeHttpConfigFetcherOptions);
    dispose(): void;
    fetchAsync(request: FetchRequest): Promise<FetchResponse>;
    private [fetchInternalAsyncMethodName];
    private fetchWithRetryAsync;
    private fetchCoreAsync;
    private handleResponse;
    protected setRequestHeaders(requestOptions: {
        headers?: Record<string, number | string | string[]>;
    }, headers: ReadonlyArray<readonly [string, string]>): void;
}