/**
 * Based on definition by DefinitelyTyped:
 * https://github.com/DefinitelyTyped/DefinitelyTyped/blob/6f529c6c67a447190f86bfbf894d1061e41e07b7/types/http-proxy-middleware/index.d.ts
 */
import type * as http from 'http';
import type * as httpProxy from 'http-proxy';
import type * as net from 'net';
export type NextFunction<T = (err?: any) => void> = T;
export interface RequestHandler<TReq = http.IncomingMessage, TRes = http.ServerResponse, TNext = NextFunction> {
    (req: TReq, res: TRes, next?: TNext): Promise<void>;
    upgrade: (req: http.IncomingMessage, socket: net.Socket, head: Buffer) => void;
}
export type Filter<TReq = http.IncomingMessage> = string | string[] | ((pathname: string, req: TReq) => boolean);
export interface Plugin<TReq = http.IncomingMessage, TRes = http.ServerResponse> {
    (proxyServer: httpProxy<TReq, TRes>, options: Options<TReq, TRes>): void;
}
export interface OnProxyEvent<TReq = http.IncomingMessage, TRes = http.ServerResponse> {
    error?: httpProxy.ErrorCallback<Error, TReq, TRes>;
    proxyReq?: httpProxy.ProxyReqCallback<http.ClientRequest, TReq, TRes>;
    proxyReqWs?: httpProxy.ProxyReqWsCallback<http.ClientRequest, TReq>;
    proxyRes?: httpProxy.ProxyResCallback<TReq, TRes>;
    open?: httpProxy.OpenCallback;
    close?: httpProxy.CloseCallback<TReq>;
    start?: httpProxy.StartCallback<TReq, TRes>;
    end?: httpProxy.EndCallback<TReq, TRes>;
    econnreset?: httpProxy.EconnresetCallback<Error, TReq, TRes>;
}
export type Logger = Pick<Console, 'info' | 'warn' | 'error'>;
export interface Options<TReq = http.IncomingMessage, TRes = http.ServerResponse> extends httpProxy.ServerOptions {
    /**
     * Narrow down requests to proxy or not.
     * Filter on {@link http.IncomingMessage.url `pathname`} which is relative to the proxy's "mounting" point in the server.
     * Or use the {@link http.IncomingMessage `req`}  object for more complex filtering.
     * @link https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/pathFilter.md
     * @since v3.0.0
     */
    pathFilter?: Filter<TReq>;
    /**
     * Modify request paths before requests are send to the target.
     * @example
     * ```js
     * createProxyMiddleware({
     *   pathRewrite: {
     *     '^/api/old-path': '/api/new-path', // rewrite path
     *   }
     * });
     * ```
     * @link https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/pathRewrite.md
     */
    pathRewrite?: {
        [regexp: string]: string;
    } | ((path: string, req: TReq) => string | undefined) | ((path: string, req: TReq) => Promise<string>);
    /**
     * Access the internal http-proxy server instance to customize behavior
     *
     * @example
     * ```js
     * createProxyMiddleware({
     *   plugins: [(proxyServer, options) => {
     *     proxyServer.on('error', (error, req, res) => {
     *       console.error(error);
     *     });
     *   }]
     * });
     * ```
     * @link https://github.com/chimurai/http-proxy-middleware#plugins-array
     * @since v3.0.0
     */
    plugins?: Plugin<TReq, TRes>[];
    /**
     * Eject pre-configured plugins.
     * NOTE: register your own error handlers to prevent server from crashing.
     *
     * @link https://github.com/chimurai/http-proxy-middleware#ejectplugins-boolean-default-false
     * @since v3.0.0
     */
    ejectPlugins?: boolean;
    /**
     * Listen to http-proxy events
     * @see {@link OnProxyEvent} for available events
     * @example
     * ```js
     * createProxyMiddleware({
     *   on: {
     *     error: (error, req, res, target) => {
     *       console.error(error);
     *     }
     *   }
     * });
     * ```
     * @link https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/proxy-events.md
     * @since v3.0.0
     */
    on?: OnProxyEvent<TReq, TRes>;
    /**
     * Dynamically set the {@link Options.target `options.target`}.
     * @example
     * ```js
     * createProxyMiddleware({
     *   router: async (req) => {
     *     return 'http://127:0.0.1:3000';
     *   }
     * });
     * ```
     * @link https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/router.md
     */
    router?: {
        [hostOrPath: string]: httpProxy.ServerOptions['target'];
    } | ((req: TReq) => httpProxy.ServerOptions['target']) | ((req: TReq) => Promise<httpProxy.ServerOptions['target']>);
    /**
     * Log information from http-proxy-middleware
     * @example
     * ```js
     * createProxyMiddleware({
     *  logger: console
     * });
     * ```
     * @link https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/logger.md
     * @since v3.0.0
     */
    logger?: Logger | any;
}