// Type definitions for engine.io 3.1
// Project: https://github.com/socketio/engine.io
// Definitions by: KentarouTakeda <https://github.com/KentarouTakeda>
// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
// TypeScript Version: 2.1

/// <reference types="node" />

import http = require('http');
import net = require('net');
import { EventEmitter } from "events";

declare namespace engine {
	type Message = string|Buffer|ArrayBuffer|ArrayBufferView;
	type Transport =  "polling"|"websocket";
	interface Packet {
		type: string;
		options?: MessageOptions;
		data?: Message;
	}
	type AllowRequestFunction = (req: http.IncomingMessage, fn: (err: string|null|undefined, success: boolean) => void) => void;

	interface ServerOptions {
		/**
		 * how many ms without a pong packet to consider the connection closed (60000)
		 */
		pingTimeout?: number;
		/**
		 * how many ms before sending a new ping packet (25000)
		 */
		pingInterval?: number;
		/**
		 * how many ms before an uncompleted transport upgrade is cancelled (10000)
		 */
		upgradeTimeout?: number;
		/**
		 * how many bytes or characters a message can be, before closing the session (to avoid DoS). Default value is 10E7.
		 */
		maxHttpBufferSize?: number;
		/**
		 * A function that receives a given handshake or upgrade request as its first parameter,
		 * and can decide whether to continue or not. The second argument is a function that needs
		 * to be called with the decided information: fn(err, success), where success is a boolean
		 * value where false means that the request is rejected, and err is an error code.
		 */
		allowRequest?: AllowRequestFunction;
		/**
		 * to allow connections to (['polling', 'websocket'])
		 */
		transports?: Transport[];
		/**
		 * whether to allow transport upgrades (true)
		 */
		allowUpgrades?: boolean;
		/**
		 * parameters of the WebSocket permessage-deflate extension (see ws module api docs). Set to false to disable. (true)
		 */
		perMessageDeflate?: any;
		/**
		 * parameters of the http compression for the polling transports (see zlib api docs). Set to false to disable. (true)
		 */
		httpCompression?: any;
		/**
		 * name of the HTTP cookie that contains the client sid to send as part of handshake response headers. Set to false to not send one. (io)
		 */
		cookie?: string|boolean;
		/**
		 * path of the above cookie option. If false, no path will be sent,
		 * which means browsers will only send the cookie on the engine.io
		 * attached path (/engine.io). Set false to not save io cookie
		 * on all requests. (/)
		 */
		cookiePath?: string|boolean;
		/**
		 * If true HttpOnly io cookie cannot be accessed by client-side APIs,
		 * such as JavaScript. (true) This option has no effect
		 * if cookie or cookiePath is set to false.
		 */
		cookieHttpOnly?: boolean;
		/**
		 * what WebSocket server implementation to use. Specified module must
		 * conform to the ws interface (see ws module api docs). Default value is ws.
		 * An alternative c++ addon is also available by installing uws module.
		 */
		wsEngine?: "ws"|"uws";
		/**
		 * an optional packet which will be concatenated to the handshake packet emitted by Engine.IO.
		 */
		initialPacket?: Message;
	}
	interface AttachOptions {
		/**
		 * name of the path to capture (/engine.io).
		 */
		path?: string;
		/**
		 * destroy unhandled upgrade requests (true)
		 */
		destroyUpgrade?: boolean;
		/**
		 * milliseconds after which unhandled requests are ended (1000)
		 */
		destroyUpgradeTimeout?: number;
		/**
		 * whether to let engine.io handle the OPTIONS requests. You can also pass a custom function to handle the requests (true)
		 */
		handlePreflightRequest?: boolean|((server: Server, req: http.IncomingMessage, res: http.ServerResponse) => void);
	}
	interface ServerAttachOptions extends ServerOptions, AttachOptions {}

	interface MessageOptions {
		compress?: boolean;
	}

	/**
	 * The main server/manager. Inherits from EventEmitter.
	 */
	class Server extends EventEmitter {
		/**
		 * hash of connected clients by id.
		 */
		clients: {[sid: string]: Socket};
		/**
		 * number of connected clients.
		 */
		clientsCount: number;

		/**
		 * Initializes the server
		 */
		constructor(opts?: ServerOptions);
		/**
		 * Fired when a new connection is established.
		 */
		on(ev: 'connection'|'drain', fn: (socket: Socket) => void): this;
		on(ev: 'flush', fn: (socket: Socket, buffer: Packet[]) => void): this;
		/**
		 * Closes all clients
		 */
		close(): this;
		readonly httpServer?: http.Server;
		/**
		 * Called internally when a Engine request is intercepted.
		 */
		handleRequest(req: http.IncomingMessage, res: http.ServerResponse): this;
		/**
		 * Called internally when a Engine ws upgrade is intercepted.
		 */
		handleUpgrade(req: http.IncomingMessage, socket: net.Socket, head: Buffer): this;
		/**
		 * Attach this Server instance to an http.Server
		 * Captures upgrade requests for a http.Server. In other words, makes a regular http.Server WebSocket-compatible.
		 */
		attach(http: http.Server, opts?: AttachOptions): this;
		/**
		 * Generate a socket id.
		 * Overwrite this method to generate your custom socket id.
		 */
		generateId(req: http.IncomingMessage): string;
	}

	/**
	 * A representation of a client. Inherits from EventEmitter.
	 */
	class Socket extends EventEmitter {
		/**
		 * unique identifier
		 */
		id: string;
		/**
		 * engine parent reference
		 */
		server: Server;
		/**
		 * request that originated the Socket
		 */
		request: http.IncomingMessage;
		/**
		 * whether the transport has been upgraded
		 */
		upgraded: boolean;
		/**
		 * readyState
		 */
		readyState: 'opening'|'open'|'closing'|'closed';

		/**
		 * Sends a message, performing message = toString(arguments[0]) unless sending binary data, which is sent as is.
		 */
		send(message: Message, opts?: MessageOptions, fn?: ((transport: any) => void)): void;

		/**
		 * Disconnects the client
		 */
		close(): this;

		/**
		 * Fired when the client is disconnected.
		 */
		on(ev: "close", fn: (reason: string, description?: Error) => void): this;
		/**
		 * Fired when the client sends a message.
		 */
		on(ev: "message", fn: (data: string|Buffer) => void): this;
		/**
		 * Fired when an error occurs.
		 */
		on(ev: "error", fn: (err: Error) => void): this;
		/**
		 * Called when the write buffer is being flushed.
		 */
		on(ev: "flush", fn: (buffer: Packet[]) => void): this;
		/**
		 * Called when the write buffer is drained
		 */
		on(ev: "drain", fn: () => void): this;
		/**
		 * packet: Called when a socket received a packet (message, ping)
		 * packetCreate: Called before a socket sends a packet (message, pong)
		 */
		on(ev: "packet" | "packetCreate", fn: (packet: Packet) => void): this;
	}
	function attach(http: net.Server, opts?: ServerAttachOptions): Server;
	function listen(port: number, opts?: ServerOptions, fn?: () => void): Server;
	const protocol: number;
}

declare function engine(httpServer?: net.Server, opts?: engine.ServerOptions): engine.Server;

export = engine;