net.ts

/**
 * @fileOverview adapter for ReactNative TCP module
 * This module mimics the nodejs net api and is intended to work in RN environment.
 * @see https://github.com/Rapsssito/react-native-tcp-socket
 */

import TcpSocket from 'react-native-tcp-socket';
import TcpSockets from 'react-native-tcp-socket/lib/types/Socket';
/**
 * Constructor function. Resulting object has to act as it was a real socket (basically
 * conform to nodejs/net api)
 *
 * @constructor
 */

interface ISocket {
	_socket: TcpSockets | undefined;
	_noDelay: boolean;
	_listeners: {};
	setNoDelay: Function;
	connect: Function;
	_passOnEvent: Function;
	on: Function;
	removeListener: Function;
	end: Function;
	destroy: Function;
	write: Function;
	setTimeout?: Function;
	setEncoding?: Function;
	setKeepAlive?: Function;
}

function Socket(this: ISocket): void {
	this._socket = undefined; // reference to socket that will be created later
	// defaults:
	this._noDelay = true;

	this._listeners = {};

	this.setTimeout = (): void => {};
	this.setEncoding = (): void => {};
	this.setKeepAlive = (): void => {};

	// proxying call to real socket object:
	this.setNoDelay = (noDelay): void => {
		if (this._socket) {
			this._socket.setNoDelay(noDelay);
		}
		this._noDelay = noDelay;
	};

	this.connect = (port, host, callback): void => {
		this._socket = TcpSocket.createConnection(
			{
				port,
				host,
				tls: false,
			},
			callback,
		);

		this._socket.on('data', (data): void => {
			this._passOnEvent('data', data);
		});
		this._socket.on('error', (data): void => {
			this._passOnEvent('error', data);
		});
		this._socket.on('close', (data): void => {
			this._passOnEvent('close', data);
		});
		// @ts-ignore
		this._socket.on('connect', (data): void => {
			this._passOnEvent('connect', data);
			if (this._socket) {
				this._socket.setNoDelay(this._noDelay);
			}
		});
		// @ts-ignore
		this._socket.on('connection', (data): void => {
			this._passOnEvent('connection', data);
		});
	};

	this._passOnEvent = (event, data): void => {
		this._listeners[event] = this._listeners[event] || [];
		for (const savedListener of this._listeners[event]) {
			savedListener(data);
		}
	};

	this.on = (event, listener): void => {
		this._listeners[event] = this._listeners[event] || [];
		this._listeners[event].push(listener);
	};

	this.removeListener = (event, listener): void => {
		this._listeners[event] = this._listeners[event] || [];
		const newListeners = [];

		let found = false;
		for (const savedListener of this._listeners[event]) {
			if (savedListener === listener) {
				// found our listener
				found = true;
				// we just skip it
			} else {
				// other listeners should go back to original array
				// @ts-ignore
				newListeners.push(savedListener);
			}
		}

		if (found) {
			this._listeners[event] = newListeners;
		} else {
			// something went wrong, lets just cleanup all listeners
			this._listeners[event] = [];
		}
	};

	this.end = (): void => {
		if (this._socket) {
			// @ts-ignore
			this._socket.end();
		}
	};

	this.destroy = (): void => {
		if (this._socket) {
			this._socket.destroy();
		}
	};

	this.write = (data): void => {
		if (this._socket) {
			this._socket.write(data);
		}
	};
}

module.exports = {
	Socket,
};