index.js

const WebSocket = require('ws')
const net = require('net')

const {WebSocketServer} = WebSocket

function ln_ws_proxy_server(opts={}) {
	opts.port = opts.port || process.env.PORT || 8080

	const server = new WebSocketServer(opts)

	server.on('connection', handle_connection)

	return server
}

function handle_open(ws, req) {
	//console.log("open", req)
	console.log("open")
}

function parse_ip(str)
{
	const parts = str.split(":")
	return {host: parts[0], port: parts[1] || 9735}
}

async function handle_connection(ws, req) {
	const url = new URL(`wss://${req.headers.host}${req.url}`)
	const dest = url.pathname.substring(1)
	if (!dest) {
		ws.close()
		return
	}

	const {host, port} = parse_ip(dest)
	console.log("serving", host, port)
	const is_resolved = false
	let socket = null

	const connected = new Promise((resolve, reject) => {
		const conn = net.createConnection(port, host, () => {
			socket = conn
			resolve(conn)
		})
	});

	let messages = []
	ws.on('message', async (msg) => {
		if (socket) {
			socket.write(msg)
			return 
		}

		messages.push(msg)
	})

	// queue up messages until we're connected
	socket = await connected
	socket.on('data', (d) => ws.send(d))

	for (const message of messages) {
		socket.write(message)
	}
	messages = null
}

module.exports = ln_ws_proxy_server