quelea-web/server/server.js

const express = require("express");
const compression = require('compression');
const expressSSE = require("express-sse");
const httpProxy = require("http-proxy");
const axios = require("axios");
const path = require("path");
const methodOverride = require("method-override");

const config = require("./config.js");
const rcUrl = config.rcApi + "/lyrics";
const lyricUrl = config.lyricsApi + "/lyrics";
const apiProxy = httpProxy.createProxyServer();
const sse = new expressSSE("");

let lowerLyrics = "";
let newLyrics = "";
let rcLyrics = "";
let stageLyrics = "";

const app = express();
const PORT = process.env.PORT || 3000;

app.use(compression());
app.use(express.json());
app.use(express.urlencoded({extended: true}));
app.use(express.text());
app.use(express.json({type:"application/vnd.api+json"}));

app.use(methodOverride("_method"));

// Proxy all non-api requests to the built app
app.use(express.static(path.join(__dirname, '../app/dist')));
app.get('/', (req, res) => {
	res.sendFile(path.join(__dirname, '../app/dist/index.html'));
});

// Reverse Proxy redirect to Remote Control API
app.all("/rcApi/*", (req, res) => {
	console.log("redirecting to Remote Control API");
	apiProxy.web(req, res, {target: config.rcApi});
});

// Reverse Proxy redirect to Lyrics API
app.all("/lyricsApi/*", (req, res) => {
	console.log("redirecting to Lyrics API");
	apiProxy.web(req, res, {target: config.lyricsApi});
});

// Update lyrics by polling every 250ms
setInterval( async() => {
	// Quelea Lyrics API GET using Axios
	await axios.get(lyricUrl).then(res => {
		newLyrics = res.data;
		if (!(newLyrics === lowerLyrics)) {
			lowerLyrics = newLyrics;
			sse.updateInit(newLyrics);
			sse.send(newLyrics);
		}
	})
	.catch(error => {
		console.log(error);
	});

	// Quelea Lyrics API GET using Axios
	await axios.get(rcUrl).then(res => {
		// console.log("Here be the Lyrics " + res.data);
		rcLyrics = res.data;
		rcLyrics = rcLyrics.replace(/(\r\n|\n|\r)/gm," ");
		// console.log(newLyrics);
		if (!(rcLyrics === stageLyrics)) {
			stageLyrics = rcLyrics;
		}
	})
	.catch(error => {
		console.log(error);
	});
}, 250);

// SSE Connection to Frontend
app.get('/stream', sse.init);

// SSE Connection to the Frontend
app.get('/lowerthirdsserver', function (request, response) {
	response.status(200).set({
		"connection": "keep-alive",
		"cache-control": "no-cache",
		"content-type": "text/event-stream",
	});
	// const data = "Hello Earl!";

	setInterval(() => {
		response.write('data:' + lowerLyrics + '\n\n');
	}, 250);

});

app.get('/stagesserver', function (request, response) {
	response.status(200).set({
		"connection": "keep-alive",
		"cache-control": "no-cache",
		"content-type": "text/event-stream",
	});
	// const data = "Hello Earl!";

	setInterval(() => {
		response.write('data:' + stageLyrics + '\n\n');
	}, 250);

});

// Keep server running if connection to an API fails
process.on('uncaughtException', (err) => {
	console.log(err);
});

// Run the server
app.listen(PORT, () => {
	console.log("Server listening on: http://localhost:" + PORT);
});