server.js

import express from 'express';
import { createServer } from 'node:https';
import { readFileSync } from 'node:fs';
import { fileURLToPath } from 'node:url';
import { dirname, join } from 'node:path';
import { Server } from 'socket.io';

const app = express();
const serverOptions = {
  key: readFileSync('/etc/letsencrypt/live/heybug.tech/privkey.pem'),
  cert: readFileSync('/etc/letsencrypt/live/heybug.tech/fullchain.pem'),
};
const server = createServer(serverOptions, app);
const io = new Server(server);

const __dirname = dirname(fileURLToPath(import.meta.url));

app.get('/', (req, res) => {
  res.sendFile(join(__dirname, 'dist/index.html'));
});

app.use('/chordinate', express.static(join(__dirname, 'dist')));

let numSockets = 0;
const freeSockets = []
const userHue = {}

io.on('connection', (socket) => {
  let socketNum;
  if ( freeSockets.length >= 1 ) {
    socketNum = freeSockets.pop();
  }
  else {
    numSockets++;
    socketNum = numSockets;
  }

  if ( !userHue[socketNum] ){
    let newHue = (299 + 83*(socketNum-1))%360;

    // We'll need to put this on the frontend in a less hardcoded way later,
    // but right now we're just keeping the hue away from the blue color of the
    // "black" keys so it'll be visible
    if ( Math.abs(newHue - 182 ) < 40 ) {
      newHue += 83;
    }

    userHue[socketNum] = newHue;
  }

  socket.emit('hue assignment', userHue[socketNum]);
  console.log(`User connected.  Assigned hue: ${userHue[socketNum]}deg`);

  socket.on('midi press', (midi, velocity) => {
    console.log('MIDI: ' + midi + " " + velocity);

    socket.broadcast.emit('midi press', midi, velocity, userHue[socketNum]);
  });

  socket.on('midi release', (midi) => {
    console.log('MIDI RELEASE:' + midi);

    socket.broadcast.emit('midi release', midi, userHue[socketNum]);
  })

  socket.on('disconnect', () => {
    console.log('Socket' + socketNum + ' disconnected');
    freeSockets.push(socketNum);
  });
});

// Turn on Node.js's event loop for the server to listen for requests
server.listen(443, () => {
  console.log('Server is running on port 443 (HTTPS)');
});