index.js

'use strict';

const express = require('express');
const app = express();

app.use(express.static('public'));
const expressWs = require('express-ws')(app);

const clients = [];
const nameCounts = {};

function clientForName(name) {
  for(let i = 0; i < clients.length; i++) {
    if (clients[i].name === name) return clients[i];
  }
}

function normalizeName(name) {
  console.log('Normalizing: [' + name + ']');
  if (/[\,\<\>\\\/]/.test(name)) {
    return "onvre!"
  }
  return name.substring(0, 10);
}

function getUniqueName(name) {
  if (!nameCounts[name]) {
    nameCounts[name] = 1;
    return name;
  } else {
    nameCounts[name] ++;
    return name + ' (' + nameCounts[name] + ')';
  }
}

const SPAWN_TIME = 2000;

app.ws('/game', function(ws, req) {
  const client = { ws: ws, kills: 0, deaths: 0 };
  clients.push(client);
  ws.on('message', function(msg) {
    const now = new Date().getTime();
    if (client.disconnected) {
      return;
    }
    const parts = msg.split(',');
    const messageType = parts[0];
    if (messageType === 'c') {
      client.givenName = normalizeName(msg.substring(2) || 'New Folder');
      client.name = getUniqueName(client.givenName);
      client.color = '#' + Math.floor(Math.random() * 0xFFFFFF).toString(16);
      console.log('Client Connected: ' + client.name);
      client.ws.send(client.name + ',n,'+client.color.toString(16));
      clients.forEach(function(c) {
        if (c !== client && !c.disconnected) {
          try {
            c.ws.send(client.name+',c,'+client.color);
            client.ws.send(c.name+',c,'+c.color);
          } catch (e) {console.error(e);}
        }
      });
    } else {
      if (messageType === 'k') {
        client.kills++;
        const deadClient = clientForName(parts[1]);
        if (deadClient) {
          deadClient.deaths++;
          deadClient.dead = true;
        }
      } else if (messageType === 'p') {
        if (client.dead) {
          if (now - client.diedAt < SPAWN_TIME) return;
          client.dead = false;
        }
      }
      clients.forEach(function(c) {
        if (c !== client && !c.disconnected) {
          try { c.ws.send('' + client.name + ',' + msg); }
          catch (e) {console.error(e);}
        }
      });
    }
  });
  ws.on('close', function() {
    console.log('' + client.name + ' disconnected.');
    client.disconnected = true;
    nameCounts[client.givenName]--;
    clients.forEach(function(c) {
      if (c !== client && !c.disconnected) {
        try { c.ws.send('' + client.name + ',d'); }
        catch (e) {console.error(e);}
      }
    });
    for(let i = clients.length - 1; i >= 0; i--) {
      if(clients[i] === client) {
         clients.splice(i, 1);
         return;
      }
    }
  });
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
  console.log(`Running on port ${PORT}`);
});