server.js

var express = require("express");
var app = express();
var cfenv = require("cfenv");
var bodyParser = require('body-parser')
var PubSub = require('pubsub-js')
var expressWs = require('express-ws')(app);

// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false }))

// parse application/json
app.use(bodyParser.json())


var mydb;

/* Endpoint to greet and add a new visitor to database.
* Send a POST request to localhost:3000/api/visitors with body
* {
* 	"name": "Bob"
* }
*/
app.post("/api/visitors", function (request, response) {
  var userName = request.body.name;
  if(!mydb) {
    console.log("No database.");
    response.send("Hello " + userName + "!");
    return;
  }
  // insert the username as a document
  mydb.insert({ "name" : userName }, function(err, body, header) {
    if (err) {
      return console.log('[mydb.insert] ', err.message);
    }
    response.send("Hello " + userName + "! I added you to the database.");
  });
});

/**
 * Endpoint to get a JSON array of all the visitors in the database
 * REST API example:
 * <code>
 * GET http://localhost:3000/api/visitors
 * </code>
 *
 * Response:
 * [ "Bob", "Jane" ]
 * @return An array of all the visitor names
 */
app.get("/api/visitors", function (request, response) {
  var names = [];
  if(!mydb) {
    response.json(names);
    return;
  }

  mydb.list({ include_docs: true }, function(err, body) {
    if (!err) {
      body.rows.forEach(function(row) {
        if(row.doc.name)
          names.push(row.doc.name);
      });
      response.json(names);
    }
  });
});


// load local VCAP configuration  and service credentials
var vcapLocal;
try {
  vcapLocal = require('./vcap-local.json');
  console.log("Loaded local VCAP", vcapLocal);
} catch (e) { }

const appEnvOpts = vcapLocal ? { vcap: vcapLocal} : {}

const appEnv = cfenv.getAppEnv(appEnvOpts);

if (appEnv.services['cloudantNoSQLDB'] || appEnv.getService(/cloudant/)) {
  // Load the Cloudant library.
  var Cloudant = require('cloudant');

  // Initialize database with credentials
  if (appEnv.services['cloudantNoSQLDB']) {
     // CF service named 'cloudantNoSQLDB'
     var cloudant = Cloudant(appEnv.services['cloudantNoSQLDB'][0].credentials);
  } else {
     // user-provided service with 'cloudant' in its name
     var cloudant = Cloudant(appEnv.getService(/cloudant/).credentials);
  }

  //database name
  var dbName = 'mydb';

  // Create a new "mydb" database.
  cloudant.db.create(dbName, function(err, data) {
    if(!err) //err if database doesn't already exists
      console.log("Created database: " + dbName);
  });

  // Specify the database we are going to use (mydb)...
  mydb = cloudant.db.use(dbName);
}

//serve static file (index.html, images, css)
app.use(express.static(__dirname + '/src/views'));
app.use(express.static(__dirname + '/dist'));

app.set('views', __dirname + '/src/views');
app.set('view engine', 'jsx');
app.engine('jsx', require('express-react-views').createEngine());

// app.get('/', require('./lib/routes').index);
app.get('/', (req, res) => {
  res.sendFile(path.resolve(__dirname, './src/views/index.html'));
});

var port = process.env.PORT || 3000
app.listen(port, function() {
    console.log("To view your app, open this link in your browser: http://localhost:" + port);
});
var connectedDevices = new Set();

app.ws('/update', function(ws, req) {
  ws.on('message', function(msg) {
    var payload = JSON.parse(msg);

    // console.log(JSON.stringify(payload, null, 2));
    for (var device of connectedDevices) {
      console.log("Sending")
      device.send(msg);
    }
  });
});

app.ws('/device', function(ws, req) {


  console.log("New Device Online")
  connectedDevices.add(ws)

  ws.on('close', function() {
    console.log("Device went offline")
    connectedDevices.delete(ws)
  });
});