server.js

const express = require('express');
const cors = require('cors');
require ('dotenv').config();

const ClientsManager = require('./lib/clientsManager');
const Publisher = require('./lib/publisher');

const app = express();
app.use(cors());

const {
  PORT,
  REDIS_PORT,
  REDIS_HOST,
  JWT_KEY,
  SEC_PER_PULSE,
  API_TOPICS
} = process.env;

const clients = new ClientsManager(JWT_KEY, API_TOPICS);

const publisher = new Publisher(
  REDIS_PORT,
  REDIS_HOST,
  SEC_PER_PULSE,
  clients.list
);

publisher.listenAndPublish();

if (JWT_KEY) {
  // server set up to require JWT
  app.get('/stream/:topic/:id/:token', clients.stream.bind(clients));
} else {
  // server set up without JWT
  app.get('/stream/:topic/:id', clients.stream.bind(clients));
}

// for AWS Application Load Balancer health check
app.get('/', (req, res) => res.send('Healthy'));

app.listen(PORT, () => console.log(`listening on port: ${PORT}`));