index.js

// index.js
// where your node app starts

// init project
var express = require('express');
var app = express();

// enable CORS (https://en.wikipedia.org/wiki/Cross-origin_resource_sharing)
// so that your API is remotely testable by FCC 
var cors = require('cors');
app.use(cors({ optionsSuccessStatus: 200 }));  // some legacy browsers choke on 204

// http://expressjs.com/en/starter/static-files.html
app.use(express.static('public'));

// http://expressjs.com/en/starter/basic-routing.html
app.get("/", function(req, res) {
  res.sendFile(__dirname + '/views/index.html');
});


// your first API endpoint... 
app.get("/api/hello", function(req, res) {
  res.json({ greeting: 'hello API' });
});

app.get('/api', function(req, res) {
  let today = new Date();
  return res.json({ unix: today.getTime(), utc: today.toString() })
})

app.get('/api/:date', function(req, res) {
  let dateParam = req.params.date;
  let intRegex= /^\d+$/;
  console.log(dateParam);
  if (intRegex.test(dateParam)) {
    dateParam = parseInt(dateParam);
  }
  let date = new Date(dateParam);

  if (isNaN(date.valueOf())) {
    console.log('invalid date');
    return res.json({ error: "Invalid Date" })
  }

  let unix = date.getTime();
  let utc = date.toUTCString();
  res.json({ unix: unix, utc: utc });
})



// listen for requests :)
var listener = app.listen(process.env.PORT, function() {
  console.log('Your app is listening on port ' + listener.address().port);
});