server.js

const express = require('express');
const bodyParser = require('body-parser');
const request = require('request');
const app = express()

const apiKey = '49b2f0de66bca1b85d63cc89607527a4';

app.use(express.static('public'));
app.use(bodyParser.urlencoded({
  extended: true
}));
app.set('view engine', 'ejs')

app.get('/', function(req, res) {
  res.render('index', {
    weather: null,
    error: null
  });
})

app.post('/', function(req, res) {
  let city = req.body.city;
  let url = `http://api.openweathermap.org/data/2.5/weather?q=${city}&units=metric&appid=${apiKey}`

  request(url, function(err, response, body) {
    if (err) {
      res.render('index', {
        weather: null,
        error: 'Dude, enter correct city naa!'
      });
    } else {
      let weather = JSON.parse(body)
      if (weather.main == undefined) {
        res.render('index', {
          weather: null,
          error: 'Dude, enter correct city naa!'
        });
      } else {
        let weatherText = `Woah! It's ${weather.main.temp} degrees celcius in ${weather.name}! `;
        res.render('index', {
          weather: weatherText,
          error: null
        });


      }
    }
  });
})

app.listen(3000, function() {
  console.log('Weather App is running on port 3000')
})
listen(process.env.PORT)