server.js

const http = require('http');
const cors = require('cors');
const express = require('express');
const fetch = require('node-fetch');

const app = express();
const APIKEY = "60b10dd473063a06b60eee3b342c75a6";  //signup at api.openweathermap.org and obtain an API Key

var options = {
    host: 'api.openweathermap.org',
    port: 80,
    path: '/data/2.5/weather?q=Tokyo,jp&units=metric',
    method: 'GET'
};

app.use(cors());

app.set('view engine', 'ejs');

app.get('/', (req,res) => {
	res.render('getcity');
});

app.get('/weather',(req,res) => {
	var city = req.query.city;

	console.log(`City: ${city}`);
	setOptionPath(city);
	getWeatherDetails().then(data => {
    	data.city = city.toUpperCase();
    	res.render('weather', data);
   })
});

app.get('/api/weather',(req,res) => {
	var city = req.query.city;

	console.log(`City: ${city}`);
	setOptionPath(city);
	getWeatherDetails().then(data => {
    	res.end.json(data);
   })
})

app.listen(process.env.PORT || 8099);

const setOptionPath = (city) => {
	options.path = "/data/2.5/weather?q=" + city.replace(/ /g,"+") + "&units=metric&APPID=" + APIKEY;
}

async function getWeatherDetails() {
	let currTemp = 'N/A';
	let maxTemp = 'N/A';
	let minTemp = 'N/A';
	let letidity = 'N/A';

   const res = await fetch(`http://${options.host}/${options.path}`);
   const data = await res.json();
   
   currTemp = data.main.temp;
   maxTemp = data.main.temp_max;
   minTemp = data.main.temp_min;
   humidity = data.main.humidity;
   
   return({
      currTemp: currTemp,
      maxTemp: maxTemp,
      minTemp: minTemp,
      humidity: humidity
   });
}