const express = require('express');
const fs = require('fs');
const readdirAsync = require('util').promisify(require('fs').readdir);
const writeFileAsync = require('util').promisify(require('fs').writeFile);

const app = express();

function generate_random_data(size){
    var chars = 'abcdefghijklmnopqrstuvwxyz'.split('');
    var len = chars.length;
    var random_data = [];

    while (size--) {
        random_data.push(chars[Math.random()*len | 0]);
    }

    return random_data.join('');
}


app.use('/sync', (req, res) => {
	const files = fs.readdirSync('./node_modules');
	const files2 = fs.readdirSync('./node_modules/express/lib');
	res.send({answer:'yes'})
});

app.use('/async', async (req, res) => {
	const files = await readdirAsync('./node_modules');
	const files2 = await readdirAsync('./node_modules/express/lib');
	res.send({answer:'yes'})
});

app.use('/wsync', (req, res) => {
	const data = generate_random_data(10000);
	const files = fs.writeFileSync('./testFileS', data);
	res.send({answer:'yes'})
});

app.use('/wasync', async (req, res) => {
	const data = generate_random_data(10000);
	const files = writeFileAsync('./testFileA', data);
	res.send({answer:'yes'})
});

app.listen(5555, () => {
  console.log('Listening on port', 5555);
});