'use strict';

const util = require('util');
const fs = require('fs').promises;
const Promise = require('bluebird');
const { JSDOM } = require('jsdom');

const waitImmediate = util.promisify(setImmediate);

async function init() {
	let peak = 0;
	const files = await fs.readdir('./html');

	await Promise.map(Array.from({ length: 10 }).map(() => files).flat(), async (filename) => {
		const html = await fs.readFile(`./html/${filename}`, 'utf8');
		const dom = new JSDOM(html);

		dom.window.close();

		const usage = process.memoryUsage.rss() / 1000000;
		peak = Math.max(usage, peak);

		console.log(`Memory usage: ${usage.toFixed(2)} MB, peak ${peak.toFixed(2)} MB`);

		await waitImmediate;
	}, {
		concurrency: 100,
	});

	await Promise.delay(2000);

	console.log(`Final memory usage: ${(process.memoryUsage.rss() / 1000000).toFixed(2)} MB, max ${peak.toFixed(2)} MB`);
}

init();