Rocket.Chat/packages/random/src/createAleaGenerator.ts

import { AleaRandomGenerator } from './AleaRandomGenerator';

// instantiate RNG.  Heuristically collect entropy from various sources when a
// cryptographic PRNG isn't available.

// client sources
const height =
	(typeof window !== 'undefined' && window.innerHeight) ||
	(typeof document !== 'undefined' && document.documentElement && document.documentElement.clientHeight) ||
	(typeof document !== 'undefined' && document.body && document.body.clientHeight) ||
	1;

const width =
	(typeof window !== 'undefined' && window.innerWidth) ||
	(typeof document !== 'undefined' && document.documentElement && document.documentElement.clientWidth) ||
	(typeof document !== 'undefined' && document.body && document.body.clientWidth) ||
	1;

const agent = (typeof navigator !== 'undefined' && navigator.userAgent) || '';

export function createAleaGeneratorWithGeneratedSeed() {
	return new AleaRandomGenerator({
		seeds: [new Date(), height, width, agent, Math.random()],
	});
}