Rewrite/redirect URLs

youtube2hooktube.user.js

// ==UserScript==
// @name        YouTube2HookTube
// @namespace   https://github.com/olmokramer
// @description Automatically redirect YouTube to HookTube
// @include     *
// @run-at      document-start
// @version     3
// @author      Olmo Kramer
// ==/UserScript==

(function() {
	'use strict';
	
	if (window.location.host.match(/youtu(\.be|be\.com)/)) {
		window.location.host = 'hooktube.com';
	}

	function replaceLinkType(type, domain) {
		const elements = document.querySelectorAll(`[${type}*="${domain}"]`);
		for (let i = 0; i < elements.length; i++) {
			elements[i][type] = elements[i][type].replace(domain, 'hooktube.com');
		}
	}

	function replaceURLs() {
		const domains = [
			'youtube.com',
			'youtu.be',
			'youtube-nocookie.com',
		];

		for (let domain of domains) {
			replaceLinkType('href', domain);
			replaceLinkType('src', domain);
		}
	}

	document.addEventListener('DOMContentLoaded', function() {
		if (MutationObserver) {
			const observer = new MutationObserver(replaceURLs);
			observer.observe(document.body, {
				childList: true,
				subtree: true,
			});
		}

		replaceURLs();
	});
})();