ACT.YouTube.MO.Embed-button

Go to Embed page to uses Subtitles/CC auto-translate menu on in-page fullscreen player, for mobile users.

// ==UserScript==
// @name               ACT.YouTube.MO.Embed-button
// @name:zh-CN         ACT.YouTube.MO.转到嵌入页按钮
// @description        Go to Embed page to uses Subtitles/CC auto-translate menu on in-page fullscreen player, for mobile users.
// @description:zh-CN  一键转到嵌入式页面以在页面内全屏播放器上使用字幕自动翻译菜单，供手机用户使用。
// @author             ACTCD
// @version            20220722.1
// @license            GPL-3.0-or-later
// @namespace          ACTCD/Userscripts
// @supportURL         https://github.com/ACTCD/Userscripts#contact
// @homepageURL        https://github.com/ACTCD/Userscripts
// @match              *://m.youtube.com/*
// @match              *://www.youtube-nocookie.com/embed/*
// @grant              none
// @inject-into        content
// @run-at             document-start
// ==/UserScript==

(function () {
	"use strict";

	const button = document.createElement("button");
	button.id = "ACT_Embed";
	button.innerText = "Embed";
	button.style.setProperty("color", "white");
	button.style.setProperty("background-color", "transparent");
	button.style.setProperty("border", "2px solid");
	button.style.setProperty("border-radius", "10px");
	button.style.setProperty("padding", "1px 5px");
	button.style.setProperty("font-size", "1.5em");
	button.style.setProperty("font-weight", "500");
	button.style.setProperty("text-shadow", "black 1px 1px 2px");
	button.addEventListener(
		"click",
		(event) => {
			let vid = new URL(location).searchParams.get("v");
			if (!vid) return;
			let url = new URL(
				"https://www.youtube-nocookie.com/embed/?autoplay=1&cc_lang_pref=zh&cc_load_policy=1&hl=zh&modestbranding=1&tlang=zh-Hans",
			);
			url.pathname = "/embed/" + vid;
			location.href = url;
			event.preventDefault();
			event.stopImmediatePropagation();
		},
		true,
	);

	function insert_button() {
		if (location.hostname != "m.youtube.com") return;
		if (location.pathname != "/watch") return;
		if (button.parentNode) return;
		document
			.querySelector("ytm-home-logo", ".mobile-topbar-header-endpoint")
			?.after(button);
		console.log("insert_button");
	}

	function tweak() {
		insert_button();
		document.querySelector(".ytp-fullscreen-button")?.remove();
	}

	new MutationObserver(tweak).observe(document, {
		subtree: true,
		childList: true,
	});

	function web_app() {
		const meta = document.createElement("meta");
		meta.name = "apple-mobile-web-app-capable";
		meta.setAttribute("content", "yes");
		document.head.appendChild(meta);
	}

	function WindowLoaded() {
		console.log("WindowLoaded");
		tweak();
		location.pathname.startsWith("/embed/") && web_app();
	}

	if (document.readyState === "complete") {
		WindowLoaded();
	} else {
		window.addEventListener("load", WindowLoaded);
	}
})();