// ==UserScript==
// @name               deAMP
// @name:zh-TW         deAMP
// @description        AMP sucks, thus no AMP thanks.
// @description:zh-TW  垃圾 AMP，好走不送。
// @author             Jason Kwok
// @namespace          https://jasonhk.dev/
// @version            2.1.0
// @license            MIT
// @match              http*://*/*
// @run-at             document_end
// @grant              GM_getValue
// @grant              GM_setValue
// @require            https://cdn.jsdelivr.net/npm/uuid-random@1.3.2/uuid-random.min.js
// @supportURL         https://greasyfork.org/scripts/450569/feedback
// @downloadURL none
// ==/UserScript==

const SESSION_KEY = getSessionKey();

const isAmp = (document.querySelector("html[⚡], html[amp]") !== null);
const canonical = document.head.querySelector("link[rel=canonical][href]");

if (isAmp && (canonical !== null))
{
    const lastVisit = sessionStorage.getItem(SESSION_KEY);

    if (location.href !== lastVisit)
    {
        sessionStorage.setItem(SESSION_KEY, location.href);
        location.replace(canonical.href);
    }
    else
    {
        sessionStorage.removeItem(SESSION_KEY);
    }
}
else
{
    console.debug("[deAMP] Not a valid AMP page.");

    sessionStorage.removeItem(SESSION_KEY);
}


function getSessionKey()
{
    const key = GM_getValue("SESSION_KEY");
    if (key) { return key; }

    GM_setValue("SESSION_KEY", uuid());
    return getSessionKey();
}