// ==UserScript==
// @name         YT redirect to Invidious on login request
// @namespace    http://tampermonkey.net/
// @version      1.1.2
// @description  Redirects youtube links to invidious instances if youtube requires you to login for geo-blocking or age restriction
// @author       Xynoth
// @match        https://www.youtube.com/watch?*
// @grant        none
// @license      GPL-3.0
// @downloadURL none
// ==/UserScript==

(function() {
    // Edit your invidious instance here
    var invidiousInstance = "https://invidious.snopyta.org";

    // Enable button to Invidious on youtube?
    var enableInvButton = true;

    // Other variables
    var currentLocation = window.location.href;
    var newLocation = currentLocation.replace("https://www.youtube.com/watch?", invidiousInstance + "/watch?");
    var loginWarning;
    var subscribeDiv;
    var invButton;
    var adsOnScreen;
    var timedLoop = 0;

    // We append the "watch on invidious" button here
    subscribeDiv = document.getElementById("analytics-button");

    // We check for the "Must login" container for 5 seconds before removing checker
    var checkExist = setInterval(function() {
        loginWarning = document.querySelector(".ytp-error[role='alert']");
        adsOnScreen = document.querySelector(".ytp-ad-module");
        subscribeDiv = document.getElementById("analytics-button");
        invButton = document.getElementById("invidious-Button");
        if (loginWarning && !adsOnScreen) {
            window.location.href = newLocation;
            clearInterval(checkExist);
        } else if (subscribeDiv && invButton == null && enableInvButton) {
            var watchOnInv = document.createElement("a");
            watchOnInv.setAttribute('id', "invidious-Button");
            watchOnInv.href = newLocation;
            watchOnInv.style.background = "#444";
            watchOnInv.style.fontSize = "14px";
            watchOnInv.style.textDecoration = "none";
            watchOnInv.style.color = "#fff";
            watchOnInv.style.padding = "11px 15px";
            watchOnInv.style.borderRadius = "5px";
            watchOnInv.innerHTML = "INVIDIOUS";
            subscribeDiv.appendChild(watchOnInv);
        } else if (timedLoop >= 5) {
            clearInterval(checkExist);
        }
        timedLoop += 1;
    }, 1000);

})();