YoutubeWithoutSleep.js

// ==UserScript==
// @name         Youtube script - without sleep
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://www.youtube.com/*
// @run-at       document-end
// @grant        none
// ==/UserScript==

var expandTitlesInterval

var handleSaveOrZapiszButtonInterval

var handlePopupAppearingInterval

(async function () {
    expandTitlesInterval = setInterval(expandTitles, 4000)

    handleSaveOrZapiszButtonInterval = setInterval(handleSaveOrZapiszButton, 120);
})();

function expandTitles() {
    var elements = document.querySelectorAll('#video-title.yt-simple-endpoint.style-scope.ytd-grid-video-renderer');

    elements.forEach(element => {
        element.style.maxHeight = '7em';
        element.style.webkitLineClamp = '7'
    })
}

function handleSaveOrZapiszButton() {
    console.log("handleSaveOrZapiszButton")
    try {
        var saveButton = document.getElementsByClassName('style-scope ytd-button-renderer')

        if (saveButton[8].innerText === 'ZAPISZ') {
            clearInterval(handleSaveOrZapiszButtonInterval)

            click('style-scope ytd-button-renderer', 8)

            handlePopupAppearingInterval = setInterval(handlePopupAppearing, 120)
        } else if (saveButton[10].innerText === 'SAVE') {
            clearInterval(handleSaveOrZapiszButtonInterval)

            click('style-scope ytd-button-renderer', 10)
            handlePopupAppearingInterval = setInterval(handlePopupAppearing, 120)
        } else {
            console.error("Cannot find save button")
        }
    } catch (e) {
        console.log("handleSaveOrZapiszButton_CATCH")
    }
}

function handlePopupAppearing() {
    console.log("handlePopupAppearing")

    try {
        var popupInnerText = document.getElementsByClassName('checkbox-height style-scope ytd-playlist-add-to-option-renderer')[0].innerText
        var hasPopupAppeared = popupInnerText === 'Watch later' || popupInnerText === 'Do obejrzenia'
        if (hasPopupAppeared) {
            console.log("HERE1")
            clearInterval(handlePopupAppearingInterval)
            console.log("HERE2")

            handleWatchLaterCheckedButton()
        }
    } catch (e) {
        console.log("handlePopupAppearing_CATCH")
    }
}

function handleWatchLaterCheckedButton() {
    console.log('handleWatchLaterCheckedButton')

    var checkedAmount = document.getElementsByClassName('checked').length
    console.log("Checked amount:" + checkedAmount);

    if (checkedAmount == 0) {
        click('style-scope ytd-add-to-playlist-renderer', 3)
    }
}

function click(className, elementIndex) {
    console.log("click_begin, className:" + className + " ,elementIndex:" + elementIndex)
    var evt = document.createEvent("MouseEvents");
    evt.initMouseEvent("click", true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    document.getElementsByClassName(className)[elementIndex].dispatchEvent(evt);
    console.log("click_end")
}