// ==UserScript==
// @name         Super Duolingo Ad Blocker
// @version      0.2
// @description  Block ads and unwanted promotional content on Duolingo, including full-browser videos and dynamically named ad classes, while preserving essential lesson content.
// @author       Zinovia
// @match        https://www.duolingo.com/*
// @grant        none
// @namespace https://greasyfork.org/users/1340999
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    // Function to inject CSS into the document
    function addStyles(css) {
        const style = document.createElement('style');
        style.type = 'text/css';
        style.textContent = css;
        document.head.appendChild(style);
    }

    // CSS to hide specific promotional and ad content
    const styles = `
        /* General video ad elements */
        video {
            display: none !important;
            volume: 0;
        }

        /* Specific divs associated with ads and promotions, conditional on not being essential content */
        div[data-test="purchase-step-active"],
        div._3D_HB,
        div._16rRh,
        div._1tzFd {
            display: none !important;
        }
    `;

    // Inject styles into the document
    addStyles(styles);

    // Function to dynamically hide elements and mute videos
    function hideElementsAndMuteVideos() {
        const selectors = [
            'video',
            'div[data-test="purchase-step-active"]',
            'div._3D_HB',
            'div._16rRh',
            'div._1tzFd'
        ];

        selectors.forEach(selector => {
            document.querySelectorAll(selector).forEach(element => {
                if (!element.closest('.learning-path')) { // Ensures that elements within the learning path are not hidden
                    element.style.display = 'none';
                }
            });
        });

        // Mute and pause videos to prevent audio play
        document.querySelectorAll('video').forEach(video => {
            video.volume = 0;
            video.pause();
        });
    }

    // Run function initially to hide elements and mute videos
    hideElementsAndMuteVideos();

    // Observe DOM changes and apply modifications as necessary
    const observer = new MutationObserver(hideElementsAndMuteVideos);
    observer.observe(document.body, {
        childList: true,
        subtree: true
    });

    console.log('Super Duolingo Ad Blocker initialized.');
})();