// ==UserScript==
// @name         Super Fast Loading Optimized
// @namespace    http://tampermonkey.net/
// @version      1.2
// @description  Boost website loading speed, prevent autoplay for YouTube videos, and lazy load images and videos.
// @author       Farzan Farhangi
// @match        *://*/*
// @grant        GM_xmlhttpRequest
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    const allowAutoPlayWithinMillisecondsOfClick = 1000;
    let lastClickTimeMs = 0;

    // Function to prevent autoplay for YouTube videos
    const preventAutoplayYouTube = () => {
        const videos = document.querySelectorAll('video[data-src]');
        videos.forEach(video => {
            video.pause();
            video.removeAttribute('src');
            video.addEventListener('click', () => {
                if (!video.src) {
                    const source = video.getAttribute('data-src');
                    if (source) {
                        video.src = source;
                        video.play();
                    }
                }
            });
        });
    };

    // Lazy load videos
    const lazyLoadVideos = () => {
        const videos = document.querySelectorAll('video[data-src]');
        const observer = new IntersectionObserver(entries => {
            entries.forEach(entry => {
                if (entry.isIntersecting) {
                    const video = entry.target;
                    video.src = video.getAttribute('data-src');
                    video.play();
                    observer.unobserve(video);
                }
            });
        });

        videos.forEach(video => observer.observe(video));
    };

    // Check if autoplay is allowed based on last click time
    const isAutoPlayAllowed = () => (Date.now() - lastClickTimeMs) <= allowAutoPlayWithinMillisecondsOfClick;

    window.addEventListener('click', () => { lastClickTimeMs = Date.now(); });

    // Enable lazy loading for images
    const enableLazyLoadImages = () => {
        const images = document.querySelectorAll('img:not([loading])');
        images.forEach(img => img.setAttribute('loading', 'lazy'));
    };

    // Load scripts asynchronously
    const loadScriptAsync = (url) => {
        const script = document.createElement('script');
        script.src = url;
        script.defer = true; // Load asynchronously without blocking rendering
        document.head.appendChild(script);
    };

    // Load CSS immediately
    const loadCSS = (url) => {
        const link = document.createElement('link');
        link.rel ='stylesheet';
        link.href = url;
        document.head.appendChild(link);
    };

    // Preload critical resources at the start
    const preloadResources = async () => {
        const criticalResources = [
            'https://example.com/styles.css',
            'https://example.com/script.js',
            // Add other resources here as needed
        ];

        criticalResources.forEach(resource => {
            if (resource.endsWith('.css')) {
                loadCSS(resource);
            } else if (resource.endsWith('.js')) {
                loadScriptAsync(resource);
            }
        });
    };

    window.addEventListener('load', () => {
        enableLazyLoadImages();
        preloadResources();
        preventAutoplayYouTube();
        lazyLoadVideos(); // Call lazy loading for videos after page load
    });

})();