// ==UserScript==
// @name         4khd 广告屏蔽
// @namespace    https://viayoo.com
// @version      0.42
// @description  移除4khd广告。
// @author       Via
// @license      MIT
// @match        *://*.4khd.com/*
// @match        *://*.xxtt.ink/*
// @match        *://*.uuss.uk/*
// @run-at       document-start
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    const AD_SELECTORS = '.exo_wrapper,.popup,.centbtd,.exo-native-widget,.exo-native-widget-outer-container,ins[data-processed="true"]';
    const BLOCK_URL_PATTERNS = [/(magsrv|pemsrv)\.com/i, /\.js$/i];
    const BLOCK_CONTENT_PATTERNS = [/(magsrv|pemsrv)\.com/i, /ad-provider\.js/i];

    window.fetch = function(...args) {
        let url = '';
        if (typeof args[0] === 'string') {
            url = args[0];
        } else if (args[0] instanceof Request) {
            url = args[0].url;
        }
        return BLOCK_URL_PATTERNS.some(p => p.test(url)) ?
            Promise.resolve(new Response('', {
                status: 200
            })) :
            window.originalFetch.apply(this, args);
    };
    window.originalFetch = window.fetch;

    const origOpen = XMLHttpRequest.prototype.open;
    XMLHttpRequest.prototype.open = function(method, url) {
        if (typeof url === 'string' && BLOCK_URL_PATTERNS.some(p => p.test(url))) return;
        return origOpen.apply(this, arguments);
    };

    const origOpenWin = window.open;
    window.open = function(...args) {
        const url = args[0] || '';
        return /magsrv|ads|pop/i.test(url) ? null : origOpenWin.apply(this, args);
    };

    const blockScript = node => {
        if (node.tagName !== 'SCRIPT') return;
        const src = node.src || '';
        const txt = node.textContent || '';
        if (BLOCK_CONTENT_PATTERNS.some(re => re.test(src) || re.test(txt))) node.remove();
    };

    const removeAds = () => {
        document.querySelectorAll(AD_SELECTORS).forEach(el => el.remove());
    };

    const debouncedRemoveAds = (() => {
        let timer;
        return () => {
            clearTimeout(timer);
            timer = setTimeout(removeAds, 100);
        };
    })();

    new MutationObserver(muts => {
        for (const m of muts) {
            for (const n of m.addedNodes) {
                if (n.nodeType !== 1) continue;
                blockScript(n);
                const scripts = n.querySelectorAll ? n.querySelectorAll('script') : [];
                scripts.forEach(blockScript);
                debouncedRemoveAds();
            }
        }
    }).observe(document, {
        childList: true,
        subtree: true
    });

    const init = () => {
        removeAds();
    };

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', init);
    } else {
        init();
    }
})();