// ==UserScript==
// @name         UCAS_SessionExpireHelper
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  block the deadline alert from ucas website to avoid session expire
// @author       y4ung
// @match        https://course.ucas.ac.cn/portal/site/*/video/play*
// @grant        none
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';
    // button的title属性：Mute or Unmute
    alert("Run script BlockAlertHelper. By y4ung");
    var mute_btn = document.getElementsByClassName("vjs-mute-control vjs-control vjs-button vjs-vol-3")[0];

    window.setInterval(function(){
        clickMuteBtn(mute_btn);// （默认声音开启）关闭声音
        clickMuteBtn(mute_btn);// 无缝切换开启声音
    }, 10000);

})();

function clickMuteBtn(mute_btn) { // 模拟 浏览器的鼠标点击事件
    const event = new MouseEvent('click', {
        view: window,
        bubbles: true,
        cancelable: true
    });
    mute_btn.dispatchEvent(event);
}