// ==UserScript==
// @name        youtube默认开启最高画质
// @namespace   Violentmonkey Scripts
// @match        *://www.youtube.com/watch?v=*
// @match        *://www.youtube.com/*
// @grant       none
// @version     2.2
// @author      lazy cat
// @description 2023/7/27 11:45:08
// @run-at      document-end
// @license MIT
// @homepageURL      https://greasyfork.org/zh-CN/scripts/473553-youtube%E9%BB%98%E8%AE%A4%E5%BC%80%E5%90%AF%E6%9C%80%E9%AB%98%E7%94%BB%E8%B4%A8
// @homepage        https://greasyfork.org/zh-CN/scripts/473553-youtube%E9%BB%98%E8%AE%A4%E5%BC%80%E5%90%AF%E6%9C%80%E9%AB%98%E7%94%BB%E8%B4%A8
// @downloadURL none
// ==/UserScript==
(function(){
    function t_stop(num){
        return new Promise((resolve)=>{setTimeout(resolve, num)})
    }
    async function set_max_voice_px() {
        if (j_num>50){
            return
        }
        player = document.querySelector('div[id="movie_player"]')
        if (player && player.getAvailableQualityLevels && player.getAvailableQualityLevels().length > 0){
            let v_list = player.getAvailableQualityLevels()
            player.setPlaybackQualityRange(v_list[0])
            j_num = 0
        }
        else{
            j_num++
            await t_stop(100)
            set_max_voice_px()
        }
    }
    function list_judgment() {
        set_max_voice_px()
        //循环检查页面是否改变
        setInterval(() => {
            new_url = String(window.location.href)
            if (new_url != url){
                j_num = 0
                set_max_voice_px()
                url = new_url
            }
        }, 1000);
    }
    //开始运行程序
    var j_num = 0
    var new_url = ''
    var url = String(window.location.href)
    list_judgment()
    })()