youtubeLiveObserver.user.js

// ==UserScript==
// @name          Auto Refresh YouTube Live
// @description   Automatically tracks live head for YouTube Live
// @match         https://www.youtube.com/*
// @version       1.0.7
// @homepageURL   https://gist.github.com/kyohsuke/eac69ddef61d4cd8d165c8b2e59ff0ef
// @updateURL     https://gist.githubusercontent.com/kyohsuke/eac69ddef61d4cd8d165c8b2e59ff0ef/raw/youtubeLiveObserver.user.js
// @downloadURL   https://gist.githubusercontent.com/kyohsuke/eac69ddef61d4cd8d165c8b2e59ff0ef/raw/youtubeLiveObserver.user.js
// @icon          https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant         none
// ==/UserScript==

(function(){
    function liveTracker() {
        console.log("Init Live Tracker");

        const initialInterval = 3;

        let observer = null;
        let intervalResetTimerID = null;
        let liveInterval = initialInterval;
        let currentURL = "";

        function isObject(value) {
            return value !== null && typeof value === 'object'
        }

        function liveButton() {
            return document.getElementsByClassName("ytp-live-badge")[0];
        }

        function videoTag() {
            return document.getElementsByTagName("video")[0]?.src;
        }

        function isLive(btn) {
            return (btn != undefined && window.getComputedStyle(btn).display != "none");
        }


        function addObserver() {
            let liveBtn = liveButton();
            const handleMutation = (mutationsList, observer) => {
                mutationsList.forEach(mutation => {
                    // 変更に対する処理
                    let onLive = false;
                    mutation.target.classList.forEach(className => {
                        if(className == "ytp-live-badge-is-livehead") {
                            onLive = true;
                        }
                    });

                    if(isLive(liveBtn) && !onLive) {
                        let nextDelay = 1000 * liveInterval;
                        console.log("Move ahead after", liveInterval, "seconds");

                        if(liveInterval < 10) {
                            liveInterval += 1;
                        }

                        if(intervalResetTimerID) {
                            clearTimeout(intervalResetTimerID);
                        }

                        intervalResetTimerID = setTimeout(function(){
                            liveInterval = initialInterval;
                            console.log("Timer Reset");
                        }, 1000 * 60);

                        setTimeout(function(){
                            if(videoTag()) {
                                liveBtn.click();
                            }
                        }, nextDelay);
                    }
                });
            };

            if(observer != null) {
                observer.disconnect();
            }

            if(isObject(liveBtn)) {
                console.log("Put Observer");
                observer = new MutationObserver(handleMutation);
                observer.observe(liveBtn, {
                    attributeFilter: ["class"],
                });
            }
        }

        function putEvents() {
            liveInterval = initialInterval;
            addObserver();
        }

        setInterval(function(){
            let pickURL = location.href;
            if(currentURL != pickURL) {
                currentURL = pickURL;
                setTimeout(putEvents, 1000);
            }
        }, 1000);
    }

    liveTracker();
})();