Bookmarklet para foro de elhacker.net

mensajesrecientes.js

(function(){
    if(window.origin !== 'https://foro.elhacker.net') throw new Error('No estas en el foro');
    fetch("/index.php").then(res => {
        if(res.ok){
            return res.arrayBuffer().then(buf => {
                let decoder = new TextDecoder('iso-8859-1');
                let html = decoder.decode(buf);
                let domParser = new DOMParser();
                let dom = domParser.parseFromString(html, 'text/html');
                let mensajesRecientes = dom.evaluate(
                    "/html/body/table[last()-1]//table[1]/tbody[1]/tr[1]/td[1]/table[3]//table[1]",
                    dom,
                    null,
                    XPathResult.ANY_TYPE,
                    null
                ).iterateNext();

                let messageNodes = Array.from(
                    mensajesRecientes.querySelectorAll('tr td'),
                    td => {
                        let fragment = document.createElement('div');
                        fragment.append(...td.childNodes);
                        return fragment;
                    }
                )
                displayNewMessages(messageNodes);
            });
        } else {
            throw new Error(`${res.statusText} ${res.status}`);
        }
    });

    function displayNewMessages(messageNodes){
        let idKey = "mensajes-recientes";
        let floatingWindow = document.createDocumentFragment();
        let layout = document.createElement('div');
        layout.id = idKey;
        layout.className = "windowbg2";
        layout.style = "padding: 10px; box-shadow: 0px 0px 5px #1c6699; display: grid; grid-template-columns: 80px 1fr 100px; grid-template-rows: min-content; gap: 10px; position: fixed; top: 15%; left: 15%; height: 70%; width: 70%; ";
        floatingWindow.append(layout);
        let forum = document.createElement('div');
        let close = document.createElement('button');
        close.innerText = 'X';
        close.style= "position: absolute; top: 5px; left: 5px";
        close.addEventListener('click', () => document.getElementById(idKey).remove());
        layout.append(close);
        forum.append('Foro');
        let title = document.createElement('div');
        title.append('Tema');
        let time = document.createElement('div');
        time.append('Fecha');
        let header = [forum, title, time];
        header.forEach(function(d){
            d.style = "font-weight: bold; text-align: center; padding: 5px 0px; background-color: #abcbdc";
        });
        layout.append(...header);
        messageNodes.reduce((layout, node, i) => {
            if(i%3 === 0) node.style = "text-align: end";
            layout.append(node);
            return layout;
        }, layout);
        let check = document.getElementById(idKey);
        !check ? document.body.appendChild(floatingWindow) : check.replaceWith(floatingWindow);
    }
})();