Mewch Newposts Notifier

//New Post Notifier Test
var regclass = /<div class="[^"]*?boardsCell[^"]*?">(.*?)<\/div>/g
    var seen = {};
    var boards = ['b','wai','int','meta','nsfw','chad','fringe','tech','a','fur'];


var curboard = false;
if (boards.indexOf(window.location.href.split('/')[3]) !== -1) {
    curboard = window.location.href.split('/')[3];
};

function getnew() {
    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function () {
        if (xhr.readyState == XMLHttpRequest.DONE) {
            var counts = xhr.response.replace(/(\r\n\t|\n|\r\t)/gm, "").match(regclass);
            var hidden = document.createElement('div');
            hidden.style.display = 'none';
            document.body.appendChild(hidden);
            var dif = [];
            for (var i = 0; i < counts.length; i++) {
                hidden.innerHTML = counts[i];
                board = hidden.getElementsByClassName('linkBoard')[0].href.split('/')[3];
                count = hidden.getElementsByClassName('labelPostCount')[0].innerHTML;
                if (board == curboard){
                    var test = document.getElementById(count);
                    if (test){
                        seen[board] = count;
                    }
                }

                if (seen[board]) {
                    vdif = count - seen[board];
                    dif.push([board, vdif]);
                } else {
                    seen[board] = count;
                    dif.push([board, 0]);
                }
            };
            localStorage.setItem("seen", JSON.stringify(seen));
            owo(dif);
        }
    }
    xhr.open('GET', 'https://mewch.net/boards.js', true);
    xhr.send(null);
};

document.addEventListener("DOMContentLoaded", function(event) {
    if (localStorage.getItem("seen")) {
    seen = JSON.parse(localStorage.getItem("seen"));
}
    getnew();
});

setInterval(function () {
    if (localStorage.getItem("seen")) {
    seen = JSON.parse(localStorage.getItem("seen"));
}
    getnew();
}, 120000);

function owo(who) {
    console.log(who);
    var nav = document.getElementById('navBoardsSpan').querySelectorAll('a');
    var fav = JSON.parse(localStorage.getItem("favouriteBoards"));
    for (var i = 0; i < who.length; i++) {
        if (fav.indexOf(who[i][0]) !== -1) {
            var old = document.getElementById('a_' + who[i][0]);
            if (old) {
                old.parentNode.removeChild(old);
            }
            for (var n = 0; n < nav.length; n++) {
                if (nav[n].innerHTML == who[i][0] && who[i][1] !== 0) {
                    nav[n].innerHTML = nav[n].innerHTML + '<span id="a_' + who[i][0] + '" style="float:right;color:red;font-size:9px;">' + who[i][1] + '</span>';
                }
            };
        }
    }
}