window.addEventListener('load', function() {
    var links = document.getElementById("links").children[0].children;
    var home = document.getElementsByClassName("home");
    var menu = document.getElementById("menu");
    var content = document.getElementById("content");
    var body = document.getElementsByTagName("body")[0];

    function menuOperator(node, position, token="") {
        menu.setAttribute("class", position);
        for(var i = 0; i < links.length; i++) {
            links[i].children[0].removeAttribute("class");
        }
        node.setAttribute("class", "selected " + token);
        for(var i = 0; i < content.children.length; i++) {
            content.children[i].setAttribute("class", "hidden")
        }
        var name = node.getAttribute("data-name");
        if(name) {
            var article = document.getElementById(name);
            article.setAttribute("class", "selected");
        }
        var color = node.getAttribute("data-color");
        if(color) {
            body.setAttribute("class", color);
        }
        window.history.pushState("object or string", "Title", node.href);
    }

    for(var i = 0; i < links.length - 1; i++) {
        links[i].children[0].onclick = function(event) { 
            event.preventDefault();
            var node = event.currentTarget;
            menuOperator(node, "top");
        };
    }
    for(var i = 0; i < home.length; i++) {
        home[i].onclick = function(event) {
            event.preventDefault();
            var node = event.currentTarget;
            menuOperator(node, "middle", "home");
        }
    }
}, false);