define(function() {
    'use strict';

    var all_pages = 'home studying curriculum campus career'.split(' ');

    /* loads a page into view and execute scripts */
    function loadContent(name, text) {
        var contentElement = document.getElementById('content');
        contentElement.innerHTML = text;
        document.body.dataset.page = name;

        // execute scripts in page
        [].forEach.call(contentElement.getElementsByTagName('script'),
                function(origScript) {
            var script = document.createElement('script');
            // copy attributes
            [].forEach.call(origScript.attributes, function(a) {
                script.setAttribute(a.name, a.value);
            });
            // copy contents
            script.textContent = origScript.textContent;
            origScript.parentNode.replaceChild(script, origScript);
        });
    }

    /* tries to navigate to a page */
    function selectPage(page) {
        if (all_pages.indexOf(page) == -1) {
            // TODO: 404
            console.log("404 " + page);
            return false;
        }
        console.log("Loading " + page);
        var http = new XMLHttpRequest();
        http.onload = function() {
            loadContent(page, http.responseText);
        };
        http.open('get', 'pages/' + page + '.html');
        http.send(null);
        return true;
    }

    addEventListener('hashchange', function(ev) {
        var m = /#\/(.+)/.exec(ev.newURL);
        if (m) {
            selectPage(m[1]);
        } else if (!/#/.test(ev.newURL)) {
            location.hash = '#/home';
        }
    });

    // Tries to load the current page, falling back to "home" for unknown URLs.
    if (!selectPage(location.hash.replace(/^#\//, ''))) {
        location.hash = '#/home';
    }
});