function load() {
    var base = '//127.0.0.1:9842',
        ws = new WebSocket('ws:' + base + '/ws');
    ws.onopen = function(event) {
        document.location.href = 'http:' + base;
    };
    ws.onerror = function(event) {
        ws.close();
    };
    ws.onclose = function(event) {
        setTimeout(load, 500);
    };
};

function update() {
    var xhr = new XMLHttpRequest();
    xhr.onload = function() {
        var response = JSON.parse(this.responseText);
        if (response.step) {
            var status = response.step;
            if (response.progress) {
                status = parseInt(response.progress * 100) + '% ' + status;
            }
            document.getElementById('status').innerHTML = status;
            setTimeout(update, 1000);
        } else {
            document.getElementById('status').innerHTML = "done";
            load();
        }
    };
    xhr.onerror = function() {
        var status = document.getElementById('status').innerHTML;
        if (['done', 'setup'].indexOf(status) == -1) {
            document.getElementById('status').innerHTML = "error";
        }
        load();
    }
    xhr.open('get', '/status');
    xhr.send();

}

update();