function API(baseurl){
    
    this.baseurl = baseurl;
    
    this.get = function(page, handler = null){
        var x = new XMLHttpRequest();
        var async = (handler != null);
        
        if (async)
        {
            x.onload = function(){
                var responseText = x.responseText;
                handler( responseText );
            }
        }
        x.open("GET", this.baseurl + page, async);
        x.send();
        
        if (!async)
            return x.responseText
    }
    this.post = function(page, handler = null){
        var x = new XMLHttpRequest();
        if (handler != null)
        {
            x.onload = function(){
                var responseText = x.responseText;
                handler( responseText );
            }
        }
        x.open("POST", this.baseurl + page);
        x.send();
    }
    
    this.getJson = function(page, handler){
        var j = function(t){
                handler(JSON.parse(t));
            };
        return this.get( page, j );
    }
    
    this.call = function(endpoint,method,parameters = []){
        var x = new XMLHttpRequest();
        x.open("POST", this.baseurl + endpoint, false);
        x.setRequestHeader("content-type","application/json");
        
        var methodCall = {
            "MethodName": method,
            "Parameters": parameters
        }
        
        x.send(JSON.stringify(methodCall));
        
        var result = JSON.parse(x.responseText);
        if (result.Exception != null)
            throw result.Exception;

        return result.Result;
    }

    this.loadPage = function (page) {

        var hContent = $("content");
        var x = new XMLHttpRequest();

        x.open("GET", this.baseurl + page, false);
        x.setRequestHeader("x-template-unframed","unframed");
        x.send();

        hContent.innerHTML = x.responseText;

        history.pushState(null, page, this.baseurl + page);

        this.fireOnLoad( hContent );

        return false;
    }

    this.fireOnLoad = function(element){
        if (element.onload != null)
        {
            element.onload();
        }

        for (var n=0;n<element.children.length;n++)
            this.fireOnLoad(element.children[n]);
    }

}

function $(id)
{
    return document.getElementById(id);
}
function CE(eName)
{
    return document.createElement(eName);
}


var api = null;

function loadStatistics()
{    
    try
    {
        var stats = api.call("api/management","GetStatistics");

        $("ServerTime").innerText = "ServerTime: " + stats.ServerTime;

        $("indHttpServer").attributes["state"].value = stats.States.HttpServer;
        $("indManager").attributes["state"].value = stats.States.Manager;
        $("indCrawler").attributes["state"].value = stats.States.Crawler;
        $("indChecks").attributes["state"].value = stats.States.Checks;
        $("indDispatcher").attributes["state"].value = stats.States.Dispatcher;
    
    } catch (e)
    {
        $("ServerTime").innerText = "Server unreachable";

        $("indHttpServer").attributes["state"].value = 3;
        $("indManager").attributes["state"].value = 0;
        $("indCrawler").attributes["state"].value = 0;
        $("indChecks").attributes["state"].value = 0;
        $("indDispatcher").attributes["state"].value = 0;
    }
}


function initApi(baseurl)
{
    api = new API(baseurl);
    setInterval( loadStatistics, 1000 );

    for (var n=0;n<document.body.children.length;n++)
        api.fireOnLoad(document.body.children[n]);

}