//-------------------
//...Helper functions
//-------------------

//--------------------------------
//...Events and requests handling
//--------------------------------
function createRequestObject() {
	var xmlhttp;
	if (window.XMLHttpRequest){
		 xmlhttp=new XMLHttpRequest();
		} else {
		 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
		}
	return xmlhttp;
}

//------------------------------------------------

function prepareLink(type) {
	
	var refid = document.getElementById("refid") ? document.getElementById("refid").value : '';
	var id = document.getElementById("id") ? document.getElementById("id").value : '';
	var period = document.getElementById("period") ? document.getElementById("period").value : '';
	var outFormat = document.getElementById("out_format") ? document.getElementById("out_format").value : '';
	var parameters_bien = document.getElementById("parameters_bien") ? document.getElementById("parameters_bien").value : '';
	var parameters_am = document.getElementById("parameters_am") ? document.getElementById("parameters_am").value : '';

	if (refid === '' || id === '' || period === '' || outFormat === '' || (parameters_bien === '' && parameters_am === '')) {
        return '';
    }
	
	//...prepare request
	var link =	'chart_client.pl?' +
				'type=' + type +
				'&refid=' + refid + 
				'&id=' + id + 
				'&period=' + period + 
				'&outformat=' + outFormat + 
				'&parameters_bien=' + parameters_bien +
				'&parameters_am=' + parameters_am; 
	
	return link;
}

function warning(msg) {
	if (msg != '') {
		alert(msg);
	}
}

//------------------------------------------------
//....Send request to load chart
//------------------------------------------------
function sendRqst(type) {

	//...prepare request in order to update form
	var link = prepareLink(type);
	if (link == '') {
        return;
    }
	
	var httpReq = createRequestObject();
	httpReq.open('get', link);
	httpReq.onreadystatechange = function(){handleResponse(httpReq);};
	httpReq.send(null);
}

//------------------------------------------------
//...Handler for common requests
//------------------------------------------------
function handleResponse(req) {

	if(req.readyState == 4) {
		
		if (req.status == 200) {
			var response = req.responseText;
			var jsonResponse = JSON.parse(response);
			
			if(jsonResponse.msg == "chart_data_ok") {
				
				document.getElementById('loading').innerHTML = '';
				var json = jsonResponse.chart_data;
				showCharts(json);				
			}
			else
			{
				document.getElementById('loading').innerHTML=jsonResponse.msg;
			}
		}	//...HTTP_STATE_OK = 200
	}	//...READY_STATE_COMPLETE == 4
}


//------------------------------------------------
//...Show chart
//------------------------------------------------
function showCharts(json) {
    
	// override chart count to ensure correct resizing
	chartCount = function () { return json.Charts.length; }
	
	// prepare dlg
	dlgPrepare();
	
	// show charts
	prepareCharts(json);
}

//------------------------------------------------
//...On load
//------------------------------------------------
$(function () { // On DOM ready...
	sendRqst('load_chart');
});