var REFRESH_RATE = 5000;

//create new AJAX object, depending on browser
if (window.XMLHttpRequest) sensor_request = new XMLHttpRequest();
else sensor_request = new ActiveXObject("Microsoft.XMLHTTP");
sensor_request.onreadystatechange = parseSensorReadings;

function parseSensorReadings()
{
	if (sensor_request.readyState == 4 && sensor_request.status == 200)
	{
		var lines = sensor_request.responseText.split("\n");
		var serial;
		var stat;

		document.getElementById("localtime").innerHTML = lines.shift();
		document.getElementById("allswell").innerHTML = lines.shift();

		for (i in lines)
		{
			var sensor = lines[i].split("|");

			if (sensor[0].charAt(0) == '@')
			{
				serial = sensor[0].substring(1, sensor[0].length);
				stat = sensor[1];

				if (!document.getElementById("dev_" + serial))
				{
					window.location.reload(); //If a new serial number is encountered, refresh
				}
				continue;
			}

			meas_idx = parseInt(sensor[0]);

			try
			{
				document.getElementById("meas_" + serial + "-" + meas_idx).className = sensor[1];
				document.getElementById("meas_" + serial + "-" + meas_idx).innerHTML = sensor[2];
				document.getElementById("status_" + serial + "-" + meas_idx).innerHTML = stat;
			}
			catch(e) {}
		}
		window.setTimeout(getSensorReadings, REFRESH_RATE);
	}
}

function getSensorReadings()
{
	sensor_request.open("GET", "sensors_min.txt" + Math.floor(Math.random() * 1000) + lang_override, true);
	sensor_request.send();
}

function refreshGraphic(graph_name)
{
	var image = document.getElementById(graph_name);
	var refresh = Math.floor(Math.random() * 1000);
	var temp_src = image.src.replace(/refresh=\d*/, "refresh=" + refresh);

	if (temp_src == image.src) //if no change took place, add refresh manually
	{
		var delimeter = (image.src.lastIndexOf('?') > 0)?'&':'?';
		image.src = image.src + delimeter +"refresh=" + refresh;
	}
	else
		image.src = temp_src;
}