/*
Class: Ajax connectivity
*/

// Default constructor
function Ajax(_options) {
	// Set that reference
	var that = this;

	// Properties
	that.action = _options.action || undefined;
	that.method = _options.method || "GET";
	that.async = _options.async || true;
	that.params = _options.params || null;
	that.comet = _options.comet || false;
	that.success = _options.callback;
	that.error = _options.error;

	// Functions
	that.sanitizeToLastJson = function(_string) {
		return string.substring(_string.lastIndexOf("{"), _string.lastIndexOf("}")+1);
	}

	// Cancel if they omit this one
	if(typeof(that.action) === "undefined") {
		return false;
	}

	// Connect immediately
	try {
		that.request = new XMLHttpRequest() || new ActiveXObject("MSXML2.XMLHTTP.3.0");

		// Determine where get/post parameters go
		if(that.method === "GET" && that.params !== null) {
			that.request.open(that.method, that.action+"?"+encodeURI(that.params), that.async);
		}
		else {
			that.request.open(that.method, that.action, true);
		}

		// Set content header for json
		that.request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

		// Waiting for connect
		that.request.onreadystatechange = function() {
			// Using comet
			if(that.comet === true) {
				if(that.request.readyState === 3 && that.request.status === 200) {
					// If the success callback was set, call it
					if(typeof(that.success) !== "undefined") {
						that.success(that.sanitizeToLastJson(that.request.responseText));
					}
				}
			}

			// Success
			if(that.request.readyState === 4 && that.request.status === 200) {
				// If the success callback was set, call it
				if(typeof(that.success) !== "undefined") {
					that.success(that.request.responseText);
				}
			}
		}

		// Send the request differently if there is POST data
		if(that.method === "POST" && that.params !== null) {
			that.request.send(that.params);
		}
		else {
			that.request.send(null);
		}

		return true;
	}
	catch (e) {
		// Call the error callback if set
		if(typeof(that.error) !== "undefined") {
			that.error(e);
		}

		return false;
	}
}