/** GLOBALS ********************************************************/
var handlerGlobals = {

		/* jquery selectors */
		selectors: {
			messageConsole: "#response-message",
			registerForm : "#register-form",
			usernameField : "#username-field",
			emailField: "#email-field",
			passwordField: "#pass-field",
			pass2Field: "#pass2-field",
			requiredField: ".required-input"
		},

		/* classes */
		classes : {
				success: "success",
				error: "error"
		},

		/* base url / directory for rest calls */
		ajaxUri : "/Calendar/rest",

		ajaxUrls : {
			register : "user/register"
		},

		/* getters for globals */
		getSelector : function(key){
			return this.selectors[key];
		},

		getClass : function(key){
			return this.classes[key];
		},


		getAjaxUrl : function(key){
			return this.ajaxUrls[key];
			//return "";
		},

		print_r : function(obj){
			for(key in obj)
				alert(key + " = " + obj[key]);
		}
		/* **************************/

};
/** END GLOBALS **********************************************************************/

/** FormHandler Class ****************************************************************/
function FormHandler(){
	var handler = this;
	messages = new Array();
	success = false;
	ajaxItems = {};

	/* initialize ready events */
	initEvents = function(){
		handler = this;
		registerSelector = handlerGlobals.getSelector("registerForm");
		$(registerSelector).bind("submit", function(){
			form = $(this);
			return handler.handleRegisterForm(form);
		});

	};

	/* getter / setter for ajax items */
	getAjax = function(key){
		return this.ajaxItems[key];
	};

	addAjax = function(key, ajaxItem){
		this.ajaxItems[key] = ajaxItem;
	};

	/**
	 * ajaxError
	 * standard Ajax error handler function.
	 */
	ajaxError = function(xhr, status, error ){

		message = "An error occurred querying the server.  Please try again later.";

		addErrorMessage(message);
		displayMessages();
		return false;
	};

	/**
	 * FormHandler.registerCallback()
	 * function: callback for registering a new user with an Ajax call.
	 * 			 The JSON object returned is a UserResponse
	 * 			(@see calendar.rest.data.UserResponse.java), with the following keys:
	 * 			Root element: Response,
	 * 				boolean succeeded: -- was the user operation (registration) a success
	 * 				List<User> users: -- list of users associated with the operation
	 * 									(the newly registered user).
	 * 				List<String> messages: status messages.
	 */
	registerCallback = function(data){

		message = "";

		if(data.succeeded){
			user = data.users;
			message = "The user " + user.username + " has registered successfully";
			addSuccessMessage(message);
		}else{
			addErrorMessage(data.messages);
		}

		displayMessages();

	};

	/* ** FormHandler.messages -- Success / Error messages to display to the user **/
	/**
	 * Add a message or array of messages to be displayed to the user.
	 * @param msg - the message to be added.
	 * @param retainMessages - if true, old messages that are stored will be kept,
	 * 				otherwise, old messages will be deleted.
	 */
	addMessage = function(msg, retainMessages){

		if(!retainMessages)
			this.clearMessages();

		if(isArray(msg)){
			for(i in msg)
				this.messages.push(msg[i]);
		}else{
			this.messages.push(msg);
		}

	};

	/* delete all stored status messages */
	clearMessages = function(){
		this.messages = new Array();
	};

	/**
	 * addSuccessMessage()
	 * add a success message for the user.
	 * @param msg - the message.
	 * @param retainMessages - whether to retain the existing messages.
	 */
	addSuccessMessage = function(msg, retainMessages){
		this.setSuccess(true);
		this.addMessage(msg, retainMessages);
	};

	/* add a message, and record an error */
	addErrorMessage = function(msg, retainMessages){

		this.setSuccess(false);
		this.addMessage(msg, retainMessages);
	};

	/* display all status messages */
	displayMessages = function(retainMessages){
		selector = handlerGlobals.getSelector("messageConsole");
		msgContainer = $(selector);
		msgContainer.html("");

		containerClass = this.succeeded() ? handlerGlobals.getClass("success") :
								handlerGlobals.getClass("error");
		msgContainer.addClass(containerClass);
		for( i in this.messages)
			msgContainer.append(this.getMessageHtml(this.messages[i]));

		if(!retainMessages)
			this.clearMessages();
	};

	/* helper to render messages in html form */
	getMessageHtml = function(msg){
		return "<p>" + msg + "</p>";
	};

	/* **   FormHandler.success -- Was the submission of the form a success?        ***/
	setSuccess = function(succeeded){
		this.success = succeeded;
	};

	succeeded = function(){
		return this.success;
	};



	handleRegisterForm = function(form){

		if(this.requiredFieldsEmpty(form)){

			displayMessages();
			return false;
		}
		data = {};
		data.username = form.find(handlerGlobals.getSelector("usernameField")).val();
		data.email = form.find(handlerGlobals.getSelector("emailField")).val();
		data.password = form.find(handlerGlobals.getSelector("passwordField")).val();
		pass2 = form.find(handlerGlobals.getSelector("pass2Field")).val();


		if(data.password != pass2){
			this.addErrorMessage("Your passwords did not match.");
			this.displayMessages();
			return false;
		}

		//alert("u: " + data.username + ", e: " + data.email + ", p: " + data.password + ", p2: " + pass2);
		register = this.getAjax("register");
		register.execute(data);
		return false;
	};

	getInputLabel = function(field){
		container = field.parent();
		return container.find("label");
	};

	requiredFieldsEmpty = function(form){

		handler = this;
		fieldsEmpty = false;
		requiredSelector = handlerGlobals.getSelector("requiredField");

		form.find(requiredSelector).each(function(){
			var input = $(this);
			value = input.val();

			if(value.trim() == ""){
				fieldsEmpty = true;
				var labelHtml = getInputLabel(input).html();

				addErrorMessage("You must enter a value for the field " + labelHtml + ".",
										true);
			}
		});
		return fieldsEmpty;
	};

	addAjax("register", new AjaxItem(handlerGlobals.getAjaxUrl('register'),
				"POST", registerCallback, ajaxError, false)
	);

	initEvents();
};

/** END FormHandler Class */
/************************************************************************************/


/** AjaxItem -- Object to represent Ajax configurations ******************************/

function AjaxItem( actionUrl, actionMethod, success, failure, async){
	uri = handlerGlobals.ajaxUri;

	this.url = uri + "/" + actionUrl;
	this.method = actionMethod;
	this.success = success;
	this.error = failure;
	this.async = async;

	this.execute = function(ajaxData){
		handler = this.formHandler;
		isGet = this.method == "GET";
		if(isGet)
			this.url += ajaxData;

		$.ajax({
			url: this.url,
			type: this.method,
			async: this.async,
			data: isGet ? null : ajaxData,
			success: this.success,
			error: this.error
		});

	};

};

/** END: AjaxItem **************************************************************/