var cartList; //This is a list of Book in the shopping cart, it will be persisted to a document everytime something is added/removed 
				 //but i want them on hand so we can use them

function CartEntry ()
{
	this.unid;	//the unid of the document the entry relates to
	this.desc; //what shows as the description in the cart
	this.price;
	this.qty;	
	this.listNumber;
} //end function cart entry

//Class for cart manipulation
function ShoppingCart ()
{
	//prototypes
	this.cartUNID;
	this.totalCost;
	this.checkOutVisible;
	this.addToCart = addToCart;
	this.removeFromCart = removeFromCart;
	this.clearCart = clearCart;
	this.drawCheckOut = drawCheckOut;
	this.drawCartHTML = drawCartHTML;
	this.updateUserCart = updateUserCart;
	this.isMember = isMember;
	this.initialiseCart = initialiseCart;
	this.updateQuantity = updateQuantity;
	this.retrieveCart = retrieveCart;
	this.continueShopping = continueShopping;
	this.drawConfirmationPage = drawConfirmationPage ;
	this.getItemListHTML = getItemListHTML;
	this.submitOrder = submitOrder;
	function initialiseCart ()
	{	
		cartList = new Array ();		
		cart.cartUNID = "";
		cart.totalCost = 0;
		cart.checkOutVisible = false;			
		//when we initialise we try and retireve a cart for that user if there is one that hasn't been checked out
		cart.retrieveCart ();
	} //end initialiseCart

	//checks if a specified document is in the shopping cart
	function isMember (doc)
	{
		for (i=0; i<cartList.length; i++)
		{
			if (cartList [i].unid == doc.unid)
			{
				doc.isInCart = true;
				return true;	
			}
		}
	} //end isInCart
	
	function addToCart (doc)
	{
		var elNum = cartList.length;
		var tEl = new CartEntry ();

		tEl.unid = doc.unid;
		tEl.desc = doc.shortTitle;
		tEl.price = doc.price;
		tEl.qty = 1;
		cart.totalCost += doc.price;
		cartList [elNum] = tEl;
		cartList[elNum].listNumber = elNum;

		doc.isInCart = true;
	
		//update the notes document
		cart.updateUserCart (tEl);
		
		//redraw the cart
		cart.drawCartHTML ();
		
	} //end addToCart
	
	function removeFromCart (doc)
	{
		//need to find the document in the cart list - if we're saying remove from the docs in a view then
		for (var i = 0; i < cartList.length; i++)
		{
			if (cartList [i].unid == doc.unid)
			{
				cart.totalCost -= (cartList[i].price * cartList[i].qty);
				cartList[i].qty=0;
				//update the notes document
				cart.updateUserCart (cartList[i]);
				cartList.removeElement (i);
				i = cartList.length + 1;				
			}
		}
		
		doc.isInCart = false;		
				
		//redraw the cart
		cart.drawCartHTML ();
		
	} //end removeFromCart
	
	function clearCart ()
	{
		//clear out the list
		for (i=0; i<cartList.length; i++)
		{
			delete cartList[i];
		}
		delete cartList;
		cartList = new Array();
		cart.totalCost = 0;
		
		var xmlhttp = new XMLHttpRequest ();	
		xmlhttp.open ("POST", "(ag.Eastend.ClearCart)?OpenAgent", true) //open the agent to send the request
	
		//Add a listener so we know when the agent has finished retrieving information
		function clearCartHandler ()
		{
			//only process if we get a ready state of 4
			if (xmlhttp.readyState == 4)
			{
				//Check if we did it ok or if we got an error
				if (xmlhttp.responseXML.getElementsByTagName ("Error").length >0 ){
						alert ( xmlhttp.responseXML.getElementsByTagName ("Error")[0].firstChild.nodeValue);
				 }
				hideLoading ();
		
				//redraw the cart
				cart.drawCartHTML ();
			}
		}
		//tell the http request what to run when we're ready
		xmlhttp.onreadystatechange = clearCartHandler;
	
		//Draw the loading DIV so the user knows we're doing something
		showLoading ();

	     xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    		xmlhttp.send("&CARTUNID=" + cart.cartUNID);
		
	}	//end clearCart
	
	function continueShopping ()
	{
		removeHiddenClass ("Navigator");
		addHiddenClass ("NavigatorSpacer");
		removeHiddenClass ("ShoppingCart");
		removeHiddenClass ("Searchbar");	
		
		cart.checkOutVisible = false;
		cart.drawCartHTML ();
		var el = document.getElementById ("ViewData")
		el.innerHTML = "";		
		
	} //end continue shopping
	
	function drawConfirmationPage ()
	{
		//draws the confirmation screen - total price, any contact details etc
		var html = "";

		var actionsHTML =htmlStartTag ("div", "CheckoutActions ralign", "", "") + "<a id=\"PrevAction\" href='#' onClick=\"cart.drawCheckOut (); return false;\"><< Prev</a>" +sp + sp;
		actionsHTML += "<a href='#' onClick=\"cart.continueShopping (); return false;\">Continue Shopping</a>" + de;

		html += actionsHTML;
		html += htmlStartTag ("div", "CheckoutHeader", "", "") + "Purchase Confirmation:"+ de;

		//list the items - uneditable
		html += htmlStartTag ("table", "", "", "ItemsTable");
		html += cart.getItemListHTML (false);		
		html += te
		
		//Extra Details
		html += htmlStartTag ("div", "FloatLeft", "", "PONumber") + "Purchase Order Number:" + sp + sp + "<input size=20 class=\"small\" name=\"purchasOrderNo\" id=\"purchasOrderNo\">" + de;
		
		//Submit Action
		html += htmlStartTag ("div", "FloatRight", "", "SubmitActions") + "<a href='#' onClick=\"cart.submitOrder (); return false; \">Submit Order</a>";
		
		var el = document.getElementById ("ViewData")
		el.innerHTML = html;		
		resetScreen ();
		html += te;
		
	}
	
	function getItemListHTML (modify)
	{
		var html = "";
		html += htmlStartTag ("tr", "", "", "");
		html += htmlStartTag ("td", "", "10px", "") + sp + ce;
		html += htmlStartTag ("td", "", "300px", "")  + "Item Description" + ce;
		html += htmlStartTag ("td", "", "50px", "") + "Quantity" + ce;
		html += htmlStartTag ("td", "priceCell ralign", "100px", "") + "Cost (ex-GST)" + ce + re
		html += "<tr><td class='RowSpacer small' colspan=4>" + sp + ce+ re
	
		for (var i = 0; i < cartList.length; i++)
		{
			html += htmlStartTag ("tr", "", "", "");
			html += htmlStartTag ("td", "", "10px", "");
			if (modify) html += "<a href=\"#\" onClick=\"cart.removeFromCart (cartList[" + i +"]); return false;\">X</a>"; else html += sp;
			html += ce;
			html += htmlStartTag ("td", "", "300px", "")  + cartList[i].desc + ce;
			html += htmlStartTag ("td", "", "50px", ""); 
			if (modify) html += "<input size=1 class=\"small\" name=\"qty" + cartList[i].listNumber +"\" value=" + cartList[i].qty + " onBlur=\"cart.updateQuantity (cartList[" + i + "])\">"; else html +=  cartList[i].qty;
			html += ce;
			html += htmlStartTag ("td", "priceCell ralign", "100px", "") + formatCurrency (cartList[i].price) + ce + re
		}
		html += "<tr><td class='RowSpacer small' colspan=4>" + sp + ce+ re
		html += htmlStartTag ("tr", "", "", "") + "<td colspan=2>" + sp + ce;
		html += htmlStartTag ("td", "", "100px", "") + "Total (ex-GST):" + ce;
		html += htmlStartTag ("td", "ralign", "", "") +formatCurrency (cart.totalCost) + ce + re;
		html += "<tr><td class='RowSpacer small' colspan=4>" + sp + ce+ re				
		return (html);
	}
	
	function drawCheckOut ()
	{
		var html = "";
		//.1 Hide all current sections - viewdata, navigator and cart
		addHiddenClass ("Navigator");
		removeHiddenClass ("NavigatorSpacer");
		addHiddenClass ("ShoppingCart");
		var actionsHTML =htmlStartTag ("div", "CheckoutActions ralign", "", "") + "<a href='#' onClick=\"cart.continueShopping (); return false;\">Continue Shopping</a>" + sp + sp;
		actionsHTML += "<a href='#' onClick=\"cart.drawConfirmationPage (); return false;\">Next >></a>" + de;
		
		//.2 Write all of the Cart elements to the screen - this could be a lot but we can change it at a later stage if needed
		html += actionsHTML;
		html += htmlStartTag ("div", "CheckoutHeader", "", "") + "Items:"+ de;
		
		html += htmlStartTag ("table", "", "", "ItemsTable");
		html += cart.getItemListHTML (true);	
		html += te;
		html += actionsHTML;
		var el = document.getElementById ("ViewData")
		el.innerHTML = html;		
		resetScreen ();
		
		cart.checkOutVisible = true;
	}	//end CheckOut
	
	function drawCartHTML (startNo)
	{
		//if the checkout is visible then dont draw this draw that
		if (cart.checkOutVisible) return (cart.drawCheckOut());
		
		removeHiddenClass ("ShoppingCart");
		
		var html ="";
		var cartStart = cartList.length-1;
		if (startNo)
		{
			cartStart = startNo;
		}
		if (cartList.length > 0)
		{
			html += htmlStartTag ("div", "CartHeader ralign", "", "") + "My Items"+ de;
		}
		var cost = 0;
		//documents added
		html += htmlStartTag ("table", "", "", "CartItems");
	
		//we wont show all cause it could get messy, so we'll do 10 at the most
		for (i=cartStart; i>cartStart-10 && i>=0; i--)
		{
			html += htmlStartTag ("tr", "", "", "");
			html += htmlStartTag ("td", "", "5px", "") + "<a href=\"#\" onClick=\"cart.removeFromCart (cartList[" + i +"]); return false;\">X</a>" + ce;
			html += htmlStartTag ("td", "", "150px", "")  + cartList[i].desc + ce;
			html += htmlStartTag ("td", "priceCell ralign", "15px", "") + formatCurrency (cartList[i].price) + ce + re
			html += htmlStartTag ("tr", "", "", "");
			html += "<td colspan=2 class=\"ralign\">Qty: " + "<input size=1 class=\"small\" name=\"qty" + cartList[i].listNumber +"\" value=" + cartList[i].qty + " onBlur=\"cart.updateQuantity (cartList[" + i + "])\">" +ce + "<td>" +sp + ce + re;
 			if (!(cartList.length-1==0 && i==0))
			{
				html += "<tr><td class='RowSpacer' colspan=3>" + sp + ce+ re
			}
			cost += (cartList[i].price * cartList[i].qty);
		}	
		
		//if we dont display all then we need a 'more' link
		cartStart -= 10;
		if (cartStart>0)
		{
			html += htmlStartTag ("tr", "", "", "");
			html += "<td colspan=3 class=\"ralign\"><a href='#' onClick=\"cart.drawCartHTML(" + cartStart+ "); return false;\">more entries</a>" +ce + re;
		}
		
		html += te;
	
		//total cost
		if (cost != 0)
		{
			html += htmlStartTag ("table", "", "", "Totals");
			html += "<tr><td class='RowSpacer' colspan=2>" + sp + ce+ re
			html += htmlStartTag ("tr", "", "", "");
			html += htmlStartTag ("td", "", "50px", "") + "Sub-Total:" + ce;
			html += htmlStartTag ("td", "ralign", "", "") +formatCurrency (cost) + ce + re;
			html += htmlStartTag ("tr", "", "", "");
			html += htmlStartTag ("td", "", "50px", "") + "Cart Total:" + ce;
			html += htmlStartTag ("td", "ralign", "", "") +formatCurrency (cart.totalCost) + ce + re;
			html += re + te;
		}
		var el = document.getElementById ("CartContent");
		el.innerHTML = html;	
		if (cartList.length > 0)
		{
			removeHiddenClass ('CartActions');
		}else
		{
			addHiddenClass ('CartActions');
		}
			
		resetScreen ();
	
	}	//end drawCartHTML
	function updateQuantity (el)
	{
		var tItem = document.getElementsByName ("qty" + el.listNumber);
		var oldQty = el.qty;	
		el.qty = tItem[0].value;
		if (oldQty != el.qty)	
		{	
			//subtract the old val
			cart.totalCost -= (el.price * oldQty);
			//update total cost - add the current val
			cart.totalCost += (el.price * el.qty) 
		
			if (el.qty <= 0)
			{
				cart.removeFromCart (el);
				cart.updateUserCart (el);
			}else	
			{
				//update the notes document
				cart.updateUserCart (el);
				cart.drawCartHTML ();
			}
		}
	} //end updateQuantity
	
	function retrieveCart ()
	{
		//get the unid for an unchecked out cart for the user
		var xmlhttp = new XMLHttpRequest ();	
		xmlhttp.open ("POST", "(ag.Eastend.RetrieveCart)?OpenAgent", true) //open the view ready to send the request
	
		//Add a listener so we know when the agent has finished retrieving information
		function retrieveCartHandler ()
		{
			//only process if we get a ready state of 4
			if (xmlhttp.readyState == 4)
			{
				//Check if we did it ok or if we got an error
				if (xmlhttp.responseXML.getElementsByTagName ("Error").length >0 ){
						alert ( xmlhttp.responseXML.getElementsByTagName ("Error")[0].firstChild.nodeValue);
				 }else
				{
					//get the cart unid if there is one, other wise we dont do anything
					if (xmlhttp.responseXML.getElementsByTagName ("CARTUNID").length > 0)
					{
						cart.cartUNID = xmlhttp.responseXML.getElementsByTagName ("CARTUNID")[0].firstChild.nodeValue;
						//process the rest
						if (processRetrievedCart (xmlhttp.responseXML))
						{
							cart.retrieveCart ();
						}else
						{
							cart.drawCartHTML ();
						}
					}else
					{
							cart.drawCartHTML ();
					}
				}	
				hideLoading ();
			}
		}
		//tell the http request what to run when we're ready
		xmlhttp.onreadystatechange = retrieveCartHandler;
	
		//Draw the loading DIV so the user knows we're doing something
		showLoading ();
		var pos = cartList.length;
	     xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		xmlhttp.send("&USERNAME=" + currentUser + "&POSITION=" +pos + "&CARTUNID=" + cart.cartUNID);
	} //end retrieveCart
	function processRetrievedCart (oDomDoc)
	{
	
		var tEl;
		if (oDomDoc.getElementsByTagName ("CARTELEMENT").length>0)
		{
			var cartEls = oDomDoc.getElementsByTagName ("CARTELEMENT");
			for (i=0; i<cartEls.length; i++)
			{
				tEl = new CartEntry ();
				tEl.unid = cartEls[i].getAttribute ("UNID");
				tEl.desc = cartEls[i].getAttribute ("DESC");
				tEl.price = cartEls[i].getAttribute ("PRICE");
				tEl.qty = cartEls[i].getAttribute ("QTY");
				tEl.listNumber = cartList.length;
				cartList [cartList.length] = tEl;
				cart.totalCost += (tEl.price * tEl.qty)
			}
		} //end cart els
	
		if (oDomDoc.getElementsByTagName ("NOMOREDOCS").length>0)
		{
			return (false);
		}else{
			return (true);
		} 
	} //end processRetrievedCart
	
	function updateUserCart (el)
	{
		//if check out we tell the agent to finalise the purchase and check out
		var xmlhttp = new XMLHttpRequest ();	
		xmlhttp.open ("POST", "(ag.Eastend.UpdateCart)?OpenAgent", true) //open the agent ready to send the request
	
		//Add a listener so we know when the agent has finished retrieving information
		function updateCartHandler ()
		{
			//only process if we get a ready state of 4
			if (xmlhttp.readyState == 4)
			{
				//Check if we did it ok or if we got an error
				if (xmlhttp.responseXML.getElementsByTagName ("Error").length >0 ){
						alert ( xmlhttp.responseXML.getElementsByTagName ("Error")[0].firstChild.nodeValue);
				 }else
				{
					//get the cart unid
					if (xmlhttp.responseXML.getElementsByTagName ("CartUNID").length > 0)
					{
						cart.cartUNID = xmlhttp.responseXML.getElementsByTagName ("CartUNID")[0].firstChild.nodeValue;
					}
				}	
				hideLoading ();
			}
		}
		//tell the http request what to run when we're ready
		xmlhttp.onreadystatechange = updateCartHandler;
	
		//Draw the loading DIV so the user knows we're doing something
		showLoading ();

	     xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	     var sendHTML= "&CARTUNID=" + cart.cartUNID + "&DOCUNID=" + el.unid + "&QTY=" + el.qty + "&USERNAME=" + currentUser;;
    		xmlhttp.send(sendHTML);
	
	} //end updateUserCart
	
	function submitOrder ()
	{
		//1. hide all other divs and show just the submitting one, this will stop them from hitting it twice or anything
		addHiddenClass ("Navigator");
		removeHiddenClass ("NavigatorSpacer");
		addHiddenClass ("ShoppingCart");
		addHiddenClass ("ViewData");
		addHiddenClass ("Searchbar");		
		removeHiddenClass ("SubmitLayer");
		resetScreen ();
		//2. submit the cart, this will validate it as well - it in the agent and save it and mark it as closed
		var xmlhttp;	
		xmlhttp = new XMLHttpRequest ();	

		xmlhttp.open ("POST", "(ag.Eastend.SubmitCart)?OpenAgent", false) //open the agent ready to send the request
		xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		xmlhttp.send("&CARTUNID=" + cart.cartUNID + "&PONUMBER=" + document.getElementById ("purchasOrderNo").value);
		if(xmlhttp.responseXML.parseError != 0 || xmlhttp.responseXML.getElementsByTagName ("Error").length >0 ){
			  // construct a human readable error description
			 if (xmlhttp.responseXML.parseError != 0) alert(Sarissa.getParseErrorText(xmlhttp.responseXML)); else alert ( xmlhttp.responseXML.getElementsByTagName ("Error")[0].firstChild.nodeValue);
			 //unhide the search and the view data
			removeHiddenClass ("ViewData");
			removeHiddenClass ("Searchbar");		
			addHiddenClass ("SubmitLayer");		
			 
		}else{
		
			//Display the Order Details so they can Print it if they want, also let them email it to an email address.
			addHiddenClass ("SubmitActions");
			addHiddenClass ("PrevAction");
			removeHiddenClass ("ViewData");
			//removeHiddenClass ("Searchbar");		
			var poHTML = "<br><br><span class='bold'>Purchase Order Number: " + document.getElementById ("purchasOrderNo").value + "</span>";
			document.getElementById ("PONumber").innerHTML = poHTML;
			
			addHiddenClass ("SubmitLayer");		

			//Submit went perfectly so clear out this cart
			for (i=0; i<cartList.length; i++)
			{
				delete cartList[i];
			}
			delete cartList;
			cartList = new Array();
			cart.totalCost = 0;
			cart.unid = ""
		}	
				
	} //end submitOrder
	
	
} //end class