var vsgneSite = function()
{
	// private attributes
	var _doTest = false;
	var _doLog = false;
	var _cookieName_Tabname = "tabname";
	var _cookieName_SubTab = "subtab";
	var _coeffMsg = "<span style='font-size:16px;'>&lt;== Please select a value</span>";
	var _incompleteMsg = "<div style='font-size:12px; padding-top:4px; font-weight:normal;'>(Select Values above)</div>";
	var _noselValue = 999;
	var _paneContent = {};

	// private methods
	var _renderTabs = function()
	{
		var td = $("#tabs");
		for(var t in vsgnedata.tabs) 
		{
			var tab = vsgnedata.tabs[t];
			var tabid = _makeTabId(tab.id);
			td.append("<div id='"+tabid+"' class='tab'>"+tab.title+"</div>");
		}
		td.append("<div class='tabs_filler'></div>"); // force min-height
		
		extendNoSelect();
	};
	
	var _makeTabId = function(name)
	{
		name = _getTabName(name);	// JIC
		return "tab_"+name;
	};

	var _getTabName = function(id)
	{
		return id.replace("tab_", "");
	};
	
	var _setEventHandlers = function()
	{
		$(".tab").click(function () {
			_selectTab(this.id);
		});

		$(".tab").mouseover(function () {
			_mouseoverTab(this.id, true);
		});
		$(".tab").mouseleave(function () {
			_mouseoverTab(this.id, false);
		});
	};
	
	var _loadPane = function(tabname)
	{
		var name = _getTabName(tabname);
		$("#tab_content").html("");
		
		_fetch("pane_"+name+".html", 
				function(data){
					$("#tab_content").html(data);
					
					// The render_*() fcn is in the just-loaded content.
					// For some reason we need to delay it's invocation.
					var fcn = "render_"+name+"();";
					vsgneSite.log("Calling "+fcn+"...");
					setTimeout ( fcn, 1 );	
				});
	};
	
	var _fetch = function(url, callback)
	{
		vsgneSite.log("fetch("+url+")");
		try
		{
		
			$.ajax({
				url: url,
				success: function(data) {
					vsgneSite.log("->success");
					callback(data);
				},
				error : function(XMLHttpRequest, textStatus, errorThrown) {
					vsgneSite.logErr(errorThrown);
				}
			});		
		}
		catch(err)
		{
			vsgneSite.logErr(err);
		}
	
	};
	
	var _showContent = function(name)
	{
		$("#tab_content").html(_paneContent[name]);
	};
	
	var _selectTab = function(id)
	{
		vsgneSite.log("_selectTab("+id+")");

		var name = _getTabName(id);
		vsgneSite.saveTabname(name);
		
		$("#subtabsContainer").html("")
								.height(0)	// Else it'll overflow in IE, even when hidden
								.hide();
		$("#tab_content").removeClass("tab_content_with_subtabs");
	
		_loadPane(id);

		$(".pane").hide();
		$("#pane_"+name).show();

		// De-select all tabs: remove all generic selection and custom selection styles
		$(".tab").each(function() {
			$("#"+this.id).removeClass("tab_selected");
			var tabid = this.id;
			$("#"+tabid).removeClass(tabid+"_selected");
		});
		
		$("#"+id).addClass("tab_selected");			// Select the new tab
		$("#"+id).addClass(id+"_selected");
	};
	
	var _mouseoverTab = function(id, over)
	{
		$("#"+id).toggleClass("tab_highlight", over);
	};
	
	var _detectFlags = function()
	{
		var q = window.location.href.indexOf('?');
		if(q > 0)
		{
			var params = window.location.href.slice(q + 1);
			if(params.search(/test/i) >= 0) {
				_doTest = true;
			}
			if(params.search(/log/i) >= 0) {
				_doLog = true;
				$("#log").show();
			}
		}
	};
	
	var _getQueryValue = function(key)
	{
		var qs = window.location.search.substring(1).toLowerCase();
		var qsa = qs.split("&");
		for (i=0;i<qsa.length;i++) 
		{
			var kvp = qsa[i].split("=");
			if (kvp[0] == key) {
				return kvp[1];
			}
		}
		return "";
	};
	
	var _getInitialTab = function()
	{
		var tabid = _makeTabId(vsgnedata.tabs[0].id);	// Presumably the Home tab
		
		var qt = _getQueryValue('tab');
		if(qt.length > 0)
		{
			vsgneSite.saveTabname("");	// Clear old values
			vsgneSite.saveSubtab("");	// ""
			if(_isValidTabName(qt))
			{
				tabid = _makeTabId(qt);
				var st = _getQueryValue('subtab');
				vsgneSite.saveTabname(qt);
				vsgneSite.saveSubtab(st);
				// Reload page w/o query string
				var url = document.location.href;
				var q = url.indexOf('?');
				if(q > 0)
				{
					url = url.substr(0, q);
					document.location.href = url;
				}
			}
		}
		else
		{ 
			// Attempt to retrieve stored tabname form cookie
			var tabname = vsgneSite.readTabname();
			if(_isValidTabName(tabname)) {
				tabid = _makeTabId(tabname);
			} else {
				vsgneSite.saveTabname("");	// Clear old values
				vsgneSite.saveSubtab("");	// ""
			}
		}
		
		return  tabid;
	};
	
	var _writeSessionCookie = function(name, value)
	{
		document.cookie = name +"=" + escape(value) + "; path=/";
	};
	
	var _getCookieValue = function(cookiename)
	{
		var value = "";
		var exp = new RegExp (escape(cookiename) + "=([^;]+)");
		if (exp.test (document.cookie + ";")) 
		{
			exp.exec (document.cookie + ";");
			value = unescape(RegExp.$1);
		}
		return value;
	};
	
	var _isValidTabName = function(tabname)
	{
		var valid = false;
		try
		{
			var tabid = _makeTabId(tabname);
			valid = ($("#"+tabid).length > 0);
		}
		catch(ex)
		{
		}
		return valid;
	};

	return {
		// public attributes
		doTest : function() 
		{
			return _doTest;
		},

		// public methods
		init : function() 
		{
			_detectFlags();
		},
		
		build : function() 
		{
			_renderTabs();
			_setEventHandlers();
			
			var tabid = _getInitialTab();
			_selectTab(tabid);
		},
		
		fetch : function(url, callback) 
		{
			_fetch(url, callback);
		},
		
		dbgBreak : function()
		{
			alert("dbgBreak");
		},

		log : function(data)
		{
			if(_doLog)
			{
				var zzz = $("#log").html();
				zzz += (data + "<br>");
				$("#log").html(zzz);
			}
		},

		logErr : function(data)
		{
			if(_doLog) {
				vsgneSite.log("<span style='color:red;'>"+data+"</span>");
			}
		},
		
		saveTabname : function(tabname)
		{
			tabname = _getTabName(tabname);	// JIC
			_writeSessionCookie(_cookieName_Tabname, tabname);
		},
		
		readTabname : function()
		{
			return _getCookieValue(_cookieName_Tabname);
		},
		
		saveSubtab : function(subtab)
		{
			_writeSessionCookie(_cookieName_SubTab, subtab);
		},

		readSubtab : function()
		{
			return _getCookieValue(_cookieName_SubTab);
		}
		
	}
}();