var Spry;
if (!Spry) Spry = {};
if (!Spry.Widget) Spry.Widget = {};

Spry.Widget.Accordion = function(element, opts)
{
	this.element = this.getElement(element);
	this.defaultPanel = 0;
	this.hoverClass = "AccordionPanelTabHover";
	this.openClass = "AccordionPanelOpen";
	this.closedClass = "AccordionPanelClosed";
	this.focusedClass = "AccordionFocused";
	this.enableAnimation = true;
	this.enableKeyboardNavigation = true;
	this.currentPanel = null;
	this.animator = null;
	this.hasFocus = null;

	this.previousPanelKeyCode = Spry.Widget.Accordion.KEY_UP;
	this.nextPanelKeyCode = Spry.Widget.Accordion.KEY_DOWN;

	this.useFixedPanelHeights = true;
	this.fixedPanelHeight = 0;

	Spry.Widget.Accordion.setOptions(this, opts, true);

	this.attachBehaviors();
};

Spry.Widget.Accordion.prototype.getElement = function(ele)
{
	if (ele && typeof ele == "string")
		return document.getElementById(ele);
	return ele;
};

Spry.Widget.Accordion.prototype.addClassName = function(ele, className)
{
	if (!ele || !className || (ele.className && ele.className.search(new RegExp("\\b" + className + "\\b")) != -1))
		return;
	ele.className += (ele.className ? " " : "") + className;
};

Spry.Widget.Accordion.prototype.removeClassName = function(ele, className)
{
	if (!ele || !className || (ele.className && ele.className.search(new RegExp("\\b" + className + "\\b")) == -1))
		return;
	ele.className = ele.className.replace(new RegExp("\\s*\\b" + className + "\\b", "g"), "");
};

Spry.Widget.Accordion.setOptions = function(obj, optionsObj, ignoreUndefinedProps)
{
	if (!optionsObj)
		return;
	for (var optionName in optionsObj)
	{
		if (ignoreUndefinedProps && optionsObj[optionName] == undefined)
			continue;
		obj[optionName] = optionsObj[optionName];
	}
};

Spry.Widget.Accordion.prototype.onPanelTabMouseOver = function(e, panel)
{
	if (panel)
		this.addClassName(this.getPanelTab(panel), this.hoverClass);
	return false;
};

Spry.Widget.Accordion.prototype.onPanelTabMouseOut = function(e, panel)
{
	if (panel)
		this.removeClassName(this.getPanelTab(panel), this.hoverClass);
	return false;
};

Spry.Widget.Accordion.prototype.openPanel = function(elementOrIndex)
{
	var panelA = this.currentPanel;
	var panelB;

	if (typeof elementOrIndex == "number")
		panelB = this.getPanels()[elementOrIndex];
	else
		panelB = this.getElement(elementOrIndex);
	
	if (!panelB || panelA == panelB)	
		return null;

	var contentA = panelA ? this.getPanelContent(panelA) : null;
	var contentB = this.getPanelContent(panelB);

	if (!contentB)
		return null;

	if (this.useFixedPanelHeights && !this.fixedPanelHeight)
		this.fixedPanelHeight = (contentA.offsetHeight) ? contentA.offsetHeight : contentA.scrollHeight;

	if (this.enableAnimation)
	{
		if (this.animator)
			this.animator.stop();
		this.animator = new Spry.Widget.Accordion.PanelAnimator(this, panelB, { duration: this.duration, fps: this.fps, transition: this.transition });
		this.animator.start();
	}
	else
	{
		if(contentA)
		{
			contentA.style.display = "none";
			contentA.style.height = "0px";
		}
		contentB.style.display = "block";
		contentB.style.height = this.useFixedPanelHeights ? this.fixedPanelHeight + "px" : "auto";
	}

	if(panelA)
	{
		this.removeClassName(panelA, this.openClass);
		this.addClassName(panelA, this.closedClass);
	}

	this.removeClassName(panelB, this.closedClass);
	this.addClassName(panelB, this.openClass);

	this.currentPanel = panelB;

	return panelB;
};

Spry.Widget.Accordion.prototype.closePanel = function()
{
	// The accordion can only have one panel open at any give time, so this method only closes the current panel.

	if (!this.useFixedPanelHeights && this.currentPanel)
	{
		var panel = this.currentPanel;
		var content = this.getPanelContent(panel);
		if (content)
		{
			if (this.enableAnimation)
			{
				if (this.animator)
					this.animator.stop();
				this.animator = new Spry.Widget.Accordion.PanelAnimator(this, null, { duration: this.duration, fps: this.fps, transition: this.transition });
				this.animator.start();
			}
			else
			{
				content.style.display = "none";
				content.style.height = "0px";
			}
		}		
		this.removeClassName(panel, this.openClass);
		this.addClassName(panel, this.closedClass);
		this.currentPanel = null;
	}
};

Spry.Widget.Accordion.prototype.openNextPanel = function()
{
	return this.openPanel(this.getCurrentPanelIndex() + 1);
};

Spry.Widget.Accordion.prototype.openPreviousPanel = function()
{
	return this.openPanel(this.getCurrentPanelIndex() - 1);
};

Spry.Widget.Accordion.prototype.openFirstPanel = function()
{
	return this.openPanel(0);
};

Spry.Widget.Accordion.prototype.openLastPanel = function()
{
	var panels = this.getPanels();
	return this.openPanel(panels[panels.length - 1]);
};

Spry.Widget.Accordion.prototype.onPanelTabClick = function(e, panel)
{
	if (panel != this.currentPanel)
		this.openPanel(panel);
	else
		this.closePanel();

	if (this.enableKeyboardNavigation)
		this.focus();

	if (e.preventDefault) e.preventDefault();
	else e.returnValue = false;
	if (e.stopPropagation) e.stopPropagation();
	else e.cancelBubble = true;

	return false;
};

Spry.Widget.Accordion.prototype.onFocus = function(e)
{
	this.hasFocus = true;
	this.addClassName(this.element, this.focusedClass);
	return false;
};

Spry.Widget.Accordion.prototype.onBlur = function(e)
{
	this.hasFocus = false;
	this.removeClassName(this.element, this.focusedClass);
	return false;
};

Spry.Widget.Accordion.KEY_UP = 38;
Spry.Widget.Accordion.KEY_DOWN = 40;

Spry.Widget.Accordion.prototype.onKeyDown = function(e)
{
	var key = e.keyCode;
	if (!this.hasFocus || (key != this.previousPanelKeyCode && key != this.nextPanelKeyCode))
		return true;
	
	var panels = this.getPanels();
	if (!panels || panels.length < 1)
		return false;
	var currentPanel = this.currentPanel ? this.currentPanel : panels[0];
	var nextPanel = (key == this.nextPanelKeyCode) ? currentPanel.nextSibling : currentPanel.previousSibling;

	while (nextPanel)
	{
		if (nextPanel.nodeType == 1 /* Node.ELEMENT_NODE */)
			break;
		nextPanel = (key == this.nextPanelKeyCode) ? nextPanel.nextSibling : nextPanel.previousSibling;
	}

	if (nextPanel && currentPanel != nextPanel)
		this.openPanel(nextPanel);

	if (e.preventDefault) e.preventDefault();
	else e.returnValue = false;
	if (e.stopPropagation) e.stopPropagation();
	else e.cancelBubble = true;

	return false;
};

Spry.Widget.Accordion.prototype.attachPanelHandlers = function(panel)
{
	if (!panel)
		return;

	var tab = this.getPanelTab(panel);

	if (tab)
	{
		var self = this;
		Spry.Widget.Accordion.addEventListener(tab, "click", function(e) { return self.onPanelTabClick(e, panel); }, false);
		Spry.Widget.Accordion.addEventListener(tab, "mouseover", function(e) { return self.onPanelTabMouseOver(e, panel); }, false);
		Spry.Widget.Accordion.addEventListener(tab, "mouseout", function(e) { return self.onPanelTabMouseOut(e, panel); }, false);
	}
};

Spry.Widget.Accordion.addEventListener = function(element, eventType, handler, capture)
{
	try
	{
		if (element.addEventListener)
			element.addEventListener(eventType, handler, capture);
		else if (element.attachEvent)
			element.attachEvent("on" + eventType, handler);
	}
	catch (e) {}
};

Spry.Widget.Accordion.prototype.initPanel = function(panel, isDefault)
{
	var content = this.getPanelContent(panel);
	if (isDefault)
	{
		this.currentPanel = panel;
		this.removeClassName(panel, this.closedClass);
		this.addClassName(panel, this.openClass);

		// Attempt to set up the height of the default panel. We don't want to do any dynamic panel height calculations here because our accordion or one of its parent containers may be display:none.

		if (content)
		{
			if (this.useFixedPanelHeights)
			{
				// We are in fixed panel height mode and the user passed in a panel height for us to use.
	
				if (this.fixedPanelHeight)
					content.style.height = this.fixedPanelHeight + "px";
			}
			else
			{
				// We are in variable panel height mode, but since we can't calculate the panel height here, we just set the height to auto so that it expands to show all of its content.
	
				content.style.height = "auto";
			}
		}
	}
	else
	{
		this.removeClassName(panel, this.openClass);
		this.addClassName(panel, this.closedClass);

		if (content)
		{
			content.style.height = "0px";
			content.style.display = "none";
		}
	}
	
	this.attachPanelHandlers(panel);
};

Spry.Widget.Accordion.prototype.attachBehaviors = function()
{
	var panels = this.getPanels();
	for (var i = 0; i < panels.length; i++)
		this.initPanel(panels[i], i == this.defaultPanel);

	// Advanced keyboard navigation requires the tabindex attribute on the top-level element.

	this.enableKeyboardNavigation = (this.enableKeyboardNavigation && this.element.attributes.getNamedItem("tabindex"));
	if (this.enableKeyboardNavigation)
	{
		var self = this;
		Spry.Widget.Accordion.addEventListener(this.element, "focus", function(e) { return self.onFocus(e); }, false);
		Spry.Widget.Accordion.addEventListener(this.element, "blur", function(e) { return self.onBlur(e); }, false);
		Spry.Widget.Accordion.addEventListener(this.element, "keydown", function(e) { return self.onKeyDown(e); }, false);
	}
};

Spry.Widget.Accordion.prototype.getPanels = function()
{
	return this.getElementChildren(this.element);
};

Spry.Widget.Accordion.prototype.getCurrentPanel = function()
{
	return this.currentPanel;
};

Spry.Widget.Accordion.prototype.getPanelIndex = function(panel)
{
	var panels = this.getPanels();
	for( var i = 0 ; i < panels.length; i++ )
	{
		if( panel == panels[i] )
			return i;
	}
	return -1;
};

Spry.Widget.Accordion.prototype.getCurrentPanelIndex = function()
{
	return this.getPanelIndex(this.currentPanel);
};

Spry.Widget.Accordion.prototype.getPanelTab = function(panel)
{
	if (!panel)
		return null;
	return this.getElementChildren(panel)[0];
};

Spry.Widget.Accordion.prototype.getPanelContent = function(panel)
{
	if (!panel)
		return null;
	return this.getElementChildren(panel)[1];
};

Spry.Widget.Accordion.prototype.getElementChildren = function(element)
{
	var children = [];
	var child = element.firstChild;
	while (child)
	{
		if (child.nodeType == 1 /* Node.ELEMENT_NODE */)
			children.push(child);
		child = child.nextSibling;
	}
	return children;
};

Spry.Widget.Accordion.prototype.focus = function()
{
	if (this.element && this.element.focus)
		this.element.focus();
};

Spry.Widget.Accordion.prototype.blur = function()
{
	if (this.element && this.element.blur)
		this.element.blur();
};

/////////////////////////////////////////////////////

Spry.Widget.Accordion.PanelAnimator = function(accordion, panel, opts)
{
	this.timer = null;
	this.interval = 0;

	this.fps = 60;
	this.duration = 500;
	this.startTime = 0;

	this.transition = Spry.Widget.Accordion.PanelAnimator.defaultTransition;

	this.onComplete = null;

	this.panel = panel;
	this.panelToOpen = accordion.getElement(panel);
	this.panelData = [];
	this.useFixedPanelHeights = accordion.useFixedPanelHeights;

	Spry.Widget.Accordion.setOptions(this, opts, true);

	this.interval = Math.floor(1000 / this.fps);

	// Set up the array of panels we want to animate.

	var panels = accordion.getPanels();
	for (var i = 0; i < panels.length; i++)
	{
		var p = panels[i];
		var c = accordion.getPanelContent(p);
		if (c)
		{
			var h = c.offsetHeight;
			if (h == undefined)
				h = 0;

			if (p == panel && h == 0)
				c.style.display = "block";

			if (p == panel || h > 0)
			{
				var obj = new Object;
				obj.panel = p;
				obj.content = c;
				obj.fromHeight = h;
				obj.toHeight = (p == panel) ? (accordion.useFixedPanelHeights ? accordion.fixedPanelHeight : c.scrollHeight) : 0;
				obj.distance = obj.toHeight - obj.fromHeight;
				obj.overflow = c.style.overflow;
				this.panelData.push(obj);

				c.style.overflow = "hidden";
				c.style.height = h + "px";
			}
		}
	}
};

Spry.Widget.Accordion.PanelAnimator.defaultTransition = function(time, begin, finish, duration) { time /= duration; return begin + ((2 - time) * time * finish); };

Spry.Widget.Accordion.PanelAnimator.prototype.start = function()
{
	var self = this;
	this.startTime = (new Date).getTime();
	this.timer = setTimeout(function() { self.stepAnimation(); }, this.interval);
};

Spry.Widget.Accordion.PanelAnimator.prototype.stop = function()
{
	if (this.timer)
	{
		clearTimeout(this.timer);

		// If we're killing the timer, restore the overflow properties on the panels we were animating!

		for (i = 0; i < this.panelData.length; i++)
		{
			obj = this.panelData[i];
			obj.content.style.overflow = obj.overflow;
		}
	}

	this.timer = null;
};

Spry.Widget.Accordion.PanelAnimator.prototype.stepAnimation = function()
{
	var curTime = (new Date).getTime();
	var elapsedTime = curTime - this.startTime;

	var i, obj;

	if (elapsedTime >= this.duration)
	{
		for (i = 0; i < this.panelData.length; i++)
		{
			obj = this.panelData[i];
			if (obj.panel != this.panel)
			{
				obj.content.style.display = "none";
				obj.content.style.height = "0px";
			}
			obj.content.style.overflow = obj.overflow;
			obj.content.style.height = (this.useFixedPanelHeights || obj.toHeight == 0) ? obj.toHeight + "px" : "auto";
		}
		if (this.onComplete)
			this.onComplete();
		return;
	}

	for (i = 0; i < this.panelData.length; i++)
	{
		obj = this.panelData[i];
		var ht = this.transition(elapsedTime, obj.fromHeight, obj.distance, this.duration);
		obj.content.style.height = ((ht < 0) ? 0 : ht) + "px";
	}
	
	var self = this;
	this.timer = setTimeout(function() { self.stepAnimation(); }, this.interval);
};