var NavigationMenu = Class.create();

NavigationMenu.prototype = {
	initialize: function(el)
	{
		this.el = el;
		
		this.main_node_list = new NavigationMenuNodeList(this.fetchSingleElement(this.el, ".main_node_list", null), this, null);
		
		this.sub_node_lists = [];
		this.el.select(".sub_node_list").each( function(sub_node_list, sub_node_list_index)
		{
			// initialy hide sub_node_list
			//sub_node_list.hide();
			
			var obj = new NavigationMenuNodeList(sub_node_list, this);
			this.sub_node_lists.push(obj);
			
		}.bind(this));
		
		this.linkages = [];
		
		this.checkTimer = null;
		
	},
	
	hideAllSubNodeList: function()
	{
		if ( this.checkTimer != null )
		{
			clearTimeout(this.checkTimer);
		}
		
		this.checkTimer = setTimeout(function()
		{
			var any_selected_node = false;
			var node_lists = [this.main_node_list];
			this.sub_node_lists.each( function(sub_node_list_obj, sub_node_list_obj_index)
			{
				node_lists.push(sub_node_list_obj);
			}.bind(this));
			
			node_lists.each( function(node_list_obj, node_list_obj_index)
			{
				if ( node_list_obj.selected_node != null )
				{
					any_selected_node = true;
					return;
				}
				
			}.bind(this));
			this.checkTimer = null;
			
			// If no nodes are selected, hide all sub menus
			if ( !any_selected_node )
			{
				this.sub_node_lists.each( function(sub_node_list_obj, sub_node_list_obj_index)
				{
					sub_node_list_obj.el.hide();
					
				}.bind(this));
			}
			
		}.bindAsEventListener(this), 500);
		
	},
	
	linkNodeList: function(node, node_list)
	{
		var node_list_obj = null;
		
		// main_node_list?
		if ( node_list == this.main_node_list.el )
		{
			node_list_obj = this.main_node_list;
		}
		else
		{
			// sub_node_list?
			this.sub_node_lists.each( function(sub_node_list_obj, sub_node_list_obj_index)
			{
				if ( node_list == sub_node_list_obj.el )
				{
					node_list_obj = sub_node_list_obj;
					return;
				}
			}.bind(this));
		}
		
		if ( node_list_obj != null )
		{
			this.linkages.push({
				node: node,
				node_list_obj: node_list_obj
			});
		}
	},
	
	fetchSingleElement: function(element, selector, default_element)
	{
		var v = element.select(selector);
		if ( v.length > 0 )
		{
			return v[0];
		}
		else
		{
			return default_element;
		}
	}
};


var NavigationMenuNodeList = Class.create();

NavigationMenuNodeList.prototype = {
	initialize: function(el, menu)
	{
		this.el = el;
		this.menu = menu;
		this.nodes = this.el.select(".node");
		
		this.current_active_linkage = null;
		this.selected_node = null;
		
		// Apply event
		this.nodes.each( function(node, node_index)
		{
			node.observe("mouseover", function(event){
				this.handleNodeMouseover(node)
			}.bindAsEventListener(this) );
			
			node.observe("mouseout", function(event){
				this.handleNodeMouseout(node)
			}.bindAsEventListener(this) );
			
		}.bind(this));
	},

	handleNodeMouseover: function(node)
	{
		// Swap image
		var image = this.fetchSingleElement(node, ".image", null);
		if ( image != null)
		{
			image.src = image.src.substring(0, image.src.length - 4)+"_on"+image.src.substring(image.src.length - 4, image.src.length);
		}
		else if ( node.hasClassName("first_node"))
		{
			node.addClassName("first_node_mouseover");	
		}
		else
		{
			node.addClassName("node_mouseover");
		}
		
		// Find linkage
		var linkage_found = false;
		this.menu.linkages.each( function(linkage, linkage_index)
		{
			if ( linkage.node == node )
			{
				var node_position = Element.positionedOffset(linkage.node);
				var node_height = Element.getHeight(linkage.node);
				
				linkage.node_list_obj.el.setStyle({
					top: (node_position[1] + node_height)+"px",
					left: node_position[0]+"px"
				});
				
				this.showLinkage(linkage);
				linkage_found = true;
			}
			
		}.bind(this));
		
		if ( !linkage_found && this.current_active_linkage != null )
		{
			this.current_active_linkage.node_list_obj.el.hide();
			this.current_active_linkage = null;
		}
		
		this.selected_node = node;
		
	},
	
	handleNodeMouseout: function(node)
	{
		// Swap image
		var image = this.fetchSingleElement(node, ".image", null);
		if ( image != null)
		{
			image.src = image.src.substring(0, image.src.length - 7)+image.src.substring(image.src.length - 4, image.src.length);
		}
		else if ( node.hasClassName("first_node"))
		{
			node.removeClassName("first_node_mouseover");	
		}
		else
		{
			node.removeClassName("node_mouseover");
		}
		
		this.selected_node = null;
		this.menu.hideAllSubNodeList();
	},
	
	showLinkage: function(linkage)
	{
		if ( this.current_active_linkage != null && this.current_active_linkage != linkage )
		{
			this.current_active_linkage.node_list_obj.el.hide();
		}
		
		this.current_active_linkage = linkage;
		this.current_active_linkage.node_list_obj.el.show();
	},
	
	fetchSingleElement: function(element, selector, default_element)
	{
		var v = element.select(selector);
		if ( v.length > 0 )
		{
			return v[0];
		}
		else
		{
			return default_element;
		}
	}
}