var menuData =
{
	// construction du menu en notation JSON
  menuObject : [
	
  
  ], 
  
  
  
  // méthodes de construction du menu en HTML
  referenceChannel : undefined, 
  anchorElement : undefined, 
  focusedElement : undefined, 
  channelIDSelected : undefined, 
  hasVisibleNodeChildren : false, 
  
  
  buildMenu : function(elt, visibleNode)
  {
	var frag = document.createDocumentFragment();
	var oldNode = elt.cloneNode(false);
    menuData.anchorElement = oldNode;
    menuData.channelIDSelected = visibleNode ;
    
    //menuData.buildSubMenu(elt, menuData.menuObject, 1);
    menuData.buildSubMenu(oldNode, menuData.menuObject, 1);
    
    frag.appendChild(oldNode);
	elt.parentNode.replaceChild(frag,elt);
    
    menuData.anchorElement.select("li.extensible").each(function(item) {
          item.addClassName("collapsed");
          item.addClassName("collapsed-level"+item.level);
    });
    
    var referenceChannel= $(visibleNode);
    menuData.focusedElement = referenceChannel;
    
    if (referenceChannel != undefined && referenceChannel != null)
    {
      level = referenceChannel.level ;
      
      if ( ! menuData.hasVisibleNodeChildren && (level == 2 || level == 3 || level == 4))
        referenceChannel.addClassName("focusedLevel"+level) ;
      else if (level == 1)
        referenceChannel.addClassName("focused");
      
      
      if (!referenceChannel.hasClassName("extensible")) 
        referenceChannel = referenceChannel.up("li.extensible");
      
      if (referenceChannel != undefined)
      {
        referenceChannel.expandMenu();
        menuData.referenceChannel = referenceChannel;
      }
    }
    
    menuData.anchorElement.observe("click", menuClickObserver);
    $(document).observe("mouseover", menuOverObserver);
	
  }, 
  
  
  
  buildSubMenu : function(elt, children, level)
  {
    var ul = new Element("ul");
    children.each(function(item) {
      var li = new Element("li", {id : item.id});
      li.level=level;
      if (item.children.length > 0)
      {
        if (item.id == menuData.channelIDSelected)
          menuData.hasVisibleNodeChildren = true ;
        
        li.update("<div>"+item.label+"</div>");
        li.addClassName("extensible");
        li.collapseMenu=menuFct.collapseMenu;
        li.expandMenu=menuFct.expandMenu;
        var subUl = menuData.buildSubMenu(li, item.children, level+1);
        subUl.hide();
      }
      else
          li.update("<a href=\""+item.url_href+"\"><div onclick=\"window.location.assign('"+item.url_href+"')\">"+item.label+"</div></a>");
      
      ul.insert(li);
    });
    elt.insert(ul);
    return ul;
  }
};

var menuFct = 
{
  collapseMenu : function ()
  {
    var elt = $(this);
    
    if (elt.hasClassName("collapsed"))
        return;
    
    elt.removeClassName("expanded");
    elt.removeClassName("expanded-level"+elt.level);
    elt.addClassName("collapsed");
    elt.addClassName("collapsed-level"+elt.level);
    
    var toHide = elt.childElements()[1];
    Effect.BlindUp(toHide, { duration: 0.2 });
    
    // collapse children recursively
    elt.select('li.expanded').each(function(child)
    {
        child.collapseMenu() ;
    }) ;
    
  }, 
  
  
  expandMenu : function ()
  {
    var elt = $(this);
    
    // expand if not done yet
    if (!elt.hasClassName("expanded"))
    {
        elt.addClassName("expanded");
        elt.addClassName("expanded-level"+elt.level);
        elt.removeClassName("collapsed");
        elt.removeClassName("collapsed-level"+elt.level);
        var toShow = elt.childElements()[1];
        Effect.BlindDown(toShow, { duration: 0.3 });
        
        
    }
    
    
    // collapse sibblings
    elt.siblings().each(function(sib) {
        if (sib.match("li.extensible", "expanded"))
            sib.collapseMenu();
    });
    
    
    // expand father recursively
    var fatherToExpand = elt.up('.extensible');
    if (fatherToExpand != undefined)
        fatherToExpand.expandMenu();
    
  }
};


var backToRefID = null;


function menuOverObserver(e)
{
  var element = Event.element(e);
  if (element.descendantOf(menuData.anchorElement)) // Over menu
  { 
    // Just entered -> Cancel the back to reference channel callback
    if (backToRefID != null) {
      clearTimeout(backToRefID);
      backToRefID = null;
    }
  }
  // Not over menu and trigger not set yet
  else if (backToRefID == null) 
  {
    // Trigger the back to reference channel callback
    backToRefID = setTimeout(function()
    {
        // open the reference node
        if (menuData.referenceChannel != undefined)
        {
            menuData.referenceChannel.expandMenu();
            
            // collpase the children of the reference element
            menuData.referenceChannel.select('.expanded').each(function(child)
            {
                child.collapseMenu() ;
            }) ;
        }
        
        
        // collapse the brothers of the active element
        if (menuData.focusedElement != undefined)
        {
            menuData.focusedElement.siblings().each(function(sib) {
                if (sib.match("li.extensible", "expanded"))
                    sib.collapseMenu() ;
            }) ;
        }
    }, 5000);
  }
  
}

function menuClickObserver(e)
{
  var elt = Event.element(e);
  
  // Skip links
  if (elt.match("a div")||elt.match("a")) return;
  
  // Get the first extensible parent
  var extensibleParent = elt.match("li.extensible")?elt:elt.up("li.extensible");
  // If not found, we're not in the menu
  if (extensibleParent == undefined) return;
  
  if (extensibleParent.expandMenu != undefined) // If found
  {
    if (extensibleParent.hasClassName("expanded"))
      extensibleParent.collapseMenu();
    else 
      extensibleParent.expandMenu();
    e.stop();
  }
}