var PriorityNav = {

  // used multiple times, so saving.
  menu: $(".priority-nav"),
  allNavElements: $(".priority-nav > ul > li:not('.overflow-nav')"),

  init: function() {
    this.bindUIActions();
    this.setupMenu();
  },

  setupMenu: function() {
    
    // Checking top position of first item (sometimes changes)
    var firstPos = $(".priority-nav > ul > li:first").position();
        
    // Empty collection in which to put menu items to move
    var wrappedElements = $();

    // Used to snag the previous menu item in addition to ones that have wrapped
    var first = true;

    // Loop through all the nav items...
    PriorityNav.allNavElements.each(function(i) {
      
      var el = $(this);

      // ...in which to find wrapped elements
      var pos = el.position();
                  
      if (pos.top !== firstPos.top) {

        // If element is wrapped, add it to set
        wrappedElements = wrappedElements.add(el);

        // Add the previous one too, if first
        if (first) {
          wrappedElements = wrappedElements.add(PriorityNav.allNavElements.eq(i-1));
          first = false;
        }
      }
    });
        
    if (wrappedElements.length) {

      // Clone set before altering
      var newSet = wrappedElements.clone();

      // Hide ones that we're moving
      wrappedElements.addClass("hide");

      // Add wrapped elements to dropdown
      $(".overflow-nav-list").append(newSet);

      // Show new menu
      $(".overflow-nav").addClass("show-inline-block");

      // Make overflow visible again so dropdown can be seen.
      $(".priority-nav").css("overflow", "visible");

    }
  },

  tearDown: function() {
    $(".overflow-nav-list").empty();
    $(".overflow-nav").removeClass("show-inline-block");
    PriorityNav.allNavElements.removeClass("hide");
  },

  bindUIActions: function() {
    $(".overflow-nav-title").on("click", function() {
      $(".overflow-nav-list").toggleClass("show");
    });

    $(window)
      .resize(function() {
        PriorityNav.menu.addClass("resizing");
      })
      .resize(_.debounce(function() {
        PriorityNav.tearDown();
        PriorityNav.setupMenu();
        PriorityNav.menu.removeClass("resizing");
      }, 500));
  }

}

PriorityNav.init();