var $navbar = $('#navbar');                   // Navbar to go trough!
var $more   = $('#nav-more');                 // More More item to show/hide
var $v_wrap = $('#navbar .nav');              // Visible wrapper
var $h_wrap = $('#nav-more .dropdown-menu');  // Hidden wrapper
var breaks  = [];                             // Breakpoints
var pop_all_breakpoint = 767;                 // *** modify as needed. ***

/**
 * Return child to it's original place in the nav-wrapper
 */
function returnChild( $child, $dest_wrapper ) {
  var cplace = $child.attr('data-navorder'),
      inserted = false;

  // Find place for the child... insert if found...
  $dest_wrapper.children().each( function(idx, obj){
    if ( idx == cplace ) {
      $child.insertBefore(this);
      inserted = true;
    }
  });

  // ...if we didn't find a place to insert the childe, insert it last.
  if ( !inserted ) {
    $child.appendTo( $dest_wrapper );
  }
}

/**
 * Check navbar and handle more/show/hide.
 */
function updateNav() {

  // If collapsed bootstrap nav, return all items to default places and hide 'more' dropdown.
  if ( $(window).width() < pop_all_breakpoint ) {
    while ( breaks.length ) {
      returnChild( $h_wrap.children().first(), $v_wrap );
      breaks.pop();
    }

    // Hide the 'more' dropdown
    $more.addClass('hidden');
    return; // Don't do anything else!
  }

  // Set/save order of menu-items (needed to keep their place among static items). Only run once!
  if ( $v_wrap.attr('data-navsetup') != 'done' ) {
    $v_wrap.children().each( function(idx, obj){
      if ( $(this).hasClass('hideable') )
        $(this).attr('data-navorder', idx);
    });
    $v_wrap.attr('data-navsetup', 'done');
  }

  // Calculate available space ( -30 to make sure )
  var availableSpace = $navbar.width() - 30 - $('.navbar-header').width();
  var changes = 0; // Could be true/false as well..

  // The visible list is overflowing the nav & we have stuff we CAN hide
  if ( availableSpace < $v_wrap.width() && $v_wrap.children('.hideable:not(.active)') ) {

    // Record the width of the list
    breaks.push( $v_wrap.width() );
    changes++;

    // Move item to the hidden list
    $v_wrap.children('.hideable:not(.active)').last().prependTo( $h_wrap );

    // Show the dropdown btn
    if ($more.hasClass('hidden')) {
      $more.removeClass('hidden');
      $h_wrap.removeClass('hidden');
    }
  }
  else { // The visible list is not overflowing

    // Is there space for another item in the nav?
    if (availableSpace > breaks[breaks.length - 1]) {

      // Move the item to the visible list
      returnChild( $h_wrap.children().first(), $v_wrap );
      breaks.pop();
      changes++;
    }

    // Hide the dropdown btn if hidden list is empty
    if ( breaks.length <= 0 ) {
      $more.addClass('hidden');
      $h_wrap.addClass('hidden');
    }
  }

  // Recur if changes were made
  if ( changes ) {
    updateNav();
  }

}

// Window resize listener + trigger
$(window).resize(function() {
  updateNav();
}).trigger('resize');