/* Credit: http://jqueryui.com/demos/autocomplete/#combobox */
(function($)  {
  $.widget( "ui.combobox", {
    _create: function() {
      var self = this;
      var select = this.element.hide(),
        selected = select.children( ":selected" ),
        value = selected.val() ? selected.text() : "";
      var input = $( "<input>" )
        .insertAfter( select )
        .val( value )
        .autocomplete({
          delay: 0,
          minLength: 0,
          source: function( request, response ) {
            var matcher = new RegExp( $.ui.autocomplete.escapeRegex(request.term), "i" );
            response( select.children( "option" ).map(function() {
              var text = $( this ).text();
              if ( this.value && ( !request.term || matcher.test(text) ) )
                return {
                  label: text.replace(
                    new RegExp(
                      "(?![^&;]+;)(?!<[^<>]*)(" +
                      $.ui.autocomplete.escapeRegex(request.term) +
                      ")(?![^<>]*>)(?![^&;]+;)", "gi"
                    ), "<strong>$1</strong>" ),
                  value: text,
                  option: this
                };
            }) );
          },
          select: function( event, ui ) {
            ui.item.option.selected = true;
            select.val( ui.item.option.value );
            select.trigger('change');
            self._trigger( "selected", event, {
              item: ui.item.option
            });
          },
          change: function( event, ui ) {
            if ( !ui.item ) {
              var matcher = new RegExp( "^" + $.ui.autocomplete.escapeRegex( $(this).val() ) + "$", "i" ),
                valid = false;
              select.children( "option" ).each(function() {
                if ( this.value.match( matcher ) ) {
                  this.selected = valid = true;
                  return false;
                }
              });
              if ( !valid ) {
                // remove invalid value, as it didn't match anything
                $( this ).val( "" );
                select.val( "" );
                select.trigger('change');
                return false;
              }
            }
          }
        })
        .addClass( "ui-widget ui-widget-content ui-corner-left" )
        .css({ margin: 0, padding: '0.48em 0 0.47em 0.45em'});

      input.data( "autocomplete" )._renderItem = function( ul, item ) {
        return $( "<li></li>" )
          .data( "item.autocomplete", item )
          .append( "<a>" + item.label + "</a>" )
          .appendTo( ul );
      };

      $( "<button>&nbsp;</button>" )
        .attr( "tabIndex", -1 )
        .attr( "title", "Show All Items" )
        .insertAfter( input )
        .button({
          icons: {
            primary: "ui-icon-triangle-1-s"
          },
          text: false
        })
        .removeClass( "ui-corner-all" )
        .addClass( "ui-corner-right ui-button-icon" )
        .css('marginLeft', '-1px')
        .click(function(e) {
          e.preventDefault();
          // close if already visible
          if ( input.autocomplete( "widget" ).is( ":visible" ) ) {
            input.autocomplete( "close" );
            return;
          }

          // pass empty string as value to search for, displaying all results
          input.autocomplete( "search", "" );
          input.focus();
        })
        .find('.ui-button-text').css('padding', '0.35em');
    }
  });
})(jQuery);