How to use tag input and autocomplete in user directive?

Question

I created a custom directive, I want to use it with input tags. But when I select any value from the autocomplete result, it is not selected. I do not know why it does not work. Demo Plunker

Index.html

 <my-directive  apipoint="customerApi" modeldisplay="customer.selected"  
    ng-model="customer.selected" searchresults="customeruserprofile" change="customerChanged"></my-directive>

Directive

app.directive("myDirective", ['$http',function($http){
  return {
    restrict: "E",
    templateUrl: 'auto-complete.html',

    require: 'ngModel',
    scope : {
      modeldisplay: "=",
      apipoint: "=",
      change: "="
    },
    link : function(scope, element, attrs, ctrl){
      scope.loadTags = function(query) {
         return $http.get(scope.apipoint[0]);
      };
      scope.addCustomerTag = function($tag){
          var selectedCustomer = scope.modeldisplay;
          if(selectedCustomer === undefined){
              return true;
          }
          return false;
      };
       scope.tagAdded = function($tag){
         scope.selectedmodel = $tag
         var selectFun=scope.change;
         selectFun();

      };
      scope.removedCustomerTag = function(){
          scope.modeldisplay = undefined;
          scope.selectedmodel = undefined;
      };

      scope.tagAdded = function($tag){
          scope.selectedmodel = $tag;
          scope.tagid = $tag.customer_id;
          scope.change();
      };
    }
  };
}]);