/**
    * Copyright 2010 The Kuali Foundation Licensed under the
    * Educational Community License, Version 2.0 (the "License"); you may
    * not use this file except in compliance with the License. You may
    * obtain a copy of the License at
    *
    * http://www.osedu.org/licenses/ECL-2.0
    *
    * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an "AS IS"
   * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
   * or implied. See the License for the specific language governing
   * permissions and limitations under the License.
   */
  
  package org.kuali.student.common.ui.client.configurable.mvc;
  
  import java.util.List;
  
  import org.kuali.student.common.ui.client.mvc.Callback;
  import org.kuali.student.common.ui.client.mvc.Controller;
  import org.kuali.student.common.ui.client.mvc.ModelRequestCallback;
  import org.kuali.student.common.ui.client.mvc.dto.ReferenceModel;
  
  import com.google.gwt.user.client.Window;
  import com.google.gwt.user.client.ui.LazyPanel;
  import com.google.gwt.user.client.ui.Widget;
  
  /**
   * A view that delays its generation until it is requested to be shown.
   * 
   * @author Kuali Student Team
   *
   */
  public abstract class DelayedToolView extends LazyPanel implements ToolView{
      private Controller controller;    
      private Enum<?> viewEnum;
      private String viewName;    //View name is being used as menu item label   
  
      private HasReferenceId reference;
      
      private ModelRequestCallback<ReferenceModel> modelRequestCallback = 
          new ModelRequestCallback<ReferenceModel>(){
              public void onModelReady(ReferenceModel model) {
                  reference.setReferenceId(model.getReferenceId());
                  reference.setReferenceTypeKey(model.getReferenceTypeKey());
                  reference.setReferenceType(model.getReferenceType());
                  reference.setReferenceState(model.getReferenceState());
                  DelayedToolView.this.setVisible(true);       
              }
      
              public void onRequestFail(Throwable cause) {
                  Window.alert(cause.toString());
              }
      };
      
      
      /**
       * @param controller
       * @param name
       */
      public DelayedToolView(Controller controller, Enum<?> viewEnum, String viewName) {
          this.controller = controller;
          this.viewName = viewName;
          this.viewEnum = viewEnum;
      }
  
  
      public DelayedToolView(Enum<?> viewEnum, String viewName) {
          this.controller = null;
          this.viewEnum = viewEnum;
          this.viewName = viewName;
      }
     
      @Override
      public void beforeShow(final Callback<Boolean> onReadyCallback){
          if (getWidget() instanceof HasReferenceId){
              reference = (HasReferenceId)getWidget();
              controller.requestModel(ReferenceModel.class, modelRequestCallback);
          } else if (this instanceof HasReferenceId){
              reference = (HasReferenceId)this;
              controller.requestModel(ReferenceModel.class, modelRequestCallback);            
          } else {
              this.setVisible(true);
          }
          // FIXME ? need to wire onReadyCallback into the model request, so that we aren't indicating that we're ready before the model is available?
          onReadyCallback.exec(true);
      }
  
      /**
       * @see org.kuali.student.common.ui.client.mvc.View#beforeHide()
       */
      @Override
      public boolean beforeHide() {
          return true;
      }
  
  
      /**
      * @see org.kuali.student.common.ui.client.mvc.View#getController()
      */
     @Override
     public Controller getController() {
         return this.controller;
     }
 
 
     /**
      * @see org.kuali.student.common.ui.client.mvc.View#getName()
      */
     @Override
     public String getName() {
         return this.viewName;
     }
 
     public Enum<?> getViewEnum() {
         return viewEnum;
     }
 
     /**
      * @see org.kuali.student.common.ui.client.mvc.View#updateModel()
      */
     @Override
     public void updateModel() {
         //There is no model to update here, reference model is read-only        
     }
     
     public void setController(Controller controller){
         this.controller = controller;
     }
 
     
     public Widget asWidget(){
     	return this;
     }
     
     @Override
     public String collectHistory(String historyStack) {
     	return null;
     }
 
 
 	@Override
 	protected Widget createWidget() {
 		// TODO Auto-generated method stub
 		return null;
 	}
 
 	@Override
 	public void onHistoryEvent(String historyStack) {
 		
 	}
 
 	@Override
 	public void collectBreadcrumbNames(List<String> names) {
 		names.add(this.getName());
 		
 	}
 	
 	   public boolean isExportButtonActive() {
 	        return false;
 	    }
 }