/**
    * 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.views;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.kuali.student.common.assembly.data.Metadata;
  import org.kuali.student.common.assembly.data.ModelDefinition;
  import org.kuali.student.common.ui.client.configurable.mvc.FieldDescriptor;
  import org.kuali.student.common.ui.client.configurable.mvc.LayoutController;
  import org.kuali.student.common.ui.client.configurable.mvc.sections.BaseSection;
  import org.kuali.student.common.ui.client.configurable.mvc.sections.Section;
  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.DataModel;
  import org.kuali.student.common.ui.client.mvc.ModelRequestCallback;
  import org.kuali.student.common.ui.client.mvc.View;
  
  import com.google.gwt.user.client.Window;
  import com.google.gwt.user.client.ui.Widget;
  
  
  /**
   * A view implementation of a section.  A section view is used to add sections as views to a controller.
   * 
   * @author Kuali Student
   *
   */
  public abstract class SectionView extends BaseSection implements View {
  
      protected String modelId;
      protected DataModel model;
  
      private Enum<?> viewEnum;
      private String viewName;
  
      private List<View> views = new ArrayList<View>();
  
      public SectionView() {}
  
      /**
       * @param viewEnum Enumeration of this view - id used for navigation, history, and showing a view
       * @param viewName Name of this view - what this view is called in the breadcrumb
       */
      public SectionView(Enum<?> viewEnum, String viewName) {
          this.viewEnum = viewEnum;
          this.viewName = viewName;
      }
      
      public void init(Enum<?> viewEnum, String viewName) {
          this.viewEnum = viewEnum;
          this.viewName = viewName;
      }
  
      /**
       * This method gets view name enumeration
       *
       * @return
       */
      @Override
      public Enum<?> getViewEnum() {
          return viewEnum;
      }
  
      public void setViewEnum(Enum<?> viewEnum) {
          this.viewEnum = viewEnum;
      }
  
  
      /**
       * Called by controller before the view is displayed to allow lazy initialization or any other preparatory work to be
       * done.
       * In SectionView, the section is cleared of all validation errors, the model is requested from its parent
       * controller, the widgets are updated with the latest data, and beforeShow is called on all of its potential child
       * views.
       */
      @Override
      public void beforeShow(final Callback<Boolean> onReadyCallback) {
  
          super.clearValidationErrors();
          
          if (getController() != null) {
              getController().requestModel(modelId, new ModelRequestCallback<DataModel>() {
  
                  @Override
                 public void onRequestFail(Throwable cause) {	//Don't place a breakpoint here:  It will stall debugging for some unknown reason!
                     Window.alert("Failed to get model: "  + modelId + " for SectionView " + getName());
                     onReadyCallback.exec(false);
                 }
 
                 @Override	//Don't place a breakpoint here:  It will stall debugging for some unknown reason!
                 public void onModelReady(DataModel m) {
                     model = m;
                     updateWidgetData(m);
                     resetFieldInteractionFlags();
                     onReadyCallback.exec(true);
                 }
 
             });
         }
 
         for (Section section : sections) {
             if (section instanceof SectionView) {
                 ((SectionView) section).beforeShow(new Callback<Boolean>() {
                     @Override	//Don't place a breakpoint here:  It will stall debugging for some unknown reason!
                     public void exec(Boolean result) {
                     }
                 });
             }
         }
         for (View view : views) {
             view.beforeShow(Controller.NO_OP_CALLBACK);
         }
 
     }
 
     public String getModelId() {
         return modelId;
     }
 
     public void setModelId(String modelId) {
         this.modelId = modelId;
     }
 
     /**
      * Called by the controller before the view is hidden to allow the view to perform cleanup or request confirmation from
      * the user, etc. Can cancel the action by returning false.
      *
      * @return true if the view can be hidden, or false to cancel the action.
      */
     @Override
     public boolean beforeHide() {
         return true;
     }
 
     /**
      * Returns the controller associated with the view
      *
      * @see org.kuali.student.common.ui.client.mvc.View#getController()
      */
     @Override
     public Controller getController() {
         return super.getLayoutController();
     }
 
     /**
      * Returns the view's name
      *
      * @see org.kuali.student.common.ui.client.mvc.View#getName()
      */
     @Override
     public String getName() {
         return viewName;
     }
 
     public void setName(String name) {
         this.viewName = name;
     }
 
     public void setController(Controller controller) {
         if (controller instanceof LayoutController) {
             super.setLayoutController((LayoutController) controller);
         } else {
             throw new IllegalArgumentException("Configurable UI sections require a LayoutController, not a base MVC controller");
         }
     }
 
     /**
      * Update the fields on the screen with the model received back from requestModel on the parent controller
      */
     public void updateView() {
         getController().requestModel(modelId, new ModelRequestCallback<DataModel>() {
             @Override
             public void onModelReady(DataModel m) {
                 // TODO review this, shouldn't it assign this.model = m?
                 SectionView.this.model = m;
                 updateWidgetData(m);
             }
 
 
             @Override
             public void onRequestFail(Throwable cause) {
                 Window.alert("Failed to get model");
             }
         });
 
     }
 
     /**
      * Force an update of fields on this section with the model passed in
      * @param m
      */
     public void updateView(DataModel m) {
         this.model = m;
         updateWidgetData(m);
     }
 
     /**
      * @see org.kuali.student.common.ui.client.mvc.View#asWidget()
      */
     public Widget asWidget() {
         return this.getLayout();
     }
 
     /**
      * @see org.kuali.student.common.ui.client.mvc.history.HistorySupport#collectHistory(java.lang.String)
      */
     @Override
     public String collectHistory(String historyStack) {
         return null;
     }
 
     /**
      * @see org.kuali.student.common.ui.client.mvc.history.HistorySupport#onHistoryEvent(java.lang.String)
      */
     @Override
     public void onHistoryEvent(String historyStack) {
 
     }
 
     /**
      * @see org.kuali.student.common.ui.client.mvc.breadcrumb.BreadcrumbSupport#collectBreadcrumbNames(java.util.List)
      */
     @Override
     public void collectBreadcrumbNames(List<String> names) {
         names.add(this.getName());
     }
 
     /**
      * Add a view as a widget to this section
      * @param view
      */
     public void addView(View view) {
         views.add(view);
         addWidget(view.asWidget());
     }
 
     public DataModel getModel() {
         return model;
     }
 
     public void updateMetadata(ModelDefinition modelDefinition) {
         updateMetadata(modelDefinition, this);
     }
 
     private void updateMetadata(ModelDefinition modelDefinition, Section topSection) {
         for (Section section : topSection.getSections()) {
             updateMetadata(modelDefinition, section);
         }
         for (FieldDescriptor field : topSection.getFields()) {
             Metadata newMetadata = modelDefinition.getMetadata(field.getFieldKey());
             if (newMetadata != null) {
                 field.setMetadata(newMetadata);
             }
         }
     }
 
     @Override
     public String toString() {
         return viewName;
     }
     
     public boolean isExportButtonActive() {
         return false;
     }
 
 	@Override
 	public void showExport(boolean show) {
 		// TODO Auto-generated method stub
 		
 	}
 }