/**

  * 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 com.google.gwt.user.client.Window;

 import com.google.gwt.user.client.ui.Widget;

 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.*;

 import org.kuali.student.core.assembly.data.Metadata;

 import org.kuali.student.core.assembly.data.ModelDefinition;

 import java.util.ArrayList;

 import java.util.List;

 /**

  * 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>();

     /**

      * @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;

     }

     /**

      * 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.clearValidation();

         if (getController() != null) {

             getController().requestModel(modelId, new ModelRequestCallback<DataModel>() {

                 @Override

                 public void onRequestFail(Throwable cause) {

                     Window.alert("Failed to get model: " + getName());

                     onReadyCallback.exec(false);

                 }

                 @Override

                 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

                     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;

     }

 }