/**
    * 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.lum.common.client.widgets;
  
  import java.util.List;
  
  import org.kuali.student.r1.common.assembly.data.Data;
  import org.kuali.student.r1.common.assembly.data.Metadata;
  import org.kuali.student.common.ui.client.configurable.mvc.DefaultWidgetFactory;
  import org.kuali.student.common.ui.client.configurable.mvc.sections.VerticalSection;
  import org.kuali.student.common.ui.client.mvc.Callback;
  import org.kuali.student.common.ui.client.mvc.HasDataValue;
  import org.kuali.student.common.ui.client.widgets.KSDropDown;
  import org.kuali.student.common.ui.client.widgets.KSLabel;
  import org.kuali.student.common.ui.client.widgets.field.layout.element.MessageKeyInfo;
  import org.kuali.student.common.ui.client.widgets.impl.KSDropDownImpl;
  import org.kuali.student.common.ui.client.widgets.list.SelectionChangeEvent;
  import org.kuali.student.common.ui.client.widgets.list.SelectionChangeHandler;
  import org.kuali.student.common.ui.client.widgets.list.impl.SimpleListItems;
  import org.kuali.student.common.ui.client.widgets.progress.BlockingTask;
  import org.kuali.student.common.ui.client.widgets.progress.KSBlockingProgressIndicator;
  import org.kuali.student.common.ui.client.widgets.search.KSPicker;
  import org.kuali.student.core.statement.ui.client.widgets.rules.AccessWidgetValue;
  
  import com.google.gwt.user.client.ui.Composite;
  
  public class CourseWidget extends Composite implements AccessWidgetValue, HasDataValue {
  
      private CluSetRetriever courseMetadataRetriever  = new CluSetRetrieverImpl();
      private Callback getCluNameCallback;
  
      //widgets
      protected VerticalSection layout = new VerticalSection();
      protected KSDropDown courseTypeWidget;
      protected KSPicker courseWidget = null;
      private KSLabel previousCourseCode;
      private String previousCourseId;
  
      //data
      private Metadata searchCourseMetadata = null;
      private BlockingTask initializeTask = new BlockingTask("Initializing");
  
      public CourseWidget() {
          this.initWidget(layout);
      }
  
      @Override
      public void initWidget(List<Metadata> fieldsMetadata) {
  
          previousCourseCode = null;
          previousCourseId = null;
          
          layout.clear();
  
          final VerticalSection choosingSection = new VerticalSection();
          choosingSection.addWidget(new KSLabel("<b>Add a course</b>"));
  
          //first metadata is a drop down to select type of course
          createAndAddCourseTypesDropdown();
  
          retrieveMetadata();
      }
  
      protected void createAndAddCourseTypesDropdown() {
          courseTypeWidget = new KSDropDown();
          SimpleListItems courseTypes = new SimpleListItems();
          courseTypes.addItem(CommonWidgetConstants.CLU_SET_APPROVED_CLUS_FIELD, "Approved Courses");
          courseTypes.addItem(CommonWidgetConstants.CLU_SET_PROPOSED_CLUS_FIELD, "Proposed Courses");
          courseTypeWidget.setListItems(courseTypes);
          courseTypeWidget.addSelectionChangeHandler(new SelectionChangeHandler() {
  
              @Override
              public void onSelectionChange(SelectionChangeEvent event) {
                  String courseTypeSelected = ((KSDropDownImpl)event.getWidget()).getSelectedItem();
                  if (courseTypeSelected == null) {
                      if (courseWidget != null) {
                          layout.remove(courseWidget);
                      }                    
                      return;
                  }
                  addCourseListWidget(true, courseTypeSelected);
              }
          });        
          layout.add(courseTypeWidget);
      }
  
      private void retrieveMetadata() {
         if (searchCourseMetadata == null) {
             KSBlockingProgressIndicator.addTask(initializeTask);
             courseMetadataRetriever.getMetadata("courseSet", new Callback<Metadata>(){
                 @Override
                 public void exec(Metadata result) {
                     searchCourseMetadata = result;
                     searchCourseMetadata.getProperties().get(CommonWidgetConstants.CLU_SET_APPROVED_CLUS_FIELD).getConstraints().get(0).setMaxOccurs(1);
                     searchCourseMetadata.getProperties().get(CommonWidgetConstants.CLU_SET_PROPOSED_CLUS_FIELD).getConstraints().get(0).setMaxOccurs(1);
                     searchCourseMetadata.getProperties().get(CommonWidgetConstants.CLU_SET_APPROVED_CLUS_FIELD).getConstraints().get(0).setId("single");
                     searchCourseMetadata.getProperties().get(CommonWidgetConstants.CLU_SET_PROPOSED_CLUS_FIELD).getConstraints().get(0).setId("single");
                     KSBlockingProgressIndicator.removeTask(initializeTask);
 
                     if (previousCourseCode == null) {
                         courseTypeWidget.selectItem(CommonWidgetConstants.CLU_SET_APPROVED_CLUS_FIELD);
                         addCourseListWidget(true, courseTypeWidget.getSelectedItem());
                     }
                 }
             });
         } else {
             if (previousCourseCode == null) {
                 courseTypeWidget.selectItem(CommonWidgetConstants.CLU_SET_APPROVED_CLUS_FIELD);
                 addCourseListWidget(true, courseTypeWidget.getSelectedItem());
             }
         }
     }
 
     protected void addCourseListWidget(boolean enabled, String courseType) {
         if (courseWidget != null) {
             layout.remove(courseWidget);
         }
         if (previousCourseCode != null) {
             layout.remove(previousCourseCode);
             previousCourseCode = null;
             previousCourseId = null;
         }
         courseWidget = (KSPicker) DefaultWidgetFactory.getInstance().getWidget(searchCourseMetadata.getProperties().get(courseType));
         courseWidget.getSearchPanel().setMutipleSelect(false);
     //    ((KSSuggestBox) courseWidget.getInputWidget()).setEnabled(enabled);
         layout.add(courseWidget);
     }
 
     protected MessageKeyInfo generateMessageInfo(String labelKey) {
         return new MessageKeyInfo("clusetmanagement", "clusetmanagement", "draft", labelKey);
     }
 
 	@Override
 	public void addValueChangeCallback(Callback<Data.Value> callback) {
 	}
 
 	@Override
 	public void setValue(Data.Value value) {    
 	}
 
     @Override
     public void getValue(Callback<String> doneSaveCallback) { 
     }
 
     @Override
     public void setValue(final String id) {
         if (id != null) {
             getCluNameCallback.exec(id);
         }        
     }
 
     public void setLabelContent(String id, final String code) {
         layout.clear();
         previousCourseId = id;
         previousCourseCode = new KSLabel(code);
         layout.add(previousCourseCode);
         createAndAddCourseTypesDropdown();
     }
 
     public void addGetCluNameCallback(Callback callback) {
         this.getCluNameCallback = callback;    
     }
 
     @Override
     public Data.Value getValue() {
         Data.Value pickerValue = courseWidget.getValue();
         if ((pickerValue.toString().isEmpty()) && (previousCourseCode != null) && (!previousCourseCode.getText().isEmpty())) {
             return new Data.StringValue(previousCourseId);
         }
 
         return pickerValue;
     }
 }