/**
    * 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.common.assembly.data.Data;
  import org.kuali.student.common.assembly.data.Metadata;
  import org.kuali.student.common.search.dto.SearchResultCell;
  import org.kuali.student.common.search.dto.SearchResultRow;
  import org.kuali.student.common.ui.client.configurable.mvc.DefaultWidgetFactory;
  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.impl.KSDropDownImpl;
  import org.kuali.student.common.ui.client.widgets.list.KSRadioButtonList;
  import org.kuali.student.common.ui.client.widgets.list.KSSelectItemWidgetAbstract;
  import org.kuali.student.common.ui.client.widgets.list.SearchResultListItems;
  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.KSRadioButtonListImpl;
  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;
  import com.google.gwt.user.client.ui.FlowPanel;
  import com.google.gwt.user.client.ui.Widget;
  
  public class GradeWidget extends Composite implements AccessWidgetValue, HasDataValue {
  
      protected static final String GRADE_TYPE_ID_CELL_KEY = "lrc.resultColumn.resultComponent.id";
      protected static final String GRADE_TYPE_NAME_CELL_KEY = "lrc.resultColumn.resultComponent.name";
      private FlowPanel layout = new FlowPanel();
      KSPicker gradeTypeWidget;
      KSPicker gradeWidget = null;
      Metadata gradeMetadata;
      private String initialGradeValue = null;
  
      public GradeWidget() {
          this.initWidget(layout);
      }
  
      @Override
      public void initWidget(List<Metadata> fieldsMetadata) {
          layout.clear();
          gradeTypeWidget = (KSPicker) DefaultWidgetFactory.getInstance().getWidget(fieldsMetadata.get(0));
          layout.add(gradeTypeWidget);
          gradeMetadata = fieldsMetadata.get(1);
          setupHandlers();
      }
  
      private void setupHandlers() {
  
          ((KSRadioButtonList)gradeTypeWidget.getInputWidget()).addSelectionChangeHandler(new SelectionChangeHandler() {
  
              @Override
              public void onSelectionChange(SelectionChangeEvent event) {
                  String gradeTypeSelected = ((KSRadioButtonListImpl)event.getWidget()).getSelectedItem();
                  gradeMetadata.getInitialLookup().getParams().get(0).setDefaultValueList(null);
                  gradeMetadata.getInitialLookup().getParams().get(0).setDefaultValueString(gradeTypeSelected);
                  
                  addGradeListWidget(true, !event.isUserInitiated());
              }
          });
      }
  
      private void addGradeListWidget(boolean enabled, boolean addInitialValueCallback) {
          if (gradeWidget != null) {
              layout.remove(gradeWidget);
          }
          
          // this callback ensures the initial grade value is selected if it should be set
          // since the values are populated async, a widget ready callback must be used
          if(addInitialValueCallback) {
              ((KSSelectItemWidgetAbstract)gradeWidget.getInputWidget()).addWidgetReadyCallback(new Callback<Widget>() {
              
                  @Override
                  public void exec(Widget result) {
                      gradeWidget.setValue(initialGradeValue);
                      KSDropDownImpl theWidget = (KSDropDownImpl) result;
                      theWidget.selectItem(initialGradeValue);
                  }
              });
          }
          
          gradeWidget = (KSPicker) DefaultWidgetFactory.getInstance().getWidget(gradeMetadata);
          ((KSDropDown)gradeWidget.getInputWidget()).setEnabled(enabled);
         layout.add(gradeWidget);
     }
 
 	@Override
 	public void addValueChangeCallback(Callback<Data.Value> callback) {
 	}
 
 	@Override
 	public void setValue(Data.Value value) {
 	    
 	    if(value != null && value.toString() != null) {
 	        initialGradeValue = value.toString();
 	    }
 	    
         addGradeListWidget((initialGradeValue != null), false);
         gradeWidget.setValue(value);
 	    
 		// if setting an initial value that is not the blank default (i.e. populating the grade widget from a previously saved value)
 		if(initialGradeValue != null) {
 		    
 		    // add a callback to select the grade type after the grade dropdown has been initialized
 	        final String selectedGradeValue = value.toString();
 		
     		Callback<Widget> afterInitCallback = new Callback<Widget>(){
                 @Override
                 public void exec(Widget widget) {
     
                     List<SearchResultRow> gradeItems = ((SearchResultListItems) ((KSSelectItemWidgetAbstract)gradeWidget.getInputWidget()).getListItems()).getReadOnlyResults();
                     
                     // find the selected row for the grade
                     SearchResultRow selectedGradeRow = null;
                     String selectedGradeTypeId = null;
                     for(SearchResultRow row : gradeItems) {
                         for(SearchResultCell cell : row.getCells()) {
                             if(cell.getValue().equals(selectedGradeValue)) {
                                 selectedGradeRow = row;
                             }
                             
                             // get the grade type id from any row  
                             // If the right row is found, this value will contain the grade type we are looking for
                             if(cell.getKey().equals(GRADE_TYPE_ID_CELL_KEY)) {
                                 selectedGradeTypeId = cell.getValue();
                             }
                             
                         }
                         
                         // once the grade row is found, break
                         if(selectedGradeRow != null) {
                             break;
                         }
                     }
                     
                     // make sure to check for null, though it would indicate bad data if true
                     if(selectedGradeRow == null) {
                         return;
                     }
                     
                     // now we can select the grade type in the grade type widget
                     ((KSSelectItemWidgetAbstract)gradeTypeWidget.getInputWidget()).selectItem(selectedGradeTypeId);
                     
                 }
             };
     		
     		((KSSelectItemWidgetAbstract)gradeWidget.getInputWidget()).addWidgetReadyCallback(afterInitCallback);
 		}
 	}
 
     @Override
     public void getValue(Callback<String> doneSaveCallback) { 
     }
 
     @Override
     public void setValue(String id) {
     }
 
     @Override
     public Data.Value getValue() {
         return (gradeWidget != null ? gradeWidget.getValue() : null);
     }
 }