/**
    * 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.binding;
  
  import java.util.Iterator;
  import java.util.List;
  
  import org.kuali.student.common.ui.client.mvc.Callback;
  import org.kuali.student.common.ui.client.mvc.DataModel;
  import org.kuali.student.common.ui.client.widgets.list.KSSelectItemWidgetAbstract;
  import org.kuali.student.core.assembly.data.Data;
  import org.kuali.student.core.assembly.data.QueryPath;
  import org.kuali.student.core.assembly.data.Data.DataValue;
  import org.kuali.student.core.assembly.data.Data.Property;
  import org.kuali.student.core.assembly.data.Data.StringValue;
  import org.kuali.student.core.assembly.data.Data.Value;
  
  import com.google.gwt.user.client.ui.Widget;
  
  public class SelectItemWidgetBinding extends ModelWidgetBindingSupport<KSSelectItemWidgetAbstract> {
  
      public static SelectItemWidgetBinding INSTANCE = new SelectItemWidgetBinding();
  
      private SelectItemWidgetBinding() {}
  
      @Override
      public void setModelValue(KSSelectItemWidgetAbstract object, DataModel model, String path) {
          QueryPath qPath = QueryPath.parse(path);
  
  
          if (object.isMultipleSelect()) {
          	Data newValue = (Data)getWidgetValue(object).get();
              Data oldValue = model.get(qPath);
              if (!nullsafeEquals(oldValue, newValue)) {
                  model.set(qPath, newValue);
                  setDirtyFlag(model, qPath);
              }
          } else {
              String newValue = object.getSelectedItem();
              String oldValue = model.get(qPath);
              if (!nullsafeEquals(oldValue, newValue)) {
                  model.set(qPath, object.getSelectedItem());
                  setDirtyFlag(model, qPath);
              }
          }
  
      }
  
      @Override
      public void setWidgetValue(KSSelectItemWidgetAbstract object, final DataModel model, final String path) {
          QueryPath qPath = QueryPath.parse(path);
          Object value = model.get(qPath);
          setWidgetValue(object, value);
      }
      
      /**
       * Helper method get list item widget's values as a Data object
       * 
       * @param object
       * @param value
       * @return
       */
      public Value getWidgetValue(KSSelectItemWidgetAbstract object){
      	Value value;
      	
          if (object.isMultipleSelect()) {
          	Data data = new Data();
          	List<String> selectedItems = object.getSelectedItems();
  	        for (String stringItem : selectedItems) {
  	           data.add(stringItem);
  	        }
  	        value = new Data.DataValue(data);
          } else {
          	value = new Data.StringValue(object.getSelectedItem());
          }
  
          return value;
      }
      
      /**
       * Helper method to set Data object to a list item widget
       * @param object
       * @param value
       */
      public void setWidgetValue(KSSelectItemWidgetAbstract object, final Object value){
      	Callback<Widget> selectListItemsCallback = new Callback<Widget>(){
             @Override
             public void exec(Widget widget) {
 
                 ((KSSelectItemWidgetAbstract)widget).clear();
                 if (value != null){
 	                if (value instanceof String || value instanceof StringValue) {
 	                	String itemId = (String)(value instanceof String ? value:((StringValue)value).get());
 	                    ((KSSelectItemWidgetAbstract)widget).selectItem(itemId);
 	                } else if (value instanceof Data || value instanceof DataValue) {
 	                	Data data = (Data)(value instanceof Data ? value:((DataValue)value).get());
 	                    for (Iterator itr = data.iterator(); itr.hasNext();) {
 	                        Property p = (Property) itr.next();
 	                        ((KSSelectItemWidgetAbstract)widget).selectItem((String) p.getValue());
 	                    }
 	                }
                 }
             }            
         };
 
         if (!object.isInitialized()){
             object.addWidgetReadyCallback(selectListItemsCallback);
         } else{
             selectListItemsCallback.exec(object);
         }    	
     }
     
 
 }