/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache 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.apache.org/licenses/LICENSE-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.apache.myfaces.custom.selectitems;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  
  import javax.faces.context.FacesContext;
  import javax.faces.model.SelectItem;
  import javax.faces.model.SelectItemGroup;
  
  /**
   * An extended version of the standard UISelectItems. Populates the 
   * SelectItem collection from the given value automatically using 
   * the itemLabel and itemValue attributes. By using the component 
   * there is no need to manually create a SelectItem collection 
   * because component automatically populates SelectItem objects 
   * from types like Collection, Map and etc..
   * 
   * @JSFComponent
   *   name = "t:selectItems"
   *   class = "org.apache.myfaces.custom.selectitems.UISelectItems"
   *   tagClass = "org.apache.myfaces.custom.selectitems.SelectItemsTag"
   * @since 1.1.7
   * @author cagatay (latest modification by $Author: lu4242 $)
   * @version $Revision: 891039 $ $Date: 2009-12-15 17:29:01 -0500 (Tue, 15 Dec 2009) $
   */
  public abstract class AbstractUISelectItems extends javax.faces.component.UISelectItems {
      
      public static final String COMPONENT_TYPE = "org.apache.myfaces.UISelectItems";
      
      /**
       * name of the iterator
       * 
       * @JSFProperty
       */
      public abstract String getVar();
      
      /**
       * name of the selectitem
       * 
       * @JSFProperty
       */
      public abstract Object getItemLabel();
  
      /**
       * value of the selectitem
       * 
       * @JSFProperty
       */
      public abstract Object getItemValue();
      
      /**
       * indicate if the label should be escaped of the selectitem
       * 
       * @since 1.1.9
       * @JSFProperty
       */
      public abstract Object getItemLabelEscaped();
      
      /**
       * name of the selectitem
       * 
       * @since 1.1.9
       * @JSFProperty
       */
      public abstract Object getItemDescription();
      
      /**
       * disabled state of the selectitem
       * 
       * @since 1.1.9
       * @JSFProperty
       */
      public abstract Object getItemDisabled();
      
      /**
       * Only applies when value points to a map. Use the Entry instance instead
       * the value for resolve EL Expressions
      * 
      * @since 1.1.10
      * @JSFProperty
      *    defaultValue = "false"
      */
     public abstract boolean isUseEntryAsItem();
     
     public Object getValue() {
         Object value = super.getValue();
         String var = getVar(); 
         if (var != null && var.length() > 0)
         {
             return createSelectItems(value);
         }
         else
         {
             return value;
         }
     }
 
     private SelectItem[] createSelectItems(Object value) {
         List items = new ArrayList();
         
         if (value instanceof SelectItem[]) {
             return (SelectItem[]) value;
         }
         else if (value instanceof Collection) {
             Collection collection = (Collection) value;
             for (Iterator iter = collection.iterator(); iter.hasNext();) {
                 Object currentItem = (Object) iter.next();
                 if (currentItem instanceof SelectItemGroup) {
                     SelectItemGroup itemGroup = (SelectItemGroup) currentItem;        
                     SelectItem[] itemsFromGroup = itemGroup.getSelectItems();
                     for (int i = 0; i < itemsFromGroup.length; i++) {
                         items.add(itemsFromGroup[i]);
                     }
                 }
                 else {
                     putIteratorToRequestParam(currentItem);
                     SelectItem selectItem = createSelectItem();
                     removeIteratorFromRequestParam();
                     items.add(selectItem);
                 }
             }
         }
         else if (value instanceof Map) {
             Map map = (Map) value;
             if (isUseEntryAsItem())
             {
                 for (Iterator iter = map.entrySet().iterator(); iter.hasNext();) {
                     Entry currentItem = (Entry) iter.next();
                     putIteratorToRequestParam(currentItem);
                     SelectItem selectItem = createSelectItem();
                     removeIteratorFromRequestParam();
                     items.add(selectItem);
                 }
             }
             else
             {
                 for (Iterator iter = map.entrySet().iterator(); iter.hasNext();) {
                     Entry currentItem = (Entry) iter.next();
                     putIteratorToRequestParam(currentItem.getValue());
                     SelectItem selectItem = createSelectItem();
                     removeIteratorFromRequestParam();
                     items.add(selectItem);
                 }
             }
         }
         
         return (SelectItem[]) items.toArray(new SelectItem[0]);
     }
 
     private SelectItem createSelectItem() {
         SelectItem item = null;
         Object value = getItemValue();
         String label = getItemLabel() != null ? getItemLabel().toString() : null;
         String description = getItemDescription() != null ? getItemDescription().toString() : null;
         Boolean disabled = (Boolean) (getItemDisabled() != null ? getItemDisabled() : Boolean.FALSE);
         Boolean escaped = (Boolean) (getItemLabelEscaped() != null ? getItemLabelEscaped() : Boolean.TRUE);
         
         if(label != null)
             item = new SelectItem(value, label, description, disabled, escaped);
         else
             item = new SelectItem(value, value == null ? null : value.toString(), description, disabled, escaped);
         
         return item;
     }
     
     private void putIteratorToRequestParam(Object object) {
         FacesContext.getCurrentInstance().getExternalContext().getRequestMap().put(getVar(), object);
     }
     
     private void removeIteratorFromRequestParam() {
         FacesContext.getCurrentInstance().getExternalContext().getRequestMap().remove(getVar());
     }
     
 }