/*
    * 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.view.facelets.tag.composite;
  
  import java.beans.BeanDescriptor;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import javax.faces.component.UIComponent;
  import javax.faces.view.AttachedObjectTarget;
  import javax.faces.view.facelets.FaceletContext;
  import javax.faces.view.facelets.TagAttribute;
  import javax.faces.view.facelets.TagConfig;
  import javax.faces.view.facelets.TagHandler;
  
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletAttribute;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletTag;
  import org.apache.myfaces.view.facelets.FaceletCompositionContext;
  
  /**
   * composite:actionSource, composite:valueHolder and composite:editableValueHolder
   * do the same: register an AttachedObjectTarget on the "targetList" mentioned on
   * ViewDeclarationLanguage.retargetAttachedObjects. AttachedObjectTargetHandler group the
   * common behavior
   * 
   * @author Leonardo Uribe (latest modification by $Author$)
   * @version $Revision$ $Date$
   */
  @JSFFaceletTag
  public abstract class AttachedObjectTargetHandler<T extends AttachedObjectTarget> 
      extends TagHandler implements InterfaceDescriptorCreator
  {
  
      private static final Logger log = Logger.getLogger(AttachedObjectTargetHandler.class.getName());
      
      /**
       * Indicate the name of the attribute that the component should expose
       * to page authors.
       * 
       */
      @JSFFaceletAttribute(name="name",
              className="javax.el.ValueExpression",
              deferredValueType="java.lang.String",
              required=true)
      protected final TagAttribute _name;
  
      /**
       * 
       */
      @JSFFaceletAttribute(name="targets",
              className="javax.el.ValueExpression",
              deferredValueType="java.lang.String")
      protected final TagAttribute _targets;
  
      /**
       * Check if the PropertyDescriptor instance created by this handler
       * can be cacheable or not. 
       */
      private boolean _cacheable;
      
      private AttachedObjectTarget _target;
  
      public AttachedObjectTargetHandler(TagConfig config)
      {
          super(config);
          _name = getRequiredAttribute("name");
          _targets = getAttribute("targets");
          if (_name.isLiteral())
          {
              _cacheable = true;
          }
          else
          {
              _cacheable = false;
          }
      }
  
      @SuppressWarnings("unchecked")
      public void apply(FaceletContext ctx, UIComponent parent)
              throws IOException
     {
         UIComponent compositeBaseParent
                 = FaceletCompositionContext.getCurrentInstance(ctx).getCompositeComponentFromStack();
 
         CompositeComponentBeanInfo beanInfo = 
             (CompositeComponentBeanInfo) compositeBaseParent.getAttributes()
             .get(UIComponent.BEANINFO_KEY);
         
         if (beanInfo == null)
         {
             if (log.isLoggable(Level.SEVERE))
             {
                 log.severe("Cannot find composite bean descriptor UIComponent.BEANINFO_KEY ");
             }
             return;
         }
         
         BeanDescriptor beanDescriptor = beanInfo.getBeanDescriptor(); 
         
         //1. Obtain the list mentioned as "targetList" on ViewDeclarationLanguage.retargetAttachedObjects
         List<AttachedObjectTarget> targetList = (List<AttachedObjectTarget>)
             beanDescriptor.getValue(
                     AttachedObjectTarget.ATTACHED_OBJECT_TARGETS_KEY);
         
         if (targetList == null)
         {
             //2. If not found create it and set
             targetList = new ArrayList<AttachedObjectTarget>();
             beanDescriptor.setValue(
                     AttachedObjectTarget.ATTACHED_OBJECT_TARGETS_KEY,
                     targetList);
         }
         
         //3. Create the instance of AttachedObjectTarget
         if (isCacheable())
         {
             if (_target == null)
             {
                 _target = createAttachedObjectTarget(ctx);
             }
             targetList.add(_target);
         }
         else
         {
             AttachedObjectTarget target = createAttachedObjectTarget(ctx);
             targetList.add(target);
         }
         
         this.nextHandler.apply(ctx, parent);
     }
     
     public boolean isCacheable()
     {
         return _cacheable;
     }
     
     public void setCacheable(boolean cacheable)
     {
         _cacheable = cacheable;
     }
     
     //@Override
     //public FaceletHandler getNextHandler()
     //{
     //    return nextHandler;
     //}
 
     /**
      * Create a new AttachedObjectTarget instance to be added on the 
      * target list.
      * 
      * @return
      */
     protected abstract T createAttachedObjectTarget(FaceletContext ctx);    
 }