/*
    * 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.ui;
  
  import java.io.IOException;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import javax.el.ELException;
  import javax.faces.FacesException;
  import javax.faces.component.UIComponent;
  import javax.faces.view.facelets.FaceletContext;
  import javax.faces.view.facelets.FaceletException;
  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.AbstractFaceletContext;
  import org.apache.myfaces.view.facelets.FaceletCompositionContext;
  import org.apache.myfaces.view.facelets.TemplateClient;
  import org.apache.myfaces.view.facelets.tag.TagHandlerUtils;
  
  /**
   * TODO: REFACTOR - This class could easily use a common parent with DecoratorHandler
   * 
   * @author Jacob Hookom
   * @version $Id$
   */
  @JSFFaceletTag(name="ui:composition")
  public final class CompositionHandler extends TagHandler implements TemplateClient
  {
  
      //private static final Logger log = Logger.getLogger("facelets.tag.ui.composition");
      private static final Logger log = Logger.getLogger(CompositionHandler.class.getName());
  
      public final static String NAME = "composition";
  
      /**
       * The resolvable URI of the template to use. The content within the composition tag will 
       * be used in populating the template specified.
       */
      @JSFFaceletAttribute(
              name="template",
              className="javax.el.ValueExpression",
              deferredValueType="java.lang.String")
      protected final TagAttribute _template;
  
      protected final Map<String, DefineHandler> _handlers;
  
      protected final ParamHandler[] _params;
  
      /**
       * @param config
       */
      public CompositionHandler(TagConfig config)
      {
          super(config);
          _template = getAttribute("template");
          if (_template != null)
          {
              _handlers = new HashMap<String, DefineHandler>();
              for (DefineHandler handler : TagHandlerUtils.findNextByType(nextHandler, DefineHandler.class))
              {
                  _handlers.put(handler.getName(), handler);
                  if (log.isLoggable(Level.FINE))
                  {
                      log.fine(tag + " found Define[" + handler.getName() + "]");
                  }
              }
  
              Collection<ParamHandler> params = TagHandlerUtils.findNextByType(nextHandler, ParamHandler.class);
              if (!params.isEmpty())
              {
                  int i = 0;
                  _params = new ParamHandler[params.size()];
                  for (ParamHandler handler : params)
                  {
                      _params[i++] = handler;
                 }
             }
             else
             {
                 _params = null;
             }
         }
         else
         {
             _params = null;
             _handlers = null;
         }
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see javax.faces.view.facelets.FaceletHandler#apply(javax.faces.view.facelets.FaceletContext,
      * javax.faces.component.UIComponent)
      */
     public void apply(FaceletContext ctx, UIComponent parent) throws IOException, FacesException, FaceletException,
             ELException
     {
         if (_template != null)
         {
             //VariableMapper orig = ctx.getVariableMapper();
             //if (_params != null)
             //{
             //    VariableMapper vm = new VariableMapperWrapper(orig);
             //    ctx.setVariableMapper(vm);
             //    for (int i = 0; i < _params.length; i++)
             //    {
             //        _params[i].apply(ctx, parent);
             //    }
             //}
             AbstractFaceletContext actx = (AbstractFaceletContext) ctx;
             FaceletCompositionContext fcc = FaceletCompositionContext.getCurrentInstance(ctx);
             actx.extendClient(this);
             if (_params != null)
             {
                 String uniqueId = fcc.generateUniqueComponentId();
                 //VariableMapper vm = new VariableMapperWrapper(orig);
                 //ctx.setVariableMapper(vm);
                 for (int i = 0; i < _params.length; i++)
                 {
                     _params[i].apply(ctx, parent, _params[i].getName(ctx), _params[i].getValue(ctx), uniqueId);
                 }
             }
 
             try
             {
                 ctx.includeFacelet(parent, _template.getValue(ctx));
             }
             finally
             {
                 actx.popExtendedClient(this);
                 //ctx.setVariableMapper(orig);
             }
         }
         else
         {
             this.nextHandler.apply(ctx, parent);
         }
     }
 
     public boolean apply(FaceletContext ctx, UIComponent parent, String name) throws IOException, FacesException,
             FaceletException, ELException
     {
         if (name != null)
         {
             if (_handlers == null)
             {
                 return false;
             }
             
             DefineHandler handler = _handlers.get(name);
             if (handler != null)
             {
                 handler.applyDefinition(ctx, parent);
                 return true;
             }
             else
             {
                 return false;
             }
         }
         else
         {
             this.nextHandler.apply(ctx, parent);
             return true;
         }
     }
 
 }