/*
    * 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;
  
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.net.URL;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  import javax.el.ELException;
  import javax.el.ValueExpression;
  import javax.el.VariableMapper;
  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.TagException;
  import javax.faces.view.facelets.TagHandler;
  
  import org.apache.myfaces.view.facelets.AbstractFaceletContext;
  import org.apache.myfaces.view.facelets.TemplateClient;
  import org.apache.myfaces.view.facelets.TemplateContext;
  import org.apache.myfaces.view.facelets.el.VariableMapperWrapper;
  import org.apache.myfaces.view.facelets.impl.TemplateContextImpl;
  import org.apache.myfaces.view.facelets.tag.ui.DefineHandler;
  
  /**
   * A Tag that is specified in a FaceletFile. Takes all attributes specified and sets them on the FaceletContext before
   * including the targeted Facelet file.
   * 
   * @author Jacob Hookom
   * @version $Id: UserTagHandler.java 1306698 2012-03-29 03:13:06Z lu4242 $
   */
  final class UserTagHandler extends TagHandler implements TemplateClient, ComponentContainerHandler
  {
  
      protected final TagAttribute[] _vars;
  
      protected final URL _location;
  
      protected final Map<String, DefineHandler> _handlers;
  
      /**
       * @param config
       */
      public UserTagHandler(TagConfig config, URL location)
      {
          super(config);
          this._vars = this.tag.getAttributes().getAll();
          this._location = location;
          
          Collection<DefineHandler> defines = TagHandlerUtils.findNextByType(nextHandler, DefineHandler.class);
          if (defines.isEmpty())
          {
              _handlers = null;
          }
          else
          {
              _handlers = new HashMap<String, DefineHandler>();
              for (DefineHandler handler : defines)
              {
                  _handlers.put(handler.getName(), handler);
              }
          }
      }
  
      /**
       * Iterate over all TagAttributes and set them on the FaceletContext's VariableMapper, then include the target
       * Facelet. Finally, replace the old VariableMapper.
       * 
       * @see TagAttribute#getValueExpression(FaceletContext, Class)
       * @see VariableMapper
       * @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
      {
          //VariableMapper orig = ctx.getVariableMapper();
  
         // setup a variable map
         //if (this._vars.length > 0)
         //{
             //VariableMapper varMapper = new VariableMapperWrapper(orig);
             //for (int i = 0; i < this._vars.length; i++)
             //{
             //    varMapper.setVariable(this._vars[i].getLocalName(), this._vars[i].getValueExpression(ctx, Object.class));
             //}
             //ctx.setVariableMapper(varMapper);
         //}
 
         AbstractFaceletContext actx = (AbstractFaceletContext) ctx;
         // eval include
         try
         {
             String[] names = null;
             ValueExpression[] values = null;
             if (this._vars.length > 0)
             {
                 names = new String[_vars.length];
                 values = new ValueExpression[_vars.length];
                 for (int i = 0; i < _vars.length; i++)
                 {
                     names[i] = _vars[i].getLocalName();
                     values[i] = _vars[i].getValueExpression(ctx, Object.class);
                 }
             }
             actx.pushTemplateContext(new TemplateContextImpl());
             if (this._vars.length > 0)
             {
                 for (int i = 0; i < this._vars.length; i++)
                 {
                     ((AbstractFaceletContext) ctx).getTemplateContext().setParameter(names[i], values[i]);
                 }
             }
             //Disable caching always, even in 'always' mode
             actx.getTemplateContext().setAllowCacheELExpressions(false);
             actx.pushClient(this);
             ctx.includeFacelet(parent, this._location);
         }
         catch (FileNotFoundException e)
         {
             throw new TagException(this.tag, e.getMessage());
         }
         finally
         {
 
             // make sure we undo our changes
             actx.popClient(this);
             actx.popTemplateContext();
             //ctx.setVariableMapper(orig);
         }
     }
 
     public boolean apply(FaceletContext ctx, UIComponent parent, String name) throws IOException, FacesException,
             FaceletException, ELException
     {
         if (name != null)
         {
             if (this._handlers == null)
             {
                 return false;
             }
             DefineHandler handler = (DefineHandler) this._handlers.get(name);
             if (handler != null)
             {
                 AbstractFaceletContext actx = (AbstractFaceletContext) ctx;
                 TemplateContext itc = actx.popTemplateContext();
                 try
                 {
                     handler.applyDefinition(ctx, parent);
                 }
                 finally
                 {
                     actx.pushTemplateContext(itc);
                 }
                 return true;
             }
             else
             {
                 return false;
             }
         }
         else
         {
             AbstractFaceletContext actx = (AbstractFaceletContext) ctx;
             TemplateContext itc = actx.popTemplateContext();
             try
             {
                 this.nextHandler.apply(ctx, parent);
             }
             finally
             {
                 actx.pushTemplateContext(itc);
             }
             return true;
         }
     }
 
 }