/*
    * 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.compiler;
  
  import java.io.IOException;
  import java.lang.reflect.Method;
  import java.util.Map;
  import javax.el.ELContext;
  
  import javax.el.ELException;
  import javax.el.FunctionMapper;
  import javax.faces.FacesException;
  import javax.faces.component.UIComponent;
  import javax.faces.view.facelets.ComponentHandler;
  import javax.faces.view.facelets.FaceletContext;
  import javax.faces.view.facelets.FaceletException;
  import javax.faces.view.facelets.FaceletHandler;
  import org.apache.myfaces.el.unified.FacesELContext;
  
  import org.apache.myfaces.view.facelets.el.CompositeFunctionMapper;
  import org.apache.myfaces.view.facelets.tag.TagLibrary;
  import org.apache.myfaces.view.facelets.tag.composite.CompositeComponentResourceTagHandler;
  
  final class NamespaceHandler extends FunctionMapper implements FaceletHandler
  {
  
      private final TagLibrary library;
      private final Map<String, String> ns;
      private FaceletHandler next;
  
      public NamespaceHandler(FaceletHandler next, TagLibrary library, Map<String, String> ns)
      {
          this.library = library;
          this.ns = ns;
          this.next = next;
      }
  
      public void apply(FaceletContext ctx, UIComponent parent) throws IOException, FacesException, FaceletException,
              ELException
      {
          FunctionMapper orig = ctx.getFunctionMapper();
          ELContext elContext = ctx.getFacesContext().getELContext();
          if (elContext instanceof FacesELContext)
          {
              ((FacesELContext) elContext).setFunctionMapper(this);
          }
          ctx.setFunctionMapper(new CompositeFunctionMapper(this, orig));
          try
          {
              next.apply(ctx, parent);
          }
          finally
          {
              ctx.setFunctionMapper(orig);
          }
      }
  
      public Method resolveFunction(String prefix, String localName)
      {
          String uri = (String) this.ns.get(prefix);
          if (uri != null)
          {
              return this.library.createFunction(uri, localName);
          }
          return null;
      }
  
      public boolean isNextHandlerComponent()
      {
          return (next instanceof ComponentHandler);
      }
      
      public boolean isNextHandlerCompositeComponent()
      {
          return (next instanceof CompositeComponentResourceTagHandler);
      }
  }