/*
    * 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.config.impl;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.JarURLConnection;
  import java.net.URL;
  import java.util.jar.JarEntry;
  import java.util.logging.Logger;
  
  import javax.faces.context.ExternalContext;
  
  import org.apache.myfaces.shared.util.ClassUtils;
  import org.xml.sax.EntityResolver;
  import org.xml.sax.InputSource;
  
  /**
   * SAX EntityResolver to provide JSF-specific resources (DTDs) for well-known identifiers.
   *
   * @author Manfred Geiler (latest modification by $Author$)
   * @author Thomas Spiegl
   * @version $Revision$ $Date$
   */
  public class FacesConfigEntityResolver implements EntityResolver
  {
      private static final Logger log = Logger.getLogger(FacesConfigEntityResolver.class.getName());
  
      private static final String FACES_CONFIG_1_0_DTD_SYSTEM_ID = "http://java.sun.com/dtd/web-facesconfig_1_0.dtd";
      private static final String FACES_CONFIG_1_0_DTD_RESOURCE
              = "org.apache.myfaces.resource".replace('.', '/') + "/web-facesconfig_1_0.dtd";
      private static final String FACES_CONFIG_1_1_DTD_SYSTEM_ID = "http://java.sun.com/dtd/web-facesconfig_1_1.dtd";
      private static final String FACES_CONFIG_1_1_DTD_RESOURCE
              = "org.apache.myfaces.resource".replace('.', '/') + "/web-facesconfig_1_1.dtd";
  
      private ExternalContext _externalContext = null;
  
      public FacesConfigEntityResolver(ExternalContext context)
      {
          _externalContext = context;
      }
  
      public FacesConfigEntityResolver()
      {
      }
  
      public InputSource resolveEntity(String publicId,
                                       String systemId)
          throws IOException
      {
          InputStream stream;
          if (systemId.equals(FACES_CONFIG_1_0_DTD_SYSTEM_ID))
          {
              stream = ClassUtils.getResourceAsStream(FACES_CONFIG_1_0_DTD_RESOURCE);
          }
          else if (systemId.equals(FACES_CONFIG_1_1_DTD_SYSTEM_ID))
          {
              stream = ClassUtils.getResourceAsStream(FACES_CONFIG_1_1_DTD_RESOURCE);
          }
  
          else if (systemId.startsWith("jar:"))
          {
              URL url = new URL(systemId);
              JarURLConnection conn = (JarURLConnection) url.openConnection();
              
              // see MYFACES-1982
              conn.setUseCaches(false);
              JarEntry jarEntry = conn.getJarEntry();
              if (jarEntry == null)
              {
                  log.severe("JAR entry '" + systemId + "' not found.");
              }
              //_jarFile.getInputStream(jarEntry);
              stream = conn.getJarFile().getInputStream(jarEntry);
          }
          else
          {
              if (_externalContext == null)
              {
                  stream = ClassUtils.getResourceAsStream(systemId);
              }
              else
              {
                 if (systemId.startsWith("file:"))
                 {
                     systemId = systemId.substring(7); // remove file://
                 }
                 stream = _externalContext.getResourceAsStream(systemId);
             }
         }
 
         if (stream == null)
         {
             return null;
         }
         InputSource is = new InputSource(stream);
         is.setPublicId(publicId);
         is.setSystemId(systemId);
         is.setEncoding("ISO-8859-1");
         return is;
     }
 
 }