/*
    *  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.trinidad.resource;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  
  import java.net.URLConnection;
  import java.net.URLStreamHandler;
  import java.util.List;
  import java.util.Map;
  import java.io.OutputStream;
  import java.security.Permission;
  
  import org.apache.myfaces.trinidad.util.URLUtils;
  
  /**
   * A resource loader implementation that proxies another
   * resource loader, controlling the URLConnection.
   *
   */
  public class ProxyResourceLoader extends ResourceLoader
  {
    /**
     * Constructs a new ProxyResourceLoader with specified parent.
     * 
     * @param parent  the parent resource loader
     */
    public ProxyResourceLoader(
      ResourceLoader parent)
    {
      super(parent);
    }
    
    @Override
    public URL getResource(
      String path) throws IOException
    {
      URL url = super.getResource(path);
      return (url != null) 
                ? new URL("proxy", null, -1, url.toExternalForm(),  
                          new ProxyURLStreamHandler(url))
                : null;
    }
  
    /**
     * Helper class used to manage decorated URL input stream.
     */
    private class ProxyURLStreamHandler extends URLStreamHandler
    {
      public ProxyURLStreamHandler(
        URL proxied)
      {
        _proxied = proxied;
      }
      
      @Override
      protected URLConnection openConnection(
        URL url
        ) throws IOException
      {
        return new ProxyURLConnection(url, _proxied);
      }
      
      private final URL _proxied;
    }
  
    /**
     * Helper class used to manage aggregated URL input stream.
     */
    protected class ProxyURLConnection extends URLConnection
    {
      public ProxyURLConnection(
        URL url,
        URL proxied
        ) throws IOException
      {
        super(url);
        
        _delegate = proxied.openConnection();
      }
  
     @Override
     public void addRequestProperty(String key, String value)
     {
       getURLConnection().addRequestProperty(key, value);
     }
 
     @Override
     public void connect() throws IOException
     {
       getURLConnection().connect();
     }
 
     @Override
     public boolean getAllowUserInteraction()
     {
       return getURLConnection().getAllowUserInteraction();
     }
 
     @Override
     public Object getContent() throws IOException
     {
       return getURLConnection().getContent();
     }
 
     @Override
     public Object getContent(Class[] classes) throws IOException
     {
       return getURLConnection().getContent(classes);
     }
 
     @Override
     public String getContentEncoding()
     {
       return getURLConnection().getContentEncoding();
     }
 
     @Override
     public int getContentLength()
     {
       return getURLConnection().getContentLength();
     }
 
     @Override
     public String getContentType()
     {
       return ProxyResourceLoader.this.getContentType(getURLConnection());
     }
 
     @Override
     public long getDate()
     {
       return getURLConnection().getDate();
     }
 
     @Override
     public boolean getDefaultUseCaches()
     {
       return getURLConnection().getDefaultUseCaches();
     }
 
     @Override
     public boolean getDoInput()
     {
       return getURLConnection().getDoInput();
     }
 
     @Override
     public boolean getDoOutput()
     {
       return getURLConnection().getDoOutput();
     }
 
     @Override
     public long getExpiration()
     {
       return getURLConnection().getExpiration();
     }
 
     @Override
     public String getHeaderField(int n)
     {
       return getURLConnection().getHeaderField(n);
     }
 
     @Override
     public String getHeaderField(String name)
     {
       return getURLConnection().getHeaderField(name);
     }
 
     @Override
     public long getHeaderFieldDate(String name, long Default)
     {
       return getURLConnection().getHeaderFieldDate(name, Default);
     }
 
     @Override
     public int getHeaderFieldInt(String name, int Default)
     {
       return getURLConnection().getHeaderFieldInt(name, Default);
     }
 
     @Override
     public String getHeaderFieldKey(int n)
     {
       return getURLConnection().getHeaderFieldKey(n);
     }
 
     @Override
     public Map<String, List<String>> getHeaderFields()
     {
       return getURLConnection().getHeaderFields();
     }
 
     @Override
     public long getIfModifiedSince()
     {
       return getURLConnection().getIfModifiedSince();
     }
 
     @Override
     public InputStream getInputStream() throws IOException
     {
       return getURLConnection().getInputStream();
     }
 
     @Override
     public long getLastModified()
     {
       try
       {
         return URLUtils.getLastModified(getURLConnection());
       }
       catch (IOException exception)
       {
         return -1;
       }
     }
 
     @Override
     public OutputStream getOutputStream() throws IOException
     {
       return getURLConnection().getOutputStream();
     }
 
     @Override
     public Permission getPermission() throws IOException
     {
       return getURLConnection().getPermission();
     }
 
     @Override
     public Map<String, List<String>> getRequestProperties()
     {
       return getURLConnection().getRequestProperties();
     }
 
     @Override
     public String getRequestProperty(String key)
     {
       return getURLConnection().getRequestProperty(key);
     }
 
     @Override
     public boolean getUseCaches()
     {
       return getURLConnection().getUseCaches();
     }
 
     @Override
     public void setAllowUserInteraction(boolean allowuserinteraction)
     {
       getURLConnection().setAllowUserInteraction(allowuserinteraction);
     }
 
     @Override
     public void setDefaultUseCaches(boolean defaultusecaches)
     {
       getURLConnection().setDefaultUseCaches(defaultusecaches);
     }
 
     @Override
     public void setDoInput(boolean doinput)
     {
       getURLConnection().setDoInput(doinput);
     }
 
     @Override
     public void setDoOutput(boolean dooutput)
     {
       getURLConnection().setDoOutput(dooutput);
     }
 
     @Override
     public void setIfModifiedSince(long ifmodifiedsince)
     {
       getURLConnection().setIfModifiedSince(ifmodifiedsince);
     }
 
     @Override
     public void setRequestProperty(String key, String value)
     {
       getURLConnection().setRequestProperty(key, value);
     }
 
     @Override
     public void setUseCaches(boolean usecaches)
     {
       getURLConnection().setUseCaches(usecaches);
     }
     
     protected URLConnection getURLConnection()
     {
       return _delegate;
     }
     
     private final URLConnection _delegate;
   }
 }