/*
    * 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.ByteArrayInputStream;
  import java.io.InputStream;
  import java.net.URL;
  import java.io.IOException;
  import java.net.URLConnection;
  import java.net.URLStreamHandler;
  
  public abstract class StringContentResourceLoader extends DynamicResourceLoader 
  {
    public StringContentResourceLoader(String path)
    {
      super(path);
    }
    
    public StringContentResourceLoader(String path, ResourceLoader parent)
    {
      super(path, parent);
    }
    
    protected String getContentType(String path)
    {
      return "text";
    }
    
    protected abstract String getString(String path) throws IOException;
  
    @Override
    protected URL getURL(String path) throws IOException
    {
      return new URL("dynamic", null, -1, path, new StringContentURLStreamHandler(getString(path), getContentType(path)));
    }
    
    /**
     * This is a stream handler that can be used to construct a URL whose connection will return content
     * specified in a String.
     * 
     */
    static private class StringContentURLStreamHandler extends URLStreamHandler
    { 
      /**
       * Created a StringContentURLStreamHandler which will provide the specified content on the
       * connection.
       * 
       * @param content the content of the connection
       * @param contentType the content type of this connection (i.e. "text/javascript")
       */
      public StringContentURLStreamHandler(String content, String contentType)
      {
        _buff = content.getBytes();
        _contentType = contentType;
      }
    
      /**
       * Returns a URLConnection containing the specified content.
       * 
       * @param u the URL for this connection
       * @return a connection containing the string of data
       * @throws IOException when something bad happens
       */
      @Override
      protected URLConnection openConnection(URL u) throws IOException
      {
        return new StringContentURLConnection(u, _buff, _contentType); 
      }
    
      private byte[] _buff;
      private String _contentType;
    }
    
    static private class StringContentURLConnection extends URLConnection 
    {
      public StringContentURLConnection(URL url, byte[] buff, String contentType)
      {
        super(url);
        connected = false;
        _buff = buff;
        _contentType = contentType;
      }
    
     @Override
     public void connect() throws IOException
     {
       connected = true;
     }
   
     @Override
     public String getContentEncoding()
     {
       //No content Encoding in Strings (like gzip or deflate)
       return null;
     }
   
     @Override
     public int getContentLength()
     {
       return _buff.length;
     }
   
     @Override
     public String getContentType()
     {
       return _contentType;
     }
   
     @Override
     public String getHeaderField(String name)
     {
       if("content-encoding".equals(name))
       {
         return getContentEncoding();
       }
       else if ("content-length".equals(name))
       {
         return String.valueOf(getContentLength());
       }
       else if ("content-type".equals(name))
       {
         return getContentType();
       }
       
       return null;
     }
   
     @Override
     public InputStream getInputStream() throws IOException
     {
       return new ByteArrayInputStream(_buff);
     }
     
     private byte[] _buff;
     private String _contentType;
   }
 }