//
   //  ========================================================================
   //  Copyright (c) 1995-2015 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.http;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.ByteBuffer;
  import java.nio.channels.ReadableByteChannel;
  
  import org.eclipse.jetty.http.MimeTypes.Type;
  import org.eclipse.jetty.util.BufferUtil;
  import org.eclipse.jetty.util.resource.Resource;
  
  
  /* ------------------------------------------------------------ */
  /** HttpContent created from a {@link Resource}.
   * <p>The HttpContent is used to server static content that is not
   * cached. So fields and values are only generated as need be an not 
   * kept for reuse</p>
   */
  public class ResourceHttpContent implements HttpContent
  {
      final Resource _resource;
      final String _contentType;
      final int _maxBuffer;
      HttpContent _gzip;
      String _etag;
  
      /* ------------------------------------------------------------ */
      public ResourceHttpContent(final Resource resource, final String contentType)
      {
          this(resource,contentType,-1,null);
      }
  
      /* ------------------------------------------------------------ */
      public ResourceHttpContent(final Resource resource, final String contentType, int maxBuffer)
      {
          this(resource,contentType,maxBuffer,null);
      }
      
      /* ------------------------------------------------------------ */
      public ResourceHttpContent(final Resource resource, final String contentType, int maxBuffer, HttpContent gzip)
      {
          _resource=resource;
          _contentType=contentType;
          _maxBuffer=maxBuffer;
          _gzip=gzip;
      }
  
      /* ------------------------------------------------------------ */
      @Override
      public String getContentTypeValue()
      {
          return _contentType;
      }
      
      /* ------------------------------------------------------------ */
      @Override
      public HttpField getContentType()
      {
          return _contentType==null?null:new HttpField(HttpHeader.CONTENT_TYPE,_contentType);
      }
  
      /* ------------------------------------------------------------ */
      @Override
      public HttpField getContentEncoding()
      {
          return null;
      }
  
      /* ------------------------------------------------------------ */
      @Override
      public String getContentEncodingValue()
      {
          return null;
      }
  
      /* ------------------------------------------------------------ */
      @Override
      public String getCharacterEncoding()
      {
          return _contentType==null?null:MimeTypes.getCharsetFromContentType(_contentType);
      }
 
     /* ------------------------------------------------------------ */
     @Override
     public Type getMimeType()
     {
         return _contentType==null?null:MimeTypes.CACHE.get(MimeTypes.getContentTypeWithoutCharset(_contentType));
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public HttpField getLastModified()
     {
         long lm = _resource.lastModified();
         return lm>=0?new HttpField(HttpHeader.LAST_MODIFIED,DateGenerator.formatDate(lm)):null;
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public String getLastModifiedValue()
     {
         long lm = _resource.lastModified();
         return lm>=0?DateGenerator.formatDate(lm):null;
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public ByteBuffer getDirectBuffer()
     {
         if (_resource.length()<=0 || _maxBuffer<_resource.length())
             return null;
         try
         {
             return BufferUtil.toBuffer(_resource,true);
         }
         catch(IOException e)
         {
             throw new RuntimeException(e);
         }
     }
     
     /* ------------------------------------------------------------ */
     @Override
     public HttpField getETag()
     {
         return new HttpField(HttpHeader.ETAG,getETagValue());
     }
     
     /* ------------------------------------------------------------ */
     @Override
     public String getETagValue()
     {
         return _resource.getWeakETag();
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public ByteBuffer getIndirectBuffer()
     {
         if (_resource.length()<=0 || _maxBuffer<_resource.length())
             return null;
         try
         {
             return BufferUtil.toBuffer(_resource,false);
         }
         catch(IOException e)
         {
             throw new RuntimeException(e);
         }
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public HttpField getContentLength()
     {
         long l=_resource.length();
         return l==-1?null:new HttpField.LongValueHttpField(HttpHeader.CONTENT_LENGTH,_resource.length());
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public long getContentLengthValue()
     {
         return _resource.length();
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public InputStream getInputStream() throws IOException
     {
         return _resource.getInputStream();
     }
     
     /* ------------------------------------------------------------ */
     @Override
     public ReadableByteChannel getReadableByteChannel() throws IOException
     {
         return _resource.getReadableByteChannel();
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public Resource getResource()
     {
         return _resource;
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public void release()
     {
         _resource.close();
     }
     
     /* ------------------------------------------------------------ */
     @Override
     public String toString()
     {
         return String.format("%s@%x{r=%s,gz=%b}",this.getClass().getSimpleName(),hashCode(),_resource,_gzip!=null);
     }
 
     /* ------------------------------------------------------------ */
     @Override
     public HttpContent getGzipContent()
     {
         return _gzip==null?null:new GzipHttpContent(this,_gzip);
     }
 
 }