/**
    * Copyright 2012 Hippo.
    * 
    * This file is part of HST PDF Renderer.
    * 
    * HST PDF Renderer is free software: you can redistribute it and/or modify it 
    * under the terms of the GNU General Public License as published by the Free 
    * Software Foundation, either version 3 of the License, or (at your option) 
    * any later version.
   * 
   * HST PDF Renderer is distributed in the hope that it will be useful, but 
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
   * or FITNESS FOR A PARTICULAR PURPOSE.
   * See the GNU General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public License along with
   * HST PDF Renderer. If not, see http://www.gnu.org/licenses/.
   */
  package org.onehippo.forge.hst.pdf.renderer.servlet;
  
  import java.io.ByteArrayOutputStream;
  import java.io.CharArrayWriter;
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.util.Locale;
  
  import javax.servlet.ServletOutputStream;
  import javax.servlet.http.HttpServletResponse;
  import javax.servlet.http.HttpServletResponseWrapper;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang.ArrayUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * ContentCapturingHttpServletResponse
   */
  public class ContentCapturingHttpServletResponse extends HttpServletResponseWrapper {
  
      private static Logger log = LoggerFactory.getLogger(ContentCapturingHttpServletResponse.class);
  
      private static class CharArrayWriterBuffer extends CharArrayWriter {
          @Override
          public void close() {
          }
  
          public void closeWriter() {
              super.close();
          }
      }
  
      private static class ByteArrayOutputStreamBuffer extends ByteArrayOutputStream {
          @Override
          public void close() {
          }
  
          public void closeOutputStream() {
              try {
                  super.close();
              } catch (IOException e) {
                  log.error("Failed to close byte array output stream", e);
              }
          }
      }
  
      private CharArrayWriterBuffer charOutputBuffer;
      private PrintWriter printWriter;
  
      private ByteArrayOutputStreamBuffer byteOutputBuffer;
      private ServletOutputStream servletOutputStream;
  
      private String characterEncoding;
      private String contentType;
      private int bufferSize;
      private int contentLength;
      private boolean committed;
      private Locale locale;
  
      public ContentCapturingHttpServletResponse(HttpServletResponse response) {
          super(response);
      }
  
      /*
       * (non-Javadoc)
       * 
       * @see javax.servlet.ServletResponseWrapper#getWriter()
       */
      public PrintWriter getWriter() throws IOException {
          if (printWriter == null) {
              if (servletOutputStream != null) {
                  throw new IllegalStateException("getOutputStream() has already been called on this response");
              }
  
              charOutputBuffer = new CharArrayWriterBuffer();
              printWriter = new PrintWriter(charOutputBuffer);
          }
  
          return printWriter;
     }
 
     /*
      * (non-Javadoc)
      * 
      * @see javax.servlet.ServletResponseWrapper#getOutputStream()
      */
     public ServletOutputStream getOutputStream() throws IOException {
         if (servletOutputStream == null) {
             if (printWriter != null) {
                 throw new IllegalStateException("getWriter() has already been called on this response");
             }
 
             byteOutputBuffer = new ByteArrayOutputStreamBuffer();
             servletOutputStream = new ServletOutputStream() {
                 @Override
                 public void write(int b) throws IOException {
                     byteOutputBuffer.write(b);
                 }
             };
         }
 
         return servletOutputStream;
     }
 
     public boolean isWrittenToPrintWriter() {
         return (printWriter != null);
     }
 
     public char [] toCharArray() {
         if (charOutputBuffer != null) {
             return charOutputBuffer.toCharArray();
         }
 
         return ArrayUtils.EMPTY_CHAR_ARRAY;
     }
 
     public byte [] toByteArray() {
         if (byteOutputBuffer != null) {
             return byteOutputBuffer.toByteArray();
         }
 
         return ArrayUtils.EMPTY_BYTE_ARRAY;
     }
 
     public void close() {
         IOUtils.closeQuietly(servletOutputStream);
 
         if (byteOutputBuffer != null) {
             byteOutputBuffer.closeOutputStream();
         }
 
         IOUtils.closeQuietly(printWriter);
 
         if (charOutputBuffer != null) {
             charOutputBuffer.closeWriter();
         }
     }
 
     @Override
     public void setCharacterEncoding(String characterEncoding) {
         this.characterEncoding = characterEncoding;
     }
 
     @Override
     public String getCharacterEncoding() {
         return characterEncoding;
     }
 
     @Override
     public void setContentLength(int contentLength) {
         this.contentLength = contentLength;
     }
 
     public int getContentLength() {
         return contentLength;
     }
 
     @Override
     public void setContentType(String contentType) {
         this.contentType = contentType;
     }
 
     @Override
     public String getContentType() {
         return contentType;
     }
 
     @Override
     public void setBufferSize(int bufferSize) {
         this.bufferSize = bufferSize;
     }
 
     @Override
     public int getBufferSize() {
         return bufferSize;
     }
 
     @Override
     public void flushBuffer() throws IOException {
         // TODO
     }
 
     @Override
     public void resetBuffer() {
         // TODO
     }
 
     @Override
     public boolean isCommitted() {
         if (getResponse().isCommitted()) {
             return true;
         }
 
         return committed;
     }
 
     @Override
     public void reset() {
         // TODO
     }
 
     @Override
     public void setLocale(Locale locale) {
         this.locale = locale;
     }
 
     @Override
     public Locale getLocale() {
         return locale;
     }
 }