/*
    * Copyright (C) 2015, Matthias Sohn <matthias.sohn@sap.com>
    * and other copyright owners as documented in the project's IP log.
    *
    * This program and the accompanying materials are made available
    * under the terms of the Eclipse Distribution License v1.0 which
    * accompanies this distribution, is reproduced below, and is
    * available at http://www.eclipse.org/org/documents/edl-v10.php
    *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or
   * without modification, are permitted provided that the following
   * conditions are met:
   *
   * - Redistributions of source code must retain the above copyright
   *   notice, this list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above
   *   copyright notice, this list of conditions and the following
   *   disclaimer in the documentation and/or other materials provided
   *   with the distribution.
   *
   * - Neither the name of the Eclipse Foundation, Inc. nor the
   *   names of its contributors may be used to endorse or promote
   *   products derived from this software without specific prior
   *   written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package org.eclipse.jgit.lfs.server.fs;
  
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.nio.channels.Channels;
  import java.nio.channels.ReadableByteChannel;
  import java.nio.channels.WritableByteChannel;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import javax.servlet.AsyncContext;
  import javax.servlet.ReadListener;
  import javax.servlet.ServletInputStream;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.http.HttpStatus;
  import org.eclipse.jgit.lfs.errors.CorruptLongObjectException;
  import org.eclipse.jgit.lfs.internal.AtomicObjectOutputStream;
  import org.eclipse.jgit.lfs.lib.AnyLongObjectId;
  import org.eclipse.jgit.lfs.lib.Constants;
  
  /**
   * Handle asynchronous object upload.
   *
   * @since 4.6
   */
  public class ObjectUploadListener implements ReadListener {
  
  	private static Logger LOG = Logger
  			.getLogger(ObjectUploadListener.class.getName());
  
  	private final AsyncContext context;
  
  	private final HttpServletResponse response;
  
  	private final ServletInputStream in;
  
  	private final ReadableByteChannel inChannel;
  
  	private final AtomicObjectOutputStream out;
  
  	private WritableByteChannel channel;
  
  	private final ByteBuffer buffer = ByteBuffer.allocateDirect(8192);
  
  	/**
  	 * @param repository
  	 *            the repository storing large objects
  	 * @param context
  	 * @param request
  	 * @param response
  	 * @param id
  	 * @throws FileNotFoundException
  	 * @throws IOException
  	 */
 	public ObjectUploadListener(FileLfsRepository repository,
 			AsyncContext context, HttpServletRequest request,
 			HttpServletResponse response, AnyLongObjectId id)
 					throws FileNotFoundException, IOException {
 		this.context = context;
 		this.response = response;
 		this.in = request.getInputStream();
 		this.inChannel = Channels.newChannel(in);
 		this.out = repository.getOutputStream(id);
 		this.channel = Channels.newChannel(out);
 		response.setContentType(Constants.CONTENT_TYPE_GIT_LFS_JSON);
 	}
 
 	/**
 	 * Writes all the received data to the output channel
 	 *
 	 * @throws IOException
 	 */
 	@Override
 	public void onDataAvailable() throws IOException {
 		while (in.isReady()) {
 			if (inChannel.read(buffer) > 0) {
 				buffer.flip();
 				channel.write(buffer);
 				buffer.compact();
 			} else {
 				buffer.flip();
 				while (buffer.hasRemaining()) {
 					channel.write(buffer);
 				}
 				close();
 				return;
 			}
 		}
 	}
 
 	/**
 	 * @throws IOException
 	 */
 	@Override
 	public void onAllDataRead() throws IOException {
 		close();
 	}
 
 	/**
 	 * @throws IOException
 	 */
 	protected void close() throws IOException {
 		try {
 			inChannel.close();
 			channel.close();
 			// TODO check if status 200 is ok for PUT request, HTTP foresees 204
 			// for successful PUT without response body
 			response.setStatus(HttpServletResponse.SC_OK);
 		} finally {
 			context.complete();
 		}
 	}
 
 	/**
 	 * @param e
 	 *            the exception that caused the problem
 	 */
 	@Override
 	public void onError(Throwable e) {
 		try {
 			out.abort();
 			inChannel.close();
 			channel.close();
 			int status;
 			if (e instanceof CorruptLongObjectException) {
 				status = HttpStatus.SC_BAD_REQUEST;
 				LOG.log(Level.WARNING, e.getMessage(), e);
 			} else {
 				status = HttpStatus.SC_INTERNAL_SERVER_ERROR;
 				LOG.log(Level.SEVERE, e.getMessage(), e);
 			}
 			FileLfsServlet.sendError(response, status, e.getMessage());
 		} catch (IOException ex) {
 			LOG.log(Level.SEVERE, ex.getMessage(), ex);
 		}
 	}
 }