/**
    * Copyright (c) 2011, The University of Southampton and the individual contributors.
    * 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 University of Southampton 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.openimaj.tools.imagecollection.processor;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.net.URI;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.LocalFileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.io.BytesWritable;
  import org.apache.hadoop.io.Text;
  import org.openimaj.hadoop.sequencefile.SequenceFileUtility;
  import org.openimaj.hadoop.sequencefile.TextBytesSequenceFileUtility;
  import org.openimaj.image.Image;
  import org.openimaj.image.ImageUtilities;
  import org.openimaj.tools.imagecollection.collection.ImageCollectionEntry;
  
  public class SequenceFileProcessor<T extends Image<?, T>> extends ImageCollectionProcessor<T> {
  	
  	String sequenceFile = "output.seq";
  	boolean force = true;
  	private TextBytesSequenceFileUtility utility;
  	private int seen = 0;
  
  	public SequenceFileProcessor(String output, boolean force) {
  		this.sequenceFile = output;
  		this.force = force;
  	}
  
  	public static FileSystem getFileSystem(URI uri) throws IOException {
  		Configuration config = new Configuration();
  		FileSystem fs = FileSystem.get(uri, config);
  		if (fs instanceof LocalFileSystem) fs = ((LocalFileSystem)fs).getRaw();
  		return fs;
  	}
  	
  	@Override
  	public void start() throws IOException{
  		if(force)
  		{
  			URI outuri = SequenceFileUtility.convertToURI(sequenceFile);
  			FileSystem fs = getFileSystem(outuri);
  			fs.delete(new Path(outuri.toString()), true);
  		}
  		
  		utility = new TextBytesSequenceFileUtility(sequenceFile, false);
  	}
  
  	@Override
  	public String process(ImageCollectionEntry<T> image) throws Exception {
  		ByteArrayOutputStream bos = new ByteArrayOutputStream();
  		ImageUtilities.write(image.image, "png", bos);
  		BytesWritable bw = new BytesWritable(bos.toByteArray());
  		String imageName = "" + this.seen ;
  		utility.appendData(new Text(imageName), bw);
  		this.seen ++;
  		return imageName;
  	}
  	
  	@Override
  	public void end() throws IOException{
  		utility.close();
  	}
  
  }