package eu.dnetlib.data.collective.harvest.provider;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.StringWriter;
import java.util.concurrent.BlockingQueue;

import org.apache.commons.compress.tar.TarEntry;
import org.apache.commons.compress.tar.TarInputStream;
import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import eu.dnetlib.data.collective.harvest.provider.DataProvider.FileType;

/**
 * 
 * TODO: Why is this code type parametric but actually only reads strings from files?
 * 
 * @author marko
 * 
 * @param <T>
 */
public class ArchiveWalker<T> {

	private static final Log log = LogFactory.getLog(ArchiveWalker.class); // NOPMD by marko on 11/24/08 5:02 PM

	private BlockingQueue<T> queue;
	private FileType type;
	private File source;

	public ArchiveWalker(BlockingQueue<T> queue, FileType type, File source) {
		super();
		this.queue = queue;
		this.type = type;
		this.source = source;
	}

	@SuppressWarnings("unchecked")
	public void doWalk() throws IOException {
		TarInputStream tis = new TarInputStream(new FileInputStream(source));

		TarEntry entry;

		while ((entry = tis.getNextEntry()) != null) {
			if (entry.isDirectory())
				continue;

			StringWriter buf = new StringWriter();
			IOUtils.copy(tis, buf);
			enqueue(queue, (T) buf.toString());
		}

		finish();
	}

	/**
	 * Adds the element to the queue
	 */
	private void enqueue(BlockingQueue<T> queue, T element) {
		try {
			queue.put(element);
		} catch (InterruptedException e) {
			log.warn("ops... ", e); // TODO: I hate this things, copied from claudio's code.
		}
	}

	@SuppressWarnings("unchecked")
	protected void finish() {
		enqueue(queue, (T) FileWalker.done);
	}

	public BlockingQueue<T> getQueue() {
		return queue;
	}

	public void setQueue(BlockingQueue<T> queue) {
		this.queue = queue;
	}

	public FileType getType() {
		return type;
	}

	public void setType(FileType type) {
		this.type = type;
	}

	public File getSource() {
		return source;
	}

	public void setSource(File source) {
		this.source = source;
	}

}