/*
    GNU LESSER GENERAL PUBLIC LICENSE
    Copyright (C) 2006 The Lobo Project

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Contact info: lobochief@users.sourceforge.net
*/
/*
 * Created on Apr 15, 2005
 */
package org.lobobrowser.util;

import java.io.*;

/**
 * @author J. H. S.
 */
public class MonitoredInputStream extends InputStream {
	private final InputStream delegate;
	private int progress = 0;
	private final long minProgressEventGap;
	public final EventDispatch evtProgress = new EventDispatch();
	
	public MonitoredInputStream(InputStream delegate, int minProgressEventGap) {
		this.delegate = delegate;
		this.minProgressEventGap = minProgressEventGap;
	}

	public MonitoredInputStream(InputStream delegate) {
		this(delegate, 200);
	}

	/* (non-Javadoc)
	 * @see java.io.InputStream#available()
	 */
	public int available() throws IOException {
		return this.delegate.available();
	}

	/* (non-Javadoc)
	 * @see java.io.InputStream#close()
	 */
	public void close() throws IOException {
		this.delegate.close();
	}

	/* (non-Javadoc)
	 * @see java.io.InputStream#markSupported()
	 */
	public boolean markSupported() {
		return false;
	}
	
	/* (non-Javadoc)
	 * @see java.io.InputStream#read()
	 */
	public int read() throws IOException {
		int b = this.delegate.read();
		if(b != -1) {
			this.progress++;
		}
		return b;
	}

	private long lastEvenPosted = 0;
	
	/* (non-Javadoc)
	 * @see java.io.InputStream#read(byte[], int, int)
	 */
	public int read(byte[] arg0, int arg1, int arg2) throws IOException {
		int numRead = this.delegate.read(arg0, arg1, arg2);
		if(numRead != -1) {
			this.progress += numRead;
			long currentTime = System.currentTimeMillis();
			if(currentTime - this.lastEvenPosted > this.minProgressEventGap) {
				this.evtProgress.fireEvent(new InputProgressEvent(this, this.progress));
				this.lastEvenPosted = currentTime;				
			}
		}
		return numRead;
	}
}