/**
 *#########################################################################
 *
 * A component of the GAT application, part of the Greenstone digital
 * library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * Author: John Thompson, Greenstone Digital Library, University of Waikato
 *
 * Copyright (C) New Zealand Digital Library Project
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *########################################################################
 */
package org.greenstone.core.gui;

import java.math.BigInteger;
import javax.swing.JProgressBar;
import javax.swing.SwingUtilities;

/** A progress bar that doesn't pack a sad when you feed it longs (such as the sizes of files) which get mangled into negative numbers. I know how it feels, as I often have negative progress. Also tries to be efficent when updating the JProgressBar, so only updates when the value actually changes, which become necessary when you move a large number of files with millions of bytes (where upon shifting a file of a thousand bytes would be pretty insignificant, maybe not even a percent, but would fire several progress updates). 
 * @author John Thompson, Greenstone Digital Library, University of Waikato
 * @version 2.3c
 */
final public class LongProgressBar
    extends JProgressBar {
    private BigInteger cur_value = null;
    private BigInteger max_value = null;
    private BigInteger min_value = null;
    /** The previous percentage value. */
    private int previous = -1;
    private SafeSetIndeterminate safe_set_indeterminate = null;
    private SafeSetString safe_set_string = null;
    private SafeSetValue safe_set_value = null;

    public LongProgressBar() {
	super(0, 100);
	cur_value = BigInteger.ZERO;
	min_value = BigInteger.ZERO;
	max_value = BigInteger.ZERO;
    }

    public void addMaximum(int size) {
	///ystem.err.println("Add maximum " + size);
	if(size > 0) {
	    max_value = max_value.add(new BigInteger((new Integer(size)).toString()));
	    update();
	}
    }

    public void addMaximum(long size) {
	///ystem.err.println("Add maximum " + size);
	if(size > 0) {
	    max_value = max_value.add(new BigInteger((new Long(size)).toString()));
	    update();
	}
    }

    public void addValue(int size) {
	///ystem.err.println("Add value " + size);
	if(size > 0) {
	    cur_value = cur_value.add(new BigInteger((new Integer(size)).toString()));
	    update();
	}
    }

    public void addValue(long size) {
	///ystem.err.println("Add value " + size);
	if(size > 0) {
	    cur_value = cur_value.add(new BigInteger((new Long(size)).toString()));
	    update();
	}
    }

    public void clear()
    {
	previous = -1;
	update();
    }

    public void reset() {
	cur_value = BigInteger.ZERO;
	max_value = BigInteger.ZERO;
	previous = -1;
	update();
    }

    public void setIndeterminate(boolean state) {
	if(safe_set_indeterminate == null) {
	    safe_set_indeterminate = new SafeSetIndeterminate(state);
	}
	else {
	    safe_set_indeterminate.setState(state);
	}
	SwingUtilities.invokeLater(safe_set_indeterminate);		  
    }

    public void setMaximum(int size) {
	///ystem.err.println("Add maximum " + size);
	if(size > 0) {
	    max_value = new BigInteger((new Integer(size)).toString());
	    update();
	}
    }

    public void setMaximum(long size) {
	///ystem.err.println("Add maximum " + size);
	if(size > 0) {
	    max_value = new BigInteger((new Long(size)).toString());
	    update();
	}
    }

    public void setString(String label) {
	safeSetString(label);
    }
	 
    public void setValue(int size) {
	///ystem.err.println("Set value " + size);
	cur_value = new BigInteger((new Integer(size)).toString());
	update();
    }

    public void setValue(long size) {
	///ystem.err.println("Set value " + size);
	cur_value = new BigInteger((new Long(size)).toString());
	update();
    }

    /** This method is an unsafe way to set the progress bar to be indeterminate, -unless- it is called from the Event Queue. */
    private void unsafeSetIndeterminate(boolean state) {
	super.setIndeterminate(state);
    }

    private void unsafeSetString(String label) {
	super.setString(label);
    }

    private void unsafeSetValue(int value) {
	super.setValue(value);
    }

    private void update() {
	int percentage = -1;
	if(cur_value.equals(BigInteger.ZERO) || max_value.equals(BigInteger.ZERO)) {
	    percentage = 0;
	}
	else {
	    BigInteger tmp_value = cur_value.multiply(new BigInteger("100"));
	    BigInteger per_value = tmp_value.divide(max_value);
	    percentage = per_value.intValue();
	    if(percentage > 100) {
		percentage = 100;
	    }
	}
	if(percentage != previous) {
	    ///ystem.err.println("Progress bar status: value = " + getValue());
	    previous = percentage;
	    safeSetValue(percentage);
	    safeSetString(percentage + "%");
	}
    }
    /** Change the string displayed on the progress bar.
     * @param label The name progress bar label as a <strong>String</strong>.
     * Original code: Tad Frysinger (TeamB)
     */
    private void safeSetString(String label) {
	if(safe_set_string == null) {
	    safe_set_string = new SafeSetString(label);
	}
	else {
	    safe_set_string.setLabel(label);
	}
	
	SwingUtilities.invokeLater(safe_set_string);  
    }
	 
    /** Increase the value of the progress bar.
     * @param ammount The ammount to increase as an <i>int</i>.
     * Original code: Tad Frysinger (TeamB)
     */
    private void safeSetValue(final int ammount) {
	// Update progress bar,
	if(safe_set_value == null) {
	    safe_set_value = new SafeSetValue(ammount);
	}
	else {
	    safe_set_value.setValue(ammount);
	}
	SwingUtilities.invokeLater(safe_set_value);  
    }

    private class SafeSetIndeterminate 
	implements Runnable {
	private boolean value;
	public SafeSetIndeterminate(boolean value) {
	    this.value = value;
	}
	public void run() {
	    unsafeSetIndeterminate(value);
	}
	synchronized public void setState(boolean value) {
	    this.value = value;
	}
    }

    private class SafeSetString 
	implements Runnable {
	private String label = null;
	public SafeSetString(String label) {
	    this.label = label;
	}
	public void run() {
	    unsafeSetString(label);
	}
	synchronized public void setLabel(String label) {
	    this.label = label;
	}
    }

    private class SafeSetValue 
	implements Runnable {
	private int value = -1;
	public SafeSetValue(int value) {
	    this.value = value;
	}
	public void run() {
	    unsafeSetValue(value);
	}
	synchronized public void setValue(int value) {
	    this.value = value;
	}
    }
}