package org.eclipse.jdt.debug.testplugin;

/**********************************************************************
Copyright (c) 2000, 2002 IBM Corp. and others.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Common Public License v0.5
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v05.html

Contributors:
    IBM Corporation - Initial implementation
**********************************************************************/

import org.eclipse.debug.core.DebugEvent;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.IDebugEventSetListener;

/**
 * The <code>DebugEventWaiter</code> is
 * to wait for a specific kind of debug event.
 * <p>
 * When a <code>DebugEventWaiter</code> is created, it
 * registers itself with the <code>IDebugModelManager</code> as
 * a <code>IDebugModelEventListener</code>.
 * <p>
 * NOTE: <code>DebugEventWaiter</code> objects are intended for
 * one time use only!
 */
public class DebugEventWaiter implements IDebugEventSetListener {
	/**
	 * The kind of event the waiter is waiting for
	 */
	protected int fEventType;

	/**
	 * The number of milliseconds the waiter will wait before timing out.
	 */
	protected long fTimeout;

	/**
	 * The <code>IDebugModelManager</code> this waiter is listening to.
	 */
	protected DebugPlugin fDebugPlugin;

	/**
	 * The <code>DebugEvent</code> received.
	 */
	protected DebugEvent fEvent;
	
	/**
	 * The event set that was accepted
	 */
	protected DebugEvent[] fEventSet;

	/**
	 * The default timeout value if none is given (20000).
	 */
	public static final long DEFAULT_TIMEOUT= 15000;

	/**
	 * Creates a new <code>DebugEventWaiter</code> which
	 * waits for events of a kind <code>eventType</code>.
	 * The wait method will wait the default timeout value.
	 */
	public DebugEventWaiter(int eventType) {
		fDebugPlugin= DebugPlugin.getDefault();
		fEventType= eventType;
		fTimeout= DEFAULT_TIMEOUT;

		fDebugPlugin.addDebugEventListener(this);
	}

	/**
	 * Answers true if the <code>DebugEvent</code> is acceptable.
	 */
	public boolean accept(DebugEvent event) {
		return event.getKind() == fEventType;
	}
	/**
	 * Answers the event name associated with the given flag.
	 */
	public String getEventName(int flag) {
		switch (flag) {
			case DebugEvent.CREATE :
				return "Create";
			case DebugEvent.TERMINATE :
				return "Terminate";
			case DebugEvent.RESUME :
				return "Resume";
			case DebugEvent.SUSPEND :
				return "Suspend";
			default :
				return "UNKNOWN";
		}
	}

	/**
	 * Handles debug events.
	 *
	 * @see IDebugEventListener
	 * @see #accept(DebugEvent)
	 */
	public synchronized void handleDebugEvents(DebugEvent[] events) {
		//printReceived(event);
		//printReceived(event);
		for (int i = 0; i < events.length; i++) {
			if (accept(events[i])) {
				fEvent= events[i];
				fEventSet = events;
				notifyAll();
				return;
			}
		}
	}

	/**
	 * Prints a message indicating which event was received.
	 */
	protected void printReceived(DebugEvent event) {
		System.out.println(this +" got " + event);
	}

	/**
	 * Sets the number of milliseconds to wait for this callback
	 */
	public void setTimeout(long milliseconds) {
		fTimeout= milliseconds;
	}

	/**
	 * Unregisters this waiter as a listener
	 */
	public void unregister() {
		fDebugPlugin.removeDebugEventListener(this);
	}

	/**
	 * Returns the source of the accepted event, or <code>null</code>
	 * if no event was accepted.
	 */
	public synchronized Object waitForEvent() {
		if (fEvent == null) {
			try {
				wait(fTimeout);
			} catch (InterruptedException ie) {
				System.err.println("Interrupted waiting for event");
			}
		}
		unregister();
		if (fEvent == null)
			return null;
		return fEvent.getSource();
	}

	/**
	 * Returns the accepted event, if any.
	 */
	public DebugEvent getEvent() {
		return fEvent;
	}
	
	/**
	 * Returns the accepted event set, if any.
	 */
	public DebugEvent[] getEventSet() {
		return fEventSet;
	}	
}