/**
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
 *    statements and notices.  Redistributions must also contain a
 *    copy of this document.
 *
 * 2. 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.
 *
 * 3. The name "Exolab" must not be used to endorse or promote
 *    products derived from this Software without prior written
 *    permission of Exoffice Technologies.  For written permission,
 *    please contact info@exolab.org.
 *
 * 4. Products derived from this Software may not be called "Exolab"
 *    nor may "Exolab" appear in their names without prior written
 *    permission of Exoffice Technologies. Exolab is a registered
 *    trademark of Exoffice Technologies.
 *
 * 5. Due credit should be given to the Exolab Project
 *    (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESSED 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
 * EXOFFICE TECHNOLOGIES OR ITS 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.
 *
 * Copyright 2000-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: MulticastCallerListener.java,v 1.1 2010/06/18 16:44:41 smhuang Exp $
 */
package org.exolab.jms.net.connector;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.exolab.jms.net.uri.InvalidURIException;
import org.exolab.jms.net.uri.URI;
import org.exolab.jms.net.uri.URIHelper;


/**
 * A listener for {@link Caller} events, which asynchronously propagates events
 * to one or more registered listeners.
 *
 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
 * @version $Revision: 1.1 $ $Date: 2010/06/18 16:44:41 $
 */
public class MulticastCallerListener implements CallerListener {

    /**
     * The listeners. A set of <code>List</code> instances, keyed on
     * URI.
     */
    private Map _listeners = Collections.synchronizedMap(new HashMap());

    /**
     * Helper for casts.
     */
    private static final CallerListener[] EMPTY = new CallerListener[0];


    /**
     * Registers an event listener for caller events.
     *
     * @param uri      the remote URI to listen for events on
     * @param listener the event listener
     * @throws InvalidURIException if <code>uri</code> is invalid
     */
    public void addCallerListener(String uri, CallerListener listener)
        throws InvalidURIException{
        URI parsed = URIHelper.parse(uri);
        parsed = URIHelper.convertHostToAddress(parsed);
        List list = null;
        synchronized (_listeners) {
            list = (List) _listeners.get(parsed);
            if (list == null) {
                list = Collections.synchronizedList(new ArrayList());
                _listeners.put(parsed, list);
            }
        }
        list.add(listener);
    }

    /**
     * Removes an event listener for caller events.
     *
     * @param uri      the remote URI to remove the listener for
     * @param listener the event listener to remove
     * @throws InvalidURIException if <code>uri</code> is invalid
     */
    public void removeCallerListener(String uri, CallerListener listener)
        throws InvalidURIException {
        URI parsed = URIHelper.parse(uri);
        parsed = URIHelper.convertHostToAddress(parsed);
        List list = null;
        synchronized (_listeners) {
            list = (List) _listeners.get(parsed);
            if (list != null) {
                list.remove(listener);
            }
        }
    }

    /**
     * Notifies that a connection has been disconnected.
     *
     * @param caller the caller that was disconnected
     */
    public void disconnected(Caller caller) {
        CallerListener[] listeners = getListeners(caller.getRemoteURI());
        for (int i = 0; i < listeners.length; ++i) {
            listeners[i].disconnected(caller);
        }
    }

    /**
     * Returns the registered listeners for a given URI.
     *
     * @param uri the URI to return the registered listsners for
     * @return the registered listeners
     */
    private CallerListener[] getListeners(URI uri) {
        CallerListener[] result = EMPTY;
        List list = null;
        synchronized (_listeners) {
            list = (List) _listeners.get(uri);
            if (list == null) {
                list = (List) _listeners.get(uri);
            }
        }
        if (list != null) {
            result = (CallerListener[]) list.toArray(EMPTY);
        }
        return result;
    }
}
