/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright (C) 2004 Jive Software. All rights reserved.
 *
 * This software is published under the terms of the GNU Public License (GPL),
 * a copy of which is included in this distribution.
 */

package org.jivesoftware.messenger.disco;

import org.jivesoftware.messenger.auth.UnauthorizedException;
import org.xmpp.packet.JID;
import org.dom4j.Element;

import java.util.Iterator;

/**
 * A DiscoItemsProvider is responsible for providing the items associated with a JID's name and
 * node. For example, the room service could implement this interface in order to provide
 * the existing rooms as its items. In this case, the JID's name and node won't be used.<p>
 * <p/>
 * The items to provide must have a JID attribute specifying the JID of the item and may possess a
 * name attribute specifying a natural-language name for the item. The node attribute is optional
 * and must be used only for items that aren't addressable as a JID.
 *
 * @author Gaston Dombiak
 */
public interface DiscoItemsProvider {

    /**
     * Returns an Iterator (of Element) with the target entity's items or null if none. Each Element
     * must include a JID attribute and may include the name and node attributes of the entity. In
     * case that the sender of the disco request is not authorized to discover items an
     * UnauthorizedException will be thrown.
     *
     * @param name      the recipient JID's name.
     * @param node      the requested disco node.
     * @param senderJID the XMPPAddress of user that sent the disco items request.
     * @return an Iterator (of Element) with the target entity's items or null if none.
     * @throws UnauthorizedException if the senderJID is not authorized to discover items.
     */
    public abstract Iterator<Element> getItems(String name, String node, JID senderJID)
            throws UnauthorizedException;

}
