/*
 * Copyright (C) 2004-2008 Jive Software. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.openfire.disco;

import org.dom4j.Element;
import org.xmpp.forms.DataForm;
import org.xmpp.packet.JID;

import java.util.Iterator;

/**
 * A DiscoInfoProvider is responsible for providing information about a JID's name and its node. For
 * example, the room service could implement this interface in order to provide disco#info about
 * its rooms. In this case, the JID's name will be the room's name and node will be null.
 * <p>
 * The information to provide has to include the entity's identity and the features offered and
 * protocols supported by the target entity. The identity will be provided as an Element that will
 * include the categoty, type and name attributes. Whilst the features will be just plain Strings.
 * </p>
 *
 * @author Gaston Dombiak
 */
public interface DiscoInfoProvider {

    /**
     * Returns an Iterator (of Element) with the target entity's identities. Each Element must
     * include the categoty, type and name attributes of the entity.
     *
     * @param name the recipient JID's name.
     * @param node the requested disco node.
     * @param senderJID the XMPPAddress of user that sent the disco info request.
     * @return an Iterator (of Element) with the target entity's identities.
     */
    Iterator<Element> getIdentities( String name, String node, JID senderJID );

    /**
     * Returns an Iterator (of String) with the supported features. The features to include are the
     * features offered and supported protocols by the target entity identified by the requested
     * name and node.
     *
     * @param name the recipient JID's name.
     * @param node the requested disco node.
     * @param senderJID the XMPPAddress of user that sent the disco info request.
     * @return an Iterator (of String) with the supported features.
     */
    Iterator<String> getFeatures( String name, String node, JID senderJID );

    /**
     * Returns an XDataForm with the extended information about the entity or null if none. Each bit
     * of information about the entity must be included as a value of a field of the form.
     *
     * @param name the recipient JID's name.
     * @param node the requested disco node.
     * @param senderJID the XMPPAddress of user that sent the disco info request.
     * @return an XDataForm with the extended information about the entity or null if none.
     */
    DataForm getExtendedInfo( String name, String node, JID senderJID );

    /**
     * Returns true if we can provide information related to the requested name and node. For
     * example, if the requested name refers to a non-existant MUC room then the answer will be
     * false. In case that the sender of the disco request is not authorized to discover this
     * information 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 info request.
     * @return true if we can provide information related to the requested name and node.
     */
    boolean hasInfo( String name, String node, JID senderJID );
}