/**
 *
 * Copyright the original author or authors
 *
 * 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.smackx.pubsub;

import java.util.Arrays;
import java.util.List;

import org.jivesoftware.smack.packet.ExtensionElement;
import org.jivesoftware.smack.packet.Stanza;
import org.jivesoftware.smack.util.XmlStringBuilder;

import org.jivesoftware.smackx.pubsub.packet.PubSubNamespace;

/**
 * Represents the top level element of a pubsub event extension.  All types of pubsub events are
 * represented by this class.  The specific type can be found by {@link #getEventType()}.  The 
 * embedded event information, which is specific to the event type, can be retrieved by the {@link #getEvent()}
 * method.
 * 
 * @author Robin Collier
 */
public class EventElement implements EmbeddedPacketExtension
{
    /**
     * The constant String "event".
     */
    public static final String ELEMENT = "event";

    /**
     * The constant String "http://jabber.org/protocol/pubsub#event".
     */
    public static final String NAMESPACE = PubSubNamespace.EVENT.getXmlns();

    private EventElementType type;
    private NodeExtension ext;

    public EventElement(EventElementType eventType, NodeExtension eventExt)
    {
        type = eventType;
        ext = eventExt;
    }

    public EventElementType getEventType()
    {
        return type;
    }

    @Override
    public List<ExtensionElement> getExtensions()
    {
        return Arrays.asList(new ExtensionElement[] {getEvent()});
    }

    public NodeExtension getEvent()
    {
        return ext;
    }

    @Override
    public String getElementName()
    {
        return "event";
    }

    @Override
    public String getNamespace()
    {
        return PubSubNamespace.EVENT.getXmlns();
    }

    @Override
    public XmlStringBuilder toXML() {
        XmlStringBuilder xml = new XmlStringBuilder(this);
        xml.rightAngleBracket();
        xml.append(ext.toXML());
        xml.closeElement(this);
        return xml;
    }

    public static EventElement from(Stanza stanza) {
        return stanza.getExtension(ELEMENT, NAMESPACE);
    }
}
