/**
 *
 * 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 javax.xml.namespace.QName;

import org.jivesoftware.smack.packet.ExtensionElement;
import org.jivesoftware.smack.packet.Stanza;
import org.jivesoftware.smack.packet.XmlElement;
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, ExtensionElement {
    /**
     * 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();

    public static final QName QNAME = new QName(NAMESPACE, ELEMENT);

    private final EventElementType type;
    private final NodeExtension ext;

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

    public EventElementType getEventType() {
        return type;
    }

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

    public NodeExtension getEvent() {
        return ext;
    }

    @Override
    public String getElementName() {
        return QNAME.getLocalPart();
    }

    @Override
    public String getNamespace() {
        return QNAME.getNamespaceURI();
    }

    @Override
    public XmlStringBuilder toXML(org.jivesoftware.smack.packet.XmlEnvironment enclosingNamespace) {
        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(EventElement.class);
    }
}