/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright 2003-2007 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.smackx.packet;

import org.jivesoftware.smack.packet.PacketExtension;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

/**
 * An XHTML sub-packet, which is used by XMPP clients to exchange formatted text. The XHTML 
 * extension is only a subset of XHTML 1.0.<p>
 * 
 * The following link summarizes the requirements of XHTML IM:
 * <a href="http://www.jabber.org/jeps/jep-0071.html#sect-id2598018">Valid tags</a>.<p>
 * 
 * Warning: this is an non-standard protocol documented by
 * <a href="http://www.jabber.org/jeps/jep-0071.html">JEP-71</a>. Because this is a
 * non-standard protocol, it is subject to change.
 *
 * @author Gaston Dombiak
 */
public class XHTMLExtension implements PacketExtension {

    private List<String> bodies = new ArrayList<String>();

    /**
    * Returns the XML element name of the extension sub-packet root element.
    * Always returns "html"
    *
    * @return the XML element name of the packet extension.
    */
    public String getElementName() {
        return "html";
    }

    /** 
     * Returns the XML namespace of the extension sub-packet root element.
     * According the specification the namespace is always "http://jabber.org/protocol/xhtml-im"
     *
     * @return the XML namespace of the packet extension.
     */
    public String getNamespace() {
        return "http://jabber.org/protocol/xhtml-im";
    }

    /**
     * Returns the XML representation of a XHTML extension according the specification.
     * 
     * Usually the XML representation will be inside of a Message XML representation like
     * in the following example:
     * <pre>
     * <message id="MlIpV-4" to="gato1@gato.home" from="gato3@gato.home/Smack">
     *     <subject>Any subject you want</subject>
     *     <body>This message contains something interesting.</body>
     *     <html xmlns="http://jabber.org/protocol/xhtml-im">
     *         <body><p style='font-size:large'>This message contains something <em>interesting</em>.</p></body>
     *     </html>
     * </message>
     * </pre>
     * 
     */
    public String toXML() {
        StringBuilder buf = new StringBuilder();
        buf.append("<").append(getElementName()).append(" xmlns=\"").append(getNamespace()).append(
            "\">");
        // Loop through all the bodies and append them to the string buffer
        for (Iterator<String> i = getBodies(); i.hasNext();) {
            buf.append(i.next());
        }
        buf.append("</").append(getElementName()).append(">");
        return buf.toString();
    }

    /**
     * Returns an Iterator for the bodies in the packet.
     *
     * @return an Iterator for the bodies in the packet.
     */
    public Iterator<String> getBodies() {
        synchronized (bodies) {
            return Collections.unmodifiableList(new ArrayList<String>(bodies)).iterator();
        }
    }

    /**
     * Adds a body to the packet.
     *
     * @param body the body to add.
     */
    public void addBody(String body) {
        synchronized (bodies) {
            bodies.add(body);
        }
    }

    /**
     * Returns a count of the bodies in the XHTML packet.
     *
     * @return the number of bodies in the XHTML packet.
     */
    public int getBodiesCount() {
        return bodies.size();
    }

}