/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright (C) 2002-2003 Jive Software. All rights reserved.
 * ====================================================================
 * The Jive Software License (based on Apache Software License, Version 1.1)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by
 *        Jive Software (http://www.jivesoftware.com)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Smack" and "Jive Software" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please
 *    contact webmaster@coolservlets.com.
 *
 * 5. Products derived from this software may not be called "Smack",
 *    nor may "Smack" appear in their name, without prior written
 *    permission of Jive Software.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL JIVE SOFTWARE OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 */

package org.jivesoftware.smack.packet;

import org.jivesoftware.smack.util.StringUtils;

/**
 * Represents XMPP message packets. A message can be one of several types:
 *
 * <ul>
 *      <li>NORMAL -- (Default) a normal text message used in email like interface.
 *      <li>CHAT -- a typically short text message used in line-by-line chat interfaces.
 *      <li>GROUP_CHAT -- a chat message sent to a groupchat server for group chats.
 *      <li>HEADLINE -- a text message to be displayed in scrolling marquee displays.
 *      <li>ERROR -- indicates a messaging error.
 * </ul>
 *
 * For each message type, different message fields are typically used as follows:
 * <p>
 * <table border="1">
 * <tr><td>&nbsp;</td><td colspan="5"><b>Message type</b></td></tr>
 * <tr><td><i>Field</i></td><td><b>Normal</b></td><td><b>Chat</b></td><td><b>Group Chat</b></td><td><b>Headline</b></td><td><b>Error</b></td></tr>
 * <tr><td><i>subject</i></td> <td>SHOULD</td><td>SHOULD NOT</td><td>SHOULD NOT</td><td>SHOULD NOT</td><td>SHOULD NOT</td></tr>
 * <tr><td><i>thread</i></td>  <td>OPTIONAL</td><td>SHOULD</td><td>OPTIONAL</td><td>OPTIONAL</td><td>SHOULD NOT</td></tr>
 * <tr><td><i>body</i></td>    <td>SHOULD</td><td>SHOULD</td><td>SHOULD</td><td>SHOULD</td><td>SHOULD NOT</td></tr>
 * <tr><td><i>error</i></td>   <td>MUST NOT</td><td>MUST NOT</td><td>MUST NOT</td><td>MUST NOT</td><td>MUST</td></tr>
 * </table>
 *
 * @author Matt Tucker
 */
public class Message extends Packet {

    public static final Type NORMAL = new Type("normal");
    public static final Type CHAT = new Type("chat");
    public static final Type GROUP_CHAT = new Type("groupchat");
    public static final Type HEADLINE = new Type("headline");
    public static final Type ERROR = new Type("error");

    private Type type = NORMAL;
    private String subject = null;
    private String body = null;
    private String thread = null;

    /**
     * Creates a new, "normal" message.
     */
    public Message() {

    }

    /**
     * Creates a new "normal" message to the specified recipient.
     *
     * @param to the recipient of the message.
     */
    public Message(String to) {
        setTo(to);
    }

    /**
     * Creates a new message of the specified type to a recipient.
     *
     * @param to the user to send the message to.
     * @param type the message type.
     */
    public Message(String to, Type type) {
        if (to == null || type == null) {
            throw new IllegalArgumentException("Parameters cannot be null.");
        }
        setTo(to);
        this.type = type;
    }

    /**
     * Returns the type of the message.
     *
     * @return the type of the message.
     */
    public Type getType() {
        return type;
    }

    /**
     * Sets the type of the message.
     *
     * @param type the type of the message.
     */
    public void setType(Type type) {
        if (type == null) {
            throw new IllegalArgumentException("Type cannot be null.");
        }
        this.type = type;
    }

    /**
     * Returns the subject of the message, or null if the subject has not been set.
     * The subject is a short description of message contents.
     *
     * @return the subject of the message.
     */
    public String getSubject() {
        return subject;
    }

    /**
     * Sets the subject of the message. The subject is a short description of
     * message contents.
     *
     * @param subject the subject of the message.
     */
    public void setSubject(String subject) {
        this.subject = subject;
    }

    /**
     * Returns the body of the message, or null if the body has not been set. The body
     * is the main message contents.
     *
     * @return the body of the message.
     */
    public String getBody() {
        return body;
    }

    /**
     * Sets the body of the message. The body is the main message contents.
     * @param body
     */
    public void setBody(String body) {
        this.body = body;
    }

    /**
     * Returns the thread id of the message, which is a unique identifier for a sequence
     * of "chat" messages.
     *
     * @return the thread id of the message.
     */
    public String getThread() {
        return thread;
    }

    /**
     * Sets the thread id of the message, which is a unique identifier for a sequence
     * of "chat" messages.
     *
     * @param thread the thread id of the message.
     */
    public void setThread(String thread) {
        this.thread = thread;
    }

    /**
     * Returns the message as XML.
     *
     * @return the message as XML.
     */
    public String toXML() {
        StringBuffer buf = new StringBuffer();
        buf.append("<message");
        buf.append(" id=\"").append(getPacketID()).append("\"");
        if (getTo() != null) {
            buf.append(" to=\"").append(getTo()).append("\"");
        }
        if (getFrom() != null) {
            buf.append(" from=\"").append(getFrom()).append("\"");
        }
        if (type != NORMAL) {
            buf.append(" type=\"").append(type).append("\"");
        }
        buf.append(">");
        if (subject != null) {
            buf.append("<subject>").append(StringUtils.escapeForXML(subject)).append("</subject>");
        }
        if (body != null) {
            buf.append("<body>").append(StringUtils.escapeForXML(body)).append("</body>");
        }
        if (thread != null) {
            buf.append("<thread>").append(thread).append("</thread>");
        }
        // Append the error subpacket if the message type is an error.
        if (type == ERROR) {
            Error error = getError();
            if (error != null) {
                buf.append(error.toXML());
            }
        }
        String properties = getPropertiesXML();
        if (properties != null) {
            buf.append(properties);
        }
        buf.append("</message>");
        return buf.toString();
    }

    /**
     * Represents the type of a message.
     */
    public static class Type {

        public static Type fromString(String type) {
            if (CHAT.toString().equals(type)) {
                return CHAT;
            }
            else if (GROUP_CHAT.toString().equals(type)) {
                return GROUP_CHAT;
            }
            else if (HEADLINE.toString().equals(type)) {
                return HEADLINE;
            }
            else if (ERROR.toString().equals(type)) {
                return ERROR;
            }
            else {
                return NORMAL;
            }
        }

        private String value;

        private Type(String value) {
            this.value = value;
        }

        public String toString() {
            return value;
        }
    }
}