/*
 * Copyright (c) 2008 Paul C. Buetow, vs@dev.buetow.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * All icons of the icons/ folder are 	under a Creative Commons
 * Attribution-Noncommercial-Share Alike License a CC-by-nc-sa.
 *
 * The icon's homepage is http://code.google.com/p/ultimate-gnome/
 */

package core;

import core.time.*;
import events.*;
import prefs.VSPrefs;

/**
 * An object of this class represents a message which is sent from one process
 * to another process in the simulator.
 *
 * @author Paul C. Buetow
 */
public class VSMessage extends VSPrefs {
    /** The serial version uid */
    private static final long serialVersionUID = 1L;

    /** The constant IS_SERVER_MESSAGE. */
    public static final boolean IS_SERVER_MESSAGE = true;

    /** The constant IS_CLIENT_MESSAGE. */
    public static final boolean IS_CLIENT_MESSAGE = false;

    /** true, if the message has been sent from a server. false, if the message
     * has been sent from a client.
     */
    private boolean isServerMessage;

    /** Each message belongs to a specific protocol. This variable defined the
     * class name of the protocol being used.
     */
    private String protocolClassname;

    /** The default application preferences. */
    private VSPrefs prefs;

    /** A reference to the process who sent this message. */
    private VSInternalProcess sendingProcess;

    /** The vector time of the sending process after sending. The receiver
     * process will use this vector time in order to update the local vector
     * time.
     */
    private VSVectorTime vectorTime;

    /** The lamport time of the sending process after sending. The receiver
     * process will use this lamport time in order to update the local vector
     * time.
     */
    private long lamportTime;

    /** Each message has its own unique ID. The ID will show up in the loging
     * window of the simulator
     */
    private long messageID;

    /** This counter is used in order to generate unique message ID's. */
    private static long messageCounter;

    /**
     * The constructor of the message. Creates a new message object.
     */
    public VSMessage() {
        this.messageID = ++messageCounter;
    }

    /**
     * Initializes the message.
     *
     * @param process The sending process of this message.
     * @param protocolClassname The classname of the protocol this message.
     * @param isServerMessage Sets if the message has been sent by a server.
     */
    void init(VSInternalProcess process, String protocolClassname,
              boolean isServerMessage) {
        this.sendingProcess = process;
        this.protocolClassname = protocolClassname;
        this.isServerMessage = isServerMessage;
        this.prefs = process.getPrefs();

        lamportTime = sendingProcess.getLamportTime();
        vectorTime = sendingProcess.getVectorTime().getCopy();
    }

    /**
     * Gets the protocol name of the message.
     *
     * @return The protocol name of the message.
     */
    public String getName() {
        return VSRegisteredEvents.getNameByClassname(getProtocolClassname());
    }

    /**
     * Gets the protocol classname.
     *
     * @return The protocol classname of the message.
     */
    public String getProtocolClassname() {
        return protocolClassname;
    }

    /**
     * Gets the message id.
     *
     * @return The id of the message.
     */
    public long getMessageID() {
        return messageID;
    }

    /**
     * Gets a reference of the sending process.
     *
     * @return The process which sent this message.
     */
    public VSAbstractProcess getSendingProcess() {
        return sendingProcess;
    }

    /**
     * Gets the lamport time.
     *
     * @return The lamport time of the sending process.
     */
    public long getLamportTime() {
        return lamportTime;
    }

    /**
     * Gets the vector time.
     *
     * @return The vector time of the sending process.
     */
    public VSVectorTime getVectorTime() {
        return vectorTime;
    }

    /**
     * Checks if the message has been sent by a server or a client.
     *
     * @return true, if the message has been sent by a server. false, if the
     *	message has been sent by a client.
     */
    public boolean isServerMessage() {
        return isServerMessage;
    }

    /* (non-Javadoc)
     * @see prefs.VSPrefs#toString()
     */
    public String toString() {
        StringBuffer buffer = new StringBuffer();

        buffer.append("ID: ");
        buffer.append(messageID);
        buffer.append("; ");
        buffer.append(prefs.getString("lang.en.protocol"));
        buffer.append(": ");
        buffer.append(VSRegisteredEvents.getShortnameByClassname(
                          getProtocolClassname()));

        return buffer.toString();
    }

    /**
     * Extended string representation of the message object.
     *
     * @return Extended string representation of the message object.
     */
    public String toStringFull() {
        return toString() + "; " + super.toString();
    }

    /**
     * Compares two messages.
     *
     * @param message The message to compare with.
     *
     * @return true, if the messages have the same id. Otherwise false.
     */
    public boolean equals(VSMessage message) {
        return messageID == message.getMessageID();
    }
}