/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

package com.nokia.mj.impl.fileutils;

import java.util.Vector;

import com.nokia.mj.impl.utils.Logger;

import com.nokia.mj.impl.comms.CommsListener;

import com.nokia.mj.impl.comms.CommsEndpoint;

import com.nokia.mj.impl.comms.CommsMessage;

import com.nokia.mj.impl.comms.exception.CommsException;

final class DriveListenerImpl implements CommsListener

{

    public static boolean registerListenerStatic(DriveListener aListener)

    {

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "--> DriveListenerImpl.registerListenerStatic()");

        boolean regSuccess = getInstance().registerListener(aListener);

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "<-- DriveListenerImpl.registerListenerStatic() returns "

                   + regSuccess);

        return regSuccess;

    }

    public static boolean unregisterListenerStatic(DriveListener aListener)

    {

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "--> DriveListenerImpl.unregisterListenerStatic()");

        boolean unregSuccess = getInstance().unregisterListener(aListener);

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "<-- DriveListenerImpl.unregisterListenerStatic() returns "

                   + unregSuccess);

        return unregSuccess;

    }

    private static Vector iDriveListeners = null;

    private static Vector getListeners()

    {

        if (null == iDriveListeners)

        {

            iDriveListeners = new Vector();

        }

        return iDriveListeners;

    }

    private static CommsEndpoint iComms = null;

    private static boolean iCommsOwner = false;

    private static CommsEndpoint getComms()

    {

        if (null == iComms)

        {

            iComms = CommsEndpoint.find("javacaptain");

            if (null == iComms)

            {

                iComms = new CommsEndpoint();

                iComms.connect(CommsEndpoint.JAVA_CAPTAIN);

                iCommsOwner = true;

            }

            iComms.registerListener(DriveObserverMessages.PLUGIN_ID_DRIVE_OBSERVER_JAVA_C,

                                    getInstance());

        }

        return iComms;

    }

    private static DriveListenerImpl iDriveListenerImpl = null;

    private static DriveListenerImpl getInstance()

    {

        if (null == iDriveListenerImpl)

        {

            iDriveListenerImpl = new DriveListenerImpl();

        }

        return iDriveListenerImpl;

    }

    boolean registerListener(DriveListener aListener)

    {

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "--> DriveListenerImpl.registerListener()");

        boolean regSuccess = true;

        try

        {

            Logger.LOG(Logger.EJavaFile, Logger.EInfo, "    listeners before " + getListeners().size());

            if (getListeners().size() == 0 &&

                    null != getComms())

            {

                DriveObserverMessages.subscribeEvents(getComms(), false);

            }

            getListeners().addElement(aListener);

            Logger.LOG(Logger.EJavaFile, Logger.EInfo, "    listeners after " + getListeners().size());

        }

        catch (CommsException e)

        {

            regSuccess = false;

            Logger.ELOG(Logger.EJavaFile, "registerListener failed", e);

        }

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "<-- DriveListenerImpl.registerListener() returns "+

                   regSuccess);

        return regSuccess;

    }

    boolean unregisterListener(DriveListener aListener)

    {

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "--> DriveListenerImpl.unregisterListener()");

        boolean unregSuccess = true;

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "    listeners before " + getListeners().size());

        getListeners().removeElement(aListener);

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "    listeners after " + getListeners().size());

        try

        {

            if (getListeners().size() == 0 &&

                    null != getComms())

            {

                DriveObserverMessages.subscribeEvents(getComms(), true);

                getComms().unregisterListener(DriveObserverMessages.PLUGIN_ID_DRIVE_OBSERVER_JAVA_C);

                if (iCommsOwner)

                {

                    getComms().destroy();

                    iCommsOwner = false;

                }

                iComms = null;

            }

        }

        catch (CommsException e)

        {

            unregSuccess = false;

            Logger.ELOG(Logger.EJavaFile, "unregisterListener failed", e);

        }

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "<-- DriveListenerImpl.unregisterListener()");

        return unregSuccess;

    }

    public void processMessage(CommsMessage aMessage)

    {

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "--> DriveListenerImpl.processMessage()");

        switch (aMessage.getMessageId())

        {

        case DriveObserverMessages.DRIVEOBSERVER_MSG_DRIVE_CHANGED_EVENT:

            int oper = aMessage.readInt();

            DriveInfo drive = DriveObserverMessages.extractDriveInfo(aMessage);

            int listenersCount = getListeners().size();

            for (int i = 0 ; i < listenersCount ; ++i)

            {

                DriveListener listener = (DriveListener) getListeners().elementAt(i);

                listener.driveChanged(oper, drive);

            }

            break;

        }

        Logger.LOG(Logger.EJavaFile, Logger.EInfo, "<-- DriveListenerImpl.processMessage()");

    }

}