// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.GWT.eventbus.server.nonpublic;

import java.util.*;
import javax.servlet.http.*;

import org.litesoft.GWT.eventbus.server.*;
import org.litesoft.logger.*;

public class SEBSessionTracker implements HttpSessionBindingListener,
                                          ServerEventBusDisposeListener
{
    private static final Logger LOGGER = LoggerFactory.getLogger( SEBSessionTracker.class );

    private Set<Integer> mClientIdNumbers = new HashSet<Integer>();
    private ThreadLocalContextFactory mThreadLocalContextFactory;

    public SEBSessionTracker( ThreadLocalContextFactory pThreadLocalContextFactory )
    {
        if ( pThreadLocalContextFactory == null )
        {
            throw new NoThreadLocalContextFactoryException();
        }
        mThreadLocalContextFactory = pThreadLocalContextFactory;
    }

    public synchronized boolean anyServerEventBuses()
    {
        return !mClientIdNumbers.isEmpty();
    }

    public synchronized void addServerEventBus( ServerEventBus pServerEventBus )
    {
        Integer zClientIdNumber = pServerEventBus.getClientIdNumber();

        mClientIdNumbers.add( zClientIdNumber );

        pServerEventBus.addListener( this );
    }

    public void init( IServerEventBus pServerEventBus )
    {
    }

    public synchronized void disposing( IServerEventBus pServerEventBus )
    {
        Integer zClientIdNumber = pServerEventBus.getClientIdNumber();

        mClientIdNumbers.remove( zClientIdNumber );
    }

    public void dropAllServerEventBuses( String pWhy )
    {
        for ( Integer clientIdNumber : getClientIdNumbers() )
        {
            try
            {
                ServerEventBus zSEB = ServerEventBusManager.INSTANCE.getServerEventBus( clientIdNumber );
                if ( (zSEB != null) && zSEB.isAliveAndWell() )
                {
                    mThreadLocalContextFactory.setThreadLocalContextFrom( zSEB );
                    try
                    {
                        zSEB.dispose( pWhy );
                    }
                    finally
                    {
                        mThreadLocalContextFactory.clrThreadLocalContext();
                    }
                }
            }
            catch ( RuntimeException e )
            {
                LOGGER.error.log( e );
            }
        }
        synchronized ( this )
        {
            mClientIdNumbers.clear();
        }
    }

    // todo: switch back to private when the AbstractStoredImageRetrievalServlet is corrected
    public synchronized Integer[] getClientIdNumbers()
    {
        return mClientIdNumbers.toArray( new Integer[mClientIdNumbers.size()] );
    }

    protected synchronized void finalize()
            throws Throwable
    {
        dropAllServerEventBuses( "ServerEventBusSessionMapper.finalize" );
        super.finalize();
    }

    public void valueBound( HttpSessionBindingEvent pEvent )
    {
        HttpSession session = pEvent.getSession();
        mSessionID = session.getId();
        LOGGER.debug.log( pEvent.getName(), " bound to ", (session.isNew() ? "NEW" : "OLD"), //
                          " Session Id ", mSessionID, //
                          " last access time ", session.getLastAccessedTime() );
    }

    private String mSessionID = null;

    public void valueUnbound( HttpSessionBindingEvent pEvent )
    {
        LOGGER.debug.log( pEvent.getName(), " unbound from Session Id ", mSessionID );
        dropAllServerEventBuses( "ServerEventBusSessionMapper.valueUnbound" );
    }

    private String mLogoutMessage = null;

    public String getLogoutMessage()
    {
        return mLogoutMessage;
    }

    public void setLogoutMessage( String pLogoutMessage )
    {
        mLogoutMessage = pLogoutMessage;
    }
}