/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.activemq.network;

import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.cert.X509Certificate;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;

import javax.management.ObjectName;

import org.apache.activemq.DestinationDoesNotExistException;
import org.apache.activemq.Service;
import org.apache.activemq.advisory.AdvisoryBroker;
import org.apache.activemq.advisory.AdvisorySupport;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.broker.BrokerServiceAware;
import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.broker.TransportConnection;
import org.apache.activemq.broker.region.AbstractRegion;
import org.apache.activemq.broker.region.DurableTopicSubscription;
import org.apache.activemq.broker.region.Region;
import org.apache.activemq.broker.region.RegionBroker;
import org.apache.activemq.broker.region.Subscription;
import org.apache.activemq.broker.region.policy.PolicyEntry;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ActiveMQMessage;
import org.apache.activemq.command.ActiveMQTempDestination;
import org.apache.activemq.command.ActiveMQTopic;
import org.apache.activemq.command.BrokerId;
import org.apache.activemq.command.BrokerInfo;
import org.apache.activemq.command.Command;
import org.apache.activemq.command.ConnectionError;
import org.apache.activemq.command.ConnectionId;
import org.apache.activemq.command.ConnectionInfo;
import org.apache.activemq.command.ConsumerId;
import org.apache.activemq.command.ConsumerInfo;
import org.apache.activemq.command.DataStructure;
import org.apache.activemq.command.DestinationInfo;
import org.apache.activemq.command.ExceptionResponse;
import org.apache.activemq.command.KeepAliveInfo;
import org.apache.activemq.command.Message;
import org.apache.activemq.command.MessageAck;
import org.apache.activemq.command.MessageDispatch;
import org.apache.activemq.command.MessageId;
import org.apache.activemq.command.NetworkBridgeFilter;
import org.apache.activemq.command.ProducerInfo;
import org.apache.activemq.command.RemoveInfo;
import org.apache.activemq.command.RemoveSubscriptionInfo;
import org.apache.activemq.command.Response;
import org.apache.activemq.command.SessionInfo;
import org.apache.activemq.command.ShutdownInfo;
import org.apache.activemq.command.SubscriptionInfo;
import org.apache.activemq.command.WireFormatInfo;
import org.apache.activemq.filter.DestinationFilter;
import org.apache.activemq.filter.MessageEvaluationContext;
import org.apache.activemq.security.SecurityContext;
import org.apache.activemq.transport.DefaultTransportListener;
import org.apache.activemq.transport.FutureResponse;
import org.apache.activemq.transport.ResponseCallback;
import org.apache.activemq.transport.Transport;
import org.apache.activemq.transport.TransportDisposedIOException;
import org.apache.activemq.transport.TransportFilter;
import org.apache.activemq.transport.tcp.SslTransport;
import org.apache.activemq.util.IdGenerator;
import org.apache.activemq.util.IntrospectionSupport;
import org.apache.activemq.util.LongSequenceGenerator;
import org.apache.activemq.util.MarshallingSupport;
import org.apache.activemq.util.ServiceStopper;
import org.apache.activemq.util.ServiceSupport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A useful base class for implementing demand forwarding bridges.
 */
public abstract class DemandForwardingBridgeSupport implements NetworkBridge, BrokerServiceAware {
    private static final Logger LOG = LoggerFactory.getLogger(DemandForwardingBridgeSupport.class);
    protected static final String DURABLE_SUB_PREFIX = "NC-DS_";
    protected final Transport localBroker;
    protected final Transport remoteBroker;
    protected IdGenerator idGenerator = new IdGenerator();
    protected final LongSequenceGenerator consumerIdGenerator = new LongSequenceGenerator();
    protected ConnectionInfo localConnectionInfo;
    protected ConnectionInfo remoteConnectionInfo;
    protected SessionInfo localSessionInfo;
    protected ProducerInfo producerInfo;
    protected String remoteBrokerName = "Unknown";
    protected String localClientId;
    protected ConsumerInfo demandConsumerInfo;
    protected int demandConsumerDispatched;
    protected final AtomicBoolean localBridgeStarted = new AtomicBoolean(false);
    protected final AtomicBoolean remoteBridgeStarted = new AtomicBoolean(false);
    protected final AtomicBoolean bridgeFailed = new AtomicBoolean();
    protected final AtomicBoolean disposed = new AtomicBoolean();
    protected BrokerId localBrokerId;
    protected ActiveMQDestination[] excludedDestinations;
    protected ActiveMQDestination[] dynamicallyIncludedDestinations;
    protected ActiveMQDestination[] staticallyIncludedDestinations;
    protected ActiveMQDestination[] durableDestinations;
    protected final ConcurrentMap<ConsumerId, DemandSubscription> subscriptionMapByLocalId = new ConcurrentHashMap<ConsumerId, DemandSubscription>();
    protected final ConcurrentMap<ConsumerId, DemandSubscription> subscriptionMapByRemoteId = new ConcurrentHashMap<ConsumerId, DemandSubscription>();
    protected final BrokerId localBrokerPath[] = new BrokerId[]{null};
    protected final CountDownLatch startedLatch = new CountDownLatch(2);
    protected final CountDownLatch localStartedLatch = new CountDownLatch(1);
    protected final AtomicBoolean lastConnectSucceeded = new AtomicBoolean(false);
    protected NetworkBridgeConfiguration configuration;
    protected final NetworkBridgeFilterFactory defaultFilterFactory = new DefaultNetworkBridgeFilterFactory();

    protected final BrokerId remoteBrokerPath[] = new BrokerId[]{null};
    protected BrokerId remoteBrokerId;

    final AtomicLong enqueueCounter = new AtomicLong();
    final AtomicLong dequeueCounter = new AtomicLong();

    private NetworkBridgeListener networkBridgeListener;
    private boolean createdByDuplex;
    private BrokerInfo localBrokerInfo;
    private BrokerInfo remoteBrokerInfo;

    private final FutureBrokerInfo futureRemoteBrokerInfo = new FutureBrokerInfo(remoteBrokerInfo, disposed);
    private final FutureBrokerInfo futureLocalBrokerInfo = new FutureBrokerInfo(localBrokerInfo, disposed);

    private final AtomicBoolean started = new AtomicBoolean();
    private TransportConnection duplexInitiatingConnection;
    private final AtomicBoolean duplexInitiatingConnectionInfoReceived = new AtomicBoolean();
    protected BrokerService brokerService = null;
    private ObjectName mbeanObjectName;
    private final ExecutorService serialExecutor = Executors.newSingleThreadExecutor();
    private Transport duplexInboundLocalBroker = null;
    private ProducerInfo duplexInboundLocalProducerInfo;

    public DemandForwardingBridgeSupport(NetworkBridgeConfiguration configuration, Transport localBroker, Transport remoteBroker) {
        this.configuration = configuration;
        this.localBroker = localBroker;
        this.remoteBroker = remoteBroker;
    }

    public void duplexStart(TransportConnection connection, BrokerInfo localBrokerInfo, BrokerInfo remoteBrokerInfo) throws Exception {
        this.localBrokerInfo = localBrokerInfo;
        this.remoteBrokerInfo = remoteBrokerInfo;
        this.duplexInitiatingConnection = connection;
        start();
        serviceRemoteCommand(remoteBrokerInfo);
    }

    @Override
    public void start() throws Exception {
        if (started.compareAndSet(false, true)) {

            if (brokerService == null) {
                throw new IllegalArgumentException("BrokerService is null on " + this);
            }

            if (isDuplex()) {
                duplexInboundLocalBroker = NetworkBridgeFactory.createLocalTransport(brokerService.getBroker());
                duplexInboundLocalBroker.setTransportListener(new DefaultTransportListener() {

                    @Override
                    public void onCommand(Object o) {
                        Command command = (Command) o;
                        serviceLocalCommand(command);
                    }

                    @Override
                    public void onException(IOException error) {
                        serviceLocalException(error);
                    }
                });
                duplexInboundLocalBroker.start();
            }

            localBroker.setTransportListener(new DefaultTransportListener() {

                @Override
                public void onCommand(Object o) {
                    Command command = (Command) o;
                    serviceLocalCommand(command);
                }

                @Override
                public void onException(IOException error) {
                    if (!futureLocalBrokerInfo.isDone()) {
                        futureLocalBrokerInfo.cancel(true);
                        return;
                    }
                    serviceLocalException(error);
                }
            });

            remoteBroker.setTransportListener(new DefaultTransportListener() {

                @Override
                public void onCommand(Object o) {
                    Command command = (Command) o;
                    serviceRemoteCommand(command);
                }

                @Override
                public void onException(IOException error) {
                    if (!futureRemoteBrokerInfo.isDone()) {
                        futureRemoteBrokerInfo.cancel(true);
                        return;
                    }
                    serviceRemoteException(error);
                }
            });

            remoteBroker.start();
            localBroker.start();

            if (!disposed.get()) {
                try {
                    triggerStartAsyncNetworkBridgeCreation();
                } catch (IOException e) {
                    LOG.warn("Caught exception from remote start", e);
                }
            } else {
                LOG.warn("Bridge was disposed before the start() method was fully executed.");
                throw new TransportDisposedIOException();
            }
        }
    }

    @Override
    public void stop() throws Exception {
        if (started.compareAndSet(true, false)) {
            if (disposed.compareAndSet(false, true)) {
                LOG.debug(" stopping {} bridge to {}", configuration.getBrokerName(), remoteBrokerName);

                futureRemoteBrokerInfo.cancel(true);
                futureLocalBrokerInfo.cancel(true);

                NetworkBridgeListener l = this.networkBridgeListener;
                if (l != null) {
                    l.onStop(this);
                }
                try {
                    // local start complete
                    if (startedLatch.getCount() < 2) {
                        LOG.trace("{} unregister bridge ({}) to {}", new Object[]{
                                configuration.getBrokerName(), this, remoteBrokerName
                        });
                        brokerService.getBroker().removeBroker(null, remoteBrokerInfo);
                        brokerService.getBroker().networkBridgeStopped(remoteBrokerInfo);
                    }

                    remoteBridgeStarted.set(false);
                    final CountDownLatch sendShutdown = new CountDownLatch(1);

                    brokerService.getTaskRunnerFactory().execute(new Runnable() {
                        @Override
                        public void run() {
                            try {
                                serialExecutor.shutdown();
                                if (!serialExecutor.awaitTermination(5, TimeUnit.SECONDS)) {
                                    List<Runnable> pendingTasks = serialExecutor.shutdownNow();
                                    LOG.info("pending tasks on stop {}", pendingTasks);
                                }
                                localBroker.oneway(new ShutdownInfo());
                                remoteBroker.oneway(new ShutdownInfo());
                            } catch (Throwable e) {
                                LOG.debug("Caught exception sending shutdown", e);
                            } finally {
                                sendShutdown.countDown();
                            }

                        }
                    }, "ActiveMQ ForwardingBridge StopTask");

                    if (!sendShutdown.await(10, TimeUnit.SECONDS)) {
                        LOG.info("Network Could not shutdown in a timely manner");
                    }
                } finally {
                    ServiceStopper ss = new ServiceStopper();
                    ss.stop(remoteBroker);
                    ss.stop(localBroker);
                    ss.stop(duplexInboundLocalBroker);
                    // Release the started Latch since another thread could be
                    // stuck waiting for it to start up.
                    startedLatch.countDown();
                    startedLatch.countDown();
                    localStartedLatch.countDown();

                    ss.throwFirstException();
                }
            }

            LOG.info("{} bridge to {} stopped", configuration.getBrokerName(), remoteBrokerName);
        }
    }

    protected void triggerStartAsyncNetworkBridgeCreation() throws IOException {
        brokerService.getTaskRunnerFactory().execute(new Runnable() {
            @Override
            public void run() {
                final String originalName = Thread.currentThread().getName();
                Thread.currentThread().setName("triggerStartAsyncNetworkBridgeCreation: " +
                        "remoteBroker=" + remoteBroker + ", localBroker= " + localBroker);

                try {
                    // First we collect the info data from both the local and remote ends
                    collectBrokerInfos();

                    // Once we have all required broker info we can attempt to start
                    // the local and then remote sides of the bridge.
                    doStartLocalAndRemoteBridges();
                } finally {
                    Thread.currentThread().setName(originalName);
                }
            }
        });
    }

    private void collectBrokerInfos() {

        // First wait for the remote to feed us its BrokerInfo, then we can check on
        // the LocalBrokerInfo and decide is this is a loop.
        try {
            remoteBrokerInfo = futureRemoteBrokerInfo.get();
            if (remoteBrokerInfo == null) {
                serviceLocalException(new Throwable("remoteBrokerInfo is null"));
                return;
            }
        } catch (Exception e) {
            serviceRemoteException(e);
            return;
        }

        try {
            localBrokerInfo = futureLocalBrokerInfo.get();
            if (localBrokerInfo == null) {
                serviceLocalException(new Throwable("localBrokerInfo is null"));
                return;
            }

            // Before we try and build the bridge lets check if we are in a loop
            // and if so just stop now before registering anything.
            remoteBrokerId = remoteBrokerInfo.getBrokerId();
            if (localBrokerId.equals(remoteBrokerId)) {
                LOG.trace("{} disconnecting remote loop back connector for: {}, with id: {}", new Object[]{
                        configuration.getBrokerName(), remoteBrokerName, remoteBrokerId
                });
                ServiceSupport.dispose(localBroker);
                ServiceSupport.dispose(remoteBroker);
                // the bridge is left in a bit of limbo, but it won't get retried
                // in this state.
                return;
            }

            // Fill in the remote broker's information now.
            remoteBrokerPath[0] = remoteBrokerId;
            remoteBrokerName = remoteBrokerInfo.getBrokerName();
            if (configuration.isUseBrokerNamesAsIdSeed()) {
                idGenerator = new IdGenerator(brokerService.getBrokerName() + "->" + remoteBrokerName);
            }
        } catch (Throwable e) {
            serviceLocalException(e);
        }
    }

    private void doStartLocalAndRemoteBridges() {

        if (disposed.get()) {
            return;
        }

        if (isCreatedByDuplex()) {
            // apply remote (propagated) configuration to local duplex bridge before start
            Properties props = null;
            try {
                props = MarshallingSupport.stringToProperties(remoteBrokerInfo.getNetworkProperties());
                IntrospectionSupport.getProperties(configuration, props, null);
                if (configuration.getExcludedDestinations() != null) {
                    excludedDestinations = configuration.getExcludedDestinations().toArray(
                            new ActiveMQDestination[configuration.getExcludedDestinations().size()]);
                }
                if (configuration.getStaticallyIncludedDestinations() != null) {
                    staticallyIncludedDestinations = configuration.getStaticallyIncludedDestinations().toArray(
                            new ActiveMQDestination[configuration.getStaticallyIncludedDestinations().size()]);
                }
                if (configuration.getDynamicallyIncludedDestinations() != null) {
                    dynamicallyIncludedDestinations = configuration.getDynamicallyIncludedDestinations().toArray(
                            new ActiveMQDestination[configuration.getDynamicallyIncludedDestinations().size()]);
                }
            } catch (Throwable t) {
                LOG.error("Error mapping remote configuration: {}", props, t);
            }
        }

        try {
            startLocalBridge();
        } catch (Throwable e) {
            serviceLocalException(e);
            return;
        }

        try {
            startRemoteBridge();
        } catch (Throwable e) {
            serviceRemoteException(e);
            return;
        }

        try {
            if (safeWaitUntilStarted()) {
                setupStaticDestinations();
            }
        } catch (Throwable e) {
            serviceLocalException(e);
        }
    }

    private void startLocalBridge() throws Throwable {
        if (!bridgeFailed.get() && localBridgeStarted.compareAndSet(false, true)) {
            synchronized (this) {
                LOG.trace("{} starting local Bridge, localBroker={}", configuration.getBrokerName(), localBroker);
                if (!disposed.get()) {

                    if (idGenerator == null) {
                        throw new IllegalStateException("Id Generator cannot be null");
                    }

                    localConnectionInfo = new ConnectionInfo();
                    localConnectionInfo.setConnectionId(new ConnectionId(idGenerator.generateId()));
                    localClientId = configuration.getName() + "_" + remoteBrokerName + "_inbound_" + configuration.getBrokerName();
                    localConnectionInfo.setClientId(localClientId);
                    localConnectionInfo.setUserName(configuration.getUserName());
                    localConnectionInfo.setPassword(configuration.getPassword());
                    Transport originalTransport = remoteBroker;
                    while (originalTransport instanceof TransportFilter) {
                        originalTransport = ((TransportFilter) originalTransport).getNext();
                    }
                    if (originalTransport instanceof SslTransport) {
                        X509Certificate[] peerCerts = ((SslTransport) originalTransport).getPeerCertificates();
                        localConnectionInfo.setTransportContext(peerCerts);
                    }
                    // sync requests that may fail
                    Object resp = localBroker.request(localConnectionInfo);
                    if (resp instanceof ExceptionResponse) {
                        throw ((ExceptionResponse) resp).getException();
                    }
                    localSessionInfo = new SessionInfo(localConnectionInfo, 1);
                    localBroker.oneway(localSessionInfo);

                    if (configuration.isDuplex()) {
                        // separate in-bound channel for forwards so we don't
                        // contend with out-bound dispatch on same connection
                        remoteBrokerInfo.setNetworkConnection(true);
                        duplexInboundLocalBroker.oneway(remoteBrokerInfo);

                        ConnectionInfo duplexLocalConnectionInfo = new ConnectionInfo();
                        duplexLocalConnectionInfo.setConnectionId(new ConnectionId(idGenerator.generateId()));
                        duplexLocalConnectionInfo.setClientId(configuration.getName() + "_" + remoteBrokerName + "_inbound_duplex_"
                                + configuration.getBrokerName());
                        duplexLocalConnectionInfo.setUserName(configuration.getUserName());
                        duplexLocalConnectionInfo.setPassword(configuration.getPassword());

                        if (originalTransport instanceof SslTransport) {
                            X509Certificate[] peerCerts = ((SslTransport) originalTransport).getPeerCertificates();
                            duplexLocalConnectionInfo.setTransportContext(peerCerts);
                        }
                        // sync requests that may fail
                        resp = duplexInboundLocalBroker.request(duplexLocalConnectionInfo);
                        if (resp instanceof ExceptionResponse) {
                            throw ((ExceptionResponse) resp).getException();
                        }
                        SessionInfo duplexInboundSession = new SessionInfo(duplexLocalConnectionInfo, 1);
                        duplexInboundLocalProducerInfo = new ProducerInfo(duplexInboundSession, 1);
                        duplexInboundLocalBroker.oneway(duplexInboundSession);
                        duplexInboundLocalBroker.oneway(duplexInboundLocalProducerInfo);
                    }
                    brokerService.getBroker().networkBridgeStarted(remoteBrokerInfo, this.createdByDuplex, remoteBroker.toString());
                    NetworkBridgeListener l = this.networkBridgeListener;
                    if (l != null) {
                        l.onStart(this);
                    }

                    // Let the local broker know the remote broker's ID.
                    localBroker.oneway(remoteBrokerInfo);
                    // new peer broker (a consumer can work with remote broker also)
                    brokerService.getBroker().addBroker(null, remoteBrokerInfo);

                    LOG.info("Network connection between {} and {} ({}) has been established.", new Object[]{
                            localBroker, remoteBroker, remoteBrokerName
                    });
                    LOG.trace("{} register bridge ({}) to {}", new Object[]{
                            configuration.getBrokerName(), this, remoteBrokerName
                    });
                } else {
                    LOG.warn("Bridge was disposed before the startLocalBridge() method was fully executed.");
                }
                startedLatch.countDown();
                localStartedLatch.countDown();
            }
        }
    }

    protected void startRemoteBridge() throws Exception {
        if (!bridgeFailed.get() && remoteBridgeStarted.compareAndSet(false, true)) {
            LOG.trace("{} starting remote Bridge, remoteBroker={}", configuration.getBrokerName(), remoteBroker);
            synchronized (this) {
                if (!isCreatedByDuplex()) {
                    BrokerInfo brokerInfo = new BrokerInfo();
                    brokerInfo.setBrokerName(configuration.getBrokerName());
                    brokerInfo.setBrokerURL(configuration.getBrokerURL());
                    brokerInfo.setNetworkConnection(true);
                    brokerInfo.setDuplexConnection(configuration.isDuplex());
                    // set our properties
                    Properties props = new Properties();
                    IntrospectionSupport.getProperties(configuration, props, null);
                    props.remove("networkTTL");
                    String str = MarshallingSupport.propertiesToString(props);
                    brokerInfo.setNetworkProperties(str);
                    brokerInfo.setBrokerId(this.localBrokerId);
                    remoteBroker.oneway(brokerInfo);
                }
                if (remoteConnectionInfo != null) {
                    remoteBroker.oneway(remoteConnectionInfo.createRemoveCommand());
                }
                remoteConnectionInfo = new ConnectionInfo();
                remoteConnectionInfo.setConnectionId(new ConnectionId(idGenerator.generateId()));
                remoteConnectionInfo.setClientId(configuration.getName() + "_" + configuration.getBrokerName() + "_outbound");
                remoteConnectionInfo.setUserName(configuration.getUserName());
                remoteConnectionInfo.setPassword(configuration.getPassword());
                remoteBroker.oneway(remoteConnectionInfo);

                SessionInfo remoteSessionInfo = new SessionInfo(remoteConnectionInfo, 1);
                remoteBroker.oneway(remoteSessionInfo);
                producerInfo = new ProducerInfo(remoteSessionInfo, 1);
                producerInfo.setResponseRequired(false);
                remoteBroker.oneway(producerInfo);
                // Listen to consumer advisory messages on the remote broker to determine demand.
                if (!configuration.isStaticBridge()) {
                    demandConsumerInfo = new ConsumerInfo(remoteSessionInfo, 1);
                    // always dispatch advisory message asynchronously so that
                    // we never block the producer broker if we are slow
                    demandConsumerInfo.setDispatchAsync(true);
                    String advisoryTopic = configuration.getDestinationFilter();
                    if (configuration.isBridgeTempDestinations()) {
                        advisoryTopic += "," + AdvisorySupport.TEMP_DESTINATION_COMPOSITE_ADVISORY_TOPIC;
                    }
                    demandConsumerInfo.setDestination(new ActiveMQTopic(advisoryTopic));
                    demandConsumerInfo.setPrefetchSize(configuration.getPrefetchSize());
                    remoteBroker.oneway(demandConsumerInfo);
                }
                startedLatch.countDown();
            }
        }
    }

    @Override
    public void serviceRemoteException(Throwable error) {
        if (!disposed.get()) {
            if (error instanceof SecurityException || error instanceof GeneralSecurityException) {
                LOG.error("Network connection between {} and {} shutdown due to a remote error: {}", new Object[]{
                        localBroker, remoteBroker, error
                });
            } else {
                LOG.warn("Network connection between {} and {} shutdown due to a remote error: {}", new Object[]{
                        localBroker, remoteBroker, error
                });
            }
            LOG.debug("The remote Exception was: {}", error, error);
            brokerService.getTaskRunnerFactory().execute(new Runnable() {
                @Override
                public void run() {
                    ServiceSupport.dispose(getControllingService());
                }
            });
            fireBridgeFailed(error);
        }
    }

    protected void serviceRemoteCommand(Command command) {
        if (!disposed.get()) {
            try {
                if (command.isMessageDispatch()) {
                    safeWaitUntilStarted();
                    MessageDispatch md = (MessageDispatch) command;
                    serviceRemoteConsumerAdvisory(md.getMessage().getDataStructure());
                    ackAdvisory(md.getMessage());
                } else if (command.isBrokerInfo()) {
                    futureRemoteBrokerInfo.set((BrokerInfo) command);
                } else if (command.getClass() == ConnectionError.class) {
                    ConnectionError ce = (ConnectionError) command;
                    serviceRemoteException(ce.getException());
                } else {
                    if (isDuplex()) {
                        LOG.trace("{} duplex command type: {}", configuration.getBrokerName(), command.getDataStructureType());
                        if (command.isMessage()) {
                            final ActiveMQMessage message = (ActiveMQMessage) command;
                            if (NetworkBridgeFilter.isAdvisoryInterpretedByNetworkBridge(message)) {
                                serviceRemoteConsumerAdvisory(message.getDataStructure());
                                ackAdvisory(message);
                            } else {
                                if (!isPermissableDestination(message.getDestination(), true)) {
                                    return;
                                }
                                // message being forwarded - we need to
                                // propagate the response to our local send
                                if (canDuplexDispatch(message)) {
                                    message.setProducerId(duplexInboundLocalProducerInfo.getProducerId());
                                    if (message.isResponseRequired() || configuration.isAlwaysSyncSend()) {
                                        duplexInboundLocalBroker.asyncRequest(message, new ResponseCallback() {
                                            final int correlationId = message.getCommandId();

                                            @Override
                                            public void onCompletion(FutureResponse resp) {
                                                try {
                                                    Response reply = resp.getResult();
                                                    reply.setCorrelationId(correlationId);
                                                    remoteBroker.oneway(reply);
                                                } catch (IOException error) {
                                                    LOG.error("Exception: {} on duplex forward of: {}", error, message);
                                                    serviceRemoteException(error);
                                                }
                                            }
                                        });
                                    } else {
                                        duplexInboundLocalBroker.oneway(message);
                                    }
                                    serviceInboundMessage(message);
                                } else {
                                    if (message.isResponseRequired() || configuration.isAlwaysSyncSend()) {
                                        Response reply = new Response();
                                        reply.setCorrelationId(message.getCommandId());
                                        remoteBroker.oneway(reply);
                                    }
                                }
                            }
                        } else {
                            switch (command.getDataStructureType()) {
                                case ConnectionInfo.DATA_STRUCTURE_TYPE:
                                    if (duplexInitiatingConnection != null && duplexInitiatingConnectionInfoReceived.compareAndSet(false, true)) {
                                        // end of initiating connection setup - propogate to initial connection to get mbean by clientid
                                        duplexInitiatingConnection.processAddConnection((ConnectionInfo) command);
                                    } else {
                                        localBroker.oneway(command);
                                    }
                                    break;
                                case SessionInfo.DATA_STRUCTURE_TYPE:
                                    localBroker.oneway(command);
                                    break;
                                case ProducerInfo.DATA_STRUCTURE_TYPE:
                                    // using duplexInboundLocalProducerInfo
                                    break;
                                case MessageAck.DATA_STRUCTURE_TYPE:
                                    MessageAck ack = (MessageAck) command;
                                    DemandSubscription localSub = subscriptionMapByRemoteId.get(ack.getConsumerId());
                                    if (localSub != null) {
                                        ack.setConsumerId(localSub.getLocalInfo().getConsumerId());
                                        localBroker.oneway(ack);
                                    } else {
                                        LOG.warn("Matching local subscription not found for ack: {}", ack);
                                    }
                                    break;
                                case ConsumerInfo.DATA_STRUCTURE_TYPE:
                                    localStartedLatch.await();
                                    if (started.get()) {
                                        addConsumerInfo((ConsumerInfo) command);
                                    } else {
                                        // received a subscription whilst stopping
                                        LOG.warn("Stopping - ignoring ConsumerInfo: {}", command);
                                    }
                                    break;
                                case ShutdownInfo.DATA_STRUCTURE_TYPE:
                                    // initiator is shutting down, controlled case
                                    // abortive close dealt with by inactivity monitor
                                    LOG.info("Stopping network bridge on shutdown of remote broker");
                                    serviceRemoteException(new IOException(command.toString()));
                                    break;
                                default:
                                    LOG.debug("Ignoring remote command: {}", command);
                            }
                        }
                    } else {
                        switch (command.getDataStructureType()) {
                            case KeepAliveInfo.DATA_STRUCTURE_TYPE:
                            case WireFormatInfo.DATA_STRUCTURE_TYPE:
                            case ShutdownInfo.DATA_STRUCTURE_TYPE:
                                break;
                            default:
                                LOG.warn("Unexpected remote command: {}", command);
                        }
                    }
                }
            } catch (Throwable e) {
                LOG.debug("Exception processing remote command: {}", command, e);
                serviceRemoteException(e);
            }
        }
    }

    private void ackAdvisory(Message message) throws IOException {
        demandConsumerDispatched++;
        if (demandConsumerDispatched > (demandConsumerInfo.getPrefetchSize() * .75)) {
            MessageAck ack = new MessageAck(message, MessageAck.STANDARD_ACK_TYPE, demandConsumerDispatched);
            ack.setConsumerId(demandConsumerInfo.getConsumerId());
            remoteBroker.oneway(ack);
            demandConsumerDispatched = 0;
        }
    }

    private void serviceRemoteConsumerAdvisory(DataStructure data) throws IOException {
        final int networkTTL = configuration.getConsumerTTL();
        if (data.getClass() == ConsumerInfo.class) {
            // Create a new local subscription
            ConsumerInfo info = (ConsumerInfo) data;
            BrokerId[] path = info.getBrokerPath();

            if (info.isBrowser()) {
                LOG.debug("{} Ignoring sub from {}, browsers explicitly suppressed", configuration.getBrokerName(), remoteBrokerName);
                return;
            }

            if (path != null && networkTTL > -1 && path.length >= networkTTL) {
                LOG.debug("{} Ignoring sub from {}, restricted to {} network hops only: {}", new Object[]{
                        configuration.getBrokerName(), remoteBrokerName, networkTTL, info
                });
                return;
            }

            if (contains(path, localBrokerPath[0])) {
                // Ignore this consumer as it's a consumer we locally sent to the broker.
                LOG.debug("{} Ignoring sub from {}, already routed through this broker once: {}", new Object[]{
                        configuration.getBrokerName(), remoteBrokerName, info
                });
                return;
            }

            if (!isPermissableDestination(info.getDestination())) {
                // ignore if not in the permitted or in the excluded list
                LOG.debug("{} Ignoring sub from {}, destination {} is not permitted: {}", new Object[]{
                        configuration.getBrokerName(), remoteBrokerName, info.getDestination(), info
                });
                return;
            }

            // in a cyclic network there can be multiple bridges per broker that can propagate
            // a network subscription so there is a need to synchronize on a shared entity
            synchronized (brokerService.getVmConnectorURI()) {
                addConsumerInfo(info);
            }
        } else if (data.getClass() == DestinationInfo.class) {
            // It's a destination info - we want to pass up information about temporary destinations
            final DestinationInfo destInfo = (DestinationInfo) data;
            BrokerId[] path = destInfo.getBrokerPath();
            if (path != null && networkTTL > -1 && path.length >= networkTTL) {
                LOG.debug("{} Ignoring destination {} restricted to {} network hops only", new Object[]{
                        configuration.getBrokerName(), destInfo, networkTTL
                });
                return;
            }
            if (contains(destInfo.getBrokerPath(), localBrokerPath[0])) {
                LOG.debug("{} Ignoring destination {} already routed through this broker once", configuration.getBrokerName(), destInfo);
                return;
            }
            destInfo.setConnectionId(localConnectionInfo.getConnectionId());
            if (destInfo.getDestination() instanceof ActiveMQTempDestination) {
                // re-set connection id so comes from here
                ActiveMQTempDestination tempDest = (ActiveMQTempDestination) destInfo.getDestination();
                tempDest.setConnectionId(localSessionInfo.getSessionId().getConnectionId());
            }
            destInfo.setBrokerPath(appendToBrokerPath(destInfo.getBrokerPath(), getRemoteBrokerPath()));
            LOG.trace("{} bridging {} destination on {} from {}, destination: {}", new Object[]{
                    configuration.getBrokerName(), (destInfo.isAddOperation() ? "add" : "remove"), localBroker, remoteBrokerName, destInfo
            });
            if (destInfo.isRemoveOperation()) {
                // Serialize with removeSub operations such that all removeSub advisories
                // are generated
                serialExecutor.execute(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            localBroker.oneway(destInfo);
                        } catch (IOException e) {
                            LOG.warn("failed to deliver remove command for destination: {}", destInfo.getDestination(), e);
                        }
                    }
                });
            } else {
                localBroker.oneway(destInfo);
            }
        } else if (data.getClass() == RemoveInfo.class) {
            ConsumerId id = (ConsumerId) ((RemoveInfo) data).getObjectId();
            removeDemandSubscription(id);
        } else if (data.getClass() == RemoveSubscriptionInfo.class) {
            RemoveSubscriptionInfo info = ((RemoveSubscriptionInfo) data);
            SubscriptionInfo subscriptionInfo = new SubscriptionInfo(info.getClientId(), info.getSubscriptionName());
            for (Iterator<DemandSubscription> i = subscriptionMapByLocalId.values().iterator(); i.hasNext(); ) {
                DemandSubscription ds = i.next();
                boolean removed = ds.getDurableRemoteSubs().remove(subscriptionInfo);
                if (removed) {
                    if (ds.getDurableRemoteSubs().isEmpty()) {

                        // deactivate subscriber
                        RemoveInfo removeInfo = new RemoveInfo(ds.getLocalInfo().getConsumerId());
                        localBroker.oneway(removeInfo);

                        // remove subscriber
                        RemoveSubscriptionInfo sending = new RemoveSubscriptionInfo();
                        sending.setClientId(localClientId);
                        sending.setSubscriptionName(ds.getLocalDurableSubscriber().getSubscriptionName());
                        sending.setConnectionId(this.localConnectionInfo.getConnectionId());
                        localBroker.oneway(sending);

                        //remove subscriber from map
                        i.remove();
                    }
                }
            }
        }
    }

    @Override
    public void serviceLocalException(Throwable error) {
        serviceLocalException(null, error);
    }

    public void serviceLocalException(MessageDispatch messageDispatch, Throwable error) {
        LOG.trace("serviceLocalException: disposed {} ex", disposed.get(), error);
        if (!disposed.get()) {
            if (error instanceof DestinationDoesNotExistException && ((DestinationDoesNotExistException) error).isTemporary()) {
                // not a reason to terminate the bridge - temps can disappear with
                // pending sends as the demand sub may outlive the remote dest
                if (messageDispatch != null) {
                    LOG.warn("PoisonAck of {} on forwarding error: {}", messageDispatch.getMessage().getMessageId(), error);
                    try {
                        MessageAck poisonAck = new MessageAck(messageDispatch, MessageAck.POSION_ACK_TYPE, 1);
                        poisonAck.setPoisonCause(error);
                        localBroker.oneway(poisonAck);
                    } catch (IOException ioe) {
                        LOG.error("Failed to posion ack message following forward failure: ", ioe);
                    }
                    fireFailedForwardAdvisory(messageDispatch, error);
                } else {
                    LOG.warn("Ignoring exception on forwarding to non existent temp dest: ", error);
                }
                return;
            }

            LOG.info("Network connection between {} and {} shutdown due to a local error: {}", new Object[]{localBroker, remoteBroker, error});
            LOG.debug("The local Exception was: {}", error, error);

            brokerService.getTaskRunnerFactory().execute(new Runnable() {
                @Override
                public void run() {
                    ServiceSupport.dispose(getControllingService());
                }
            });
            fireBridgeFailed(error);
        }
    }

    private void fireFailedForwardAdvisory(MessageDispatch messageDispatch, Throwable error) {
        if (configuration.isAdvisoryForFailedForward()) {
            AdvisoryBroker advisoryBroker = null;
            try {
                advisoryBroker = (AdvisoryBroker) brokerService.getBroker().getAdaptor(AdvisoryBroker.class);

                if (advisoryBroker != null) {
                    ConnectionContext context = new ConnectionContext();
                    context.setSecurityContext(SecurityContext.BROKER_SECURITY_CONTEXT);
                    context.setBroker(brokerService.getBroker());

                    ActiveMQMessage advisoryMessage = new ActiveMQMessage();
                    advisoryMessage.setStringProperty("cause", error.getLocalizedMessage());
                    advisoryBroker.fireAdvisory(context, AdvisorySupport.getNetworkBridgeForwardFailureAdvisoryTopic(), messageDispatch.getMessage(), null,
                            advisoryMessage);

                }
            } catch (Exception e) {
                LOG.warn("failed to fire forward failure advisory, cause: {}", e);
                LOG.debug("detail", e);
            }
        }
    }

    protected Service getControllingService() {
        return duplexInitiatingConnection != null ? duplexInitiatingConnection : DemandForwardingBridgeSupport.this;
    }

    protected void addSubscription(DemandSubscription sub) throws IOException {
        if (sub != null) {
            if (isDuplex()) {
                // async vm transport, need to wait for completion
                localBroker.request(sub.getLocalInfo());
            } else {
                localBroker.oneway(sub.getLocalInfo());
            }
        }
    }

    protected void removeSubscription(final DemandSubscription sub) throws IOException {
        if (sub != null) {
            LOG.trace("{} remove local subscription: {} for remote {}", new Object[]{configuration.getBrokerName(), sub.getLocalInfo().getConsumerId(), sub.getRemoteInfo().getConsumerId()});

            // ensure not available for conduit subs pending removal
            subscriptionMapByLocalId.remove(sub.getLocalInfo().getConsumerId());
            subscriptionMapByRemoteId.remove(sub.getRemoteInfo().getConsumerId());

            // continue removal in separate thread to free up this thread for outstanding responses
            // Serialize with removeDestination operations so that removeSubs are serialized with
            // removeDestinations such that all removeSub advisories are generated
            serialExecutor.execute(new Runnable() {
                @Override
                public void run() {
                    sub.waitForCompletion();
                    try {
                        localBroker.oneway(sub.getLocalInfo().createRemoveCommand());
                    } catch (IOException e) {
                        LOG.warn("failed to deliver remove command for local subscription, for remote {}", sub.getRemoteInfo().getConsumerId(), e);
                    }
                }
            });
        }
    }

    protected Message configureMessage(MessageDispatch md) throws IOException {
        Message message = md.getMessage().copy();
        // Update the packet to show where it came from.
        message.setBrokerPath(appendToBrokerPath(message.getBrokerPath(), localBrokerPath));
        message.setProducerId(producerInfo.getProducerId());
        message.setDestination(md.getDestination());
        message.setMemoryUsage(null);
        if (message.getOriginalTransactionId() == null) {
            message.setOriginalTransactionId(message.getTransactionId());
        }
        message.setTransactionId(null);
        if (configuration.isUseCompression()) {
            message.compress();
        }
        return message;
    }

    protected void serviceLocalCommand(Command command) {
        if (!disposed.get()) {
            try {
                if (command.isMessageDispatch()) {
                    safeWaitUntilStarted();
                    enqueueCounter.incrementAndGet();
                    final MessageDispatch md = (MessageDispatch) command;
                    final DemandSubscription sub = subscriptionMapByLocalId.get(md.getConsumerId());
                    if (sub != null && md.getMessage() != null && sub.incrementOutstandingResponses()) {

                        if (suppressMessageDispatch(md, sub)) {
                            LOG.debug("{} message not forwarded to {} because message came from there or fails TTL, brokerPath: {}, message: {}", new Object[]{
                                    configuration.getBrokerName(), remoteBrokerName, Arrays.toString(md.getMessage().getBrokerPath()), md.getMessage()
                            });
                            // still ack as it may be durable
                            try {
                                localBroker.oneway(new MessageAck(md, MessageAck.INDIVIDUAL_ACK_TYPE, 1));
                            } finally {
                                sub.decrementOutstandingResponses();
                            }
                            return;
                        }

                        Message message = configureMessage(md);
                        LOG.debug("bridging ({} -> {}), consumer: {}, destination: {}, brokerPath: {}, message: {}", new Object[]{
                                configuration.getBrokerName(), remoteBrokerName, (LOG.isTraceEnabled() ? message : message.getMessageId()), md.getConsumerId(), message.getDestination(), Arrays.toString(message.getBrokerPath()), message
                        });

                        if (isDuplex() && NetworkBridgeFilter.isAdvisoryInterpretedByNetworkBridge(message)) {
                            try {
                                // never request b/c they are eventually acked async
                                remoteBroker.oneway(message);
                            } finally {
                                sub.decrementOutstandingResponses();
                            }
                            return;
                        }

                        if (message.isPersistent() || configuration.isAlwaysSyncSend()) {

                            // The message was not sent using async send, so we should only
                            // ack the local broker when we get confirmation that the remote
                            // broker has received the message.
                            remoteBroker.asyncRequest(message, new ResponseCallback() {
                                @Override
                                public void onCompletion(FutureResponse future) {
                                    try {
                                        Response response = future.getResult();
                                        if (response.isException()) {
                                            ExceptionResponse er = (ExceptionResponse) response;
                                            serviceLocalException(md, er.getException());
                                        } else {
                                            localBroker.oneway(new MessageAck(md, MessageAck.INDIVIDUAL_ACK_TYPE, 1));
                                            dequeueCounter.incrementAndGet();
                                        }
                                    } catch (IOException e) {
                                        serviceLocalException(md, e);
                                    } finally {
                                        sub.decrementOutstandingResponses();
                                    }
                                }
                            });

                        } else {
                            // If the message was originally sent using async send, we will
                            // preserve that QOS by bridging it using an async send (small chance
                            // of message loss).
                            try {
                                remoteBroker.oneway(message);
                                localBroker.oneway(new MessageAck(md, MessageAck.INDIVIDUAL_ACK_TYPE, 1));
                                dequeueCounter.incrementAndGet();
                            } finally {
                                sub.decrementOutstandingResponses();
                            }
                        }
                        serviceOutbound(message);
                    } else {
                        LOG.debug("No subscription registered with this network bridge for consumerId: {} for message: {}", md.getConsumerId(), md.getMessage());
                    }
                } else if (command.isBrokerInfo()) {
                    futureLocalBrokerInfo.set((BrokerInfo) command);
                } else if (command.isShutdownInfo()) {
                    LOG.info("{} Shutting down {}", configuration.getBrokerName(), configuration.getName());
                    stop();
                } else if (command.getClass() == ConnectionError.class) {
                    ConnectionError ce = (ConnectionError) command;
                    serviceLocalException(ce.getException());
                } else {
                    switch (command.getDataStructureType()) {
                        case WireFormatInfo.DATA_STRUCTURE_TYPE:
                            break;
                        default:
                            LOG.warn("Unexpected local command: {}", command);
                    }
                }
            } catch (Throwable e) {
                LOG.warn("Caught an exception processing local command", e);
                serviceLocalException(e);
            }
        }
    }

    private boolean suppressMessageDispatch(MessageDispatch md, DemandSubscription sub) throws Exception {
        boolean suppress = false;
        // for durable subs, suppression via filter leaves dangling acks so we
        // need to check here and allow the ack irrespective
        if (sub.getLocalInfo().isDurable()) {
            MessageEvaluationContext messageEvalContext = new MessageEvaluationContext();
            messageEvalContext.setMessageReference(md.getMessage());
            messageEvalContext.setDestination(md.getDestination());
            suppress = !sub.getNetworkBridgeFilter().matches(messageEvalContext);
        }
        return suppress;
    }

    public static boolean contains(BrokerId[] brokerPath, BrokerId brokerId) {
        if (brokerPath != null) {
            for (BrokerId id : brokerPath) {
                if (brokerId.equals(id)) {
                    return true;
                }
            }
        }
        return false;
    }

    protected BrokerId[] appendToBrokerPath(BrokerId[] brokerPath, BrokerId[] pathsToAppend) {
        if (brokerPath == null || brokerPath.length == 0) {
            return pathsToAppend;
        }
        BrokerId rc[] = new BrokerId[brokerPath.length + pathsToAppend.length];
        System.arraycopy(brokerPath, 0, rc, 0, brokerPath.length);
        System.arraycopy(pathsToAppend, 0, rc, brokerPath.length, pathsToAppend.length);
        return rc;
    }

    protected BrokerId[] appendToBrokerPath(BrokerId[] brokerPath, BrokerId idToAppend) {
        if (brokerPath == null || brokerPath.length == 0) {
            return new BrokerId[]{idToAppend};
        }
        BrokerId rc[] = new BrokerId[brokerPath.length + 1];
        System.arraycopy(brokerPath, 0, rc, 0, brokerPath.length);
        rc[brokerPath.length] = idToAppend;
        return rc;
    }

    protected boolean isPermissableDestination(ActiveMQDestination destination) {
        return isPermissableDestination(destination, false);
    }

    protected boolean isPermissableDestination(ActiveMQDestination destination, boolean allowTemporary) {
        // Are we not bridging temporary destinations?
        if (destination.isTemporary()) {
            if (allowTemporary) {
                return true;
            } else {
                return configuration.isBridgeTempDestinations();
            }
        }

        ActiveMQDestination[] dests = staticallyIncludedDestinations;
        if (dests != null && dests.length > 0) {
            for (ActiveMQDestination dest : dests) {
                DestinationFilter inclusionFilter = DestinationFilter.parseFilter(dest);
                if (dest != null && inclusionFilter.matches(destination) && dest.getDestinationType() == destination.getDestinationType()) {
                    return true;
                }
            }
        }

        dests = excludedDestinations;
        if (dests != null && dests.length > 0) {
            for (ActiveMQDestination dest : dests) {
                DestinationFilter exclusionFilter = DestinationFilter.parseFilter(dest);
                if (dest != null && exclusionFilter.matches(destination) && dest.getDestinationType() == destination.getDestinationType()) {
                    return false;
                }
            }
        }

        dests = dynamicallyIncludedDestinations;
        if (dests != null && dests.length > 0) {
            for (ActiveMQDestination dest : dests) {
                DestinationFilter inclusionFilter = DestinationFilter.parseFilter(dest);
                if (dest != null && inclusionFilter.matches(destination) && dest.getDestinationType() == destination.getDestinationType()) {
                    return true;
                }
            }

            return false;
        }
        return true;
    }

    /**
     * Subscriptions for these destinations are always created
     */
    protected void setupStaticDestinations() {
        ActiveMQDestination[] dests = staticallyIncludedDestinations;
        if (dests != null) {
            for (ActiveMQDestination dest : dests) {
                DemandSubscription sub = createDemandSubscription(dest);
                sub.setStaticallyIncluded(true);
                try {
                    addSubscription(sub);
                } catch (IOException e) {
                    LOG.error("Failed to add static destination {}", dest, e);
                }
                LOG.trace("{}, bridging messages for static destination: {}", configuration.getBrokerName(), dest);
            }
        }
    }

    protected void addConsumerInfo(final ConsumerInfo consumerInfo) throws IOException {
        ConsumerInfo info = consumerInfo.copy();
        addRemoteBrokerToBrokerPath(info);
        DemandSubscription sub = createDemandSubscription(info);
        if (sub != null) {
            if (duplicateSuppressionIsRequired(sub)) {
                undoMapRegistration(sub);
            } else {
                if (consumerInfo.isDurable()) {
                    sub.getDurableRemoteSubs().add(new SubscriptionInfo(sub.getRemoteInfo().getClientId(), consumerInfo.getSubscriptionName()));
                }
                addSubscription(sub);
                LOG.debug("{} new demand subscription: {}", configuration.getBrokerName(), sub);
            }
        }
    }

    private void undoMapRegistration(DemandSubscription sub) {
        subscriptionMapByLocalId.remove(sub.getLocalInfo().getConsumerId());
        subscriptionMapByRemoteId.remove(sub.getRemoteInfo().getConsumerId());
    }

    /*
     * check our existing subs networkConsumerIds against the list of network
     * ids in this subscription A match means a duplicate which we suppress for
     * topics and maybe for queues
     */
    private boolean duplicateSuppressionIsRequired(DemandSubscription candidate) {
        final ConsumerInfo consumerInfo = candidate.getRemoteInfo();
        boolean suppress = false;

        if (consumerInfo.getDestination().isQueue() && !configuration.isSuppressDuplicateQueueSubscriptions() || consumerInfo.getDestination().isTopic()
                && !configuration.isSuppressDuplicateTopicSubscriptions()) {
            return suppress;
        }

        List<ConsumerId> candidateConsumers = consumerInfo.getNetworkConsumerIds();
        Collection<Subscription> currentSubs = getRegionSubscriptions(consumerInfo.getDestination());
        for (Subscription sub : currentSubs) {
            List<ConsumerId> networkConsumers = sub.getConsumerInfo().getNetworkConsumerIds();
            if (!networkConsumers.isEmpty()) {
                if (matchFound(candidateConsumers, networkConsumers)) {
                    if (isInActiveDurableSub(sub)) {
                        suppress = false;
                    } else {
                        suppress = hasLowerPriority(sub, candidate.getLocalInfo());
                    }
                    break;
                }
            }
        }
        return suppress;
    }

    private boolean isInActiveDurableSub(Subscription sub) {
        return (sub.getConsumerInfo().isDurable() && sub instanceof DurableTopicSubscription && !((DurableTopicSubscription) sub).isActive());
    }

    private boolean hasLowerPriority(Subscription existingSub, ConsumerInfo candidateInfo) {
        boolean suppress = false;

        if (existingSub.getConsumerInfo().getPriority() >= candidateInfo.getPriority()) {
            LOG.debug("{} Ignoring duplicate subscription from {}, sub: {} is duplicate by network subscription with equal or higher network priority: {}, networkConsumerIds: {}", new Object[]{
                    configuration.getBrokerName(), remoteBrokerName, candidateInfo, existingSub, existingSub.getConsumerInfo().getNetworkConsumerIds()
            });
            suppress = true;
        } else {
            // remove the existing lower priority duplicate and allow this candidate
            try {
                removeDuplicateSubscription(existingSub);

                LOG.debug("{} Replacing duplicate subscription {} with sub from {}, which has a higher priority, new sub: {}, networkConsumerIds: {}", new Object[]{
                        configuration.getBrokerName(), existingSub.getConsumerInfo(), remoteBrokerName, candidateInfo, candidateInfo.getNetworkConsumerIds()
                });
            } catch (IOException e) {
                LOG.error("Failed to remove duplicated sub as a result of sub with higher priority, sub: {}", existingSub, e);
            }
        }
        return suppress;
    }

    private void removeDuplicateSubscription(Subscription existingSub) throws IOException {
        for (NetworkConnector connector : brokerService.getNetworkConnectors()) {
            if (connector.removeDemandSubscription(existingSub.getConsumerInfo().getConsumerId())) {
                break;
            }
        }
    }

    private boolean matchFound(List<ConsumerId> candidateConsumers, List<ConsumerId> networkConsumers) {
        boolean found = false;
        for (ConsumerId aliasConsumer : networkConsumers) {
            if (candidateConsumers.contains(aliasConsumer)) {
                found = true;
                break;
            }
        }
        return found;
    }

    protected final Collection<Subscription> getRegionSubscriptions(ActiveMQDestination dest) {
        RegionBroker region_broker = (RegionBroker) brokerService.getRegionBroker();
        Region region;
        Collection<Subscription> subs;

        region = null;
        switch (dest.getDestinationType()) {
            case ActiveMQDestination.QUEUE_TYPE:
                region = region_broker.getQueueRegion();
                break;
            case ActiveMQDestination.TOPIC_TYPE:
                region = region_broker.getTopicRegion();
                break;
            case ActiveMQDestination.TEMP_QUEUE_TYPE:
                region = region_broker.getTempQueueRegion();
                break;
            case ActiveMQDestination.TEMP_TOPIC_TYPE:
                region = region_broker.getTempTopicRegion();
                break;
        }

        if (region instanceof AbstractRegion) {
            subs = ((AbstractRegion) region).getSubscriptions().values();
        } else {
            subs = null;
        }

        return subs;
    }

    protected DemandSubscription createDemandSubscription(ConsumerInfo info) throws IOException {
        // add our original id to ourselves
        info.addNetworkConsumerId(info.getConsumerId());
        return doCreateDemandSubscription(info);
    }

    protected DemandSubscription doCreateDemandSubscription(ConsumerInfo info) throws IOException {
        DemandSubscription result = new DemandSubscription(info);
        result.getLocalInfo().setConsumerId(new ConsumerId(localSessionInfo.getSessionId(), consumerIdGenerator.getNextSequenceId()));
        if (info.getDestination().isTemporary()) {
            // reset the local connection Id
            ActiveMQTempDestination dest = (ActiveMQTempDestination) result.getLocalInfo().getDestination();
            dest.setConnectionId(localConnectionInfo.getConnectionId().toString());
        }

        if (configuration.isDecreaseNetworkConsumerPriority()) {
            byte priority = (byte) configuration.getConsumerPriorityBase();
            if (info.getBrokerPath() != null && info.getBrokerPath().length > 1) {
                // The longer the path to the consumer, the less it's consumer priority.
                priority -= info.getBrokerPath().length + 1;
            }
            result.getLocalInfo().setPriority(priority);
            LOG.debug("{} using priority: {} for subscription: {}", new Object[]{configuration.getBrokerName(), priority, info});
        }
        configureDemandSubscription(info, result);
        return result;
    }

    final protected DemandSubscription createDemandSubscription(ActiveMQDestination destination) {
        ConsumerInfo info = new ConsumerInfo();
        info.setNetworkSubscription(true);
        info.setDestination(destination);

        // Indicate that this subscription is being made on behalf of the remote broker.
        info.setBrokerPath(new BrokerId[]{remoteBrokerId});

        // the remote info held by the DemandSubscription holds the original
        // consumerId, the local info get's overwritten
        info.setConsumerId(new ConsumerId(localSessionInfo.getSessionId(), consumerIdGenerator.getNextSequenceId()));
        DemandSubscription result = null;
        try {
            result = createDemandSubscription(info);
        } catch (IOException e) {
            LOG.error("Failed to create DemandSubscription ", e);
        }
        return result;
    }

    protected void configureDemandSubscription(ConsumerInfo info, DemandSubscription sub) throws IOException {
        if (AdvisorySupport.isConsumerAdvisoryTopic(info.getDestination()) ||
                AdvisorySupport.isVirtualDestinationConsumerAdvisoryTopic(info.getDestination())) {
            sub.getLocalInfo().setDispatchAsync(true);
        } else {
            sub.getLocalInfo().setDispatchAsync(configuration.isDispatchAsync());
        }
        sub.getLocalInfo().setPrefetchSize(configuration.getPrefetchSize());
        subscriptionMapByLocalId.put(sub.getLocalInfo().getConsumerId(), sub);
        subscriptionMapByRemoteId.put(sub.getRemoteInfo().getConsumerId(), sub);

        sub.setNetworkBridgeFilter(createNetworkBridgeFilter(info));
        if (!info.isDurable()) {
            // This works for now since we use a VM connection to the local broker.
            // may need to change if we ever subscribe to a remote broker.
            sub.getLocalInfo().setAdditionalPredicate(sub.getNetworkBridgeFilter());
        } else {
            sub.setLocalDurableSubscriber(new SubscriptionInfo(info.getClientId(), info.getSubscriptionName()));
        }
    }

    protected void removeDemandSubscription(ConsumerId id) throws IOException {
        DemandSubscription sub = subscriptionMapByRemoteId.remove(id);
        LOG.debug("{} remove request on {} from {}, consumer id: {}, matching sub: {}", new Object[]{
                configuration.getBrokerName(), localBroker, remoteBrokerName, id, sub
        });
        if (sub != null) {
            removeSubscription(sub);
            LOG.debug("{} removed sub on {} from {}: {}", new Object[]{
                    configuration.getBrokerName(), localBroker, remoteBrokerName, sub.getRemoteInfo()
            });
        }
    }

    protected boolean removeDemandSubscriptionByLocalId(ConsumerId consumerId) {
        boolean removeDone = false;
        DemandSubscription sub = subscriptionMapByLocalId.get(consumerId);
        if (sub != null) {
            try {
                removeDemandSubscription(sub.getRemoteInfo().getConsumerId());
                removeDone = true;
            } catch (IOException e) {
                LOG.debug("removeDemandSubscriptionByLocalId failed for localId: {}", consumerId, e);
            }
        }
        return removeDone;
    }

    /**
     * Performs a timed wait on the started latch and then checks for disposed
     * before performing another wait each time the the started wait times out.
     */
    protected boolean safeWaitUntilStarted() throws InterruptedException {
        while (!disposed.get()) {
            if (startedLatch.await(1, TimeUnit.SECONDS)) {
                break;
            }
        }
        return !disposed.get();
    }

    protected NetworkBridgeFilter createNetworkBridgeFilter(ConsumerInfo info) throws IOException {
        NetworkBridgeFilterFactory filterFactory = defaultFilterFactory;
        if (brokerService != null && brokerService.getDestinationPolicy() != null) {
            PolicyEntry entry = brokerService.getDestinationPolicy().getEntryFor(info.getDestination());
            if (entry != null && entry.getNetworkBridgeFilterFactory() != null) {
                filterFactory = entry.getNetworkBridgeFilterFactory();
            }
        }
        return filterFactory.create(info, getRemoteBrokerPath(), configuration.getMessageTTL(), configuration.getConsumerTTL());
    }

    protected void addRemoteBrokerToBrokerPath(ConsumerInfo info) throws IOException {
        info.setBrokerPath(appendToBrokerPath(info.getBrokerPath(), getRemoteBrokerPath()));
    }

    protected BrokerId[] getRemoteBrokerPath() {
        return remoteBrokerPath;
    }

    @Override
    public void setNetworkBridgeListener(NetworkBridgeListener listener) {
        this.networkBridgeListener = listener;
    }

    private void fireBridgeFailed(Throwable reason) {
        LOG.trace("fire bridge failed, listener: {}", this.networkBridgeListener, reason);
        NetworkBridgeListener l = this.networkBridgeListener;
        if (l != null && this.bridgeFailed.compareAndSet(false, true)) {
            l.bridgeFailed();
        }
    }

    /**
     * @return Returns the dynamicallyIncludedDestinations.
     */
    public ActiveMQDestination[] getDynamicallyIncludedDestinations() {
        return dynamicallyIncludedDestinations;
    }

    /**
     * @param dynamicallyIncludedDestinations
     *         The dynamicallyIncludedDestinations to set.
     */
    public void setDynamicallyIncludedDestinations(ActiveMQDestination[] dynamicallyIncludedDestinations) {
        this.dynamicallyIncludedDestinations = dynamicallyIncludedDestinations;
    }

    /**
     * @return Returns the excludedDestinations.
     */
    public ActiveMQDestination[] getExcludedDestinations() {
        return excludedDestinations;
    }

    /**
     * @param excludedDestinations The excludedDestinations to set.
     */
    public void setExcludedDestinations(ActiveMQDestination[] excludedDestinations) {
        this.excludedDestinations = excludedDestinations;
    }

    /**
     * @return Returns the staticallyIncludedDestinations.
     */
    public ActiveMQDestination[] getStaticallyIncludedDestinations() {
        return staticallyIncludedDestinations;
    }

    /**
     * @param staticallyIncludedDestinations The staticallyIncludedDestinations to set.
     */
    public void setStaticallyIncludedDestinations(ActiveMQDestination[] staticallyIncludedDestinations) {
        this.staticallyIncludedDestinations = staticallyIncludedDestinations;
    }

    /**
     * @return Returns the durableDestinations.
     */
    public ActiveMQDestination[] getDurableDestinations() {
        return durableDestinations;
    }

    /**
     * @param durableDestinations The durableDestinations to set.
     */
    public void setDurableDestinations(ActiveMQDestination[] durableDestinations) {
        this.durableDestinations = durableDestinations;
    }

    /**
     * @return Returns the localBroker.
     */
    public Transport getLocalBroker() {
        return localBroker;
    }

    /**
     * @return Returns the remoteBroker.
     */
    public Transport getRemoteBroker() {
        return remoteBroker;
    }

    /**
     * @return the createdByDuplex
     */
    public boolean isCreatedByDuplex() {
        return this.createdByDuplex;
    }

    /**
     * @param createdByDuplex the createdByDuplex to set
     */
    public void setCreatedByDuplex(boolean createdByDuplex) {
        this.createdByDuplex = createdByDuplex;
    }

    @Override
    public String getRemoteAddress() {
        return remoteBroker.getRemoteAddress();
    }

    @Override
    public String getLocalAddress() {
        return localBroker.getRemoteAddress();
    }

    @Override
    public String getRemoteBrokerName() {
        return remoteBrokerInfo == null ? null : remoteBrokerInfo.getBrokerName();
    }

    @Override
    public String getRemoteBrokerId() {
        return (remoteBrokerInfo == null || remoteBrokerInfo.getBrokerId() == null) ? null : remoteBrokerInfo.getBrokerId().toString();
    }

    @Override
    public String getLocalBrokerName() {
        return localBrokerInfo == null ? null : localBrokerInfo.getBrokerName();
    }

    @Override
    public long getDequeueCounter() {
        return dequeueCounter.get();
    }

    @Override
    public long getEnqueueCounter() {
        return enqueueCounter.get();
    }

    protected boolean isDuplex() {
        return configuration.isDuplex() || createdByDuplex;
    }

    public ConcurrentMap<ConsumerId, DemandSubscription> getLocalSubscriptionMap() {
        return subscriptionMapByRemoteId;
    }

    @Override
    public void setBrokerService(BrokerService brokerService) {
        this.brokerService = brokerService;
        this.localBrokerId = brokerService.getRegionBroker().getBrokerId();
        localBrokerPath[0] = localBrokerId;
    }

    @Override
    public void setMbeanObjectName(ObjectName objectName) {
        this.mbeanObjectName = objectName;
    }

    @Override
    public ObjectName getMbeanObjectName() {
        return mbeanObjectName;
    }

    @Override
    public void resetStats() {
        enqueueCounter.set(0);
        dequeueCounter.set(0);
    }

    /*
     * Used to allow for async tasks to await receipt of the BrokerInfo from the local and
     * remote sides of the network bridge.
     */
    private static class FutureBrokerInfo implements Future<BrokerInfo> {

        private final CountDownLatch slot = new CountDownLatch(1);
        private final AtomicBoolean disposed;
        private volatile BrokerInfo info = null;

        public FutureBrokerInfo(BrokerInfo info, AtomicBoolean disposed) {
            this.info = info;
            this.disposed = disposed;
        }

        @Override
        public boolean cancel(boolean mayInterruptIfRunning) {
            slot.countDown();
            return true;
        }

        @Override
        public boolean isCancelled() {
            return slot.getCount() == 0 && info == null;
        }

        @Override
        public boolean isDone() {
            return info != null;
        }

        @Override
        public BrokerInfo get() throws InterruptedException, ExecutionException {
            try {
                if (info == null) {
                    while (!disposed.get()) {
                        if (slot.await(1, TimeUnit.SECONDS)) {
                            break;
                        }
                    }
                }
                return info;
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                LOG.debug("Operation interrupted: {}", e, e);
                throw new InterruptedException("Interrupted.");
            }
        }

        @Override
        public BrokerInfo get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
            try {
                if (info == null) {
                    long deadline = System.currentTimeMillis() + unit.toMillis(timeout);

                    while (!disposed.get() || System.currentTimeMillis() < deadline) {
                        if (slot.await(1, TimeUnit.MILLISECONDS)) {
                            break;
                        }
                    }
                    if (info == null) {
                        throw new TimeoutException();
                    }
                }
                return info;
            } catch (InterruptedException e) {
                throw new InterruptedException("Interrupted.");
            }
        }

        public void set(BrokerInfo info) {
            this.info = info;
            this.slot.countDown();
        }
    }

    protected void serviceOutbound(Message message) {
        NetworkBridgeListener l = this.networkBridgeListener;
        if (l != null) {
            l.onOutboundMessage(this, message);
        }
    }

    protected void serviceInboundMessage(Message message) {
        NetworkBridgeListener l = this.networkBridgeListener;
        if (l != null) {
            l.onInboundMessage(this, message);
        }
    }

    protected boolean canDuplexDispatch(Message message) {
        boolean result = true;
        if (configuration.isCheckDuplicateMessagesOnDuplex()){
            final long producerSequenceId = message.getMessageId().getProducerSequenceId();
            //  messages are multiplexed on this producer so we need to query the persistenceAdapter
            long lastStoredForMessageProducer = getStoredSequenceIdForMessage(message.getMessageId());
            if (producerSequenceId <= lastStoredForMessageProducer) {
                result = false;
                LOG.debug("suppressing duplicate message send [{}] from network producer with producerSequence [{}] less than last stored: {}", new Object[]{
                        (LOG.isTraceEnabled() ? message : message.getMessageId()), producerSequenceId, lastStoredForMessageProducer
                });
            }
        }
        return result;
    }

    protected long getStoredSequenceIdForMessage(MessageId messageId) {
        try {
            return brokerService.getPersistenceAdapter().getLastProducerSequenceId(messageId.getProducerId());
        } catch (IOException ignored) {
            LOG.debug("Failed to determine last producer sequence id for: {}", messageId, ignored);
        }
        return -1;
    }

}