/*
 * 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.artemis.core.server.cluster.impl;

import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.concurrent.Executor;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

import org.apache.activemq.artemis.api.core.ActiveMQAddressFullException;
import org.apache.activemq.artemis.api.core.ActiveMQException;
import org.apache.activemq.artemis.api.core.ActiveMQExceptionType;
import org.apache.activemq.artemis.api.core.ActiveMQInterruptedException;
import org.apache.activemq.artemis.api.core.Message;
import org.apache.activemq.artemis.api.core.Pair;
import org.apache.activemq.artemis.api.core.RefCountMessage;
import org.apache.activemq.artemis.api.core.RoutingType;
import org.apache.activemq.artemis.api.core.SimpleString;
import org.apache.activemq.artemis.api.core.TransportConfiguration;
import org.apache.activemq.artemis.api.core.client.ClientProducer;
import org.apache.activemq.artemis.api.core.client.ClientSession;
import org.apache.activemq.artemis.api.core.client.ClientSessionFactory;
import org.apache.activemq.artemis.api.core.client.ClusterTopologyListener;
import org.apache.activemq.artemis.api.core.client.SendAcknowledgementHandler;
import org.apache.activemq.artemis.api.core.client.SessionFailureListener;
import org.apache.activemq.artemis.api.core.client.TopologyMember;
import org.apache.activemq.artemis.api.core.management.CoreNotificationType;
import org.apache.activemq.artemis.core.client.impl.ClientProducerCredits;
import org.apache.activemq.artemis.core.client.impl.ClientProducerFlowCallback;
import org.apache.activemq.artemis.core.client.impl.ClientSessionFactoryImpl;
import org.apache.activemq.artemis.core.client.impl.ClientSessionFactoryInternal;
import org.apache.activemq.artemis.core.client.impl.ClientSessionInternal;
import org.apache.activemq.artemis.core.client.impl.ServerLocatorInternal;
import org.apache.activemq.artemis.core.config.BridgeConfiguration;
import org.apache.activemq.artemis.core.filter.Filter;
import org.apache.activemq.artemis.core.filter.impl.FilterImpl;
import org.apache.activemq.artemis.core.server.ActiveMQServer;
import org.apache.activemq.artemis.core.server.ActiveMQServerLogger;
import org.apache.activemq.artemis.core.server.HandleStatus;
import org.apache.activemq.artemis.core.server.LargeServerMessage;
import org.apache.activemq.artemis.core.server.MessageReference;
import org.apache.activemq.artemis.core.server.Queue;
import org.apache.activemq.artemis.core.server.cluster.Bridge;
import org.apache.activemq.artemis.core.server.impl.QueueImpl;
import org.apache.activemq.artemis.core.server.management.Notification;
import org.apache.activemq.artemis.core.server.management.NotificationService;
import org.apache.activemq.artemis.core.server.transformer.Transformer;
import org.apache.activemq.artemis.spi.core.protocol.EmbedMessageUtil;
import org.apache.activemq.artemis.spi.core.protocol.RemotingConnection;
import org.apache.activemq.artemis.spi.core.remoting.ReadyListener;
import org.apache.activemq.artemis.utils.FutureLatch;
import org.apache.activemq.artemis.utils.ReusableLatch;
import org.apache.activemq.artemis.utils.UUID;
import org.apache.activemq.artemis.utils.collections.TypedProperties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.lang.invoke.MethodHandles;
import org.apache.activemq.artemis.api.core.ActiveMQDisconnectedException;

/**
 * A Core BridgeImpl
 */

public class BridgeImpl implements Bridge, SessionFailureListener, SendAcknowledgementHandler, ReadyListener, ClientProducerFlowCallback {

   private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

   protected final ServerLocatorInternal serverLocator;

   protected final Executor executor;

   protected final ScheduledExecutorService scheduledExecutor;

   private final ReusableLatch pendingAcks = new ReusableLatch(0);

   private final UUID nodeUUID;

   private final long sequentialID;

   protected final Queue queue;

   private final Filter filter;

   final java.util.Map<Long, MessageReference> refs = new LinkedHashMap<>();

   private final Transformer transformer;

   private final Object connectionGuard = new Object();

   private boolean blockedOnFlowControl;

   /**
    * Used when there's a scheduled reconnection
    */
   protected ScheduledFuture<?> futureScheduledReconnection;

   protected volatile ClientSessionInternal session;

   // on cases where sub-classes need a consumer
   protected volatile ClientSessionInternal sessionConsumer;


   // this will happen if a disconnect happened
   // upon reconnection we need to send the nodeUP back into the topology
   protected volatile boolean disconnectedAndDown = false;

   protected String targetNodeID;

   protected TopologyMember targetNode;

   private volatile ClientSessionFactoryInternal csf;

   private volatile ClientProducer producer;

   private volatile boolean started;

   private volatile boolean stopping = false;

   private volatile boolean active;

   private boolean deliveringLargeMessage;

   private int reconnectAttemptsInUse;

   private int retryCount = 0;

   private NotificationService notificationService;

   private boolean keepConnecting = true;

   private ActiveMQServer server;

   private final BridgeMetrics metrics = new BridgeMetrics();

   private BridgeConfiguration configuration;

   public BridgeImpl(final ServerLocatorInternal serverLocator,
                     final BridgeConfiguration configuration,
                     final UUID nodeUUID,
                     final Queue queue,
                     final Executor executor,
                     final ScheduledExecutorService scheduledExecutor,
                     final ActiveMQServer server) throws ActiveMQException {

      this.sequentialID = server.getStorageManager().generateID();

      this.configuration = configuration;

      this.reconnectAttemptsInUse = configuration.getInitialConnectAttempts();

      this.serverLocator = serverLocator;

      this.nodeUUID = nodeUUID;

      this.queue = queue;

      this.executor = executor;

      this.scheduledExecutor = scheduledExecutor;

      this.transformer = server.getServiceRegistry().getBridgeTransformer(configuration.getName(), configuration.getTransformerConfiguration());

      this.filter = FilterImpl.createFilter(configuration.getFilterString());

      this.server = server;
   }

   /** For tests mainly */
   public boolean isBlockedOnFlowControl() {
      return blockedOnFlowControl;
   }

   public static final byte[] getDuplicateBytes(final UUID nodeUUID, final long messageID) {
      byte[] bytes = new byte[24];

      ByteBuffer bb = ByteBuffer.wrap(bytes);

      bb.put(nodeUUID.asBytes());

      bb.putLong(messageID);

      return bytes;
   }

   // for tests
   public ClientSessionFactory getSessionFactory() {
      return csf;
   }

   /* (non-Javadoc)
    * @see org.apache.activemq.artemis.core.server.Consumer#getDeliveringMessages()
    */
   @Override
   public List<MessageReference> getDeliveringMessages() {
      synchronized (refs) {
         return new ArrayList<>(refs.values());
      }
   }

   private static void cleanUpSessionFactory(ClientSessionFactoryInternal factory) {
      if (factory != null)
         factory.cleanup();
   }

   @Override
   public void setNotificationService(final NotificationService notificationService) {
      this.notificationService = notificationService;
   }

   @Override
   public void onCreditsFlow(boolean blocked, ClientProducerCredits producerCredits) {
      if (logger.isTraceEnabled()) {
         logger.trace("Bridge {} received credits, with blocked = {}", this.getName(), blocked);
      }
      this.blockedOnFlowControl = blocked;
      if (!blocked) {
         queue.deliverAsync();
      }
   }

   @Override
   public void onCreditsFail(ClientProducerCredits producerCredits) {
      ActiveMQServerLogger.LOGGER.bridgeAddressFull(String.valueOf(producerCredits.getAddress()), String.valueOf(this.getName()));
      disconnect();
   }

   @Override
   public long sequentialID() {
      return sequentialID;
   }

   @Override
   public synchronized void start() throws Exception {
      if (started) {
         return;
      }

      started = true;

      stopping = false;

      activate();

      if (notificationService != null) {
         TypedProperties props = new TypedProperties();
         props.putSimpleStringProperty(new SimpleString("name"), SimpleString.toSimpleString(configuration.getName()));
         Notification notification = new Notification(nodeUUID.toString(), CoreNotificationType.BRIDGE_STARTED, props);
         notificationService.sendNotification(notification);
      }
   }

   @Override
   public String debug() {
      return toString();
   }

   private void cancelRefs() {
      LinkedList<MessageReference> list = new LinkedList<>();

      synchronized (refs) {
         list.addAll(refs.values());
         refs.clear();
      }

      if (logger.isTraceEnabled()) {
         logger.trace("BridgeImpl::cancelRefs cancelling {} references", list.size());
      }

      if (logger.isTraceEnabled() && list.isEmpty()) {
         logger.trace("didn't have any references to cancel on bridge {}", this);
         return;
      }

      ListIterator<MessageReference> listIterator = list.listIterator(list.size());

      Queue refqueue;

      long timeBase = System.currentTimeMillis();

      while (listIterator.hasPrevious()) {
         MessageReference ref = listIterator.previous();

         logger.trace("BridgeImpl::cancelRefs Cancelling reference {} on bridge {}", ref, this);

         refqueue = ref.getQueue();

         try {
            refqueue.cancel(ref, timeBase);
         } catch (Exception e) {
            // There isn't much we can do besides log an error
            ActiveMQServerLogger.LOGGER.errorCancellingRefOnBridge(ref, e);
         }
      }
   }

   @Override
   public void flushExecutor() {
      // Wait for any create objects runnable to complete
      FutureLatch future = new FutureLatch();

      executor.execute(future);

      boolean ok = future.await(10000);

      if (!ok) {
         ActiveMQServerLogger.LOGGER.timedOutWaitingToStopBridge();
      }
   }

   @Override
   public void disconnect() {
      executor.execute(new Runnable() {
         @Override
         public void run() {
            if (session != null) {
               try {
                  session.cleanUp(false);
               } catch (Exception dontcare) {
                  logger.debug(dontcare.getMessage(), dontcare);
               }
               session = null;
            }
            if (sessionConsumer != null) {
               try {
                  sessionConsumer.cleanUp(false);
               } catch (Exception dontcare) {
                  logger.debug(dontcare.getMessage(), dontcare);
               }
               sessionConsumer = null;
            }
         }
      });
   }

   @Override
   public boolean isConnected() {
      return session != null;
   }

   /**
    * The cluster manager needs to use the same executor to close the serverLocator, otherwise the stop will break.
    * This method is intended to expose this executor to the ClusterManager
    */
   public Executor getExecutor() {
      return executor;
   }

   @Override
   public void stop() throws Exception {
      if (stopping) {
         return;
      }

      stopping = true;

      logger.debug("Bridge {} being stopped", configuration.getName());

      if (futureScheduledReconnection != null) {
         futureScheduledReconnection.cancel(true);
      }

      executor.execute(new StopRunnable());

      if (notificationService != null) {
         TypedProperties props = new TypedProperties();
         props.putSimpleStringProperty(new SimpleString("name"), SimpleString.toSimpleString(configuration.getName()));
         Notification notification = new Notification(nodeUUID.toString(), CoreNotificationType.BRIDGE_STOPPED, props);
         try {
            notificationService.sendNotification(notification);
         } catch (Exception e) {
            ActiveMQServerLogger.LOGGER.broadcastBridgeStoppedError(e);
         }
      }
   }

   @Override
   public void pause() throws Exception {
      logger.debug("Bridge {} being paused", configuration.getName());

      executor.execute(new PauseRunnable());

      if (notificationService != null) {
         TypedProperties props = new TypedProperties();
         props.putSimpleStringProperty(new SimpleString("name"), SimpleString.toSimpleString(configuration.getName()));
         Notification notification = new Notification(nodeUUID.toString(), CoreNotificationType.BRIDGE_STOPPED, props);
         try {
            notificationService.sendNotification(notification);
         } catch (Exception e) {
            ActiveMQServerLogger.LOGGER.notificationBridgeStoppedError(e);
         }
      }
   }

   @Override
   public void resume() throws Exception {
      queue.addConsumer(BridgeImpl.this);
      queue.deliverAsync();
   }

   @Override
   public boolean isStarted() {
      return started;
   }

   public synchronized void activate() {
      executor.execute(new ConnectRunnable(this));
   }

   @Override
   public SimpleString getName() {
      return SimpleString.toSimpleString(configuration.getName());
   }

   @Override
   public Queue getQueue() {
      return queue;
   }

   @Override
   public Filter getFilter() {
      return filter;
   }

   // SendAcknowledgementHandler implementation ---------------------

   @Override
   public SimpleString getForwardingAddress() {
      return SimpleString.toSimpleString(configuration.getForwardingAddress());
   }

   // For testing only
   @Override
   public RemotingConnection getForwardingConnection() {
      if (session == null) {
         return null;
      } else {
         return session.getConnection();
      }
   }

   @Override
   public void sendFailed(Message message, Exception e) {
      if (e instanceof ActiveMQAddressFullException) {
         logger.warn(e.getMessage(), e);
         failed(e);
      }
   }

   @Override
   public void sendAcknowledged(final Message message) {
      logger.trace("BridgeImpl::sendAcknowledged received confirmation for message {}", message);

      if (active) {
         try {

            final MessageReference ref;

            synchronized (refs) {
               ref = refs.remove(message.getMessageID());
            }

            if (ref != null) {
               if (logger.isTraceEnabled()) {
                  logger.trace("BridgeImpl::sendAcknowledged bridge {} Acking {} on queue {}", this, ref, ref.getQueue());
               }
               ref.getQueue().acknowledge(ref);
               pendingAcks.countDown();
               metrics.incrementMessagesAcknowledged();

               if (server.hasBrokerBridgePlugins()) {
                  server.callBrokerBridgePlugins(plugin -> plugin.afterAcknowledgeBridge(this, ref));
               }
            } else {
               logger.trace("BridgeImpl::sendAcknowledged bridge {} could not find reference for message {}", this, message);
            }
         } catch (Exception e) {
            ActiveMQServerLogger.LOGGER.bridgeFailedToAck(e);
         }
      }
   }

   @Override
   public void failed(Throwable t) {
      if (t instanceof ActiveMQException) {
         connectionFailed((ActiveMQException) t, false);
      } else {
         ActiveMQException exception = new ActiveMQException(t.getMessage());
         exception.initCause(t);
         connectionFailed(exception, false);
      }
   }

   /* Hook for processing message before forwarding */
   protected Message beforeForward(Message message, final SimpleString forwardingAddress) {
      message = message.copy();
      ((RefCountMessage)message).setParentRef((RefCountMessage)message);

      return beforeForwardingNoCopy(message, forwardingAddress);
   }

   /** ClusterConnectionBridge already makes a copy of the message.
    * So I needed I hook where the message is not copied. */
   protected Message beforeForwardingNoCopy(Message message, SimpleString forwardingAddress) {
      if (configuration.isUseDuplicateDetection()) {
         // We keep our own DuplicateID for the Bridge, so bouncing back and forth will work fine
         byte[] bytes = getDuplicateBytes(nodeUUID, message.getMessageID());

         message.putExtraBytesProperty(Message.HDR_BRIDGE_DUPLICATE_ID, bytes);
      }

      if (forwardingAddress != null) {
         // for AMQP messages this modification will be transient
         message.setAddress(forwardingAddress);
      }

      switch (configuration.getRoutingType()) {
         case ANYCAST:
            message.setRoutingType(RoutingType.ANYCAST);
            break;
         case MULTICAST:
            message.setRoutingType(RoutingType.MULTICAST);
            break;
         case STRIP:
            message.setRoutingType(null);
            break;
         case PASS:
            break;
      }

      message.messageChanged();

      if (transformer != null) {
         final Message transformedMessage = transformer.transform(message);
         if (transformedMessage != message) {
            logger.debug("The transformer {} made a copy of the message {} as transformedMessage", transformer, message);
         }
         return EmbedMessageUtil.embedAsCoreMessage(transformedMessage);
      } else {
         return EmbedMessageUtil.embedAsCoreMessage(message);
      }
   }

   @Override
   public void readyForWriting() {
      queue.deliverAsync();
   }


   @Override
   public HandleStatus handle(final MessageReference ref) throws Exception {
      if (RefCountMessage.isRefTraceEnabled() && ref.getMessage() instanceof RefCountMessage) {
         RefCountMessage.deferredDebug(ref.getMessage(), "Going through the bridge");
      }
      if (filter != null && !filter.match(ref.getMessage())) {
         logger.trace("message reference {} is no match for bridge {}", ref, configuration.getName());
         return HandleStatus.NO_MATCH;
      }

      synchronized (this) {
         if (!active || !session.isWritable(this)) {
            if (logger.isDebugEnabled()) {
               logger.debug("{}::Ignoring reference on bridge as it is set to inactive ref {}, active = {}", this, ref, active);
            }
            return HandleStatus.BUSY;
         }

         if (blockedOnFlowControl) {
            logger.debug("Bridge {} is blocked on flow control, cannot receive {}", configuration.getName(), ref);
            return HandleStatus.BUSY;
         }

         if (deliveringLargeMessage) {
            logger.trace("Bridge {} is busy delivering a large message", configuration.getName());
            return HandleStatus.BUSY;
         }

         logger.trace("Bridge {} is handling reference {} ", ref);

         ref.handled();

         synchronized (refs) {
            refs.put(ref.getMessage().getMessageID(), ref);
         }

         final SimpleString dest;

         if (configuration.getForwardingAddress() != null) {
            dest = SimpleString.toSimpleString(configuration.getForwardingAddress());
         } else {
            // Preserve the original address
            dest = ref.getMessage().getAddressSimpleString();
         }

         final Message message = beforeForward(ref.getMessage(), dest);

         pendingAcks.countUp();

         try {
            if (server.hasBrokerBridgePlugins()) {
               server.callBrokerBridgePlugins(plugin -> plugin.beforeDeliverBridge(this, ref));
            }

            final HandleStatus status;
            if (message.isLargeMessage()) {
               deliveringLargeMessage = true;
               deliverLargeMessage(dest, ref, (LargeServerMessage) message, ref.getMessage());
               status = HandleStatus.HANDLED;
            } else {
               status = deliverStandardMessage(dest, ref, message, ref.getMessage());
            }

            //Only increment messages pending acknowledgement if handled by bridge
            if (status == HandleStatus.HANDLED) {
               metrics.incrementMessagesPendingAcknowledgement();
            }

            if (server.hasBrokerBridgePlugins()) {
               server.callBrokerBridgePlugins(plugin -> plugin.afterDeliverBridge(this, ref, status));
            }

            return status;
         } catch (Exception e) {
            // If an exception happened, we must count down immediately
            pendingAcks.countDown();
            throw e;
         }
      }
   }

   // FailureListener implementation --------------------------------

   @Override
   public void proceedDeliver(MessageReference ref) {
      // no op
   }

   @Override
   public void connectionFailed(final ActiveMQException me, boolean failedOver) {
      connectionFailed(me, failedOver, null);
   }

   @Override
   public void connectionFailed(final ActiveMQException me, boolean failedOver, String scaleDownTargetNodeID) {
      if (server.isStarted()) {
         if (me instanceof ActiveMQDisconnectedException) {
            ActiveMQServerLogger.LOGGER.bridgeConnectionClosed(failedOver);
         } else {
            ActiveMQServerLogger.LOGGER.bridgeConnectionFailed(failedOver);
         }
      }

      synchronized (connectionGuard) {
         keepConnecting = true;
      }

      try {
         if (producer != null) {
            producer.close();
         }

         cleanUpSessionFactory(csf);
      } catch (Throwable dontCare) {
      }

      try {
         session.cleanUp(false);
      } catch (Throwable dontCare) {
      }

      if (scaleDownTargetNodeID != null && !scaleDownTargetNodeID.equals(nodeUUID.toString())) {
         scaleDown(scaleDownTargetNodeID);
      } else if (scaleDownTargetNodeID != null) {
         // the disconnected node is scaling down to me, no need to reconnect to it
         logger.debug("Received scaleDownTargetNodeID: {}; cancelling reconnect.", scaleDownTargetNodeID);
         fail(true, true);
      } else {
         logger.debug("Received invalid scaleDownTargetNodeID: {}", scaleDownTargetNodeID);

         fail(me.getType() == ActiveMQExceptionType.DISCONNECTED, false);
      }

      tryScheduleRetryReconnect(me.getType());
   }

   protected void scaleDown(String scaleDownTargetNodeID) {
      synchronized (this) {
         try {
            if (logger.isDebugEnabled()) {
               logger.debug("Moving {} messages from {} to {}", queue.getMessageCount(), queue.getName(), scaleDownTargetNodeID);
            }
            ((QueueImpl) queue).moveReferencesBetweenSnFQueues(SimpleString.toSimpleString(scaleDownTargetNodeID));

            // stop the bridge from trying to reconnect and clean up all the bindings
            fail(true, true);

         } catch (Exception e) {
            logger.warn(e.getMessage(), e);
         }
      }
   }

   protected void tryScheduleRetryReconnect(final ActiveMQExceptionType type) {
      scheduleRetryConnect();
   }

   @Override
   public void beforeReconnect(final ActiveMQException exception) {
   }

   private void deliverLargeMessage(final SimpleString dest,
                                    final MessageReference ref,
                                    final LargeServerMessage message,
                                    final Message originalMessage) {
      executor.execute(new Runnable() {
         @Override
         public void run() {
            try {
               producer.send(dest, message.toMessage());

               // as soon as we are done sending the large message
               // we unset the delivery flag and we will call the deliveryAsync on the queue
               // so the bridge will be able to resume work
               unsetLargeMessageDelivery();

               if (queue != null) {
                  queue.deliverAsync();
               }
            } catch (final ActiveMQException e) {
               unsetLargeMessageDelivery();
               ActiveMQServerLogger.LOGGER.bridgeUnableToSendMessage(ref, e);

               connectionFailed(e, false);
            }
         }
      });
   }

   /**
    * @param ref
    * @param message
    * @return
    */
   private HandleStatus deliverStandardMessage(SimpleString dest, final MessageReference ref, Message message, Message originalMessage) {
      // if we failover during send then there is a chance that the
      // that this will throw a disconnect, we need to remove the message
      // from the acks so it will get resent, duplicate detection will cope
      // with any messages resent

      logger.trace("going to send message: {} from {}", message, queue);

      try {
         producer.send(dest, message);
      } catch (final ActiveMQException e) {
         ActiveMQServerLogger.LOGGER.bridgeUnableToSendMessage(ref, e);

         synchronized (refs) {
            // We remove this reference as we are returning busy which means the reference will never leave the Queue.
            // because of this we have to remove the reference here
            refs.remove(message.getMessageID());

            // The delivering count should also be decreased as to avoid inconsistencies
            ((QueueImpl) ref.getQueue()).decDelivering(ref);
         }

         connectionFailed(e, false);

         return HandleStatus.BUSY;
      } finally {
         originalMessage.usageDown();
      }

      return HandleStatus.HANDLED;
   }

   /**
    * for use in tests mainly
    *
    * @return
    */
   public TopologyMember getTargetNodeFromTopology() {
      return this.targetNode;
   }

   @Override
   public BridgeMetrics getMetrics() {
      return this.metrics;
   }

   @Override
   public String toString() {
      return this.getClass().getSimpleName() + "@" +
         Integer.toHexString(System.identityHashCode(this)) +
         " [name=" +
         configuration.getName() +
         ", queue=" +
         queue +
         " targetConnector=" +
         this.serverLocator +
         "]";
   }

   @Override
   public String toManagementString() {
      return this.getClass().getSimpleName() +
         " [name=" +
         configuration.getName() +
         ", queue=" +
         queue.getName() + "/" + queue.getID() + "]";
   }

   public ClientSessionFactoryImpl getCSF() {
      return (ClientSessionFactoryImpl) csf;
   }

   public Transformer getTransformer() {
      return transformer;
   }

   @Override
   public BridgeConfiguration getConfiguration() {
      return configuration;
   }

   protected void fail(final boolean permanently, boolean scaleDown) {
      logger.debug("{}\n\t::fail being called, permanently={}", this, permanently);
      //we need to make sure we remove the node from the topology so any incoming quorum requests are voted correctly
      if (targetNodeID != null) {
         this.disconnectedAndDown = true;
         serverLocator.notifyNodeDown(System.currentTimeMillis(), targetNodeID);
      }
      if (queue != null) {
         try {
            logger.trace("Removing consumer on fail {} from queue {}", this, queue);

            queue.removeConsumer(this);
         } catch (Exception dontcare) {
            logger.debug(dontcare.getMessage(), dontcare);
         }
      }

      cancelRefs();
      if (queue != null) {
         queue.deliverAsync();
      }
   }

   /* Hook for doing extra stuff after connection */
   protected void afterConnect() throws Exception {
      if (disconnectedAndDown && targetNodeID != null && targetNode != null) {
         serverLocator.notifyNodeUp(System.currentTimeMillis(), targetNodeID, targetNode.getBackupGroupName(), targetNode.getScaleDownGroupName(),
                                    new Pair<>(targetNode.getPrimary(), targetNode.getBackup()), false);
         disconnectedAndDown = false;
      }
      retryCount = 0;
      reconnectAttemptsInUse = configuration.getReconnectAttempts();
      if (futureScheduledReconnection != null) {
         futureScheduledReconnection.cancel(true);
         futureScheduledReconnection = null;
      }
   }

   /* Hook for creating session factory */
   protected ClientSessionFactoryInternal createSessionFactory() throws Exception {
      if (targetNodeID != null && (this.configuration.getReconnectAttemptsOnSameNode() < 0 || retryCount <= this.configuration.getReconnectAttemptsOnSameNode())) {
         csf = reconnectOnOriginalNode();
      } else {
         serverLocator.resetToInitialConnectors();
         csf = (ClientSessionFactoryInternal) serverLocator.createSessionFactory();
      }

      // null here means the targetNodeIS is not available yet
      if (csf != null) {
         csf.setReconnectAttempts(0);
      }

      return csf;
   }

   protected ClientSessionFactoryInternal reconnectOnOriginalNode() throws Exception {
      String targetNodeIdUse = targetNodeID;
      TopologyMember nodeUse = targetNode;
      if (targetNodeIdUse != null && nodeUse != null) {
         TransportConfiguration[] configs = new TransportConfiguration[2]; // primary and backup
         int numberOfConfigs = 0;

         if (nodeUse.getPrimary() != null) {
            configs[numberOfConfigs++] = nodeUse.getPrimary();
         }
         if (nodeUse.getBackup() != null) {
            configs[numberOfConfigs++] = nodeUse.getBackup();
         }

         if (numberOfConfigs > 0) {
            // It will bounce between all the available configs
            int nodeTry = (retryCount - 1) % numberOfConfigs;

            return (ClientSessionFactoryInternal) serverLocator.createSessionFactory(configs[nodeTry]);
         }
      }

      return null;
   }

   protected void setSessionFactory(ClientSessionFactoryInternal sfi) {
      csf = sfi;
   }

   /* This is called only when the bridge is activated */
   protected void connect() {
      if (stopping)
         return;

      synchronized (connectionGuard) {
         if (!keepConnecting) {
            return;
         }

         if (logger.isDebugEnabled()) {
            logger.debug("Connecting  {} to its destination [{}], csf={}", this, nodeUUID, csf);
         }
         retryCount++;

         try {
            if (csf == null || csf.isClosed()) {
               if (stopping)
                  return;
               csf = createSessionFactory();
               if (csf == null) {
                  // Retrying. This probably means the node is not available (for the cluster connection case)
                  scheduleRetryConnect();
                  return;
               }
               // Session is pre-acknowledge
               session = (ClientSessionInternal) csf.createSession(configuration.getUser(), configuration.getPassword(), false, true, true, true, 1);
               session.getProducerCreditManager().setCallback(this);
               sessionConsumer = (ClientSessionInternal) csf.createSession(configuration.getUser(), configuration.getPassword(), false, true, true, true, 1);
            }

            if (configuration.getForwardingAddress() != null) {
               ClientSession.AddressQuery query = null;

               try {
                  query = session.addressQuery(SimpleString.toSimpleString(configuration.getForwardingAddress()));
               } catch (Throwable e) {
                  ActiveMQServerLogger.LOGGER.errorQueryingBridge(configuration.getName(), e);
                  // This was an issue during startup, we will not count this retry
                  retryCount--;

                  scheduleRetryConnectFixedTimeout(100);
                  return;
               }

               if (!query.isExists()) {
                  ActiveMQServerLogger.LOGGER.errorQueryingBridge(configuration.getForwardingAddress(), retryCount);
                  scheduleRetryConnect();
                  return;
               }
            }

            // need to reset blockedOnFlowControl after creating a new producer
            // otherwise in case the bridge was blocked before a previous failure
            // this would never resume
            blockedOnFlowControl = false;
            producer = session.createProducer();
            session.addFailureListener(BridgeImpl.this);

            session.setSendAcknowledgementHandler(BridgeImpl.this);

            afterConnect();

            active = true;

            queue.addConsumer(BridgeImpl.this);
            queue.deliverAsync();

            ActiveMQServerLogger.LOGGER.bridgeConnected(this);

            serverLocator.addClusterTopologyListener(new TopologyListener());

            keepConnecting = false;
            return;
         } catch (ActiveMQException e) {
            // the session was created while its server was starting, retry it:
            if (e.getType() == ActiveMQExceptionType.SESSION_CREATION_REJECTED) {
               ActiveMQServerLogger.LOGGER.errorStartingBridge(configuration.getName());

               // We are not going to count this one as a retry
               retryCount--;

               scheduleRetryConnectFixedTimeout(this.configuration.getRetryInterval());
               return;
            } else {
               ActiveMQServerLogger.LOGGER.errorConnectingBridgeRetry(this);
               logger.debug("Underlying bridge connection failure", e);

               scheduleRetryConnect();
            }
         } catch (ActiveMQInterruptedException | InterruptedException e) {
            ActiveMQServerLogger.LOGGER.errorConnectingBridge(this, e);
         } catch (Exception e) {
            ActiveMQServerLogger.LOGGER.errorConnectingBridge(this, e);
            if (csf != null) {
               try {
                  csf.close();
                  csf = null;
               } catch (Throwable ignored) {
               }
            }
            fail(false, false);
            scheduleRetryConnect();
         }
      }
   }

   protected void scheduleRetryConnect() {
      if (serverLocator.isClosed()) {
         ActiveMQServerLogger.LOGGER.bridgeLocatorShutdown();
         return;
      }

      if (stopping) {
         ActiveMQServerLogger.LOGGER.bridgeStopping();
         return;
      }

      if (reconnectAttemptsInUse >= 0 && retryCount > reconnectAttemptsInUse) {
         ActiveMQServerLogger.LOGGER.bridgeAbortStart(configuration.getName(), retryCount, configuration.getReconnectAttempts());
         fail(true, false);
         return;
      }

      long timeout = (long) (this.configuration.getRetryInterval() * Math.pow(this.configuration.getRetryIntervalMultiplier(), retryCount));
      if (timeout == 0) {
         timeout = this.configuration.getRetryInterval();
      }
      if (timeout > configuration.getMaxRetryInterval()) {
         timeout = configuration.getMaxRetryInterval();
      }

      if (logger.isDebugEnabled()) {
         logger.debug("Bridge {} retrying connection #{}, maxRetry={}, timeout={}", this, retryCount, reconnectAttemptsInUse, timeout);
      }

      scheduleRetryConnectFixedTimeout(timeout);
   }


   // To be called by the topology update
   // This logic will be updated on the cluster connection
   protected void nodeUP(TopologyMember member, boolean last) {
      if (member != null) {
         ClientSessionInternal sessionToUse = session;
         RemotingConnection connectionToUse = sessionToUse != null ? sessionToUse.getConnection() : null;
         if (this.targetNodeID != null && this.targetNodeID.equals(member.getNodeId())) {
            // this could be an update of the topology say after a backup started
            BridgeImpl.this.targetNode = member;
         } else {
            // we don't need synchronization here, but we need to make sure we won't get a NPE on races
            if (connectionToUse != null && member.isMember(connectionToUse)) {
               this.targetNode = member;
               this.targetNodeID = member.getNodeId();
            }
         }
      }

   }



   protected void scheduleRetryConnectFixedTimeout(final long milliseconds) {
      try {
         cleanUpSessionFactory(csf);
      } catch (Throwable ignored) {
      }

      if (stopping)
         return;

      if (logger.isDebugEnabled()) {
         logger.debug("Scheduling retry for bridge {} in {} milliseconds", configuration.getName(), milliseconds);
      }

      futureScheduledReconnection = scheduledExecutor.schedule(new FutureConnectRunnable(executor, this), milliseconds, TimeUnit.MILLISECONDS);
   }

   private void internalCancelReferences() {
      cancelRefs();

      if (queue != null) {
         queue.deliverAsync();
      }
   }

   /**
    * just set deliveringLargeMessage to false
    */
   private synchronized void unsetLargeMessageDelivery() {
      deliveringLargeMessage = false;
   }

   // The scheduling will still use the main executor here
   private static class FutureConnectRunnable implements Runnable {

      private final BridgeImpl bridge;

      private final Executor executor;

      private FutureConnectRunnable(Executor exe, BridgeImpl bridge) {
         executor = exe;
         this.bridge = bridge;
      }

      @Override
      public void run() {
         if (bridge.isStarted())
            executor.execute(new ConnectRunnable(bridge));
      }
   }

   private static final class ConnectRunnable implements Runnable {

      private final BridgeImpl bridge;

      private ConnectRunnable(BridgeImpl bridge2) {
         bridge = bridge2;
      }

      @Override
      public void run() {
         bridge.connect();
      }
   }

   private class StopRunnable implements Runnable {

      @Override
      public void run() {
         logger.debug("stopping bridge {}", BridgeImpl.this);
         queue.removeConsumer(BridgeImpl.this);

         synchronized (BridgeImpl.this) {
            logger.debug("Closing Session for bridge {}", configuration.getName());
            started = false;
            active = false;
         }

         if (session != null) {
            logger.debug("Cleaning up session {}", session);
            session.removeFailureListener(BridgeImpl.this);
            try {
               session.close();
               session = null;
            } catch (ActiveMQException dontcare) {
            }
         }

         if (sessionConsumer != null) {
            logger.debug("Cleaning up session {}", session);
            try {
               sessionConsumer.close();
               sessionConsumer = null;
            } catch (ActiveMQException dontcare) {
            }
         }

         internalCancelReferences();

         if (csf != null) {
            csf.cleanup();
         }

         synchronized (connectionGuard) {
            keepConnecting = true;
         }

         logger.trace("Removing consumer on stopRunnable {} from queue {}", this, queue);

         ActiveMQServerLogger.LOGGER.bridgeStopped(configuration.getName());
      }
   }

   private class PauseRunnable implements Runnable {

      @Override
      public void run() {
         try {
            queue.removeConsumer(BridgeImpl.this);

            if (!pendingAcks.await(60, TimeUnit.SECONDS)) {
               ActiveMQServerLogger.LOGGER.timedOutWaitingCompletions(BridgeImpl.this.toString(), pendingAcks.getCount());
            }

            synchronized (BridgeImpl.this) {
               started = false;
               active = false;
            }

            internalCancelReferences();

            ActiveMQServerLogger.LOGGER.bridgePaused(configuration.getName());
         } catch (Exception e) {
            ActiveMQServerLogger.LOGGER.errorPausingBridge(e);
         }
      }

   }

   private class TopologyListener implements ClusterTopologyListener {

      // ClusterListener
      @Override
      public void nodeUP(TopologyMember member, boolean last) {
         BridgeImpl.this.nodeUP(member, last);
      }

      @Override
      public void nodeDown(long eventUID, String nodeID) {

      }
   }
}
