/**
 * 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.transport.amqp.client;

import javax.jms.InvalidDestinationException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.activemq.transport.amqp.client.util.AsyncResult;
import org.apache.activemq.transport.amqp.client.util.ClientFuture;
import org.apache.activemq.transport.amqp.client.util.UnmodifiableSender;
import org.apache.qpid.proton.amqp.Binary;
import org.apache.qpid.proton.amqp.Symbol;
import org.apache.qpid.proton.amqp.messaging.Accepted;
import org.apache.qpid.proton.amqp.messaging.Modified;
import org.apache.qpid.proton.amqp.messaging.Outcome;
import org.apache.qpid.proton.amqp.messaging.Rejected;
import org.apache.qpid.proton.amqp.messaging.Released;
import org.apache.qpid.proton.amqp.messaging.Source;
import org.apache.qpid.proton.amqp.messaging.Target;
import org.apache.qpid.proton.amqp.transaction.TransactionalState;
import org.apache.qpid.proton.amqp.transport.DeliveryState;
import org.apache.qpid.proton.amqp.transport.ErrorCondition;
import org.apache.qpid.proton.amqp.transport.ReceiverSettleMode;
import org.apache.qpid.proton.amqp.transport.SenderSettleMode;
import org.apache.qpid.proton.engine.Delivery;
import org.apache.qpid.proton.engine.Sender;
import org.apache.qpid.proton.message.Message;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Sender class that manages a Proton sender endpoint.
 */
public class AmqpSender extends AmqpAbstractResource<Sender> {

   private static final Logger LOG = LoggerFactory.getLogger(AmqpSender.class);
   private static final byte[] EMPTY_BYTE_ARRAY = new byte[]{};

   public static final long DEFAULT_SEND_TIMEOUT = 15000;

   private final AmqpTransferTagGenerator tagGenerator = new AmqpTransferTagGenerator(true);
   private final AtomicBoolean closed = new AtomicBoolean();

   private final AmqpSession session;
   private final String address;
   private final String senderId;
   private final Target userSpecifiedTarget;

   private boolean presettle;
   private long sendTimeout = DEFAULT_SEND_TIMEOUT;

   private final Set<Delivery> pending = new LinkedHashSet<>();
   private byte[] encodeBuffer = new byte[1024 * 8];

   private Symbol[] desiredCapabilities;
   private Symbol[] offeredCapabilities;
   private Map<Symbol, Object> properties;

   /**
    * Create a new sender instance.
    *
    * @param session  The parent session that created the session.
    * @param address  The address that this sender produces to.
    * @param senderId The unique ID assigned to this sender.
    */
   public AmqpSender(AmqpSession session, String address, String senderId) {

      if (address != null && address.isEmpty()) {
         throw new IllegalArgumentException("Address cannot be empty.");
      }

      this.session = session;
      this.address = address;
      this.senderId = senderId;
      this.userSpecifiedTarget = null;
   }

   /**
    * Create a new sender instance using the given Target when creating the link.
    *
    * @param session  The parent session that created the session.
    * @param target   The target that this sender produces to.
    * @param senderId The unique ID assigned to this sender.
    */
   public AmqpSender(AmqpSession session, Target target, String senderId) {

      if (target == null) {
         throw new IllegalArgumentException("User specified Target cannot be null");
      }

      this.session = session;
      this.userSpecifiedTarget = target;
      this.address = target.getAddress();
      this.senderId = senderId;
   }

   /**
    * Sends the given message to this senders assigned address.
    *
    * @param message the message to send.
    * @throws IOException if an error occurs during the send.
    */
   public void send(final AmqpMessage message) throws IOException {
      checkClosed();
      send(message, null);
   }

   /**
    * Sends the given message to this senders assigned address using the supplied transaction ID.
    *
    * @param message the message to send.
    * @param txId    the transaction ID to assign the outgoing send.
    * @throws IOException if an error occurs during the send.
    */
   public void send(final AmqpMessage message, final AmqpTransactionId txId) throws IOException {
      checkClosed();
      final ClientFuture sendRequest = new ClientFuture();

      session.getScheduler().execute(new Runnable() {

         @Override
         public void run() {
            try {
               doSend(message, sendRequest, txId);
               session.pumpToProtonTransport(sendRequest);
            } catch (Exception e) {
               sendRequest.onFailure(e);
               session.getConnection().fireClientException(e);
            }
         }
      });

      if (sendTimeout <= 0) {
         sendRequest.sync();
      } else {
         sendRequest.sync(sendTimeout, TimeUnit.MILLISECONDS);
      }
   }

   /**
    * Close the sender, a closed sender will throw exceptions if any further send
    * calls are made.
    *
    * @throws IOException if an error occurs while closing the sender.
    */
   public void close() throws IOException {
      if (closed.compareAndSet(false, true)) {
         final ClientFuture request = new ClientFuture();
         session.getScheduler().execute(new Runnable() {

            @Override
            public void run() {
               checkClosed();
               close(request);
               session.pumpToProtonTransport(request);
            }
         });

         request.sync();
      }
   }

   /**
    * @return this session's parent AmqpSession.
    */
   public AmqpSession getSession() {
      return session;
   }

   /**
    * @return an unmodifiable view of the underlying Sender instance.
    */
   public Sender getSender() {
      return new UnmodifiableSender(getEndpoint());
   }

   /**
    * @return the assigned address of this sender.
    */
   public String getAddress() {
      return address;
   }

   //----- Sender configuration ---------------------------------------------//

   /**
    * @return will messages be settle on send.
    */
   public boolean isPresettle() {
      return presettle;
   }

   /**
    * Configure is sent messages are marked as settled on send, defaults to false.
    *
    * @param presettle configure if this sender will presettle all sent messages.
    */
   public void setPresettle(boolean presettle) {
      this.presettle = presettle;
   }

   /**
    * @return the currently configured send timeout.
    */
   public long getSendTimeout() {
      return sendTimeout;
   }

   /**
    * Sets the amount of time the sender will block on a send before failing.
    *
    * @param sendTimeout time in milliseconds to wait.
    */
   public void setSendTimeout(long sendTimeout) {
      this.sendTimeout = sendTimeout;
   }


   public void setDesiredCapabilities(Symbol[] desiredCapabilities) {
      if (getEndpoint() != null) {
         throw new IllegalStateException("Endpoint already established");
      }

      this.desiredCapabilities = desiredCapabilities;
   }

   public void setOfferedCapabilities(Symbol[] offeredCapabilities) {
      if (getEndpoint() != null) {
         throw new IllegalStateException("Endpoint already established");
      }

      this.offeredCapabilities = offeredCapabilities;
   }

   public void setProperties(Map<Symbol, Object> properties) {
      if (getEndpoint() != null) {
         throw new IllegalStateException("Endpoint already established");
      }

      this.properties = properties;
   }

   //----- Private Sender implementation ------------------------------------//

   private void checkClosed() {
      if (isClosed()) {
         throw new IllegalStateException("Sender is already closed");
      }
   }

   @Override
   protected void doOpen() {

      Symbol[] outcomes = new Symbol[]{Accepted.DESCRIPTOR_SYMBOL, Rejected.DESCRIPTOR_SYMBOL};
      Source source = new Source();
      source.setAddress(senderId);
      source.setOutcomes(outcomes);

      Target target = userSpecifiedTarget;
      if (target == null) {
         target = new Target();
         target.setAddress(address);
      }

      String senderName = senderId + ":" + address;

      Sender sender = session.getEndpoint().sender(senderName);
      sender.setSource(source);
      sender.setTarget(target);
      if (presettle) {
         sender.setSenderSettleMode(SenderSettleMode.SETTLED);
      } else {
         sender.setSenderSettleMode(SenderSettleMode.UNSETTLED);
      }
      sender.setReceiverSettleMode(ReceiverSettleMode.FIRST);

      sender.setDesiredCapabilities(desiredCapabilities);
      sender.setOfferedCapabilities(offeredCapabilities);
      sender.setProperties(properties);

      setEndpoint(sender);

      super.doOpen();
   }

   @Override
   protected void doOpenCompletion() {
      // Verify the attach response contained a non-null target
      org.apache.qpid.proton.amqp.transport.Target t = getEndpoint().getRemoteTarget();
      if (t != null) {
         super.doOpenCompletion();
      } else {
         // No link terminus was created, the peer will now detach/close us.
      }
   }

   @Override
   protected void doOpenInspection() {
      try {
         getStateInspector().inspectOpenedResource(getSender());
      } catch (Throwable error) {
         getStateInspector().markAsInvalid(error.getMessage());
      }
   }

   @Override
   protected void doClosedInspection() {
      try {
         getStateInspector().inspectClosedResource(getSender());
      } catch (Throwable error) {
         getStateInspector().markAsInvalid(error.getMessage());
      }
   }

   @Override
   protected void doDetachedInspection() {
      try {
         getStateInspector().inspectDetachedResource(getSender());
      } catch (Throwable error) {
         getStateInspector().markAsInvalid(error.getMessage());
      }
   }

   @Override
   protected Exception getOpenAbortException() {
      // Verify the attach response contained a non-null target
      org.apache.qpid.proton.amqp.transport.Target t = getEndpoint().getRemoteTarget();
      if (t != null) {
         return super.getOpenAbortException();
      } else {
         // No link terminus was created, the peer has detach/closed us, create IDE.
         return new InvalidDestinationException("Link creation was refused");
      }
   }

   private void doSend(AmqpMessage message, AsyncResult request, AmqpTransactionId txId) throws Exception {
      LOG.trace("Producer sending message: {}", message);

      Delivery delivery = null;
      if (presettle) {
         delivery = getEndpoint().delivery(EMPTY_BYTE_ARRAY, 0, 0);
      } else {
         byte[] tag = tagGenerator.getNextTag();
         delivery = getEndpoint().delivery(tag, 0, tag.length);
      }

      delivery.setContext(request);

      Binary amqpTxId = null;
      if (txId != null) {
         amqpTxId = txId.getRemoteTxId();
      } else if (session.isInTransaction()) {
         amqpTxId = session.getTransactionId().getRemoteTxId();
      }

      if (amqpTxId != null) {
         TransactionalState state = new TransactionalState();
         state.setTxnId(amqpTxId);
         delivery.disposition(state);
      }

      encodeAndSend(message.getWrappedMessage(), delivery);

      if (presettle) {
         delivery.settle();
         request.onSuccess();
      } else {
         pending.add(delivery);
         getEndpoint().advance();
      }
   }

   private void encodeAndSend(Message message, Delivery delivery) throws IOException {

      int encodedSize;
      while (true) {
         try {
            encodedSize = message.encode(encodeBuffer, 0, encodeBuffer.length);
            break;
         } catch (java.nio.BufferOverflowException e) {
            encodeBuffer = new byte[encodeBuffer.length * 2];
         }
      }

      int sentSoFar = 0;

      while (true) {
         int sent = getEndpoint().send(encodeBuffer, sentSoFar, encodedSize - sentSoFar);
         if (sent > 0) {
            sentSoFar += sent;
            if ((encodedSize - sentSoFar) == 0) {
               break;
            }
         } else {
            LOG.warn("{} failed to send any data from current Message.", this);
         }
      }
   }

   @Override
   public void processDeliveryUpdates(AmqpConnection connection) throws IOException {
      List<Delivery> toRemove = new ArrayList<>();

      for (Delivery delivery : pending) {
         DeliveryState state = delivery.getRemoteState();
         if (state == null) {
            continue;
         }

         Outcome outcome = null;
         if (state instanceof TransactionalState) {
            LOG.trace("State of delivery is Transactional, retrieving outcome: {}", state);
            outcome = ((TransactionalState) state).getOutcome();
         } else if (state instanceof Outcome) {
            outcome = (Outcome) state;
         } else {
            LOG.warn("Message send updated with unsupported state: {}", state);
            outcome = null;
         }

         AsyncResult request = (AsyncResult) delivery.getContext();
         Exception deliveryError = null;

         if (outcome instanceof Accepted) {
            LOG.trace("Outcome of delivery was accepted: {}", delivery);
            if (request != null && !request.isComplete()) {
               request.onSuccess();
            }
         } else if (outcome instanceof Rejected) {
            LOG.trace("Outcome of delivery was rejected: {}", delivery);
            ErrorCondition remoteError = ((Rejected) outcome).getError();
            if (remoteError == null) {
               remoteError = getEndpoint().getRemoteCondition();
            }

            deliveryError = AmqpSupport.convertToException(remoteError);
         } else if (outcome instanceof Released) {
            LOG.trace("Outcome of delivery was released: {}", delivery);
            deliveryError = new IOException("Delivery failed: released by receiver");
         } else if (outcome instanceof Modified) {
            LOG.trace("Outcome of delivery was modified: {}", delivery);
            deliveryError = new IOException("Delivery failed: failure at remote");
         }

         if (deliveryError != null) {
            if (request != null && !request.isComplete()) {
               request.onFailure(deliveryError);
            } else {
               connection.fireClientException(deliveryError);
            }
         }

         tagGenerator.returnTag(delivery.getTag());
         delivery.settle();
         toRemove.add(delivery);

         doDeliveryUpdate(delivery);
      }

      pending.removeAll(toRemove);
   }

   @Override
   public String toString() {
      return getClass().getSimpleName() + "{ address = " + address + "}";
   }

   @Override
   protected void doDeliveryUpdate(Delivery delivery) {
      try {
         getStateInspector().inspectDeliveryUpdate(delivery);
      } catch (Throwable error) {
         getStateInspector().markAsInvalid(error.getMessage());
      }
   }
}
