/*
 * 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 java.util.HashMap;
import java.util.Map;
import java.util.NoSuchElementException;

import org.apache.activemq.transport.amqp.client.util.UnmodifiableDelivery;
import org.apache.qpid.proton.Proton;
import org.apache.qpid.proton.amqp.Binary;
import org.apache.qpid.proton.amqp.DescribedType;
import org.apache.qpid.proton.amqp.Symbol;
import org.apache.qpid.proton.amqp.messaging.AmqpValue;
import org.apache.qpid.proton.amqp.messaging.ApplicationProperties;
import org.apache.qpid.proton.amqp.messaging.Data;
import org.apache.qpid.proton.amqp.messaging.DeliveryAnnotations;
import org.apache.qpid.proton.amqp.messaging.Header;
import org.apache.qpid.proton.amqp.messaging.MessageAnnotations;
import org.apache.qpid.proton.amqp.messaging.Properties;
import org.apache.qpid.proton.engine.Delivery;
import org.apache.qpid.proton.message.Message;

public class AmqpMessage {

   private final AmqpReceiver receiver;
   private final Message message;
   private final Delivery delivery;

   private Map<Symbol, Object> deliveryAnnotationsMap;
   private Map<Symbol, Object> messageAnnotationsMap;
   private Map<String, Object> applicationPropertiesMap;

   /**
    * Creates a new AmqpMessage that wraps the information necessary to handle
    * an outgoing message.
    */
   public AmqpMessage() {
      receiver = null;
      delivery = null;

      message = Proton.message();
   }

   /**
    * Creates a new AmqpMessage that wraps the information necessary to handle
    * an outgoing message.
    *
    * @param message the Proton message that is to be sent.
    */
   public AmqpMessage(Message message) {
      this(null, message, null);
   }

   /**
    * Creates a new AmqpMessage that wraps the information necessary to handle
    * an incoming delivery.
    *
    * @param receiver the AmqpReceiver that received this message.
    * @param message  the Proton message that was received.
    * @param delivery the Delivery instance that produced this message.
    */
   @SuppressWarnings("unchecked")
   public AmqpMessage(AmqpReceiver receiver, Message message, Delivery delivery) {
      this.receiver = receiver;
      this.message = message;
      this.delivery = delivery;

      if (message.getMessageAnnotations() != null) {
         messageAnnotationsMap = message.getMessageAnnotations().getValue();
      }

      if (message.getApplicationProperties() != null) {
         applicationPropertiesMap = message.getApplicationProperties().getValue();
      }

      if (message.getDeliveryAnnotations() != null) {
         deliveryAnnotationsMap = message.getDeliveryAnnotations().getValue();
      }
   }

   //----- Access to interal client resources -------------------------------//

   /**
    * @return the AMQP Delivery object linked to a received message.
    */
   public Delivery getWrappedDelivery() {
      if (delivery != null) {
         return new UnmodifiableDelivery(delivery);
      }

      return null;
   }

   /**
    * @return the AMQP Message that is wrapped by this object.
    */
   public Message getWrappedMessage() {
      return message;
   }

   /**
    * @return the AmqpReceiver that consumed this message.
    */
   public AmqpReceiver getAmqpReceiver() {
      return receiver;
   }

   //----- Message disposition control --------------------------------------//

   /**
    * Accepts the message marking it as consumed on the remote peer.
    *
    * @throws Exception if an error occurs during the accept.
    */
   public void accept() throws Exception {
      accept(true);
   }

   /**
    * Accepts the message marking it as consumed on the remote peer.
    *
    * @param settle
    *        true if the client should also settle the delivery when sending the accept.
    *
    * @throws Exception if an error occurs during the accept.
    */
   public void accept(boolean settle) throws Exception {
      if (receiver == null) {
         throw new IllegalStateException("Can't accept non-received message.");
      }

      receiver.accept(delivery, settle);
   }

   /**
    * Accepts the message marking it as consumed on the remote peer.
    *
    * @param txnSession The session that is used to manage acceptance of the message.
    * @throws Exception if an error occurs during the accept.
    */
   public void accept(AmqpSession txnSession) throws Exception {
      accept(txnSession, true);
   }

   /**
    * Accepts the message marking it as consumed on the remote peer.
    *
    * @param txnSession
    *      The session that is used to manage acceptance of the message.
    *
    * @throws Exception if an error occurs during the accept.
    */
   public void accept(AmqpSession txnSession, boolean settle) throws Exception {
      if (receiver == null) {
         throw new IllegalStateException("Can't accept non-received message.");
      }

      receiver.accept(delivery, txnSession, settle);
   }

   /**
    * Marks the message as Modified, indicating whether it failed to deliver and is not deliverable here.
    *
    * @param deliveryFailed    indicates that the delivery failed for some reason.
    * @param undeliverableHere marks the delivery as not being able to be process by link it was sent to.
    * @throws Exception if an error occurs during the process.
    */
   public void modified(Boolean deliveryFailed, Boolean undeliverableHere) throws Exception {
      if (receiver == null) {
         throw new IllegalStateException("Can't modify non-received message.");
      }

      receiver.modified(delivery, deliveryFailed, undeliverableHere);
   }

   /**
    * Release the message, remote can redeliver it elsewhere.
    *
    * @throws Exception if an error occurs during the reject.
    */
   public void release() throws Exception {
      if (receiver == null) {
         throw new IllegalStateException("Can't release non-received message.");
      }

      receiver.release(delivery);
   }

   //----- Convenience methods for constructing outbound messages -----------//

   /**
    * Sets the address which is applied to the AMQP message To field in the message properties
    *
    * @param address The address that should be applied in the Message To field.
    */
   public void setAddress(String address) {
      checkReadOnly();
      lazyCreateProperties();
      getWrappedMessage().setAddress(address);
   }

   /**
    * Return the set address that was set in the Message To field.
    *
    * @return the set address String form or null if not set.
    */
   public String getAddress() {
      if (message.getProperties() == null) {
         return null;
      }

      return message.getProperties().getTo();
   }

   /**
    * Sets the replyTo address which is applied to the AMQP message reply-to field in the message properties
    *
    * @param address The replyTo address that should be applied in the Message To field.
    */
   public void setReplyToAddress(String address) {
      checkReadOnly();
      lazyCreateProperties();
      getWrappedMessage().setReplyTo(address);
   }

   /**
    * Return the set replyTo address that was set in the Message To field.
    *
    * @return the set replyTo address String form or null if not set.
    */
   public String getReplyToAddress() {
      if (message.getProperties() == null) {
         return null;
      }

      return message.getProperties().getReplyTo();
   }

   /**
    * Sets the MessageId property on an outbound message using the provided String
    *
    * @param messageId the String message ID value to set.
    */
   public void setMessageId(String messageId) {
      checkReadOnly();
      lazyCreateProperties();
      getWrappedMessage().setMessageId(messageId);
   }

   /**
    * Return the set MessageId value in String form, if there are no properties
    * in the given message return null.
    *
    * @return the set message ID in String form or null if not set.
    */
   public String getMessageId() {
      if (message.getProperties() == null || message.getProperties().getMessageId() == null) {
         return null;
      }

      return message.getProperties().getMessageId().toString();
   }

   /**
    * Return the set MessageId value in the original form, if there are no properties
    * in the given message return null.
    *
    * @return the set message ID in its original form or null if not set.
    */
   public Object getRawMessageId() {
      if (message.getProperties() == null) {
         return null;
      }

      return message.getProperties().getMessageId();
   }

   /**
    * Sets the MessageId property on an outbound message using the provided value
    *
    * @param messageId the message ID value to set.
    */
   public void setRawMessageId(Object messageId) {
      checkReadOnly();
      lazyCreateProperties();
      getWrappedMessage().setMessageId(messageId);
   }

   /**
    * Sets the CorrelationId property on an outbound message using the provided String
    *
    * @param correlationId the String Correlation ID value to set.
    */
   public void setCorrelationId(String correlationId) {
      checkReadOnly();
      lazyCreateProperties();
      getWrappedMessage().setCorrelationId(correlationId);
   }

   /**
    * Return the set CorrelationId value in String form, if there are no properties
    * in the given message return null.
    *
    * @return the set correlation ID in String form or null if not set.
    */
   public String getCorrelationId() {
      if (message.getProperties() == null || message.getProperties().getCorrelationId() == null) {
         return null;
      }

      return message.getProperties().getCorrelationId().toString();
   }

   /**
    * Return the set CorrelationId value in the original form, if there are no properties
    * in the given message return null.
    *
    * @return the set message ID in its original form or null if not set.
    */
   public Object getRawCorrelationId() {
      if (message.getProperties() == null) {
         return null;
      }

      return message.getProperties().getCorrelationId();
   }

   /**
    * Sets the CorrelationId property on an outbound message using the provided value
    *
    * @param correlationId the correlation ID value to set.
    */
   public void setRawCorrelationId(Object correlationId) {
      checkReadOnly();
      lazyCreateProperties();
      getWrappedMessage().setCorrelationId(correlationId);
   }

   /**
    * Sets the GroupId property on an outbound message using the provided String
    *
    * @param groupId the String Group ID value to set.
    */
   public void setGroupId(String groupId) {
      checkReadOnly();
      lazyCreateProperties();
      getWrappedMessage().setGroupId(groupId);
   }

   /**
    * Return the set GroupId value in String form, if there are no properties
    * in the given message return null.
    *
    * @return the set GroupID in String form or null if not set.
    */
   public String getGroupId() {
      if (message.getProperties() == null) {
         return null;
      }

      return message.getProperties().getGroupId();
   }

   /**
    * Sets the durable header on the outgoing message.
    *
    * @param durable the boolean durable value to set.
    */
   public void setDurable(boolean durable) {
      checkReadOnly();
      lazyCreateHeader();
      getWrappedMessage().setDurable(durable);
   }

   /**
    * Checks the durable value in the Message Headers to determine if
    * the message was sent as a durable Message.
    *
    * @return true if the message is marked as being durable.
    */
   public boolean isDurable() {
      if (message.getHeader() == null || message.getHeader().getDurable() == null) {
         return false;
      }

      return message.getHeader().getDurable();
   }

   /**
    * Sets a given application property on an outbound message.
    *
    * @param key   the name to assign the new property.
    * @param value the value to set for the named property.
    */
   public void setApplicationProperty(String key, Object value) {
      checkReadOnly();
      lazyCreateApplicationProperties();
      applicationPropertiesMap.put(key, value);
   }

   /**
    * Gets the application property that is mapped to the given name or null
    * if no property has been set with that name.
    *
    * @param key the name used to lookup the property in the application properties.
    * @return the property value or null if not set.
    */
   public Object getApplicationProperty(String key) {
      if (applicationPropertiesMap == null) {
         return null;
      }

      return applicationPropertiesMap.get(key);
   }

   /**
    * Perform a proper annotation set on the AMQP Message based on a Symbol key and
    * the target value to append to the current annotations.
    *
    * @param key   The name of the Symbol whose value is being set.
    * @param value The new value to set in the annotations of this message.
    */
   public void setMessageAnnotation(String key, Object value) {
      checkReadOnly();
      lazyCreateMessageAnnotations();
      messageAnnotationsMap.put(Symbol.valueOf(key), value);
   }

   /**
    * Given a message annotation name, lookup and return the value associated with
    * that annotation name.  If the message annotations have not been created yet
    * then this method will always return null.
    *
    * @param key the Symbol name that should be looked up in the message annotations.
    * @return the value of the annotation if it exists, or null if not set or not accessible.
    */
   public Object getMessageAnnotation(String key) {
      if (messageAnnotationsMap == null) {
         return null;
      }

      return messageAnnotationsMap.get(Symbol.valueOf(key));
   }

   /**
    * Perform a proper delivery annotation set on the AMQP Message based on a Symbol
    * key and the target value to append to the current delivery annotations.
    *
    * @param key   The name of the Symbol whose value is being set.
    * @param value The new value to set in the delivery annotations of this message.
    */
   public void setDeliveryAnnotation(String key, Object value) {
      checkReadOnly();
      lazyCreateDeliveryAnnotations();
      deliveryAnnotationsMap.put(Symbol.valueOf(key), value);
   }

   /**
    * Given a message annotation name, lookup and return the value associated with
    * that annotation name.  If the message annotations have not been created yet
    * then this method will always return null.
    *
    * @param key the Symbol name that should be looked up in the message annotations.
    * @return the value of the annotation if it exists, or null if not set or not accessible.
    */
   public Object getDeliveryAnnotation(String key) {
      if (deliveryAnnotationsMap == null) {
         return null;
      }

      return deliveryAnnotationsMap.get(Symbol.valueOf(key));
   }

   //----- Methods for manipulating the Message body ------------------------//

   /**
    * Sets a String value into the body of an outgoing Message, throws
    * an exception if this is an incoming message instance.
    *
    * @param value the String value to store in the Message body.
    * @throws IllegalStateException if the message is read only.
    */
   public void setText(String value) throws IllegalStateException {
      checkReadOnly();
      AmqpValue body = new AmqpValue(value);
      getWrappedMessage().setBody(body);
   }

   /**
    * Sets a byte array value into the body of an outgoing Message, throws
    * an exception if this is an incoming message instance.
    *
    * @param bytes the byte array value to store in the Message body.
    * @throws IllegalStateException if the message is read only.
    */
   public void setBytes(byte[] bytes) throws IllegalStateException {
      checkReadOnly();
      Data body = new Data(new Binary(bytes));
      getWrappedMessage().setBody(body);
   }

   /**
    * Sets a described type into the body of an outgoing Message, throws
    * an exception if this is an incoming message instance.
    *
    * @param described the described type value to store in the Message body.
    * @throws IllegalStateException if the message is read only.
    */
   public void setDescribedType(DescribedType described) throws IllegalStateException {
      checkReadOnly();
      AmqpValue body = new AmqpValue(described);
      getWrappedMessage().setBody(body);
   }

   /**
    * Attempts to retrieve the message body as an DescribedType instance.
    *
    * @return an DescribedType instance if one is stored in the message body.
    * @throws NoSuchElementException if the body does not contain a DescribedType.
    */
   public DescribedType getDescribedType() throws NoSuchElementException {
      DescribedType result = null;

      if (getWrappedMessage().getBody() == null) {
         return null;
      } else {
         if (getWrappedMessage().getBody() instanceof AmqpValue) {
            AmqpValue value = (AmqpValue) getWrappedMessage().getBody();

            if (value.getValue() == null) {
               result = null;
            } else if (value.getValue() instanceof DescribedType) {
               result = (DescribedType) value.getValue();
            } else {
               throw new NoSuchElementException("Message does not contain a DescribedType body");
            }
         }
      }

      return result;
   }

   //----- Internal implementation ------------------------------------------//

   private void checkReadOnly() throws IllegalStateException {
      if (delivery != null) {
         throw new IllegalStateException("Message is read only.");
      }
   }

   private void lazyCreateMessageAnnotations() {
      if (messageAnnotationsMap == null) {
         messageAnnotationsMap = new HashMap<Symbol, Object>();
         message.setMessageAnnotations(new MessageAnnotations(messageAnnotationsMap));
      }
   }

   private void lazyCreateDeliveryAnnotations() {
      if (deliveryAnnotationsMap == null) {
         deliveryAnnotationsMap = new HashMap<Symbol, Object>();
         message.setDeliveryAnnotations(new DeliveryAnnotations(deliveryAnnotationsMap));
      }
   }

   private void lazyCreateApplicationProperties() {
      if (applicationPropertiesMap == null) {
         applicationPropertiesMap = new HashMap<String, Object>();
         message.setApplicationProperties(new ApplicationProperties(applicationPropertiesMap));
      }
   }

   private void lazyCreateHeader() {
      if (message.getHeader() == null) {
         message.setHeader(new Header());
      }
   }

   private void lazyCreateProperties() {
      if (message.getProperties() == null) {
         message.setProperties(new Properties());
      }
   }
}
