/*
 * 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.message.impl;

import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import io.netty.buffer.ByteBuf;
import org.apache.activemq.artemis.api.core.ActiveMQBuffer;
import org.apache.activemq.artemis.api.core.ActiveMQBuffers;
import org.apache.activemq.artemis.api.core.ActiveMQException;
import org.apache.activemq.artemis.api.core.ActiveMQPropertyConversionException;
import org.apache.activemq.artemis.api.core.Message;
import org.apache.activemq.artemis.api.core.SimpleString;
import org.apache.activemq.artemis.core.buffers.impl.ChannelBufferWrapper;
import org.apache.activemq.artemis.core.buffers.impl.ResetLimitWrappedActiveMQBuffer;
import org.apache.activemq.artemis.core.message.BodyEncoder;
import org.apache.activemq.artemis.core.protocol.core.impl.PacketImpl;
import org.apache.activemq.artemis.utils.ByteUtil;
import org.apache.activemq.artemis.utils.DataConstants;
import org.apache.activemq.artemis.utils.TypedProperties;
import org.apache.activemq.artemis.utils.UUID;

/**
 * A concrete implementation of a message
 * <p>
 * All messages handled by ActiveMQ Artemis core are of this type
 */
public abstract class MessageImpl implements MessageInternal {

   public static final SimpleString HDR_ROUTE_TO_IDS = new SimpleString("_AMQ_ROUTE_TO");

   public static final SimpleString HDR_SCALEDOWN_TO_IDS = new SimpleString("_AMQ_SCALEDOWN_TO");

   public static final SimpleString HDR_ROUTE_TO_ACK_IDS = new SimpleString("_AMQ_ACK_ROUTE_TO");

   // used by the bridges to set duplicates
   public static final SimpleString HDR_BRIDGE_DUPLICATE_ID = new SimpleString("_AMQ_BRIDGE_DUP");

   public static final int BUFFER_HEADER_SPACE = PacketImpl.PACKET_HEADERS_SIZE;

   public static final int BODY_OFFSET = BUFFER_HEADER_SPACE + DataConstants.SIZE_INT;

   protected long messageID;

   protected SimpleString address;

   protected byte type;

   protected boolean durable;

   /**
    * GMT milliseconds at which this message expires. 0 means never expires *
    */
   private long expiration;

   protected long timestamp;

   protected TypedProperties properties;

   protected byte priority;

   protected ActiveMQBuffer buffer;

   protected ResetLimitWrappedActiveMQBuffer bodyBuffer;

   protected volatile boolean bufferValid;

   private int endOfBodyPosition = -1;

   private int endOfMessagePosition;

   private UUID userID;

   // Constructors --------------------------------------------------

   protected MessageImpl() {
      properties = new TypedProperties();
   }

   /**
    * overridden by the client message, we need access to the connection so we can create the appropriate ActiveMQBuffer.
    *
    * @param type
    * @param durable
    * @param expiration
    * @param timestamp
    * @param priority
    * @param initialMessageBufferSize
    */
   protected MessageImpl(final byte type,
                         final boolean durable,
                         final long expiration,
                         final long timestamp,
                         final byte priority,
                         final int initialMessageBufferSize) {
      this();
      this.type = type;
      this.durable = durable;
      this.expiration = expiration;
      this.timestamp = timestamp;
      this.priority = priority;
      createBody(initialMessageBufferSize);
   }

   protected MessageImpl(final int initialMessageBufferSize) {
      this();
      createBody(initialMessageBufferSize);
   }

   /*
    * Copy constructor
    */
   protected MessageImpl(final MessageImpl other) {
      this(other, other.getProperties());
   }

   /*
    * Copy constructor
    */
   protected MessageImpl(final MessageImpl other, TypedProperties properties) {
      messageID = other.getMessageID();
      userID = other.getUserID();
      address = other.getAddress();
      type = other.getType();
      durable = other.isDurable();
      expiration = other.getExpiration();
      timestamp = other.getTimestamp();
      priority = other.getPriority();
      this.properties = new TypedProperties(properties);

      // This MUST be synchronized using the monitor on the other message to prevent it running concurrently
      // with getEncodedBuffer(), otherwise can introduce race condition when delivering concurrently to
      // many subscriptions and bridging to other nodes in a cluster
      synchronized (other) {
         bufferValid = false;
         endOfBodyPosition = -1;
         endOfMessagePosition = other.endOfMessagePosition;

         if (other.buffer != null) {
            // We need to copy the underlying buffer too, since the different messsages thereafter might have different
            // properties set on them, making their encoding different
            buffer = other.buffer.copy(0, other.buffer.capacity());

            buffer.setIndex(other.buffer.readerIndex(), buffer.capacity());

            bodyBuffer = new ResetLimitWrappedActiveMQBuffer(BODY_OFFSET, buffer, this);
            bodyBuffer.readerIndex(BODY_OFFSET);
            bodyBuffer.writerIndex(other.getBodyBuffer().writerIndex());
         }
      }
   }

   // Message implementation ----------------------------------------

   public int getEncodeSize() {
      int headersPropsSize = getHeadersAndPropertiesEncodeSize();

      int bodyPos = getEndOfBodyPosition();

      int bodySize = bodyPos - BUFFER_HEADER_SPACE - DataConstants.SIZE_INT;

      return DataConstants.SIZE_INT + bodySize + DataConstants.SIZE_INT + headersPropsSize;
   }

   public int getHeadersAndPropertiesEncodeSize() {
      return DataConstants.SIZE_LONG + // Message ID
         DataConstants.SIZE_BYTE + // user id null?
         (userID == null ? 0 : 16) +
             /* address */SimpleString.sizeofNullableString(address) +
         DataConstants./* Type */SIZE_BYTE +
         DataConstants./* Durable */SIZE_BOOLEAN +
         DataConstants./* Expiration */SIZE_LONG +
         DataConstants./* Timestamp */SIZE_LONG +
         DataConstants./* Priority */SIZE_BYTE +
             /* PropertySize and Properties */properties.getEncodeSize();
   }

   public void encodeHeadersAndProperties(final ActiveMQBuffer buffer) {
      buffer.writeLong(messageID);
      buffer.writeNullableSimpleString(address);
      if (userID == null) {
         buffer.writeByte(DataConstants.NULL);
      }
      else {
         buffer.writeByte(DataConstants.NOT_NULL);
         buffer.writeBytes(userID.asBytes());
      }
      buffer.writeByte(type);
      buffer.writeBoolean(durable);
      buffer.writeLong(expiration);
      buffer.writeLong(timestamp);
      buffer.writeByte(priority);
      properties.encode(buffer);
   }

   public void decodeHeadersAndProperties(final ActiveMQBuffer buffer) {
      messageID = buffer.readLong();
      address = buffer.readNullableSimpleString();
      if (buffer.readByte() == DataConstants.NOT_NULL) {
         byte[] bytes = new byte[16];
         buffer.readBytes(bytes);
         userID = new UUID(UUID.TYPE_TIME_BASED, bytes);
      }
      else {
         userID = null;
      }
      type = buffer.readByte();
      durable = buffer.readBoolean();
      expiration = buffer.readLong();
      timestamp = buffer.readLong();
      priority = buffer.readByte();
      properties.decode(buffer);
   }

   public void copyHeadersAndProperties(final MessageInternal msg) {
      messageID = msg.getMessageID();
      address = msg.getAddress();
      userID = msg.getUserID();
      type = msg.getType();
      durable = msg.isDurable();
      expiration = msg.getExpiration();
      timestamp = msg.getTimestamp();
      priority = msg.getPriority();
      properties = msg.getTypedProperties();
   }

   public ActiveMQBuffer getBodyBuffer() {
      if (bodyBuffer == null) {
         bodyBuffer = new ResetLimitWrappedActiveMQBuffer(BODY_OFFSET, buffer, this);
      }

      return bodyBuffer;
   }

   public Message writeBodyBufferBytes(byte[] bytes) {
      getBodyBuffer().writeBytes(bytes);

      return this;
   }

   public Message writeBodyBufferString(String string) {
      getBodyBuffer().writeString(string);

      return this;
   }

   public void checkCompletion() throws ActiveMQException {
      // no op on regular messages
   }

   public synchronized ActiveMQBuffer getBodyBufferDuplicate() {

      // Must copy buffer before sending it

      ByteBuf byteBuf = ChannelBufferWrapper.unwrap(getBodyBuffer().byteBuf());
      byteBuf = byteBuf.duplicate();
      byteBuf.readerIndex(getBodyBuffer().readerIndex());
      byteBuf.writerIndex(getBodyBuffer().writerIndex());

      return new ResetLimitWrappedActiveMQBuffer(BODY_OFFSET, byteBuf, null);
   }

   public long getMessageID() {
      return messageID;
   }

   public UUID getUserID() {
      return userID;
   }

   public MessageImpl setUserID(final UUID userID) {
      this.userID = userID;
      return this;
   }

   /**
    * this doesn't need to be synchronized as setAddress is protecting the buffer,
    * not the address
    */
   public SimpleString getAddress() {
      return address;
   }

   /**
    * The only reason this is synchronized is because of encoding a message versus invalidating the buffer.
    * This synchronization can probably be removed since setAddress is always called from a single thread.
    * However I will keep it as it's harmless and it's been well tested
    */
   public Message setAddress(final SimpleString address) {
      // This is protecting the buffer
      synchronized (this) {
         if (this.address != address) {
            this.address = address;

            bufferValid = false;
         }
      }

      return this;
   }

   public byte getType() {
      return type;
   }

   public void setType(byte type) {
      this.type = type;
   }

   public boolean isDurable() {
      return durable;
   }

   public MessageImpl setDurable(final boolean durable) {
      if (this.durable != durable) {
         this.durable = durable;

         bufferValid = false;
      }
      return this;
   }

   public long getExpiration() {
      return expiration;
   }

   public MessageImpl setExpiration(final long expiration) {
      if (this.expiration != expiration) {
         this.expiration = expiration;

         bufferValid = false;
      }
      return this;
   }

   public long getTimestamp() {
      return timestamp;
   }

   public MessageImpl setTimestamp(final long timestamp) {
      if (this.timestamp != timestamp) {
         this.timestamp = timestamp;

         bufferValid = false;
      }
      return this;
   }

   public byte getPriority() {
      return priority;
   }

   public MessageImpl setPriority(final byte priority) {
      if (this.priority != priority) {
         this.priority = priority;

         bufferValid = false;
      }
      return this;
   }

   public boolean isExpired() {
      if (expiration == 0) {
         return false;
      }

      return System.currentTimeMillis() - expiration >= 0;
   }

   public Map<String, Object> toMap() {
      Map<String, Object> map = new HashMap<String, Object>();

      map.put("messageID", messageID);
      if (userID != null) {
         map.put("userID", "ID:" + userID.toString());
      }
      map.put("address", address.toString());
      map.put("type", type);
      map.put("durable", durable);
      map.put("expiration", expiration);
      map.put("timestamp", timestamp);
      map.put("priority", priority);
      for (SimpleString propName : properties.getPropertyNames()) {
         map.put(propName.toString(), properties.getProperty(propName));
      }
      return map;
   }

   public void decodeFromBuffer(final ActiveMQBuffer buffer) {
      this.buffer = buffer;

      decode();

      // Setting up the BodyBuffer based on endOfBodyPosition set from decode
      ResetLimitWrappedActiveMQBuffer tmpbodyBuffer = new ResetLimitWrappedActiveMQBuffer(BODY_OFFSET, buffer, null);
      tmpbodyBuffer.readerIndex(BODY_OFFSET);
      tmpbodyBuffer.writerIndex(endOfBodyPosition);
      // only set this after the writer and reader is set,
      // otherwise the buffer would be reset through the listener
      tmpbodyBuffer.setMessage(this);
      this.bodyBuffer = tmpbodyBuffer;


   }

   public void bodyChanged() {
      bufferValid = false;

      endOfBodyPosition = -1;
   }

   public int getEndOfMessagePosition() {
      return endOfMessagePosition;
   }

   public int getEndOfBodyPosition() {
      if (endOfBodyPosition < 0) {
         endOfBodyPosition = getBodyBuffer().writerIndex();
      }
      return endOfBodyPosition;
   }

   // Encode to journal or paging
   public void encode(final ActiveMQBuffer buff) {
      encodeToBuffer();

      buff.writeBytes(buffer, BUFFER_HEADER_SPACE, endOfMessagePosition - BUFFER_HEADER_SPACE);
   }

   // Decode from journal or paging
   public void decode(final ActiveMQBuffer buff) {
      int start = buff.readerIndex();

      endOfBodyPosition = buff.readInt();

      endOfMessagePosition = buff.getInt(endOfBodyPosition - BUFFER_HEADER_SPACE + start);

      int length = endOfMessagePosition - BUFFER_HEADER_SPACE;

      buffer.setIndex(0, BUFFER_HEADER_SPACE);

      buffer.writeBytes(buff, start, length);

      decode();

      buff.readerIndex(start + length);
   }

   public synchronized ActiveMQBuffer getEncodedBuffer() {
      ActiveMQBuffer buff = encodeToBuffer();
      return buff.duplicate();
   }

   public void setAddressTransient(final SimpleString address) {
      this.address = address;
   }

   // Properties
   // ---------------------------------------------------------------------------------------

   public Message putBooleanProperty(final SimpleString key, final boolean value) {
      properties.putBooleanProperty(key, value);

      bufferValid = false;

      return this;
   }

   public Message putByteProperty(final SimpleString key, final byte value) {
      properties.putByteProperty(key, value);

      bufferValid = false;

      return this;
   }

   public Message putBytesProperty(final SimpleString key, final byte[] value) {
      properties.putBytesProperty(key, value);

      bufferValid = false;

      return this;
   }

   @Override
   public Message putCharProperty(SimpleString key, char value) {
      properties.putCharProperty(key, value);
      bufferValid = false;

      return this;
   }

   @Override
   public Message putCharProperty(String key, char value) {
      properties.putCharProperty(new SimpleString(key), value);
      bufferValid = false;

      return this;
   }

   public Message putShortProperty(final SimpleString key, final short value) {
      properties.putShortProperty(key, value);
      bufferValid = false;

      return this;
   }

   public Message putIntProperty(final SimpleString key, final int value) {
      properties.putIntProperty(key, value);
      bufferValid = false;

      return this;
   }

   public Message putLongProperty(final SimpleString key, final long value) {
      properties.putLongProperty(key, value);
      bufferValid = false;

      return this;
   }

   public Message putFloatProperty(final SimpleString key, final float value) {
      properties.putFloatProperty(key, value);

      bufferValid = false;

      return this;
   }

   public Message putDoubleProperty(final SimpleString key, final double value) {
      properties.putDoubleProperty(key, value);

      bufferValid = false;

      return this;
   }

   public Message putStringProperty(final SimpleString key, final SimpleString value) {
      properties.putSimpleStringProperty(key, value);

      bufferValid = false;

      return this;
   }

   public Message putObjectProperty(final SimpleString key,
                                    final Object value) throws ActiveMQPropertyConversionException {
      TypedProperties.setObjectProperty(key, value, properties);
      bufferValid = false;

      return this;
   }

   public Message putObjectProperty(final String key, final Object value) throws ActiveMQPropertyConversionException {
      putObjectProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putBooleanProperty(final String key, final boolean value) {
      properties.putBooleanProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putByteProperty(final String key, final byte value) {
      properties.putByteProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putBytesProperty(final String key, final byte[] value) {
      properties.putBytesProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putShortProperty(final String key, final short value) {
      properties.putShortProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putIntProperty(final String key, final int value) {
      properties.putIntProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putLongProperty(final String key, final long value) {
      properties.putLongProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putFloatProperty(final String key, final float value) {
      properties.putFloatProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putDoubleProperty(final String key, final double value) {
      properties.putDoubleProperty(new SimpleString(key), value);

      bufferValid = false;

      return this;
   }

   public Message putStringProperty(final String key, final String value) {
      properties.putSimpleStringProperty(new SimpleString(key), SimpleString.toSimpleString(value));

      bufferValid = false;

      return this;
   }

   public Message putTypedProperties(final TypedProperties otherProps) {
      properties.putTypedProperties(otherProps);

      bufferValid = false;

      return this;
   }

   public Object getObjectProperty(final SimpleString key) {
      return properties.getProperty(key);
   }

   public Boolean getBooleanProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getBooleanProperty(key);
   }

   public Boolean getBooleanProperty(final String key) throws ActiveMQPropertyConversionException {
      return properties.getBooleanProperty(new SimpleString(key));
   }

   public Byte getByteProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getByteProperty(key);
   }

   public Byte getByteProperty(final String key) throws ActiveMQPropertyConversionException {
      return properties.getByteProperty(new SimpleString(key));
   }

   public byte[] getBytesProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getBytesProperty(key);
   }

   public byte[] getBytesProperty(final String key) throws ActiveMQPropertyConversionException {
      return getBytesProperty(new SimpleString(key));
   }

   public Double getDoubleProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getDoubleProperty(key);
   }

   public Double getDoubleProperty(final String key) throws ActiveMQPropertyConversionException {
      return properties.getDoubleProperty(new SimpleString(key));
   }

   public Integer getIntProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getIntProperty(key);
   }

   public Integer getIntProperty(final String key) throws ActiveMQPropertyConversionException {
      return properties.getIntProperty(new SimpleString(key));
   }

   public Long getLongProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getLongProperty(key);
   }

   public Long getLongProperty(final String key) throws ActiveMQPropertyConversionException {
      return properties.getLongProperty(new SimpleString(key));
   }

   public Short getShortProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getShortProperty(key);
   }

   public Short getShortProperty(final String key) throws ActiveMQPropertyConversionException {
      return properties.getShortProperty(new SimpleString(key));
   }

   public Float getFloatProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getFloatProperty(key);
   }

   public Float getFloatProperty(final String key) throws ActiveMQPropertyConversionException {
      return properties.getFloatProperty(new SimpleString(key));
   }

   public String getStringProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      SimpleString str = getSimpleStringProperty(key);

      if (str == null) {
         return null;
      }
      else {
         return str.toString();
      }
   }

   public String getStringProperty(final String key) throws ActiveMQPropertyConversionException {
      return getStringProperty(new SimpleString(key));
   }

   public SimpleString getSimpleStringProperty(final SimpleString key) throws ActiveMQPropertyConversionException {
      return properties.getSimpleStringProperty(key);
   }

   public SimpleString getSimpleStringProperty(final String key) throws ActiveMQPropertyConversionException {
      return properties.getSimpleStringProperty(new SimpleString(key));
   }

   public Object getObjectProperty(final String key) {
      return properties.getProperty(new SimpleString(key));
   }

   public Object removeProperty(final SimpleString key) {
      bufferValid = false;

      return properties.removeProperty(key);
   }

   public Object removeProperty(final String key) {
      bufferValid = false;

      return properties.removeProperty(new SimpleString(key));
   }

   public boolean containsProperty(final SimpleString key) {
      return properties.containsProperty(key);
   }

   public boolean containsProperty(final String key) {
      return properties.containsProperty(new SimpleString(key));
   }

   public Set<SimpleString> getPropertyNames() {
      return properties.getPropertyNames();
   }

   public ActiveMQBuffer getWholeBuffer() {
      return buffer;
   }

   public BodyEncoder getBodyEncoder() throws ActiveMQException {
      return new DecodingContext();
   }

   public TypedProperties getTypedProperties() {
      return this.properties;
   }

   @Override
   public boolean equals(Object other) {

      if (this == other) {
         return true;
      }

      if (other instanceof MessageImpl) {
         MessageImpl message = (MessageImpl) other;

         if (this.getMessageID() == message.getMessageID())
            return true;
      }

      return false;
   }

   /**
    * Debug Helper!!!!
    *
    * I'm leaving this message here without any callers for a reason:
    * During debugs it's important eventually to identify what's on the bodies, and this method will give you a good idea about them.
    * Add the message.bodyToString() to the Watch variables on the debugger view and this will show up like a charm!!!
    *
    * @return
    */
   public String bodyToString() {
      getEndOfBodyPosition();
      int readerIndex1 = this.buffer.readerIndex();
      buffer.readerIndex(0);
      byte[] buffer1 = new byte[buffer.writerIndex()];
      buffer.readBytes(buffer1);
      buffer.readerIndex(readerIndex1);

      byte[] buffer2 = null;
      if (bodyBuffer != null) {
         int readerIndex2 = this.bodyBuffer.readerIndex();
         bodyBuffer.readerIndex(0);
         buffer2 = new byte[bodyBuffer.writerIndex() - bodyBuffer.readerIndex()];
         bodyBuffer.readBytes(buffer2);
         bodyBuffer.readerIndex(readerIndex2);
         return "ServerMessage@" + Integer.toHexString(System.identityHashCode(this)) + "[writerIndex=" + buffer.writerIndex() + ",capacity=" + buffer.capacity() + ",bodyStart=" + getEndOfBodyPosition() + " buffer=" + ByteUtil.bytesToHex(buffer1, 1) + ", bodyBuffer=" + ByteUtil.bytesToHex(buffer2, 1);
      }
      else {
         return "ServerMessage@" + Integer.toHexString(System.identityHashCode(this)) + "[writerIndex=" + buffer.writerIndex() + ",capacity=" + buffer.capacity() + ",bodyStart=" + getEndOfBodyPosition() + " buffer=" + ByteUtil.bytesToHex(buffer1, 1);
      }

   }

   @Override
   public int hashCode() {
      return 31 + (int) (messageID ^ (messageID >>> 32));
   }

   // Public --------------------------------------------------------

   // Package protected ---------------------------------------------

   // Protected -----------------------------------------------------

   // Private -------------------------------------------------------

   public TypedProperties getProperties() {
      return properties;
   }

   // This must be synchronized as it can be called concurrently id the message is being delivered
   // concurrently to
   // many queues - the first caller in this case will actually encode it
   private synchronized ActiveMQBuffer encodeToBuffer() {
      if (!bufferValid) {
         int bodySize = getEndOfBodyPosition();

         // write it
         buffer.setInt(BUFFER_HEADER_SPACE, bodySize);

         // Position at end of body and skip past the message end position int.
         // check for enough room in the buffer even though it is dynamic
         if ((bodySize + 4) > buffer.capacity()) {
            buffer.setIndex(0, bodySize);
            buffer.writeInt(0);
         }
         else {
            buffer.setIndex(0, bodySize + DataConstants.SIZE_INT);
         }

         encodeHeadersAndProperties(buffer);

         // Write end of message position

         endOfMessagePosition = buffer.writerIndex();

         buffer.setInt(bodySize, endOfMessagePosition);

         bufferValid = true;
      }

      return buffer;
   }

   private void decode() {
      endOfBodyPosition = buffer.getInt(BUFFER_HEADER_SPACE);

      buffer.readerIndex(endOfBodyPosition + DataConstants.SIZE_INT);

      decodeHeadersAndProperties(buffer);

      endOfMessagePosition = buffer.readerIndex();

      bufferValid = true;
   }

   public void createBody(final int initialMessageBufferSize) {
      buffer = ActiveMQBuffers.dynamicBuffer(initialMessageBufferSize);

      // There's a bug in netty which means a dynamic buffer won't resize until you write a byte
      buffer.writeByte((byte) 0);

      buffer.setIndex(BODY_OFFSET, BODY_OFFSET);
   }

   private void forceCopy() {
      // Must copy buffer before sending it

      buffer = buffer.copy(0, buffer.capacity());

      buffer.setIndex(0, getEndOfBodyPosition());

      if (bodyBuffer != null) {
         bodyBuffer.setBuffer(buffer);
      }
   }

   // Inner classes -------------------------------------------------

   private final class DecodingContext implements BodyEncoder {

      private int lastPos = 0;

      public DecodingContext() {
      }

      public void open() {
      }

      public void close() {
      }

      public long getLargeBodySize() {
         return buffer.writerIndex();
      }

      public int encode(final ByteBuffer bufferRead) throws ActiveMQException {
         ActiveMQBuffer buffer = ActiveMQBuffers.wrappedBuffer(bufferRead);
         return encode(buffer, bufferRead.capacity());
      }

      public int encode(final ActiveMQBuffer bufferOut, final int size) {
         bufferOut.writeBytes(getWholeBuffer(), lastPos, size);
         lastPos += size;
         return size;
      }
   }

}
