/*
 *
 * 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.qpid.server.queue;

import org.apache.log4j.Logger;
import org.apache.qpid.AMQException;
import org.apache.qpid.framing.AMQBody;
import org.apache.qpid.framing.AMQDataBlock;
import org.apache.qpid.framing.AMQFrame;
import org.apache.qpid.framing.BasicContentHeaderProperties;
import org.apache.qpid.framing.ContentHeaderBody;
import org.apache.qpid.framing.abstraction.ContentChunk;
import org.apache.qpid.framing.abstraction.MessagePublishInfo;
import org.apache.qpid.framing.abstraction.ProtocolVersionMethodConverter;
import org.apache.qpid.server.protocol.AMQProtocolSession;
import org.apache.qpid.server.registry.ApplicationRegistry;
import org.apache.qpid.server.store.MessageStore;
import org.apache.qpid.server.store.StoreContext;
import org.apache.qpid.server.txn.TransactionalContext;
import org.apache.qpid.server.exchange.Exchange;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * A deliverable message.
 */
public class AMQMessage
{
    /** Used for debugging purposes. */
    private static final Logger _log = Logger.getLogger(AMQMessage.class);

    /** Used in clustering. @todo What for? */
    private Set<Object> _tokens;

    /** Only use in clustering. @todo What for? */
    private AMQProtocolSession _publisher;

    private final Long _messageId;

    private final AtomicInteger _referenceCount = new AtomicInteger(1);

    private AMQMessageHandle _messageHandle;

    /** Holds the transactional context in which this message is being processed. */
    private TransactionalContext _txnContext;

    /**
     * Flag to indicate whether this message has been delivered to a consumer. Used in implementing return functionality
     * for messages published with the 'immediate' flag.
     */
    private boolean _deliveredToConsumer;

    /** Flag to indicate that this message requires 'immediate' delivery. */
    private boolean _immediate;

    private TransientMessageData _transientMessageData = new TransientMessageData();

    private long _expiration;




    private Exchange _exchange;
    private static final boolean SYNCED_CLOCKS =
            ApplicationRegistry.getInstance().getConfiguration().getBoolean("advanced.synced-clocks", false);


    public String debugIdentity()
    {
        return "(HC:" + System.identityHashCode(this) + " ID:" + _messageId + " Ref:" + _referenceCount.get() + ")";
    }

    public void setExpiration()
    {
        long expiration =
                ((BasicContentHeaderProperties) _transientMessageData.getContentHeaderBody().properties).getExpiration();
        long timestamp =
                ((BasicContentHeaderProperties) _transientMessageData.getContentHeaderBody().properties).getTimestamp();

        if (SYNCED_CLOCKS)
        {
            _expiration = expiration;
        }
        else
        {
            // Update TTL to be in broker time.
            if (expiration != 0L)
            {
                if (timestamp != 0L)
                {
                    // todo perhaps use arrival time
                    long diff = (System.currentTimeMillis() - timestamp);

                    if ((diff > 1000L) || (diff < 1000L))
                    {
                        _expiration = expiration + diff;
                    }
                }
            }
        }

    }

    public boolean isReferenced()
    {
        return _referenceCount.get() > 0;
    }

    public void setExchange(final Exchange exchange)
    {
        _exchange = exchange;
    }

    public void route() throws AMQException
    {
        _exchange.route(this);
    }

    public void enqueue(final List<AMQQueue> queues)
    {
        _transientMessageData.setDestinationQueues(queues);
    }

    /**
     * Used to iterate through all the body frames associated with this message. Will not keep all the data in memory
     * therefore is memory-efficient.
     */
    private class BodyFrameIterator implements Iterator<AMQDataBlock>
    {
        private int _channel;

        private int _index = -1;
        private AMQProtocolSession _protocolSession;

        private BodyFrameIterator(AMQProtocolSession protocolSession, int channel)
        {
            _channel = channel;
            _protocolSession = protocolSession;
        }

        public boolean hasNext()
        {
            try
            {
                return _index < (_messageHandle.getBodyCount(getStoreContext(), _messageId) - 1);
            }
            catch (AMQException e)
            {
                _log.error("Unable to get body count: " + e, e);

                return false;
            }
        }

        public AMQDataBlock next()
        {
            try
            {

                AMQBody cb =
                        getProtocolVersionMethodConverter().convertToBody(_messageHandle.getContentChunk(getStoreContext(),
                                                                                                         _messageId, ++_index));

                return new AMQFrame(_channel, cb);
            }
            catch (AMQException e)
            {
                // have no choice but to throw a runtime exception
                throw new RuntimeException("Error getting content body: " + e, e);
            }

        }

        private ProtocolVersionMethodConverter getProtocolVersionMethodConverter()
        {
            return _protocolSession.getMethodRegistry().getProtocolVersionMethodConverter();
        }

        public void remove()
        {
            throw new UnsupportedOperationException();
        }
    }

    public StoreContext getStoreContext()
    {
        return _txnContext.getStoreContext();
    }

    private class BodyContentIterator implements Iterator<ContentChunk>
    {

        private int _index = -1;

        public boolean hasNext()
        {
            try
            {
                return _index < (_messageHandle.getBodyCount(getStoreContext(), _messageId) - 1);
            }
            catch (AMQException e)
            {
                _log.error("Error getting body count: " + e, e);

                return false;
            }
        }

        public ContentChunk next()
        {
            try
            {
                return _messageHandle.getContentChunk(getStoreContext(), _messageId, ++_index);
            }
            catch (AMQException e)
            {
                throw new RuntimeException("Error getting content body: " + e, e);
            }
        }

        public void remove()
        {
            throw new UnsupportedOperationException();
        }
    }

    public AMQMessage(Long messageId, MessagePublishInfo info, TransactionalContext txnContext)
    {
        _messageId = messageId;
        _txnContext = txnContext;
        _immediate = info.isImmediate();
        _transientMessageData.setMessagePublishInfo(info);

    }

    /**
     * Used when recovering, i.e. when the message store is creating references to messages. In that case, the normal
     * enqueue/routingComplete is not done since the recovery process is responsible for routing the messages to
     * queues.
     *
     * @param messageId
     * @param store
     * @param factory
     *
     * @throws AMQException
     */
    public AMQMessage(Long messageId, MessageStore store, MessageHandleFactory factory, TransactionalContext txnConext)
            throws AMQException
    {
        _messageId = messageId;
        _messageHandle = factory.createMessageHandle(messageId, store, true);
        _txnContext = txnConext;
        _transientMessageData = null;
    }

    /**
     * Used in testing only. This allows the passing of the content header immediately on construction.
     *
     * @param messageId
     * @param info
     * @param txnContext
     * @param contentHeader
     */
    public AMQMessage(Long messageId, MessagePublishInfo info, TransactionalContext txnContext,
                      ContentHeaderBody contentHeader) throws AMQException
    {
        this(messageId, info, txnContext);
        setContentHeaderBody(contentHeader);
    }

    /* *
     * Used in testing only. This allows the passing of the content header and some body fragments on construction.
     *
     * @param messageId
     * @param info
     * @param txnContext
     * @param contentHeader
     * @param destinationQueues
     * @param contentBodies
     *
     * @throws AMQException
     */        /*
    public AMQMessage(Long messageId, MessagePublishInfo info, TransactionalContext txnContext,
                      ContentHeaderBody contentHeader, List<AMQQueue> destinationQueues, List<ContentChunk> contentBodies,
                      MessageStore messageStore, StoreContext storeContext, MessageHandleFactory messageHandleFactory) throws AMQException
    {
        this(messageId, info, txnContext, contentHeader);
        _transientMessageData.setDestinationQueues(destinationQueues);
        routingComplete(messageStore, storeContext, messageHandleFactory);
        for (ContentChunk cb : contentBodies)
        {
            addContentBodyFrame(storeContext, cb);
        }
    }
                 */
    protected AMQMessage(AMQMessage msg) throws AMQException
    {
        _messageId = msg._messageId;
        _messageHandle = msg._messageHandle;
        _txnContext = msg._txnContext;
        _deliveredToConsumer = msg._deliveredToConsumer;
        _transientMessageData = msg._transientMessageData;
    }

    public Iterator<AMQDataBlock> getBodyFrameIterator(AMQProtocolSession protocolSession, int channel)
    {
        return new BodyFrameIterator(protocolSession, channel);
    }

    public Iterator<ContentChunk> getContentBodyIterator()
    {
        return new BodyContentIterator();
    }

    public ContentHeaderBody getContentHeaderBody() throws AMQException
    {
        if (_transientMessageData != null)
        {
            return _transientMessageData.getContentHeaderBody();
        }
        else
        {
            return _messageHandle.getContentHeaderBody(getStoreContext(), _messageId);
        }
    }

    public void setContentHeaderBody(ContentHeaderBody contentHeaderBody) throws AMQException
    {
        _transientMessageData.setContentHeaderBody(contentHeaderBody);
    }

    public void routingComplete(MessageStore store, StoreContext storeContext, MessageHandleFactory factory)
            throws AMQException
    {
        final boolean persistent = isPersistent();
        _messageHandle = factory.createMessageHandle(_messageId, store, persistent);
        if (persistent)
        {
            _txnContext.beginTranIfNecessary();
        }

        // enqueuing the messages ensure that if required the destinations are recorded to a
        // persistent store

        for (AMQQueue q : _transientMessageData.getDestinationQueues())
        {
            _messageHandle.enqueue(storeContext, _messageId, q);
        }

        if (_transientMessageData.getContentHeaderBody().bodySize == 0)
        {
            deliver(storeContext);
        }
    }

    public boolean addContentBodyFrame(StoreContext storeContext, ContentChunk contentChunk) throws AMQException
    {
        _transientMessageData.addBodyLength(contentChunk.getSize());
        final boolean allContentReceived = isAllContentReceived();
        _messageHandle.addContentBodyFrame(storeContext, _messageId, contentChunk, allContentReceived);
        if (allContentReceived)
        {
            deliver(storeContext);

            return true;
        }
        else
        {
            return false;
        }
    }

    public boolean isAllContentReceived() throws AMQException
    {
        return _transientMessageData.isAllContentReceived();
    }

    public Long getMessageId()
    {
        return _messageId;
    }

    /**
     * Creates a long-lived reference to this message, and increments the count of such references, as an atomic
     * operation.
     */
    public AMQMessage takeReference()
    {
        incrementReference(); // _referenceCount.incrementAndGet();

        return this;
    }

    /** Threadsafe. Increment the reference count on the message. */
    public void incrementReference()
    {
        _referenceCount.incrementAndGet();
        // if (_log.isDebugEnabled())
        // {
        // _log.debug("Ref count on message " + debugIdentity() + " incremented " + Arrays.asList(Thread.currentThread().getStackTrace()).subList(3, 6));
        // }
    }

    /**
     * Threadsafe. This will decrement the reference count and when it reaches zero will remove the message from the
     * message store.
     *
     * @param storeContext
     *
     * @throws MessageCleanupException when an attempt was made to remove the message from the message store and that
     *                                 failed
     */
    public void decrementReference(StoreContext storeContext) throws MessageCleanupException
    {
        int count = _referenceCount.decrementAndGet();

        // note that the operation of decrementing the reference count and then removing the message does not
        // have to be atomic since the ref count starts at 1 and the exchange itself decrements that after
        // the message has been passed to all queues. i.e. we are
        // not relying on the all the increments having taken place before the delivery manager decrements.
        if (count == 0)
        {
            try
            {
                // if (_log.isDebugEnabled())
                // {
                // _log.debug("Decremented ref count on message " + debugIdentity() + " is zero; removing message" + Arrays.asList(Thread.currentThread().getStackTrace()).subList(3, 6));
                // }

                // must check if the handle is null since there may be cases where we decide to throw away a message
                // and the handle has not yet been constructed
                if (_messageHandle != null)
                {
                    _messageHandle.removeMessage(storeContext, _messageId);
                }
            }
            catch (AMQException e)
            {
                // to maintain consistency, we revert the count
                incrementReference();
                throw new MessageCleanupException(_messageId, e);
            }
        }
        else
        {
            if (count < 0)
            {
                throw new MessageCleanupException("Reference count for message id " + debugIdentity()
                                                  + " has gone below 0.");
            }
        }
    }

    public void setPublisher(AMQProtocolSession publisher)
    {
        _publisher = publisher;
    }

    public AMQProtocolSession getPublisher()
    {
        return _publisher;
    }

    /**
     * Called selectors to determin if the message has already been sent
     *
     * @return _deliveredToConsumer
     */
    public boolean getDeliveredToConsumer()
    {
        return _deliveredToConsumer;
    }


    public boolean checkToken(Object token)
    {

        if (_tokens == null)
        {
            _tokens = new HashSet<Object>();
        }

        if (_tokens.contains(token))
        {
            return true;
        }
        else
        {
            _tokens.add(token);

            return false;
        }
    }

    /**
     * Registers a queue to which this message is to be delivered. This is called from the exchange when it is routing
     * the message. This will be called before any content bodies have been received so that the choice of
     * AMQMessageHandle implementation can be picked based on various criteria.
     *
     * @param queue the queue
     *
     * @throws org.apache.qpid.AMQException if there is an error enqueuing the message
     */
    public void enqueue(AMQQueue queue) throws AMQException
    {
        _transientMessageData.addDestinationQueue(queue);
    }

    /**
     * NOTE: Think about why you are using this method. Normal usages would want to do
     * AMQQueue.dequeue(StoreContext, AMQMessage)
     * This will keep the queue statistics up-to-date.
     * Currently this method is only called _correctly_ from AMQQueue dequeue.
     * Ideally we would have a better way for the queue to dequeue the message.
     * Especially since enqueue isn't the recipriocal of this method.
     * @deprecated
     * @param storeContext
     * @param queue
     * @throws AMQException
     */
    void dequeue(StoreContext storeContext, AMQQueue queue) throws AMQException
    {
        _messageHandle.dequeue(storeContext, _messageId, queue);
    }

    public boolean isPersistent() throws AMQException
    {
        if (_transientMessageData != null)
        {
            return _transientMessageData.isPersistent();
        }
        else
        {
            return _messageHandle.isPersistent(getStoreContext(), _messageId);
        }
    }

    /**
     * Called to enforce the 'immediate' flag.
     *
     * @throws NoConsumersException if the message is marked for immediate delivery but has not been marked as delivered
     *                              to a consumer
     */
    public void checkDeliveredToConsumer() throws NoConsumersException
    {

        if (_immediate && !_deliveredToConsumer)
        {
            throw new NoConsumersException(this);
        }
    }

    public MessagePublishInfo getMessagePublishInfo() throws AMQException
    {
        MessagePublishInfo pb;
        if (_transientMessageData != null)
        {
            pb = _transientMessageData.getMessagePublishInfo();
        }
        else
        {
            pb = _messageHandle.getMessagePublishInfo(getStoreContext(), _messageId);
        }

        return pb;
    }

    public boolean isRedelivered()
    {
        return _messageHandle.isRedelivered();
    }

    public void setRedelivered(boolean redelivered)
    {
        _messageHandle.setRedelivered(redelivered);
    }

    public long getArrivalTime()
    {
        return _messageHandle.getArrivalTime();
    }

    /**
     * Checks to see if the message has expired. If it has the message is dequeued.
     *
     * @param queue The queue to check the expiration against. (Currently not used)
     *
     * @return true if the message has expire
     *
     * @throws AMQException
     */
    public boolean expired(AMQQueue queue) throws AMQException
    {

        if (_expiration != 0L)
        {
            long now = System.currentTimeMillis();

            return (now > _expiration);
        }

        return false;
    }

    /**
     * Called when this message is delivered to a consumer. (used to implement the 'immediate' flag functionality).
     * And for selector efficiency.
     */
    public void setDeliveredToConsumer()
    {
        _deliveredToConsumer = true;
    }

    private void deliver(StoreContext storeContext) throws AMQException
    {
        // we get a reference to the destination queues now so that we can clear the
        // transient message data as quickly as possible
        List<AMQQueue> destinationQueues = _transientMessageData.getDestinationQueues();
        if (_log.isDebugEnabled())
        {
            _log.debug("Delivering message " + debugIdentity() + " to " + destinationQueues);
        }

        try
        {
            // first we allow the handle to know that the message has been fully received. This is useful if it is
            // maintaining any calculated values based on content chunks
            _messageHandle.setPublishAndContentHeaderBody(storeContext, _messageId,
                                                          _transientMessageData.getMessagePublishInfo(), _transientMessageData.getContentHeaderBody());

            // we then allow the transactional context to do something with the message content
            // now that it has all been received, before we attempt delivery
            _txnContext.messageFullyReceived(isPersistent());

            for (AMQQueue q : destinationQueues)
            {
                // Increment the references to this message for each queue delivery.
                incrementReference();
                // normal deliver so add this message at the end.
                _txnContext.deliver(q.createEntry(this), false);
            }
        }
        finally
        {

            // Remove refence for routing process . Reference count should now == delivered queue count
            decrementReference(storeContext);
        }
    }


    public AMQMessageHandle getMessageHandle()
    {
        return _messageHandle;
    }

    public long getSize()
    {
        try
        {
            long size = getContentHeaderBody().bodySize;

            return size;
        }
        catch (AMQException e)
        {
            _log.error(e.toString(), e);

            return 0;
        }

    }

    public void restoreTransientMessageData() throws AMQException
    {
        TransientMessageData transientMessageData = new TransientMessageData();
        transientMessageData.setMessagePublishInfo(getMessagePublishInfo());
        transientMessageData.setContentHeaderBody(getContentHeaderBody());
        transientMessageData.addBodyLength(getContentHeaderBody().getSize());
        _transientMessageData = transientMessageData;
    }


    public String toString()
    {
        // return "Message[" + debugIdentity() + "]: " + _messageId + "; ref count: " + _referenceCount + "; taken : " +
        // _taken + " by :" + _takenBySubcription;

        return "Message[" + debugIdentity() + "]: " + _messageId + "; ref count: " + _referenceCount;
    }

}
