/*
 *
 * 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.protocol.v1_0;

import org.apache.qpid.amqp_1_0.codec.ValueHandler;
import org.apache.qpid.amqp_1_0.messaging.SectionEncoder;
import org.apache.qpid.amqp_1_0.messaging.SectionEncoderImpl;
import org.apache.qpid.amqp_1_0.transport.SendingLinkEndpoint;
import org.apache.qpid.amqp_1_0.type.AmqpErrorException;
import org.apache.qpid.amqp_1_0.type.Binary;
import org.apache.qpid.amqp_1_0.type.DeliveryState;
import org.apache.qpid.amqp_1_0.type.Outcome;
import org.apache.qpid.amqp_1_0.type.UnsignedInteger;
import org.apache.qpid.amqp_1_0.type.codec.AMQPDescribedTypeRegistry;
import org.apache.qpid.amqp_1_0.type.messaging.Accepted;
import org.apache.qpid.amqp_1_0.type.messaging.Header;
import org.apache.qpid.amqp_1_0.type.messaging.Modified;
import org.apache.qpid.amqp_1_0.type.messaging.Released;
import org.apache.qpid.amqp_1_0.type.transaction.TransactionalState;
import org.apache.qpid.amqp_1_0.type.transport.SenderSettleMode;
import org.apache.qpid.amqp_1_0.type.transport.Transfer;
import org.apache.qpid.server.consumer.ConsumerImpl;
import org.apache.qpid.server.message.MessageInstance;
import org.apache.qpid.server.message.ServerMessage;
import org.apache.qpid.server.plugin.MessageConverter;
import org.apache.qpid.server.protocol.AMQSessionModel;
import org.apache.qpid.server.protocol.MessageConverterRegistry;
import org.apache.qpid.server.consumer.AbstractConsumerTarget;
import org.apache.qpid.server.txn.ServerTransaction;
import org.apache.qpid.server.util.ConnectionScopedRuntimeException;

import java.nio.ByteBuffer;
import java.util.List;

class ConsumerTarget_1_0 extends AbstractConsumerTarget
{
    private final boolean _acquires;
    private SendingLink_1_0 _link;

    private long _deliveryTag = 0L;

    private Binary _transactionId;
    private final AMQPDescribedTypeRegistry _typeRegistry;
    private final SectionEncoder _sectionEncoder;
    private ConsumerImpl _consumer;

    public ConsumerTarget_1_0(final SendingLink_1_0 link,
                              boolean acquires)
    {
        super(State.SUSPENDED);
        _link = link;
        _typeRegistry = link.getEndpoint().getSession().getConnection().getDescribedTypeRegistry();
        _sectionEncoder = new SectionEncoderImpl(_typeRegistry);
        _acquires = acquires;
    }

    public ConsumerImpl getConsumer()
    {
        return _consumer;
    }

    private SendingLinkEndpoint getEndpoint()
    {
        return _link.getEndpoint();
    }

    public boolean isSuspended()
    {
        return _link.getSession().getConnectionModel().isStopped() || getState() != State.ACTIVE;// || !getEndpoint().hasCreditToSend();

    }

    public boolean close()
    {
        boolean closed = false;
        State state = getState();

        getConsumer().getSendLock();
        try
        {
            while(!closed && state != State.CLOSED)
            {
                closed = updateState(state, State.CLOSED);
                if(!closed)
                {
                    state = getState();
                }
            }
            return closed;
        }
        finally
        {
            getConsumer().releaseSendLock();
        }
    }

    public void send(MessageInstance entry, boolean batch)
    {
        // TODO
        send(entry);
    }

    public void flushBatched()
    {
        // TODO
    }

    public void send(final MessageInstance queueEntry)
    {
        ServerMessage serverMessage = queueEntry.getMessage();
        Message_1_0 message;
        if(serverMessage instanceof Message_1_0)
        {
            message = (Message_1_0) serverMessage;
        }
        else
        {
            final MessageConverter converter = MessageConverterRegistry.getConverter(serverMessage.getClass(), Message_1_0.class);
            message = (Message_1_0) converter.convert(serverMessage, _link.getVirtualHost());
        }

        Transfer transfer = new Transfer();
        //TODO


        List<ByteBuffer> fragments = message.getFragments();
        ByteBuffer payload;
        if(fragments.size() == 1)
        {
            payload = fragments.get(0);
        }
        else
        {
            int size = 0;
            for(ByteBuffer fragment : fragments)
            {
                size += fragment.remaining();
            }

            payload = ByteBuffer.allocate(size);

            for(ByteBuffer fragment : fragments)
            {
                payload.put(fragment.duplicate());
            }

            payload.flip();
        }

        if(queueEntry.getDeliveryCount() != 0)
        {
            payload = payload.duplicate();
            ValueHandler valueHandler = new ValueHandler(_typeRegistry);

            Header oldHeader = null;
            try
            {
                ByteBuffer encodedBuf = payload.duplicate();
                Object value = valueHandler.parse(payload);
                if(value instanceof Header)
                {
                    oldHeader = (Header) value;
                }
                else
                {
                    payload.position(0);
                }
            }
            catch (AmqpErrorException e)
            {
                //TODO
                throw new ConnectionScopedRuntimeException(e);
            }

            Header header = new Header();
            if(oldHeader != null)
            {
                header.setDurable(oldHeader.getDurable());
                header.setPriority(oldHeader.getPriority());
                header.setTtl(oldHeader.getTtl());
            }
            header.setDeliveryCount(UnsignedInteger.valueOf(queueEntry.getDeliveryCount()));
            _sectionEncoder.reset();
            _sectionEncoder.encodeObject(header);
            Binary encodedHeader = _sectionEncoder.getEncoding();

            ByteBuffer oldPayload = payload;
            payload = ByteBuffer.allocate(oldPayload.remaining() + encodedHeader.getLength());
            payload.put(encodedHeader.getArray(),encodedHeader.getArrayOffset(),encodedHeader.getLength());
            payload.put(oldPayload);
            payload.flip();
        }

        transfer.setPayload(payload);
        byte[] data = new byte[8];
        ByteBuffer.wrap(data).putLong(_deliveryTag++);
        final Binary tag = new Binary(data);

        transfer.setDeliveryTag(tag);

        synchronized(_link.getLock())
        {
            if(_link.isAttached())
            {
                if(SenderSettleMode.SETTLED.equals(getEndpoint().getSendingSettlementMode()))
                {
                    transfer.setSettled(true);
                }
                else
                {
                    UnsettledAction action = _acquires
                                             ? new DispositionAction(tag, queueEntry)
                                             : new DoNothingAction(tag, queueEntry);

                    _link.addUnsettled(tag, action, queueEntry);
                }

                if(_transactionId != null)
                {
                    TransactionalState state = new TransactionalState();
                    state.setTxnId(_transactionId);
                    transfer.setState(state);
                }
                // TODO - need to deal with failure here
                if(_acquires && _transactionId != null)
                {
                    ServerTransaction txn = _link.getTransaction(_transactionId);
                    if(txn != null)
                    {
                        txn.addPostTransactionAction(new ServerTransaction.Action(){

                            public void postCommit()
                            {
                                //To change body of implemented methods use File | Settings | File Templates.
                            }

                            public void onRollback()
                            {
                                if(queueEntry.isAcquiredBy(getConsumer()))
                                {
                                    queueEntry.release();
                                    _link.getEndpoint().updateDisposition(tag, (DeliveryState)null, true);


                                }
                            }
                        });
                    }

                }
                getSession().getConnectionModel().registerMessageDelivered(message.getSize());
                getEndpoint().transfer(transfer);
            }
            else
            {
                queueEntry.release();
            }
        }

    }

    public void queueDeleted()
    {
        //TODO
        getEndpoint().setSource(null);
        getEndpoint().detach();
    }

    public boolean allocateCredit(final ServerMessage msg)
    {
        synchronized (_link.getLock())
        {
            final boolean hasCredit = _link.isAttached() && getEndpoint().hasCreditToSend();
            if(!hasCredit && getState() == State.ACTIVE)
            {
                suspend();
            }

            return hasCredit;
        }
    }


    public void suspend()
    {
        synchronized(_link.getLock())
        {
            updateState(State.ACTIVE, State.SUSPENDED);
        }
    }


    public void restoreCredit(final ServerMessage message)
    {
        //TODO
    }

    public void queueEmpty()
    {
        synchronized(_link.getLock())
        {
            if(_link.drained())
            {
                updateState(State.ACTIVE, State.SUSPENDED);
            }
        }
    }

    public void flowStateChanged()
    {
        synchronized(_link.getLock())
        {
            if(isSuspended() && getEndpoint() != null)
            {
                updateState(State.SUSPENDED, State.ACTIVE);
                _transactionId = _link.getTransactionId();
            }
        }
    }

    public Session_1_0 getSession()
    {
        return _link.getSession();
    }

    private class DispositionAction implements UnsettledAction
    {

        private final MessageInstance _queueEntry;
        private final Binary _deliveryTag;

        public DispositionAction(Binary tag, MessageInstance queueEntry)
        {
            _deliveryTag = tag;
            _queueEntry = queueEntry;
        }

        public boolean process(DeliveryState state, final Boolean settled)
        {

            Binary transactionId = null;
            final Outcome outcome;
            // If disposition is settled this overrides the txn?
            if(state instanceof TransactionalState)
            {
                transactionId = ((TransactionalState)state).getTxnId();
                outcome = ((TransactionalState)state).getOutcome();
            }
            else if (state instanceof Outcome)
            {
                outcome = (Outcome) state;
            }
            else
            {
                outcome = null;
            }


            ServerTransaction txn = _link.getTransaction(transactionId);

            if(outcome instanceof Accepted)
            {
                txn.dequeue(_queueEntry.getOwningResource(), _queueEntry.getMessage(),
                        new ServerTransaction.Action()
                        {

                            public void postCommit()
                            {
                                if(_queueEntry.isAcquiredBy(getConsumer()))
                                {
                                    _queueEntry.delete();
                                }
                            }

                            public void onRollback()
                            {

                            }
                        });
                txn.addPostTransactionAction(new ServerTransaction.Action()
                    {
                        public void postCommit()
                        {
                            //_link.getEndpoint().settle(_deliveryTag);
                            _link.getEndpoint().updateDisposition(_deliveryTag, (DeliveryState)outcome, true);
                            _link.getEndpoint().sendFlowConditional();
                        }

                        public void onRollback()
                        {
                            if(Boolean.TRUE.equals(settled))
                            {
                                final Modified modified = new Modified();
                                modified.setDeliveryFailed(true);
                                _link.getEndpoint().updateDisposition(_deliveryTag, modified, true);
                                _link.getEndpoint().sendFlowConditional();
                            }
                        }
                    });
            }
            else if(outcome instanceof Released)
            {
                txn.addPostTransactionAction(new ServerTransaction.Action()
                {
                    public void postCommit()
                    {

                        _queueEntry.release();
                        _link.getEndpoint().settle(_deliveryTag);
                    }

                    public void onRollback()
                    {
                        _link.getEndpoint().settle(_deliveryTag);
                    }
                });
            }

            else if(outcome instanceof Modified)
            {
                txn.addPostTransactionAction(new ServerTransaction.Action()
                {
                    public void postCommit()
                    {

                        _queueEntry.release();
                        if(Boolean.TRUE.equals(((Modified)outcome).getDeliveryFailed()))
                        {
                            _queueEntry.incrementDeliveryCount();
                        }
                        _link.getEndpoint().settle(_deliveryTag);
                    }

                    public void onRollback()
                    {
                        if(Boolean.TRUE.equals(settled))
                        {
                            final Modified modified = new Modified();
                            modified.setDeliveryFailed(true);
                            _link.getEndpoint().updateDisposition(_deliveryTag, modified, true);
                            _link.getEndpoint().sendFlowConditional();
                        }
                    }
                });
            }

            return (transactionId == null && outcome != null);
        }
    }

    private class DoNothingAction implements UnsettledAction
    {
        public DoNothingAction(final Binary tag,
                               final MessageInstance queueEntry)
        {
        }

        public boolean process(final DeliveryState state, final Boolean settled)
        {
            Binary transactionId = null;
            Outcome outcome = null;
            // If disposition is settled this overrides the txn?
            if(state instanceof TransactionalState)
            {
                transactionId = ((TransactionalState)state).getTxnId();
                outcome = ((TransactionalState)state).getOutcome();
            }
            else if (state instanceof Outcome)
            {
                outcome = (Outcome) state;
            }
            return true;
        }
    }

    @Override
    public AMQSessionModel getSessionModel()
    {
        return getSession();
    }

    @Override
    public void consumerAdded(final ConsumerImpl sub)
    {
        _consumer = sub;
    }

    @Override
    public void consumerRemoved(final ConsumerImpl sub)
    {

    }

    @Override
    public long getUnacknowledgedBytes()
    {
        // TODO
        return 0;
    }

    @Override
    public long getUnacknowledgedMessages()
    {
        // TODO
        return 0;
    }

}