/*
 *
 * Copyright (c) 2006 The Apache Software Foundation
 *
 * Licensed 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.txn;

import org.apache.log4j.Logger;
import org.apache.qpid.AMQException;
import org.apache.qpid.server.queue.AMQMessage;
import org.apache.qpid.server.queue.NoConsumersException;
import org.apache.qpid.server.RequiredDeliveryException;
import org.apache.qpid.server.store.StoreContext;

import java.util.List;

/**
 * @author Apache Software Foundation
 */
public class CleanupMessageOperation implements TxnOp
{
    private static final Logger _log = Logger.getLogger(CleanupMessageOperation.class);

    private final AMQMessage _msg;

    private final List<RequiredDeliveryException> _returns;

    public CleanupMessageOperation(AMQMessage msg, List<RequiredDeliveryException> returns)
    {
        _msg = msg;
        _returns = returns;
    }

    public void prepare(StoreContext context) throws AMQException
    {
    }

    public void undoPrepare()
    {
        //don't need to do anything here, if the store's txn failed
        //when processing prepare then the message was not stored
        //or enqueued on any queues and can be discarded
    }

    public void commit(StoreContext context)
    {
        //The routers reference can now be released.  This is done
        //here to ensure that it happens after the queues that
        //enqueue it have incremented their counts (which as a
        //memory only operation is done in the commit phase).
        try
        {
            _msg.decrementReference(context);
        }
        catch (AMQException e)
        {
            _log.error("On commiting transaction, failed to cleanup unused message: " + e, e);
        }
        try
        {
            _msg.checkDeliveredToConsumer();
        }
        catch (NoConsumersException e)
        {
            //TODO: store this for delivery after the commit-ok
            _returns.add(e);
        }
        catch (AMQException e)
        {
            _log.error("On commiting transaction, unable to determine whether delivered to a consumer immediately: " +
                       e, e);
        }
    }

    public void rollback(StoreContext context)
    {
        // NO OP
    }
}
