/*
 *
 * 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.binding;

import org.apache.qpid.AMQException;
import org.apache.qpid.framing.AMQShortString;
import org.apache.qpid.framing.FieldTable;
import org.apache.qpid.server.configuration.BindingConfig;
import org.apache.qpid.server.configuration.BindingConfigType;
import org.apache.qpid.server.configuration.ConfigStore;
import org.apache.qpid.server.configuration.ConfiguredObject;
import org.apache.qpid.server.exchange.Exchange;
import org.apache.qpid.server.logging.actors.CurrentActor;
import org.apache.qpid.server.logging.messages.BindingMessages;
import org.apache.qpid.server.logging.subjects.BindingLogSubject;
import org.apache.qpid.server.queue.AMQQueue;
import org.apache.qpid.server.store.DurableConfigurationStore;
import org.apache.qpid.server.virtualhost.VirtualHost;

import java.util.Collections;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

public class BindingFactory
{

    private final VirtualHost _virtualHost;
    private final DurableConfigurationStore.Source _configSource;
    private final Exchange _defaultExchange;

    private final ConcurrentHashMap<BindingImpl, BindingImpl> _bindings = new ConcurrentHashMap<BindingImpl, BindingImpl>();


    public BindingFactory(final VirtualHost vhost)
    {
        this(vhost,vhost.getExchangeRegistry().getDefaultExchange());
    }

    public BindingFactory(final DurableConfigurationStore.Source configSource, final Exchange defaultExchange)
    {
        _configSource = configSource;
        _defaultExchange = defaultExchange;
        if(configSource instanceof VirtualHost)
        {
            _virtualHost = (VirtualHost) configSource;
        }
        else
        {
            _virtualHost = null;
        }
    }

    public VirtualHost getVirtualHost()
    {
        return _virtualHost;
    }



    private final class BindingImpl extends Binding implements AMQQueue.Task, Exchange.Task, BindingConfig
    {
        private final BindingLogSubject _logSubject;
        //TODO : persist creation time
        private long _createTime = System.currentTimeMillis();

        private BindingImpl(String bindingKey, final AMQQueue queue, final Exchange exchange, final Map<String, Object> arguments)
        {
            super(queue.getVirtualHost().getConfigStore().createId(),bindingKey, queue, exchange, arguments);
            _logSubject = new BindingLogSubject(bindingKey,exchange,queue);

        }


        public void doTask(final AMQQueue queue) throws AMQException
        {
            removeBinding(this);
        }

        public void onClose(final Exchange exchange)
        {
            removeBinding(this);
        }

        void logCreation()
        {
            CurrentActor.get().message(_logSubject, BindingMessages.BND_CREATED(String.valueOf(getArguments()), getArguments() != null && !getArguments().isEmpty()));
        }

        void logDestruction()
        {
            CurrentActor.get().message(_logSubject, BindingMessages.BND_DELETED());
        }

        public String getOrigin()
        {
            return (String) getArguments().get("qpid.fed.origin");
        }

        public long getCreateTime()
        {
            return _createTime;
        }

        public BindingConfigType getConfigType()
        {
            return BindingConfigType.getInstance();
        }

        public ConfiguredObject getParent()
        {
            return _virtualHost;
        }

        public boolean isDurable()
        {
            return getQueue().isDurable() && getExchange().isDurable();
        }

    }



    public boolean addBinding(String bindingKey, AMQQueue queue, Exchange exchange, Map<String, Object> arguments)
    {
        return makeBinding(bindingKey, queue, exchange, arguments, false, false);
    }


    public boolean replaceBinding(final String bindingKey,
                               final AMQQueue queue,
                               final Exchange exchange,
                               final Map<String, Object> arguments)
    {
        return makeBinding(bindingKey, queue, exchange, arguments, false, true);
    }

    private boolean makeBinding(String bindingKey, AMQQueue queue, Exchange exchange, Map<String, Object> arguments, boolean restore, boolean force)
    {
        assert queue != null;
        if(bindingKey == null)
        {
            bindingKey = "";
        }
        if(exchange == null)
        {
            exchange = _defaultExchange;
        }
        if(arguments == null)
        {
            arguments = Collections.EMPTY_MAP;
        }

        BindingImpl b = new BindingImpl(bindingKey,queue,exchange,arguments);
        BindingImpl existingMapping = _bindings.putIfAbsent(b,b);
        if(existingMapping == null || force)
        {
            if(existingMapping != null)
            {
                removeBinding(existingMapping);
            }

            if(b.isDurable() && !restore)
            {
                try
                {
                    _configSource.getDurableConfigurationStore().bindQueue(exchange,new AMQShortString(bindingKey),queue,FieldTable.convertToFieldTable(arguments));
                }
                catch (AMQException e)
                {
                    throw new RuntimeException(e);
                }
            }

            queue.addQueueDeleteTask(b);
            exchange.addCloseTask(b);
            queue.addBinding(b);
            exchange.addBinding(b);
            getConfigStore().addConfiguredObject(b);
            b.logCreation();
            return true;
        }
        else
        {
            return false;
        }


    }

    private ConfigStore getConfigStore()
    {
        return getVirtualHost().getConfigStore();
    }

    public void restoreBinding(final String bindingKey, final AMQQueue queue, final Exchange exchange, final Map<String, Object> argumentMap)
    {
        makeBinding(bindingKey,queue,exchange,argumentMap,true, false);
    }

    public void removeBinding(final Binding b)
    {
        removeBinding(b.getBindingKey(), b.getQueue(), b.getExchange(), b.getArguments());
    }


    public Binding removeBinding(String bindingKey, AMQQueue queue, Exchange exchange, Map<String, Object> arguments)
    {
        assert queue != null;
        if(bindingKey == null)
        {
            bindingKey = "";
        }
        if(exchange == null)
        {
            exchange = _defaultExchange;
        }
        if(arguments == null)
        {
            arguments = Collections.EMPTY_MAP;
        }

        BindingImpl b = _bindings.remove(new BindingImpl(bindingKey,queue,exchange,arguments));

        if(b != null)
        {
            exchange.removeBinding(b);
            queue.removeBinding(b);
            exchange.removeCloseTask(b);
            queue.removeQueueDeleteTask(b);

            if(b.isDurable())
            {
                try
                {
                    _configSource.getDurableConfigurationStore().unbindQueue(exchange,
                                             new AMQShortString(bindingKey),
                                             queue,
                                             FieldTable.convertToFieldTable(arguments));
                }
                catch (AMQException e)
                {
                    e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
                }
            }
            b.logDestruction();
            getConfigStore().removeConfiguredObject(b);

        }

        return b;
    }

    public Binding getBinding(String bindingKey, AMQQueue queue, Exchange exchange, Map<String, Object> arguments)
    {
        assert queue != null;
        if(bindingKey == null)
        {
            bindingKey = "";
        }
        if(exchange == null)
        {
            exchange = _defaultExchange;
        }
        if(arguments == null)
        {
            arguments = Collections.EMPTY_MAP;
        }

        BindingImpl b = new BindingImpl(bindingKey,queue,exchange,arguments);
        return _bindings.get(b);
    }
}
