/*
 * 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.
 */

#ifndef _ACTIVE_TRANSPORT_FAILOVER_FAILOVERTRANSPORT_H_
#define _ACTIVE_TRANSPORT_FAILOVER_FAILOVERTRANSPORT_H_

#include <activemq/util/Config.h>

#include <activemq/commands/Command.h>
#include <activemq/commands/ConnectionId.h>
#include <activemq/threads/TaskRunner.h>
#include <activemq/threads/CompositeTaskRunner.h>
#include <activemq/state/ConnectionStateTracker.h>
#include <activemq/transport/CompositeTransport.h>
#include <activemq/wireformat/WireFormat.h>

#include <decaf/util/List.h>
#include <decaf/util/Properties.h>
#include <decaf/net/URI.h>
#include <decaf/io/IOException.h>

namespace activemq {
namespace transport {
namespace failover {

    using namespace decaf::lang;
    using activemq::commands::Command;
    using activemq::commands::Response;

    class FailoverTransportListener;
    class BackupTransportPool;
    class FailoverTransportImpl;

    class AMQCPP_API FailoverTransport : public CompositeTransport,
                                         public activemq::threads::CompositeTask {
    private:

        friend class FailoverTransportListener;
        friend class BackupTransportPool;

        state::ConnectionStateTracker stateTracker;

        FailoverTransportImpl* impl;

    private:

        FailoverTransport(const FailoverTransport&);
        FailoverTransport& operator=(const FailoverTransport&);

    public:

        FailoverTransport();

        virtual ~FailoverTransport();

        /**
         * Indicates that the Transport needs to reconnect to another URI in its
         * list.
         *
         * @param rebalance
         *      Indicates if the current connection should be broken and reconnected.
         */
        void reconnect(bool rebalance);

        /**
         * Adds a New URI to the List of URIs this transport can Connect to.
         *
         * @param rebalance
         *      Should the transport reconnect to a different broker to balance load.
         * @param uri
         *      A String version of a URI to add to the URIs to failover to.
         */
        void add(bool rebalance, const std::string& uri);

    public: // CompositeTransport methods

        virtual void addURI(bool rebalance, const List<decaf::net::URI>& uris);

        virtual void removeURI(bool rebalance, const List<decaf::net::URI>& uris);

    public:

        virtual void start();

        virtual void stop();

        virtual void close();

        virtual void oneway(const Pointer<Command> command);

        virtual Pointer<FutureResponse> asyncRequest(const Pointer<Command> command,
                                                     const Pointer<ResponseCallback> responseCallback);

        virtual Pointer<Response> request(const Pointer<Command> command);

        virtual Pointer<Response> request(const Pointer<Command> command, unsigned int timeout);

        virtual Pointer<wireformat::WireFormat> getWireFormat() const;

        virtual void setWireFormat(const Pointer<wireformat::WireFormat> wireFormat AMQCPP_UNUSED) {}

        virtual void setTransportListener(TransportListener* listener);

        virtual TransportListener* getTransportListener() const;

        virtual bool isFaultTolerant() const {
            return true;
        }

        virtual bool isConnected() const;

        virtual bool isClosed() const;

        bool isInitialized() const;

        void setInitialized(bool value);

        virtual Transport* narrow(const std::type_info& typeId);

        virtual std::string getRemoteAddress() const;

        virtual void reconnect(const decaf::net::URI& uri);

        virtual void updateURIs(bool rebalance, const decaf::util::List<decaf::net::URI>& uris);

    public:

        /**
         * @returns true if there is a need for the iterate method to be called by this
         *          classes task runner.
         */
        virtual bool isPending() const;

        /**
         * Performs the actual Reconnect operation for the FailoverTransport, when a
         * connection is made this method returns false to indicate it doesn't need to
         * run again, otherwise it returns true to indicate its still trying to connect.
         *
         * @return false to indicate a connection, true to indicate it needs to try again.
         */
        virtual bool iterate();

    public:

        long long getTimeout() const;

        void setTimeout(long long value);

        long long getInitialReconnectDelay() const;

        void setInitialReconnectDelay(long long value);

        long long getMaxReconnectDelay() const;

        void setMaxReconnectDelay(long long value);

        long long getBackOffMultiplier() const;

        void setBackOffMultiplier(long long value);

        bool isUseExponentialBackOff() const;

        void setUseExponentialBackOff(bool value);

        bool isRandomize() const;

        void setRandomize(bool value);

        int getMaxReconnectAttempts() const;

        void setMaxReconnectAttempts(int value);

        int getStartupMaxReconnectAttempts() const;

        void setStartupMaxReconnectAttempts(int value);

        long long getReconnectDelay() const;

        void setReconnectDelay(long long value);

        bool isBackup() const;

        void setBackup(bool value);

        int getBackupPoolSize() const;

        void setBackupPoolSize(int value);

        bool isTrackMessages() const;

        void setTrackMessages(bool value);

        bool isTrackTransactionProducers() const;

        void setTrackTransactionProducers(bool value);

        int getMaxCacheSize() const;

        void setMaxCacheSize(int value);

        int getMaxPullCacheSize() const;

        void setMaxPullCacheSize(int value);

        bool isReconnectSupported() const;

        void setReconnectSupported(bool value);

        bool isUpdateURIsSupported() const;

        void setUpdateURIsSupported(bool value);

        bool isRebalanceUpdateURIs() const;

        void setRebalanceUpdateURIs(bool rebalanceUpdateURIs);

        bool isPriorityBackup() const;

        void setPriorityBackup(bool priorityBackup);

        void setPriorityURIs(const std::string& priorityURIs);

        const decaf::util::List<decaf::net::URI>& getPriorityURIs() const;

        void setConnectionInterruptProcessingComplete(const Pointer<commands::ConnectionId> connectionId);

        bool isConnectedToPriority() const;

    protected:

        /**
         * Given a Transport restore the state of the Client's connection to the Broker
         * using the data accumulated in the State Tracker.
         *
         * @param transport
         *        The new Transport connected to the Broker.
         *
         * @throw IOException if an errors occurs while restoring the old state.
         */
        void restoreTransport(const Pointer<Transport> transport);

        /**
         * Called when this class' TransportListener is notified of a Failure.
         * @param error - The CMS Exception that was thrown.
         * @throw Exception if an error occurs.
         */
        void handleTransportFailure(const decaf::lang::Exception& error);

        /**
         * Called when the Broker sends a ConnectionControl command which could
         * signal that this Client needs to reconnect in order to rebalance the
         * connections on a Broker or the set of Known brokers has changed.
         *
         * @param control
         *      The ConnectionControl command sent from the Broker.
         */
        void handleConnectionControl(const Pointer<Command> control);

    private:

        /**
         * Looks up the correct Factory and create a new Composite version of the
         * Transport requested.
         *
         * @param uri - The URI to connect to
         *
         * @throw IOException if an I/O error occurs while creating the new Transport.
         */
        Pointer<Transport> createTransport(const decaf::net::URI& location) const;

        void processNewTransports(bool rebalance, std::string newTransports);

        void processResponse(const Pointer<Response> response);

    };

}}}

#endif /* _ACTIVE_TRANSPORT_FAILOVER_FAILOVERTRANSPORT_H_ */