/**
 * Copyright - See the COPYRIGHT that is included with this distribution.
 * EPICS pvAccessCPP is distributed subject to a Software License Agreement
 * found in file LICENSE that is included with this distribution.
 */

#ifndef RPCCLIENT_H
#define RPCCLIENT_H

#include <string>

#ifdef epicsExportSharedSymbols
#   define rpcClientEpicsExportSharedSymbols
#   undef epicsExportSharedSymbols
#endif
#include <pv/pvData.h>
#ifdef rpcClientEpicsExportSharedSymbols
#   define epicsExportSharedSymbols
#	undef rpcClientEpicsExportSharedSymbols
#endif

#include <pv/rpcService.h>

#include <shareLib.h>

#define RPCCLIENT_DEFAULT_TIMEOUT 5.0

namespace epics
{

namespace pvAccess
{

    /**
     * RPCClient is an interface class that is used by a service client.
     *
     */
    class epicsShareClass RPCClient
    {
    public:
        POINTER_DEFINITIONS(RPCClient);

        /**
         * Create a RPCClient.
         *
         * @param  serviceName  the service name
         * @return              the RPCClient interface
         */
        static shared_pointer create(const std::string & serviceName);

        /**
         * Create a RPCClient.
         *
         * @param  serviceName  the service name
         * @param  pvRequest    the pvRequest for the ChannelRPC
         * @return              the RPCClient interface
         */
        static shared_pointer create(const std::string & serviceName,
             epics::pvData::PVStructure::shared_pointer const & pvRequest);

        /**
         * Performs complete blocking RPC call, opening a channel and connecting to the
         * service and sending the request.
         *
         * @param serviceName         the name of the service to connect to
         * @param request             the request sent to the service
         * @param timeout             the timeout (in seconds), 0 means forever.
         * @return                    the result of the RPC call.
         * @throws RPCRequestException exception thrown on error on timeout.
         */
        static epics::pvData::PVStructure::shared_pointer sendRequest(const std::string & serviceName,
            epics::pvData::PVStructure::shared_pointer request, double timeOut = RPCCLIENT_DEFAULT_TIMEOUT);



        /**
         * Destroy this instance (i.e. release resources).
         */
        void destroy();

        /**
         * Connect to the server.
         * The method blocks until the connection is made or a timeout occurs.
         * It is the same as calling issueConnect and then waitConnect.
         * @param timeout Timeout in seconds to wait, 0 means forever.
         * @returns (false,true) If (not connected, is connected).
         * If false then connect must be reissued.
         */
        bool connect(double timeout = RPCCLIENT_DEFAULT_TIMEOUT);

        /**
         * Issue a connect request and return immediately.
         * waitConnect must be called to complete the request.
         */
        void issueConnect();

        /**
         * Wait for the connect request to complete.
         * @param timeout timeout in seconds to wait, 0 means forever.
         * @returns (false,true) If (not connected, is connected).
         * If false then connect must be reissued.
         */
        bool waitConnect(double timeout = RPCCLIENT_DEFAULT_TIMEOUT);

        /**
         * Sends a request and wait for the response or until timeout occurs.
         * This method will also wait for client to connect, if necessary.
         *
         * @param  pvArgument  the argument for the rpc
         * @param  timeout     the time in seconds to wait for the response, 0 means forever.
         * @param  lastRequest If true an automatic destroy is made.
         * @return             request response.
         * @throws RPCRequestException exception thrown on error or timeout.
         */
        epics::pvData::PVStructure::shared_pointer request(
            epics::pvData::PVStructure::shared_pointer const & pvArgument,
            double timeout = RPCCLIENT_DEFAULT_TIMEOUT,
            bool lastRequest = false);

        /**
         * Issue a channelRPC request and return immediately.
         * waitRequest must be called to complete the request.
         * @param pvAgument The argument to pass to the server.
         * @param lastRequest If true an automatic destroy is made.
         * @throws std::runtime_error excption thrown on any runtime error condition (e.g. no connection made).
         */
        void issueRequest(
            epics::pvData::PVStructure::shared_pointer const & pvArgument,
            bool lastRequest = false);

        /**
         * Wait for the request to complete.
         * @param timeout      the time in seconds to wait for the reponse.
         * @return             request response.
         * @throws RPCRequestException exception thrown on error or timeout.
         */
        epics::pvData::PVStructure::shared_pointer waitResponse(double timeout = RPCCLIENT_DEFAULT_TIMEOUT);

        virtual ~RPCClient() {}

    protected:
        RPCClient(const std::string & serviceName,
            epics::pvData::PVStructure::shared_pointer const & pvRequest);

        std::string m_serviceName;
        Channel::shared_pointer m_channel;
        epics::pvData::PVStructure::shared_pointer m_pvRequest;
    };

}

}

#endif