/**
 * SPDX license identifier: MPL-2.0
 *
 * Copyright (C) 2012, BMW AG
 *
 * \author Christian Linke, christian.linke@bmw.de BMW 2011,2012
 * \author Alesksandar Donchev, aleksander.donchev@partner.bmw.de BMW 2015
 *
 * \copyright
 * This Source Code Form is subject to the terms of the
 * Mozilla Public License, v. 2.0. If a  copy of the MPL was not distributed with
 * this file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * \file CAmSerializer.h
 * For further information see http://www.genivi.org/.
 */

#ifndef CAMSERIALIZER_H_
#define CAMSERIALIZER_H_

#include <pthread.h>
#include <deque>
#include <cassert>
#include <memory>
#include <stdexcept>
#include <unistd.h>
#include "CAmDltWrapper.h"
#include "CAmSocketHandler.h"

/*!
 * \brief Helper structures used within std::bind for automatically identification of all placeholders.
 */
template<std::size_t ... Is>
struct indices
{
};

template<std::size_t N, std::size_t ... Is>
struct build_indices: build_indices<N - 1, N - 1, Is...>
{
};

template<std::size_t ... Is>
struct build_indices<0, Is...> : indices<Is...>
{
};

template<int I> struct placeholder
{
};

namespace std
{
    template<int I>
    struct is_placeholder<::placeholder<I>> : std::integral_constant<int, I>
    {
    };
}

/**
 * todo: performance improvement we could implement a memory pool that is more efficient here and avoids
 * allocation and deallocation times.
 */

namespace am
{

    /**
     * magic class that does the serialization of functions calls
     * The constructor must be called within the main threadcontext, after that using the
     * overloaded template function call will serialize all calls and call them within the
     * main thread context.\n
     * More details can be found here: \ref util
     * \warning asynchronous calls may be used in the mainthread context, but if you want to use synchronous calls make sure that you use one
     * instance of this class per thread otherwise you could be lost in never returning calls.\n
     * Examples of the usage can be found in IAmCommandReceiverShadow of the ControlPlugin or IAmRoutingReceiverShadow of the
     * PluginRoutingInterfaceAsync.
     *
     */
    class CAmSerializer
    {
        /**
         * Prototype for a delegate
         */
        class CAmDelegate
        {
        public:
            typedef enum
                :bool
                {
                    SyncCallType = false, AsyncCallType = true
            } CallType;

            virtual ~CAmDelegate()
            {
            }
            ;
            virtual CallType call(int* pipe)=0;
        };

        /**
         * Prototype for a delegate with variadic template arguments.
         */
        template<class TInvocation>
        class CAmDelegateAsyncImpl: public CAmDelegate
        {
            TInvocation mInvocation;
        public:
            friend class CAmSerializer;
            CAmDelegateAsyncImpl(TInvocation && invocation) :
                    mInvocation(std::move(invocation))
            {
            }

            CallType call(int* pipe)
            {
                (void) pipe;
                mInvocation();
                return (AsyncCallType);
            }
            ;
        };

        template<class TInvocation, class TRet>
        class CAmDelegateSyncImpl: public CAmDelegate
        {
            TInvocation mInvocation;
            TRet & mReturn;
        public:
            friend class CAmSerializer;
            CAmDelegateSyncImpl(TInvocation && invocation, TRet && ret) :
                    mInvocation(std::move(invocation)), mReturn(ret)
            {
            }

            CallType call(int* pipe)
            {
                mReturn = mInvocation();
                ssize_t result(-1);
                result = write(pipe[1], this, sizeof(this));
                if (result == -1)
                    logError("CAmSerializer: Problem writing into pipe! Error No:", errno);
                return (SyncCallType);
            }
            ;
        };

        template<class TInvocation>
        class CAmDelegateSyncVoidImpl: public CAmDelegate
        {
            TInvocation mInvocation;
        public:
            friend class CAmSerializer;
            CAmDelegateSyncVoidImpl(TInvocation && invocation) :
                    mInvocation(std::move(invocation))
            {
            }

            CallType call(int* pipe)
            {
                mInvocation();
                ssize_t result(-1);
                result = write(pipe[1], this, sizeof(this));
                if (result == -1)
                    logError("CAmSerializer: Problem writing into pipe! Error No:", errno);
                return (SyncCallType);
            }
            ;
        };

        typedef CAmDelegate* CAmDelegagePtr; //!< pointer to a delegate

        void sendSync(CAmDelegagePtr pDelegate)
        {
            send(pDelegate);
            int numReads;
            CAmDelegagePtr *p = NULL;
            if ((numReads = read(mReturnPipe[0], &p, sizeof(p))) == -1)
            {
                logError("CAmSerializer::doSyncCall could not read pipe!");
                throw std::runtime_error("CAmSerializer Could not read pipe!");
            }
        }

        /**
         * rings the line of the pipe and adds the delegate pointer to the queue
         * @param p delegate pointer
         */
        inline void send(CAmDelegagePtr p)
        {
            if (write(mPipe[1], &p, sizeof(p)) == -1)
            {
                throw std::runtime_error("could not write to pipe !");
            }
        }

        int mPipe[2]; //!< the pipe
        int mReturnPipe[2]; //!< pipe handling returns
        sh_pollHandle_t mHandle;
        CAmSocketHandler* mpSocketHandler;
        std::deque<CAmDelegagePtr> mListDelegatePoiters; //!< intermediate queue to store the pipe results

    public:

        /**
         * get the size of delegate pointers
         */
        int getListDelegatePoiters()
        {
            return mListDelegatePoiters.size();
        }

        /**
         * calls a function with variadic arguments threadsafe
         * @param invocation is a type is produced by std::bind
         * \section ex Example:
         * @code
         * CAmSerializer serial(&Sockethandler);
         * serial.asyncInvocation(std::bind([]()->bool{return true;}));
         * @endcode
         */
        template<class TFunc>
        void asyncInvocation(TFunc invocation)
        {
            static_assert(std::is_bind_expression<TFunc>::value,"The type is not produced by std::bind");
            typedef CAmDelegateAsyncImpl<TFunc> AsyncDelegate;
            AsyncDelegate *pImp = new AsyncDelegate(std::forward<TFunc>(invocation));
            send(pImp);
            //Do not delete the pointer. It will be deleted automatically later.
        }

        /**
         * calls a function with variadic arguments threadsafe
         * @param instance the instance of the class that shall be called
         * @param function the function that shall be called as member function pointer.
         * @tparam TClass the type of the Class to be called
         * @tparam TRet the type of the result
         * @tparam TArgs argument list
         * \section ex Example:
         * @code
         * class AClass
         * {
         * public:
         *      void instanceMethod(int x);
         * }
         * CAmSerializer serial(&Sockethandler);
         * AClass anInstance;
         * serial.asyncCall(&anInstance,&AClass::instanceMethod, 100);
         * @endcode
         */
        template<class TClass, class TMeth, class TRet, class ... TArgs>
        void asyncCall(TClass* instance, TMeth method, TArgs && ... arguments)
        {
            auto invocation = std::bind(method, instance, std::forward<TArgs>(arguments)...);
            asyncInvocation(invocation);
        }

        template<class TClass, class TMeth, class ... TArgs>
        void asyncCall(TClass* instance, TMeth method, TArgs && ... arguments)
        {
            auto invocation = std::bind(method, instance, std::forward<TArgs>(arguments)...);
            asyncInvocation(invocation);
        }

        /**
         * calls a function with variadic arguments threadsafe
         * @param invocation is a type is produced by std::bind
         * @param result from type TRet
         * \section ex Example:
         * @code
         * CAmSerializer serial(&Sockethandler);
         * bool result;
         * serial.syncCall(std::bind([]()->bool{return true;}), result);
         * @endcode
         */
        template<class TFunc, class TRet>
        void syncInvocation(TFunc invocation, TRet && result)
        {
            static_assert(std::is_bind_expression<TFunc>::value,"The type is not produced by std::bind");

            typedef CAmDelegateSyncImpl<TFunc, TRet> SyncDelegate;

            SyncDelegate *pImp = new SyncDelegate(std::forward<TFunc>(invocation), std::forward<TRet>(result));
            sendSync(pImp);
            //Delete the pointer.
            delete pImp;
        }

        /**
         * calls a function with variadic arguments threadsafe
         * @param invocation is a type is produced by std::bind
         * \section ex Example:
         * @code
         * CAmSerializer serial(&Sockethandler);
         * serial.syncCall(std::bind([]()->bool{return true;}));
         * @endcode
         */
        template<class TFunc>
        void syncInvocation(TFunc invocation)
        {
            static_assert(std::is_bind_expression<TFunc>::value,"The type is not produced by std::bind");

            typedef CAmDelegateSyncVoidImpl<TFunc> SyncDelegate;

            SyncDelegate *pImp = new SyncDelegate(std::forward<TFunc>(invocation));
            sendSync(pImp);
            //Delete the pointer.
            delete pImp;
        }
        /**
         * calls a function with variadic arguments threadsafe
         * @param instance the instance of the class that shall be called
         * @param function the function that shall be called as member function pointer.
         * @param output variable.
         * @tparam TClass the type of the Class to be called
         * @tparam TRet the type of the result
         * @tparam TArgs argument list
         * \section ex Example:
         * @code
         * class AClass
         * {
         * public:
         *      int instanceMethod(int x);
         * }
         * CAmSerializer serial(&Sockethandler);
         * AClass anInstance;
         * int result;
         * serial.syncCall(&anInstance,&AClass::instanceMethod, result, 100);
         * @endcode
         */
        template<class TClass, class TMeth, class TRet, class ... TArgs>
        void syncCall(TClass* instance, TMeth method, TRet & result, TArgs && ... arguments)
        {
            auto invocation = std::bind(method, instance, std::ref(arguments)...);
            syncInvocation(invocation, result);
        }

        template<class TClass, class TMeth, class ... TArgs>
        void syncCall(TClass* instance, TMeth method, TArgs && ... arguments)
        {
            auto invocation = std::bind(method, instance, std::ref(arguments)...);
            syncInvocation(invocation);
        }

        /**************************************** Obsolete interface! ****************************************/

        /**
         * calls a function without arguments synchronously threadsafe.
         */
        template<class TClass1, class TretVal>
        void __attribute__ ((deprecated)) syncCall(TClass1* instance, TretVal (TClass1::*function)(), TretVal& retVal)
        {
            auto invocation = std::bind(function, instance);
            syncInvocation(invocation, retVal);
        }
        /**
         * calls a function with one arguments synchronously threadsafe.
         */
        template<class TClass1, class TretVal, class TargCall, class Targ>
        void __attribute__ ((deprecated)) syncCall(TClass1* instance, TretVal (TClass1::*function)(TargCall), TretVal& retVal, Targ& argument)
        {
            auto invocation = std::bind(function, instance, std::ref(argument));
            syncInvocation(invocation, retVal);
        }
        /**
         * calls a function with two arguments synchronously threadsafe.
         */
        template<class TClass1, class TretVal, class TargCall, class TargCall1, class Targ, class Targ1>
        void __attribute__ ((deprecated)) syncCall(TClass1* instance, TretVal (TClass1::*function)(TargCall, TargCall1), TretVal& retVal, Targ& argument, Targ1& argument1)
        {
            auto invocation = std::bind(function, instance, std::ref(argument), std::ref(argument1));
            syncInvocation(invocation, retVal);
        }
        /**
         * calls a function with three arguments synchronously threadsafe.
         */
        template<class TClass1, class TretVal, class TargCall, class TargCall1, class TargCall2, class Targ, class Targ1, class Targ2>
        void __attribute__ ((deprecated)) syncCall(TClass1* instance, TretVal (TClass1::*function)(TargCall, TargCall1, TargCall2), TretVal& retVal, Targ& argument, Targ1& argument1, Targ2& argument2)
        {
            auto invocation = std::bind(function, instance, std::ref(argument), std::ref(argument1), std::ref(argument2));
            syncInvocation(invocation, retVal);
        }

        /**
         * calls a function with four arguments synchronously threadsafe.
         */
        template<class TClass1, class TretVal, class TargCall, class TargCall1, class TargCall2, class TargCall3, class Targ, class Targ1, class Targ2, class Targ3>
        void __attribute__ ((deprecated)) syncCall(TClass1* instance, TretVal (TClass1::*function)(TargCall, TargCall1, TargCall2, TargCall3), TretVal& retVal, Targ& argument, Targ1& argument1, Targ2& argument2, Targ3& argument3)
        {
            auto invocation = std::bind(function, instance, std::ref(argument), std::ref(argument1), std::ref(argument2), std::ref(argument3));
            syncInvocation(invocation, retVal);
        }

        /**
         * calls a function with five arguments synchronously threadsafe.
         */
        template<class TClass1, class TretVal, class TargCall, class TargCall1, class TargCall2, class TargCall3, class TargCall4, class Targ, class Targ1, class Targ2, class Targ3, class Targ4>
        void __attribute__ ((deprecated)) syncCall(TClass1* instance, TretVal (TClass1::*function)(TargCall, TargCall1, TargCall2, TargCall3, TargCall4), TretVal& retVal, Targ& argument, Targ1& argument1, Targ2& argument2, Targ3& argument3,
                Targ4& argument4)
        {
            auto invocation = std::bind(function, instance, std::ref(argument), std::ref(argument1), std::ref(argument2), std::ref(argument3), std::ref(argument4));
            syncInvocation(invocation, retVal);
        }
        /**
         * calls a function with six arguments synchronously threadsafe.
         */
        template<class TClass1, class TretVal, class TargCall, class TargCall1, class TargCall2, class TargCall3, class TargCall4, class TargCall5, class Targ, class Targ1, class Targ2, class Targ3, class Targ4, class Targ5>
        void __attribute__ ((deprecated)) syncCall(TClass1* instance, TretVal (TClass1::*function)(TargCall, TargCall1, TargCall2, TargCall3, TargCall4, TargCall5), TretVal& retVal, Targ& argument, Targ1& argument1, Targ2&& argument2,
                Targ3& argument3, Targ4& argument4, Targ5& argument5)
        {
            auto invocation = std::bind(function, instance, std::ref(argument), std::ref(argument1), std::ref(argument2), std::ref(argument3), std::ref(argument4), std::ref(argument5));
            syncInvocation(invocation, retVal);
        }

        /**
         * calls a function with one argument asynchronously threadsafe.
         */
        template<class TClass1, class Targ>
        void __attribute__ ((deprecated)) asyncCall(TClass1* instance, void (TClass1::*function)(Targ argument), Targ &argument)
        {
            auto invocation = std::bind(function, instance, std::ref(argument));
            asyncInvocation(invocation);
        }
        /**
         * calls a function with two arguments asynchronously threadsafe.
         */
        template<class TClass1, class Targ, class Targ1>
        void __attribute__ ((deprecated)) asyncCall(TClass1* instance, void (TClass1::*function)(Targ argument, Targ1 argument1), Targ& argument, Targ1& argument1)
        {
            auto invocation = std::bind(function, instance, std::ref(argument), std::ref(argument1));
            asyncInvocation(invocation);
        }
        /**
         * calls a function with three arguments asynchronously threadsafe.
         */
        template<class TClass1, class Targ, class Targ1, class Targ2>
        void __attribute__ ((deprecated)) asyncCall(TClass1* instance, void (TClass1::*function)(Targ argument, Targ1 argument1, Targ2 argument2), Targ& argument, Targ1& argument1, Targ2& argument2)
        {
            auto invocation = std::bind(function, instance, std::ref(argument), std::ref(argument1), std::ref(argument2));
            asyncInvocation(invocation);
        }

        /**
         * calls a function with four arguments asynchronously threadsafe.
         */
        template<class TClass1, class Targ, class Targ1, class Targ2, class Targ3>
        void __attribute__ ((deprecated)) asyncCall(TClass1* instance, void (TClass1::*function)(Targ argument, Targ1 argument1, Targ2 argument2, Targ3 argument3), Targ& argument, Targ1& argument1, Targ2& argument2, Targ3& argument3)
        {
            auto invocation = std::bind(function, instance, std::ref(argument), std::ref(argument1), std::ref(argument2), std::ref(argument3));
            asyncInvocation(invocation);
        }

        /**
         * receiver callback for sockethandling, for more, see CAmSocketHandler
         */
        void receiverCallback(const pollfd pollfd, const sh_pollHandle_t handle, void* userData)
        {
            (void) handle;
            (void) userData;
            int numReads;
            CAmDelegagePtr listPointers[3];
            if ((numReads = read(pollfd.fd, &listPointers, sizeof(listPointers))) == -1)
            {
                logError("CAmSerializer::receiverCallback could not read pipe!");
                throw std::runtime_error("CAmSerializer Could not read pipe!");
            }
            mListDelegatePoiters.assign(listPointers, listPointers + (numReads / sizeof(CAmDelegagePtr)));
        }

        /**
         * checker callback for sockethandling, for more, see CAmSocketHandler
         */
        bool checkerCallback(const sh_pollHandle_t handle, void* userData)
        {
            (void) handle;
            (void) userData;
            if (mListDelegatePoiters.empty())
                return (false);
            return (true);
        }

        /**
         * dispatcher callback for sockethandling, for more, see CAmSocketHandler
         */
        bool dispatcherCallback(const sh_pollHandle_t handle, void* userData)
        {
            (void) handle;
            (void) userData;
            CAmDelegagePtr delegatePoiter = mListDelegatePoiters.front();
            mListDelegatePoiters.pop_front();
            if (delegatePoiter->call(mReturnPipe))
                delete delegatePoiter;
            if (mListDelegatePoiters.empty())
                return (false);
            return (true);
        }

        TAmShPollFired<CAmSerializer> receiverCallbackT;
        TAmShPollDispatch<CAmSerializer> dispatcherCallbackT;
        TAmShPollCheck<CAmSerializer> checkerCallbackT;

        /**
         * The constructor must be called in the mainthread context !
         * @param iSocketHandler pointer to the CAmSocketHandler
         */
        CAmSerializer(CAmSocketHandler *iSocketHandler) :
                mPipe(), //
                        mReturnPipe(), //
                        mHandle(),
                        mpSocketHandler(iSocketHandler),
                        mListDelegatePoiters(), //
                        receiverCallbackT(this, &CAmSerializer::receiverCallback), //
                        dispatcherCallbackT(this, &CAmSerializer::dispatcherCallback), //
                        checkerCallbackT(this, &CAmSerializer::checkerCallback)
        {
            assert(NULL!=iSocketHandler);

            if (pipe(mPipe) == -1)
            {
                logError("CAmSerializer could not create pipe!");
                throw std::runtime_error("CAmSerializer Could not open pipe!");
            }

            if (pipe(mReturnPipe) == -1)
            {
                logError("CAmSerializer could not create mReturnPipe!");
                throw std::runtime_error("CAmSerializer Could not open mReturnPipe!");
            }

            short event = 0;
            event |= POLLIN;
            mpSocketHandler->addFDPoll(mPipe[0], event, NULL, &receiverCallbackT, &checkerCallbackT, &dispatcherCallbackT, NULL, mHandle);
        }

        ~CAmSerializer()
        {
            mpSocketHandler->removeFDPoll(mHandle);
            close(mPipe[0]);
            close(mPipe[1]);
            close(mReturnPipe[0]);
            close(mReturnPipe[1]);
        }
    };
} /* namespace am */
#endif /* CAMSERIALIZER_H_ */