/**
 *  Copyright (C) 2012, BMW AG
 *
 *  \author Christian Mueller, christian.ei.mueller@bmw.de BMW 2011,2012
 *
 *  \copyright
 *  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction,
 *  including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
 *  subject to the following conditions:
 *  The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 *  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
 *  THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 *  \file CAmSocketHandler.h
 *  For further information see http://www.genivi.org/.
 */

#ifndef SOCKETHANDLER_H_
#define SOCKETHANDLER_H_

#include "audiomanagertypes.h"
#include <sys/socket.h>
#include <stdint.h>
#include <sys/poll.h>
#include <list>
#include <map>
#include <signal.h>

#include <iostream> //todo: remove me
namespace am
{

#define MAX_NS 1000000000L

typedef uint16_t sh_timerHandle_t; //!<this is a handle for a timer to be used with the SocketHandler
typedef uint16_t sh_pollHandle_t; //!<this is a handle for a filedescriptor to be used with the SocketHandler

/**
 * prototype for poll prepared callback
 */
class IAmShPollPrepare
{
public:
    virtual void Call(const sh_pollHandle_t handle, void* userData)=0;
    virtual ~IAmShPollPrepare()
    {
    }
    ;
};

/**
 * prototype for poll fired callback
 */
class IAmShPollFired
{
public:
    virtual void Call(const pollfd pollfd, const sh_pollHandle_t handle, void* userData)=0;
    virtual ~ IAmShPollFired()
    {
    }
    ;
};

/**
 * prototype for poll check callback
 */
class IAmShPollCheck
{
public:
    virtual bool Call(const sh_pollHandle_t handle, void* userData)=0;
    virtual ~ IAmShPollCheck()
    {
    }
    ;
};

/**
 * prototype for dispatch callback
 */
class IAmShPollDispatch
{
public:
    virtual bool Call(const sh_pollHandle_t handle, void* userData)=0;
    virtual ~ IAmShPollDispatch()
    {
    }
    ;
};

/**
 * prototype for the timer callback
 */
class IAmShTimerCallBack
{
public:
    virtual void Call(const sh_timerHandle_t handle, void* userData)=0;
    virtual ~IAmShTimerCallBack()
    {
    }
    ;
};

/**
 * The am::CAmSocketHandler implements a mainloop for the AudioManager. Plugins and different parts of the AudioManager add their filedescriptors to the handler
 * to get called on communication of the filedescriptors.\n
 * More information can be found here : \ref mainl
 */
class CAmSocketHandler
{
public:
    template<class TClass> class TAmShPollFired: public IAmShPollFired
    {
    private:
        TClass* mInstance;
        void (TClass::*mFunction)(const pollfd pollfd, const sh_pollHandle_t handle, void* userData);

    public:
        TAmShPollFired(TClass* instance, void (TClass::*function)(const pollfd pollfd, const sh_pollHandle_t handle, void* userData)) :
                mInstance(instance), //
                mFunction(function) {};

        virtual void Call(const pollfd pollfd, const sh_pollHandle_t handle, void* userData)
        {
            (*mInstance.*mFunction)(pollfd, handle, userData);
        };
    };

    template<class TClass> class TAmShPollCheck: public IAmShPollCheck
    {
    private:
        TClass* mInstance;
        bool (TClass::*mFunction)(const sh_pollHandle_t handle, void* userData);

    public:
        TAmShPollCheck(TClass* instance, bool (TClass::*function)(const sh_pollHandle_t handle, void* userData)) :
                mInstance(instance), //
                mFunction(function) {};

        virtual bool Call(const sh_pollHandle_t handle, void* userData)
        {
            return ((*mInstance.*mFunction)(handle, userData));
        };
    };

    CAmSocketHandler();
    ~CAmSocketHandler();

    am_Error_e addFDPoll(const int fd, const short event, IAmShPollPrepare *prepare, IAmShPollFired *fired, IAmShPollCheck *check, IAmShPollDispatch *dispatch, void* userData, sh_pollHandle_t& handle);
    am_Error_e removeFDPoll(const sh_pollHandle_t handle);
    am_Error_e updateEventFlags(const sh_pollHandle_t handle, const short events);
    am_Error_e addTimer(const timespec timeouts, IAmShTimerCallBack* callback, sh_timerHandle_t& handle, void* userData);
    am_Error_e removeTimer(const sh_timerHandle_t handle);
    am_Error_e restartTimer(const sh_timerHandle_t handle);
    am_Error_e updateTimer(const sh_timerHandle_t handle, const timespec timeouts);
    am_Error_e stopTimer(const sh_timerHandle_t handle);
    void start_listenting();
    void stop_listening();
    void exit_mainloop();
    void receiverCallback(const pollfd pollfd, const sh_pollHandle_t handle, void* userData)
        {
            (void) pollfd;
            (void) handle;
            (void) userData;
        };
    bool checkerCallback(const sh_pollHandle_t handle, void* userData)
        {
            (void) handle;
            (void) userData;
            return (false);
        };

    TAmShPollFired<CAmSocketHandler> receiverCallbackT;
    TAmShPollCheck<CAmSocketHandler> checkerCallbackT;

private:

    static CAmSocketHandler* mInstance;
    int mPipe[2];
    int mDispatchDone; //this starts / stops the mainloop
    struct sh_timer_s //!<struct that holds information of timers
    {
        sh_timerHandle_t handle; //!<the handle of the timer
        timespec countdown; //!<the countdown, this value is decreased every time the timer is up
        IAmShTimerCallBack* callback; //!<the callbackfunction
        void * userData; //!<saves a void pointer together with the rest.
    };

    typedef std::reverse_iterator<sh_timer_s> rListTimerIter; //!<typedef for reverseiterator on timer lists

    struct sh_poll_s //!<struct that holds information about polls
    {
        sh_pollHandle_t handle; //!<handle to uniquely adress a filedesriptor
        IAmShPollPrepare *prepareCB; //!<pointer to preperation callback
        IAmShPollFired *firedCB; //!<pointer to fired callback
        IAmShPollCheck *checkCB; //!< pointer to check callback
        IAmShPollDispatch *dispatchCB; //!<pointer to dispatch callback
        pollfd pollfdValue; //!<the array for polling the filedescriptors
        void *userData; //!<userdata saved together with the callback.
    };

    typedef std::vector<pollfd> mListPollfd_t; //!<vector of filedescriptors
    typedef std::vector<sh_poll_s> mListPoll_t; //!<list for the callbacks

    bool fdIsValid(const int fd) const;
    void timerUp();
    void timerCorrection();
    timespec* insertTime(timespec& buffertime);

    /**
     * compares countdown values
     * @param a
     * @param b
     * @return true if b greater a
     */
    inline static bool compareCountdown(const sh_timer_s& a, const sh_timer_s& b)
    {
        return ((a.countdown.tv_sec == b.countdown.tv_sec) ? (a.countdown.tv_nsec < b.countdown.tv_nsec) : (a.countdown.tv_sec < b.countdown.tv_sec));
    }

    /**
     * Subtracts b from a
     * @param a
     * @param b
     * @return subtracted value
     */
    inline static timespec timespecSub(const timespec& a, const timespec& b)
    {
        timespec result;

        if ((a.tv_sec < b.tv_sec) || ((a.tv_sec == b.tv_sec) && (a.tv_nsec <= b.tv_nsec)))
        {
            result.tv_sec = result.tv_nsec = 0;
        }
        else
        {
            result.tv_sec = a.tv_sec - b.tv_sec;
            if (a.tv_nsec < b.tv_nsec)
            {
                result.tv_nsec = a.tv_nsec + MAX_NS - b.tv_nsec;
                result.tv_sec--; /* Borrow a second. */
            }
            else
            {
                result.tv_nsec = a.tv_nsec - b.tv_nsec;
            }
        }
        return (result);
    }

    /**
     * adds timespec values
     * @param a
     * @param b
     * @return the added values
     */
    inline timespec timespecAdd(const timespec& a, const timespec& b)
    {
        timespec result;
        result.tv_sec = a.tv_sec + b.tv_sec;
        result.tv_nsec = a.tv_nsec + b.tv_nsec;
        if (result.tv_nsec >= MAX_NS)
        {
            result.tv_sec++;
            result.tv_nsec = result.tv_nsec - MAX_NS;
        }
        return (result);
    }

    /**
     * comapares timespec values
     * @param a
     * @param b
     * @return
     */
    inline int timespecCompare(const timespec& a, const timespec& b)
    {
        //less
        if (a.tv_sec < b.tv_sec)
            return (-1);
        //greater
        else if (a.tv_sec > b.tv_sec)
            return (1);
        //less
        else if (a.tv_nsec < b.tv_nsec)
            return (-1);
        //greater
        else if (a.tv_nsec > b.tv_nsec)
            return (1);
        //equal
        else
            return (0);
    }

    /**
     * functor to return all fired events
     * @param a
     * @return
     */
    inline static bool eventFired(const pollfd& a)
    {
        return (a.revents == 0 ? false : true);
    }

    /**
     * functor to help find the items that do not need dispatching
     * @param a
     * @return
     */
    inline static bool noDispatching(const sh_poll_s& a)
    {
        //remove from list of there is no checkCB
        if (!a.checkCB)
            return (true);
        return (!a.checkCB->Call(a.handle, a.userData));
    }

    /**
     * checks if dispatching is already finished
     * @param a
     * @return
     */
    inline static bool dispatchingFinished(const sh_poll_s& a)
    {
        //remove from list of there is no dispatchCB
        if (!a.dispatchCB)
            return (true);
        return (!a.dispatchCB->Call(a.handle, a.userData));
    }

    class CAmShCopyPollfd //!< functor to copy filedescriptors into the poll array
    {
    private:
        mListPollfd_t& mArray;
    public:
        CAmShCopyPollfd(mListPollfd_t& dest) :
                mArray(dest)
        {
        }
        void operator()(const sh_poll_s& row)
        {
            pollfd temp = row.pollfdValue;
            temp.revents = 0;
            mArray.push_back(temp);
        }
    };

    class CAmShCallFire //!< functor to call the firecallbacks
    {
    public:
        CAmShCallFire()
        {
        }
        ;
        void operator()(sh_poll_s& row)
        {
            row.firedCB->Call(row.pollfdValue, row.handle, row.userData);
        }
    };

    class CAmShCallPrep //!< functor to call the preparation callbacks
    {
    public:
        CAmShCallPrep()
        {
        }
        ;
        void operator()(sh_poll_s& row)
        {
            if (row.prepareCB)
                row.prepareCB->Call(row.handle, row.userData);
        }
    };

    class CAmShCallTimer //!<functor to call a timer
    {
    public:
        CAmShCallTimer()
        {
        }
        ;
        void operator()(sh_timer_s& row)
        {
            row.callback->Call(row.handle, row.userData);
        }
    };

    class CAmShCountdownUp //!<functor that checks if a timer is up
    {
    private:
        timespec mDiffTime;
    public:
        CAmShCountdownUp(const timespec& differenceTime) :
                mDiffTime(differenceTime)
        {
        }
        ;
        bool operator()(const sh_timer_s& row)
        {
            timespec sub = timespecSub(row.countdown, mDiffTime);
            if (sub.tv_nsec == 0 && sub.tv_sec == 0)
                return (true);
            return (false);
        }
    };

    class CAmShCountdownZero //!<functor that checks if a timer is zero
    {
    public:
        CAmShCountdownZero()
        {
        }
        ;
        bool operator()(const sh_timer_s& row)
        {
            if (row.countdown.tv_nsec == 0 && row.countdown.tv_sec == 0)
                return (true);
            return (false);
        }
    };

    class CAmShSubstractTime //!<functor to easy substract from each countdown value
    {
    private:
        timespec param;
    public:
        CAmShSubstractTime(timespec param) :
                param(param)
        {
        }
        inline void operator()(sh_timer_s& t)
        {
            t.countdown = timespecSub(t.countdown, param);
        }
    };

    mListPollfd_t mfdPollingArray; //!<the polling array for ppoll
    mListPoll_t mListPoll; //!<list that holds all information for the ppoll
    std::list<sh_timer_s> mListTimer; //!<list of all timers
    std::list<sh_timer_s> mListActiveTimer; //!<list of all currently active timers
    sh_timerHandle_t mLastInsertedHandle; //!<keeps track of the last inserted timer handle
    sh_pollHandle_t mLastInsertedPollHandle; //!<keeps track of the last inserted poll handle
    bool mRecreatePollfds; //!<when this is true, the poll list needs to be recreated
    timespec mStartTime; //!<here the actual time is saved for timecorrection

//    void debugPrintTimerList ()
//    {
//        std::list<sh_timer_s>::iterator it(mListActiveTimer.begin());
//        for(;it!=mListActiveTimer.end();++it)
//        {
//            std::cout<< "Handle " << it->handle << "sec " << it->countdown.tv_sec << "nsec " << it->countdown.tv_nsec<<std::endl;
//        }
//    }
}
;

/**
 * template to create the functor for a class
 */
template<class TClass> class TAmShTimerCallBack: public IAmShTimerCallBack
{
private:
    TClass* mInstance;
    void (TClass::*mFunction)(sh_timerHandle_t handle, void* userData);

public:
    TAmShTimerCallBack(TClass* instance, void (TClass::*function)(sh_timerHandle_t handle, void* userData)) :
            mInstance(instance), //
            mFunction(function)
    {
    }
    ;

    virtual void Call(sh_timerHandle_t handle, void* userData)
    {
        (*mInstance.*mFunction)(handle, userData);
    }
};

/**
 * template for a callback
 */
template<class TClass> class TAmShPollPrepare: public IAmShPollPrepare
{
private:
    TClass* mInstance;
    void (TClass::*mFunction)(const sh_timerHandle_t handle, void* userData);

public:
    TAmShPollPrepare(TClass* instance, void (TClass::*function)(const sh_timerHandle_t handle, void* userData)) :
            mInstance(instance), //
            mFunction(function)
    {
    }
    ;

    virtual void Call(const sh_timerHandle_t handle, void* userData)
    {
        (*mInstance.*mFunction)(handle, userData);
    }
    ;
};

/**make private, not public
 * template for a callback
 */
template<class TClass> class TAmShPollFired: public IAmShPollFired
{
private:
    TClass* mInstance;
    void (TClass::*mFunction)(const pollfd pollfd, const sh_pollHandle_t handle, void* userData);

public:
    TAmShPollFired(TClass* instance, void (TClass::*function)(const pollfd pollfd, const sh_pollHandle_t handle, void* userData)) :
            mInstance(instance), //
            mFunction(function)
    {
    }
    ;

    virtual void Call(const pollfd pollfd, const sh_pollHandle_t handle, void* userData)
    {
        (*mInstance.*mFunction)(pollfd, handle, userData);
    }
    ;
};

/**
 * template for a callback
 */
template<class TClass> class TAmShPollCheck: public IAmShPollCheck
{
private:
    TClass* mInstance;
    bool (TClass::*mFunction)(const sh_pollHandle_t handle, void* userData);

public:
    TAmShPollCheck(TClass* instance, bool (TClass::*function)(const sh_pollHandle_t handle, void* userData)) :
            mInstance(instance), //
            mFunction(function)
    {
    }
    ;

    virtual bool Call(const sh_pollHandle_t handle, void* userData)
    {
        return ((*mInstance.*mFunction)(handle, userData));
    }
    ;
};

/**
 * template for a callback
 */
template<class TClass> class TAmShPollDispatch: public IAmShPollDispatch
{
private:
    TClass* mInstance;
    bool (TClass::*mFunction)(const sh_pollHandle_t handle, void* userData);

public:
    TAmShPollDispatch(TClass* instance, bool (TClass::*function)(const sh_pollHandle_t handle, void* userData)) :
            mInstance(instance), //
            mFunction(function)
    {
    }
    ;

    virtual bool Call(const sh_pollHandle_t handle, void* userData)
    {
        return ((*mInstance.*mFunction)(handle, userData));
    }
    ;
};
} /* namespace am */
#endif /* SOCKETHANDLER_H_ */