/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/

#include "hsTypes.h"
#include "plAvg.h"
#include <math.h>

template class TimeBasedAvgRing<float>;
template class TimeBasedAvgRing<double>;

#define PercisionRoundUp(x) (ceil(x / kPercision) * kPercision)

template <class T>
const float TimeBasedAvgRing<T>::kPercision = 0.001;

template <class T>
void TimeBasedAvgRing<T>::AddItem(T value, double time)
{
    hsTempMutexLock lock( fLock );

    if ( fList.empty() )
    {
        // initialize with the first time and zero the first value
        fList.insert(fList.end(),Item<T>(0.0,time));
        fRingStart = fRingEnd = fList.begin();
        fAvg = (float)value;
    }
    else
    {
        // if we're within the percision amount subtract the RingEnd value from total
        // and update the RingEnd value by adding the current value to it
        if (time - (*fRingEnd).GetTime() <= kPercision)
        {
            fTotal -= PercisionRoundUp((*fRingEnd).GetValue());
            (*fRingEnd).SetValue((*fRingEnd).GetValue() + value);
        }
        else
        {
            // clean up the begining of the ring
            //// there can be some precision loss in the loop time calc
            //// check to see if the difference is within 1 milli
            while (time - (*fRingStart).GetTime() > fLen + kPercision
                && fRingStart != fRingEnd)
            {
                // remove RingStart from the avg part of the average calc
                fTotal -= (*fRingStart).GetValue();

                typename TimeList::iterator prev = fRingStart++;

                // loop the ring if needed
                if (fRingStart == fList.end())
                    fRingStart = fList.begin();


                // if the new ring start is in the range, interpolate
                //   and reuse prev
                if (time - (*fRingStart).GetTime() < fLen)
                {
                    // remove RingStart from the avg part of the average calc
                    fTotal -= PercisionRoundUp((*fRingStart).GetValue());

                    // Set up the interp
                    double remainder = fLen - (time - (*fRingStart).GetTime());
                    double timedelta = (*fRingStart).GetTime() - (*prev).GetTime();
                    (*prev).SetTime((*fRingStart).GetTime() - remainder);
                    (*prev).SetValue(0);
                    // rounding loss occurs here if T is not floting point
                    double scale = remainder/timedelta;
                    hsAssert(scale < 1.0 && scale > 0.0,"Interp Scale Out of Bounds");
                    (*fRingStart).SetValue((float)((*fRingStart).GetValue() * scale));
                    
                    // add the new  value in
                    fTotal += (*fRingStart).GetValue();
                    
                    // put prev back as ring start
                    fRingStart = prev;
                }

            }

            // zero total & fAvg if we looped or neg
            if (fRingStart == fRingEnd || fTotal < 0.0)
            {
                fTotal = 0.0;
                fAvg = 0.0;
            }

            // put the new value in the ring by expanding the ring if needed
            //  or replacing an empty value
            fRingEnd++;
            if (fRingEnd == fList.end())
                fRingEnd = fList.begin();
            // Do we have free space?
            if (fRingEnd == fRingStart)
            {
                // no free space
                fList.insert(fRingEnd,Item<T>(value,time));
                fRingEnd--;
            }
            else
            {
                // yes free space @ fRingEnd
                (*fRingEnd) = Item<T>(value,time);
            }
        }

        //update the avg
        fTotal += (*fRingEnd).GetValue();
        double currentLen = (*fRingEnd).GetTime() - (*fRingStart).GetTime();
        if (currentLen < 1.0)
            fAvg = (float)fTotal;
        else
            fAvg = (float)(fTotal / currentLen);
    }

    // update the max avg
    fMaxAvg = hsMaximum( fMaxAvg, fAvg );

}