/* ======================================================================== *\
!
! *
! * This file is part of MARS, the MAGIC Analysis and Reconstruction
! * Software. It is distributed to you in the hope that it can be a useful
! * and timesaving tool in analysing Data of imaging Cerenkov telescopes.
! * It is distributed WITHOUT ANY WARRANTY.
! *
! * Permission to use, copy, modify and distribute this software and its
! * documentation for any purpose is hereby granted without fee,
! * provided that the above copyright notice appear in all copies and
! * that both that copyright notice and this permission notice appear
! * in supporting documentation. It is provided "as is" without express
! * or implied warranty.
! *
!
!
!   Author(s): Josep Flix 04/2001 <mailto:jflix@ifae.es>
!   Author(s): Thomas Bretz 05/2001 <mailto:tbretz@astro.uni-wuerzburg.de>
!   Author(s): Sebastian Commichau 12/2003 
!   Author(s): Javier Rico 01/2004 
!
!   Copyright: MAGIC Software Development, 2000-2004
!
!
\* ======================================================================== */

/////////////////////////////////////////////////////////////////////////////
//
//   MPedCalcPedRun
//
//  This task takes a pedestal run file and fills MPedestalCam during
//  the Process() with the pedestal and rms computed in an event basis.
//  In the PostProcess() MPedestalCam is finally filled with the pedestal
//  mean and rms computed in a run basis.
//  More than one run (file) can be merged
//
//  Input Containers:
//   MRawEvtData
//
//  Output Containers:
//   MPedestalCam
//
//
/////////////////////////////////////////////////////////////////////////////
#include "MPedCalcPedRun.h"

#include "MParList.h"

#include "MLog.h"
#include "MLogManip.h"

#include "MRawRunHeader.h"  
#include "MRawEvtPixelIter.h"
#include "MRawEvtData.h"

#include "MPedestalPix.h"
#include "MPedestalCam.h"

#include "MGeomCamMagic.h"

ClassImp(MPedCalcPedRun);

using namespace std;

// --------------------------------------------------------------------------
//
// default constructor
//
MPedCalcPedRun::MPedCalcPedRun(const char *name, const char *title)
{
    fName  = name  ? name  : "MPedCalcPedRun";
    fTitle = title ? title : "Task to calculate pedestals from pedestal runs raw data";

    AddToBranchList("fHiGainPixId");
    AddToBranchList("fHiGainFadcSamples");
}

// --------------------------------------------------------------------------
//
// Look for the following input containers:
//
//  - MRawEvtData
// 
// The following output containers are also searched and created if
// they were not found:
//
//  - MPedestalCam
//
Int_t MPedCalcPedRun::PreProcess( MParList *pList )
{
    fRawEvt = (MRawEvtData*)pList->FindObject("MRawEvtData");
    if (!fRawEvt)
    {
        *fLog << err << "MRawEvtData not found... aborting." << endl;
        return kFALSE;
    }

    fPedestals = (MPedestalCam*)pList->FindCreateObj("MPedestalCam");
    if (!fPedestals)
        return kFALSE;

    fNumSamplesTot=0;

    return kTRUE;
}

// --------------------------------------------------------------------------
//
// The ReInit searches for the following input containers:
//  - MRawRunHeader
//
// It also initializes the data arrays fSumx and fSumx2 
// (only for the first read file)
// 
Bool_t MPedCalcPedRun::ReInit(MParList *pList)
{
    const MRawRunHeader *runheader = (MRawRunHeader*)pList->FindObject("MRawRunHeader");
    if (!runheader)
    {
        *fLog << warn << dbginf;
        *fLog << "Warning - cannot check file type, MRawRunHeader not found." << endl;
    }
    else
        if (runheader->GetRunType() == kRTMonteCarlo)
            return kTRUE;

    fNumPixels = fPedestals->GetSize();

    if(fSumx.GetSize()==0)
      {
	fSumx.Set(fNumPixels);
	fSumx2.Set(fNumPixels);

	fSumx.Reset();
	fSumx2.Reset();
      }

    // Calculate an even number for the hi gain samples to avoid
    // biases due to the fluctuation in pedestal from one slice to
    // the other one
    fNumHiGainSamples = runheader->GetNumSamplesHiGain() & ~1;

    return kTRUE;
}
// --------------------------------------------------------------------------
//
// Fill the MPedestalCam container with the signal mean and rms for the event.
// Store the measured signal in arrays fSumx and fSumx2 so that we can 
// calculate the overall mean and rms in the PostProcess()
//
Int_t MPedCalcPedRun::Process()
{
    MRawEvtPixelIter pixel(fRawEvt);

    while (pixel.Next())
    {
              Byte_t *ptr = pixel.GetHiGainSamples();
        const Byte_t *end = ptr + fNumHiGainSamples;

	UInt_t sum = 0;
	UInt_t sqr = 0;
	
	do
	  {
	    sum += *ptr;
	    sqr += *ptr * *ptr;
	  }
	while (++ptr != end);
	
	const Float_t msum = (Float_t)sum;
	const Float_t msqr = (Float_t)sqr;
	
	const Float_t higainped = msum/fNumHiGainSamples;
	const Float_t higainrms = TMath::Sqrt((msqr-msum*msum/fNumHiGainSamples)/(fNumHiGainSamples-1.));
	
	const UInt_t idx = pixel.GetPixelId();
	(*fPedestals)[idx].Set(higainped, higainrms);
	
	fSumx[idx]  += msum;
        //
        // The old version:
        //
        //	fSumx2[idx] += msqr;
        //
        // The new version:
        //
	fSumx2[idx] += msum*msum;
    }
    
    fPedestals->SetReadyToSave();
    fNumSamplesTot += fNumHiGainSamples;
    
    return kTRUE;
}

// --------------------------------------------------------------------------
//
// Compute signal mean and rms in the whole run and store it in MPedestalCam
//
Int_t MPedCalcPedRun::PostProcess()
{
  // Compute pedestals and rms from the whole run
  const ULong_t n     = fNumSamplesTot;
  const ULong_t nevts = GetNumExecutions();

  MRawEvtPixelIter pixel(fRawEvt);
  
  while (pixel.Next())
    {
      const UInt_t pixid = pixel.GetPixelId();
      
      const Float_t sum  = fSumx.At(pixid);
      const Float_t sum2 = fSumx2.At(pixid);
      
      const Float_t higainped = sum/n;
      //
      // The old version:
      //
      //      const Float_t higainrms = TMath::Sqrt((sum2-sum*sum/n)/(n-1.));
      //
      // The new version:
      //
      const Float_t higainrms = TMath::Sqrt((sum2-sum*sum/nevts)/(nevts-1.)/(Float_t)fNumHiGainSamples);
      
      (*fPedestals)[pixid].Set(higainped, higainrms);
    }
  
  return kTRUE;
}