/** CbmLitWeightCalculatorOptimal.h
 *@author A.Lebedev <andrey.lebedev@gsi.de>
 *@since 2009
 **
 **
 **/

#include "CbmLitWeightCalculatorOptimal.h"

#include "CbmLitHit.h"
//#include "CbmLitStripHit.h"
//#include "CbmLitPixelHit.h"
#include "CbmLitMath.h"

//#include <iostream>
#include <cmath>

CbmLitWeightCalculatorOptimal::CbmLitWeightCalculatorOptimal()
{
}

CbmLitWeightCalculatorOptimal::~CbmLitWeightCalculatorOptimal()
{
}

LitStatus CbmLitWeightCalculatorOptimal::Initialize()
{
	return kLITSUCCESS;
}

LitStatus CbmLitWeightCalculatorOptimal::Finalize()
{
	return kLITSUCCESS;
}

LitStatus CbmLitWeightCalculatorOptimal::DoCalculate(
		const CbmLitTrackParam* par,
		HitPtrIterator itBegin,
		HitPtrIterator itEnd,
		myf T)
{
	for(HitPtrIterator it = itBegin; it != itEnd; it++) {
		if ((*it)->IsOutlier()) continue;
		if (OptimalWeight(par, *it, T) == kLITERROR) return kLITERROR;
	}
	if (Normalize(itBegin, itEnd) == kLITERROR) return kLITERROR;

	return kLITSUCCESS;
}

LitStatus CbmLitWeightCalculatorOptimal::DoCalculate(
		const CbmLitTrackParam* par,
		HitPtrVector& hits,
		myf T)
{
	return DoCalculate(par, hits.begin(), hits.end(), T);
}

LitStatus CbmLitWeightCalculatorOptimal::OptimalWeight(
		const CbmLitTrackParam* par,
		CbmLitHit* hit,
		myf T) const
{
    myf chiSq = ChiSq(par, hit);
    hit->SetW((1 + T) / (1 + T * std::exp(chiSq)));
    return kLITSUCCESS;
}

LitStatus CbmLitWeightCalculatorOptimal::Normalize(
		HitPtrIterator itBegin,
		HitPtrIterator itEnd) const
{
	myf sumW = 0.;
	myf sumCut = 0.;
	for(HitPtrIterator it = itBegin; it != itEnd; it++) {
		if ((*it)->IsOutlier()) continue;
		sumW += (*it)->GetW();
	}

	if (sumW == 0.) {
		return kLITERROR;
	} else {
		for(HitPtrIterator it = itBegin; it != itEnd; it++) {
			if ((*it)->IsOutlier()) continue;
			(*it)->SetW((*it)->GetW() / sumW);
		}
	}
	return kLITSUCCESS;
}