/**************************************************************************
 * This file is property of and copyright by                              *
 * the Relativistic Heavy Ion Group (RHIG), Yale University, US, 2009     *
 *                                                                        *
 * Primary Author: Per Thomas Hille <p.t.hille@fys.uio.no>                *
 *                                                                        *
 * Contributors are mentioned in the code where appropriate.              *
 * Please report bugs to p.t.hille@fys.uio.no                             *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/


// Extraction of amplitude and peak position
// FRom CALO raw data using
// least square fit for the
// Moment assuming identical and 
// independent errors (equivalent with chi square)
// 

#include "AliCaloRawAnalyzerLMS.h"
#include "AliCaloBunchInfo.h"
#include "AliCaloFitResults.h"
#include "AliLog.h"
#include "TMath.h"
#include <stdexcept>
#include <iostream>
#include "TF1.h"
#include "TGraph.h"

using namespace std;

ClassImp( AliCaloRawAnalyzerLMS )

AliCaloRawAnalyzerLMS::AliCaloRawAnalyzerLMS() : AliCaloRawAnalyzerFitter("Chi Square Fit", "LMS")
{
  fAlgo = Algo::kLMS;
}


AliCaloRawAnalyzerLMS::~AliCaloRawAnalyzerLMS()
{
  // delete fTf1;
}


AliCaloFitResults
AliCaloRawAnalyzerLMS::Evaluate( const vector<AliCaloBunchInfo>  &bunchvector, const UInt_t altrocfg1,  const UInt_t altrocfg2 )
{
  // Extracting signal parameters using fitting
  short maxampindex; //index of maximum amplitude
  short maxamp; //Maximum amplitude
  int index = SelectBunch( bunchvector,  &maxampindex,  &maxamp );
  
  if( index >= 0)
    {
      Float_t  ped  = ReverseAndSubtractPed( &(bunchvector.at(index))  ,  altrocfg1, altrocfg2, fReversed  );
      Float_t maxf = TMath::MaxElement( bunchvector.at(index).GetLength(),  fReversed );
      short maxrev = maxampindex  -  bunchvector.at(index).GetStartBin();
      // timebinOffset is timebin value at maximum (maxrev)
      short timebinOffset = maxampindex - (bunchvector.at(index).GetLength()-1);
      if(  maxf < fAmpCut  ||  ( maxamp - ped) > fOverflowCut  ) // (maxamp - ped) > fOverflowCut = Close to saturation (use low gain then)
	{
	  return  AliCaloFitResults( maxamp, ped, Ret::kCrude, maxf, timebinOffset);
 	}            
      else if ( maxf >= fAmpCut )
	{
	  int first = 0;
	  int last = 0;
	  SelectSubarray( fReversed,  bunchvector.at(index).GetLength(),  maxrev, &first, &last, fFitArrayCut);
	  int nsamples =  last - first + 1;
	  
	  if( ( nsamples  )  >= fNsampleCut )
	    {
	      Float_t tmax = (maxrev - first); // local tmax estimate
	      TGraph *graph =  new TGraph(  nsamples, fXaxis,  &fReversed[first] );
	      fTf1->SetParameter(0, maxf*fkEulerSquared );
	      fTf1->SetParameter(1, tmax - fTau); 
	      // set rather loose parameter limits
	      fTf1->SetParLimits(0, 0.5*maxf*fkEulerSquared, 2*maxf*fkEulerSquared );
	      fTf1->SetParLimits(1, tmax - fTau - 4, tmax - fTau + 4); 

	      if (fFixTau) {
		fTf1->FixParameter(2, fTau);
	      }
	      else {
		fTf1->ReleaseParameter(2); // allow par. to vary
		fTf1->SetParameter(2, fTau);
	      }

	      Short_t tmpStatus = 0;
	      try {
		tmpStatus =  graph->Fit(fTf1, "Q0RW");
	      }
	      catch (const std::exception & e) {
		AliError( Form("TGraph Fit exception %s", e.what()) ); 
		return AliCaloFitResults( maxamp, ped, Ret::kNoFit, maxf, timebinOffset,
					  timebinOffset, Ret::kDummy, Ret::kDummy, Ret::kDummy, AliCaloFitSubarray(index, maxrev, first, last) );
	      }

	      if( fVerbose == true )
		{
		  AliCaloRawAnalyzer::PrintBunch( bunchvector.at(index) ); 
		  PrintFitResult( fTf1 ) ;
		}  
	      // global tmax
	      tmax = fTf1->GetParameter(1) + timebinOffset - (maxrev - first) // abs. t0
		+ fTf1->GetParameter(2); // +tau, makes sum tmax
	      
	        delete graph;
		return AliCaloFitResults( maxamp, ped , Ret::kFitPar,
					  fTf1->GetParameter(0)/fkEulerSquared, 
					  tmax,
					  timebinOffset,  
					  fTf1->GetChisquare(), 
					  fTf1->GetNDF(),
					  Ret::kDummy, AliCaloFitSubarray(index, maxrev, first, last) );
		//     delete graph;
	
	    }
	  else
	    {
	      
	      Float_t chi2 = CalculateChi2(maxf, maxrev, first, last);
	      Int_t ndf = last - first - 1; // nsamples - 2
	      return AliCaloFitResults( maxamp, ped, Ret::kCrude, maxf, timebinOffset,
					timebinOffset, chi2, ndf, Ret::kDummy, AliCaloFitSubarray(index, maxrev, first, last) ); 
	    }
        } // ampcut
    }
  return AliCaloFitResults( Ret::kInvalid, Ret::kInvalid );
  
}