//
// Class AliRsnFunctionAxis
//
// Definition for a histogram type.
// Since one could do an analysis which is not an invariant mass
// the histogram definition should be more flexible, and it is stored
// separately in a new class.
// This class considers the possibility of a 1D or 2D histograms
// with its related binning, and can create a new histo from his definitions
//
#include "TObject.h"

#include "AliLog.h"

#include "AliRsnEvent.h"
#include "AliRsnPairParticle.h"
#include "AliRsnPairDef.h"
#include "AliRsnFunctionAxis.h"

ClassImp(AliRsnFunctionAxis)

//_____________________________________________________________________________
AliRsnFunctionAxis::AliRsnFunctionAxis() :
  fType(kAxisTypes),
  fNBins(0),
  fMin(0.0),
  fMax(0.0)
{
//
// Default constructor
//
}

//_____________________________________________________________________________
AliRsnFunctionAxis::AliRsnFunctionAxis
(EAxisType type, Int_t nbins, Double_t min, Double_t max) :
  fType(type),
  fNBins(0),
  fMin(0.0),
  fMax(0.0)
{
//
// Main constructor (version 1)
//

  SetBins(nbins, min, max);
}

//_____________________________________________________________________________
AliRsnFunctionAxis::AliRsnFunctionAxis
(EAxisType type, Double_t min, Double_t max, Double_t step) :
  fType(type),
  fNBins(0),
  fMin(0.0),
  fMax(0.0)
{
//
// Main constructor (version 2)
//

  SetBins(min, max, step);
}

//_____________________________________________________________________________
const char* AliRsnFunctionAxis::GetName() const
{
//
// Return the name of this object defined by the type
//

  switch (fType)
  {
    case kTrack1P:        return "P1";
    case kTrack2P:        return "P2";
    case kTrack1Pt:       return "PT1";
    case kTrack2Pt:       return "PT2";
    case kPairInvMass:    return "IM";
    case kPairInvMassMC:  return "IMMC";
    case kPairInvMassRes: return "IMRES";
    case kPairPt:         return "PT";
    case kPairEta:        return "ETA";
    case kEventMult:      return "MULT";
    default:              return "UNDEF";
  }
}

//_____________________________________________________________________________
AliRsnFunctionAxis::EAxisObject AliRsnFunctionAxis::GetAxisObject()
{
//
// Tells what kind of object must be evaluated for this axis
//

  switch (fType)
  {
    case kTrack1P:
    case kTrack2P:
    case kTrack1Pt:
    case kTrack2Pt:
    case kPairInvMass:
    case kPairInvMassMC:
    case kPairInvMassRes:
    case kPairPt:
    case kPairEta:
      return kPair;
    case kEventMult:
      return kEvent;
    default:
      return kNone;
  }
}

//_____________________________________________________________________________
void AliRsnFunctionAxis::SetBins(Int_t n, Double_t min, Double_t max)
{
//
// Set binning for histogram.
//

  fNBins = n;

  if (min < max)
  {
    fMin = min;
    fMax = max;
  }
  else
  {
    fMin = max;
    fMax = min;
  }
}

//_____________________________________________________________________________
void AliRsnFunctionAxis::SetBins(Double_t min, Double_t max, Double_t step)
{
//
// Binning for histogram.
//

  if (min < max)
  {
    fMin = min;
    fMax = max;
  }
  else
  {
    fMin = max;
    fMax = min;
  }

  fNBins = (Int_t)((fMax - fMin) / (step)) + 1;
}

//_____________________________________________________________________________
Double_t AliRsnFunctionAxis::Eval(AliRsnDaughter* /*daughter*/)
{
//
// EValuation method for single tracks
// (currently disabled)
//

  return 0.0;
}

//_____________________________________________________________________________
Double_t AliRsnFunctionAxis::Eval(AliRsnPairParticle *pair, AliRsnPairDef *pairDef)
{
//
// EValuation method for pairs.
// Requires also the pair definitions, in order to retrieve mass.
//

  switch (fType)
  {
    case kTrack1P:
      return pair->GetDaughter(0)->P();
    case kTrack2P:
      return pair->GetDaughter(1)->P();
    case kTrack1Pt:
      return pair->GetDaughter(0)->Pt();
    case kTrack2Pt:
      return pair->GetDaughter(1)->Pt();
    case kPairInvMass:
      return pair->GetInvMass(pairDef->GetMass(0), pairDef->GetMass(1));
    case kPairInvMassMC:
      return pair->GetInvMassMC(pairDef->GetMass(0), pairDef->GetMass(1));
    case kPairInvMassRes:
      {
        Double_t value;
        value  = pair->GetInvMass(pairDef->GetMass(0), pairDef->GetMass(1));
        value -= pair->GetInvMassMC(pairDef->GetMass(0), pairDef->GetMass(1));
        value /= pair->GetInvMassMC(pairDef->GetMass(0), pairDef->GetMass(1));
        return value;
      }
    case kPairPt:
      return pair->GetPt();
    case kPairEta:
      return pair->GetEta();
    default:
      AliWarning("This axis type cannot be applied to pairs");
      return -999.0;
  }
}

//_____________________________________________________________________________
Double_t AliRsnFunctionAxis::Eval(AliRsnEvent *event)
{
//
// EValuation method for events
//

  switch (fType)
  {
    case kEventMult:
      return (Double_t)event->GetMultiplicity();
    default:
      AliWarning("This axis type cannot be applied to events");
      return 0.0;
  }
}