//
// Class AliRsnFunction
//
// This class defines a base classe to implement a function
// which uses the internal RSN package event format (AliRsnEvent).
// It contains some default flags which turn out to be useful:
//  - a flag to select only the "true" pairs (tracks from same resonance)
//  - a flag to know if the computation is done over two events (mixing)
//
// Any kind of analysis object should be implemented as inheriting from this
// because the AliRsnAnalyzer which executes the analysis will accept a collection
// of such objects, in order to have a unique format of processing method
//
// The user who implements a kind of computation type should inherit from
// this class and override the virtual functions defined in it, which
// initialize the final output histogram and define how to process data.
//
//
// author: A. Pulvirenti             (email: alberto.pulvirenti@ct.infn.it)
//

#include <TString.h>
#include <TAxis.h>

#include "AliLog.h"

#include "AliRsnDaughter.h"
#include "AliRsnEvent.h"
#include "AliRsnPairDef.h"
#include "AliRsnMother.h"
#include "AliRsnValue.h"

#include "AliRsnFunction.h"

ClassImp(AliRsnFunction)

//________________________________________________________________________________________
AliRsnFunction::AliRsnFunction(Bool_t useTH1) :
    TObject(),
    fPairDef(0x0),
    fAxisList("AliRsnValue", 0),
    fPair(0x0),
    fEvent(0x0),
    fUseTH1(useTH1),
    fSize(0),
    fH1(0x0),
    fHSparse(0x0)
{
//
// Constructor.
//
}

//________________________________________________________________________________________
AliRsnFunction::AliRsnFunction(const AliRsnFunction &copy) :
    TObject(copy),
    fPairDef(copy.fPairDef),
    fAxisList(copy.fAxisList),
    fPair(copy.fPair),
    fEvent(copy.fEvent),
    fUseTH1(copy.fUseTH1),
    fSize(copy.fSize),
    fH1(0x0),
    fHSparse(0x0)
{
//
// Copy constructor.
//
}

//________________________________________________________________________________________
const AliRsnFunction& AliRsnFunction::operator=(const AliRsnFunction& copy)
{
//
// Assignment operator.
//

  //SetName(copy.GetName());
  //SetTitle(copy.GetTitle());

  fPairDef = copy.fPairDef;
  fPair = copy.fPair;
  fEvent = copy.fEvent;
  fUseTH1 = copy.fUseTH1;
  fSize = copy.fSize;

  if (fH1) delete fH1;
  fH1 = 0x0;
  
  if (fHSparse) delete fHSparse;
  fHSparse = 0x0;

  return (*this);
}

//________________________________________________________________________________________
const char* AliRsnFunction::GetName() const
{
//
// Defines the name of this object according to
// the function type and binning
//

  TString name("");

  TObjArrayIter next(&fAxisList);
  AliRsnValue *axis = 0;

  while ((axis = (AliRsnValue*)next())) {
    if (name.Length() > 1) name += '_';
    name += axis->GetName();
  }

  return name.Data();
}

//________________________________________________________________________________________
void AliRsnFunction::AddAxis(AliRsnValue *const axis)
{
  AliDebug(AliLog::kDebug+2,"<-");
  Int_t size = fAxisList.GetEntries();
  new(fAxisList[size]) AliRsnValue(*axis);
  AliDebug(AliLog::kDebug+2,"->");
  
  if (fAxisList.GetEntries() > 3)
  {
    AliWarning("A TH1-type output cannot add more than 3 axes: switching to THnSparse -- THIS COULD CAUSE VERY LARGE FILES!!!");
    fUseTH1 = kFALSE;
  }
}

//________________________________________________________________________________________
TH1* AliRsnFunction::CreateHistogram(const char *histoName, const char *histoTitle)
{
//
// Creates and returns the histogram defined using
// arguments fo name and title, and the first histoDef for binning.
// Variable-sized histogram binning is always called, due to use of histoDef,
// even if the bins are equal, since they are defined in this class.
// Eventually present histoDef's in other slots of array (1, 2) are ignored.
//
// This version produces a THnSparseF.
//

  fSize = fAxisList.GetEntries();
  if (!fSize) {
    AliError("No axes defined");
    return 0x0;
  }
  else if (fSize < 1 || fSize > 3)
  {
    AliError("Too few or too many axes defined");
    return 0x0;
  }

  // retrieve binnings for main and secondary axes
  AliRsnValue *fcnAxis;
  TArrayD      array[3];
  for (Int_t i = 0; i < fSize; i++) 
  {
    fcnAxis = (AliRsnValue*)fAxisList.At(i);
    if (!fcnAxis) 
    {
      AliError("Empty axis");
      array[i].Set(2);
      array[i][0] = -1E5;
      array[i][1] = -1E5;
      continue;
    }
    else
    {
      array[i] = fcnAxis->GetArray();
    }
  }

  // create histogram depending on the number of axes
  switch (fSize)
  {
    case 1:
      fH1 = new TH1F(histoName, histoTitle, array[0].GetSize() - 1, array[0].GetArray());
      break;
    case 2:
      fH1 = new TH2F(histoName, histoTitle, array[0].GetSize() - 1, array[0].GetArray(), array[1].GetSize() - 1, array[1].GetArray());
      break;
    case 3:
      fH1 = new TH3F(histoName, histoTitle, array[0].GetSize() - 1, array[0].GetArray(), array[1].GetSize() - 1, array[1].GetArray(), array[2].GetSize() - 1, array[2].GetArray());
      break;
  }
  fH1->Sumw2();

  return fH1;
}

//________________________________________________________________________________________
THnSparseF* AliRsnFunction::CreateHistogramSparse(const char *histoName, const char *histoTitle)
{
//
// Creates and returns the histogram defined using
// arguments fo name and title, and the first histoDef for binning.
// Variable-sized histogram binning is always called, due to use of histoDef,
// even if the bins are equal, since they are defined in this class.
// Eventually present histoDef's in other slots of array (1, 2) are ignored.
//
// This version produces a THnSparseF.
//

  fSize = fAxisList.GetEntries();
  if (!fSize) {
    AliError("No axes defined");
    return 0x0;
  }
  
  // initialize the array of number of bins for each axis
  // taking it from the stored values, while for the bins
  // they are set as summied and defined later
  Double_t     dummyD;
  Int_t       *nbins   = new Int_t[fSize];
  AliRsnValue *fcnAxis = 0;
  for (Int_t i = 0; i < fSize; i++) 
  {
    fcnAxis = (AliRsnValue*)fAxisList.At(i);
    if (!fcnAxis) 
    {
      nbins[i] = 1;
      AliError("Empty axis");
      continue;
    }
    nbins[i] = fcnAxis->GetArray().GetSize() - 1;
  }

  // create histogram
  fHSparse = new THnSparseF(histoName, histoTitle, fSize, nbins, &dummyD, &dummyD);
  fHSparse->Sumw2();
  
  // update the various axes using the definitions given in the array of axes here
  for (Int_t i = 0; i < fSize; i++) 
  {
    fcnAxis = (AliRsnValue*)fAxisList.At(i);
    if (!fcnAxis) {
      AliError("Empty axis: doing unique bin betweeen -100000 and 100000");
      continue;
    }
    fHSparse->SetBinEdges(i, fcnAxis->GetArray().GetArray());
  }

  return fHSparse;
}


//________________________________________________________________________________________
Bool_t AliRsnFunction::Fill()
{
//
// Fill function histogram with values computed from given input object.
//

  AliDebug(AliLog::kDebug +2,"->");

  Int_t  i;
  Double_t *values = new Double_t[fSize];

  AliRsnValue *fcnAxis = 0;
  for (i = 0; i < fSize; i++) {
    fcnAxis = (AliRsnValue*)fAxisList.At(i);
    if (!fcnAxis) 
    {
      values[i] = 0.0;
      continue;
    }
    if (fcnAxis->Eval(fPair, fPairDef, fEvent)) values[i] = (Double_t)((Float_t)fcnAxis->GetValue());
  }
  
  // fill histogram
  if (fUseTH1)
  {
    // check presence of output histogram
    if (!fH1) {
      AliError("Required a TH1 which is not initialized");
      delete [] values;
      return kFALSE;
    }
    
    // fill according to dimensions
    switch (fSize)
    {
      case 1:
        {
          TH1F *h1 = (TH1F*)fH1;
          h1->Fill(values[0]);
        }
        break;
      case 2:
        {
          TH2F *h2 = (TH2F*)fH1;
          h2->Fill(values[0], values[1]);
        }
        break;
      case 3:
        {
          TH3F *h3 = (TH3F*)fH1;
          h3->Fill(values[0], values[1], values[2]);
        }
        break;
      default:
        AliError(Form("Wrong size : %d", fSize));
        delete [] values;
        return kFALSE;
    }
  }
  else
  {
    // check presence of output histogram
    if (!fHSparse) {
      AliError("Required a THnSparseF which is not initialized");
      return kFALSE;
    }
    
    fHSparse->Fill(values);
  }
  
  delete [] values;

  AliDebug(AliLog::kDebug +2,"->");
  return kTRUE;
}