/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * 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.                  *
 **************************************************************************/

//_________________________________________________________________________
// This is a TTask that constructs ReconstParticles (reconstructed particles) 
// out of Digits
// 
//-- Authors: Evgeny Karpechev(INR) and Alla Maevsksia
//////////////////////////////////////////////////////////////////////////////

// --- ROOT system ---
#include "TTask.h"
#include "TTree.h"
#include "TSystem.h"
#include "TFile.h"
#include "TROOT.h"
#include "TFolder.h"
#include "TH2F.h"

// --- Standard library ---
#include <stdlib.h>
#include <Riostream.h>

// --- AliRoot header files ---

#include "AliRunLoader.h"
#include "AliLoader.h"

#include "AliFMDdigit.h"
#include "AliFMDhit.h"
#include "AliFMDReconstParticles.h"
#include "AliFMD.h"
#include "AliFMDv1.h"
#include "AliFMDReconstruction.h"
#include "AliRun.h"
#include "AliConfig.h"
#include "AliHeader.h"
#include "AliGenEventHeader.h"

ClassImp(AliFMDReconstruction)

        
//____________________________________________________________________________ 

AliFMDReconstruction::AliFMDReconstruction():TTask("AliFMDReconstruction","") 
{
  fNevents = 0 ;  // Number of events to rreconnstraction, 0 means all events in current file
  fRunLoader = 0x0;
  
}
//____________________________________________________________________________ 

AliFMDReconstruction::AliFMDReconstruction(AliRunLoader* rl):TTask("AliFMDReconstruction","")
{

  if (rl == 0x0)
   {
     Fatal("AliFMDReconstruction","Argument AliRunLoader* is null!");
     return;
   }
   
  fNevents = 0 ;    // Number of events to rreconnstraction, 0 means all events in current file

  fRunLoader = rl;
  AliLoader* gime = fRunLoader->GetLoader("FMDLoader");
  if (gime == 0x0)
   {
     Fatal("AliFMDReconstruction","Can not find FMD (loader) in specified event");
     return;//never reached
   }
  //add Task to //root/Tasks folder
  gime->PostReconstructioner(this);
}

//____________________________________________________________________________ 

AliFMDReconstruction::~AliFMDReconstruction()
{
}

//____________________________________________________________________________

void AliFMDReconstruction::Exec() 
{ 
 //Collects all digits in the same active volume into number of particles
  /*
    Reconstruct number of particles 
    in given group of pads for given FMDvolume
    determine by numberOfVolume , 
    numberOfMinSector,numberOfMaxSector,
    numberOfMinRing, numberOgMaxRing
    Reconstruction method choose dependence on number of empty pads  
  */


  cout<<"\nStart AliFMDReconstruction::Exec(...)"<<endl;
  Int_t const knumVolumes=5;
  Int_t padADC;
  Float_t eta, etain,etaout,rad,theta;
  Int_t ivol, iSector, iRing;
  Float_t rin[5]={4.2,15.4,4.2,15.4,4.2};
  Float_t rout[5]={17.4,28.4,17.4,28.4,17.4};
  Float_t z[5]={62.8, 75.2, -83.4, -75.2, -340.};
  Int_t numberOfRings[5]={512,256,512,256,512};
  Int_t numberOfSectors[5]=  {20,40,20,40,20};
  Int_t numberOfEtaIntervals[5];
  // number of ring for boundary 0.1 eta

  
  if (fRunLoader == 0x0)
   {
    Error("Exec","Run Loader loader is NULL - Session not opened");
    return;
   }
 
 
 AliLoader* gime = fRunLoader->GetLoader("FMDLoader");
  if (gime == 0x0)
   {
     Fatal("AliFMDReconstruction","Can not find FMD (loader) in specified event");
     return;//never reached
   }
   
  fRunLoader->LoadgAlice();
  fRunLoader->LoadHeader();
  Int_t retval;
  TDirectory* cwd = gDirectory;
  gDirectory = 0x0;
    Text_t buf1[20];
  TH2F* hTotal[10];
  for (Int_t j=1; j<=5; j++){
    sprintf(buf1,"hTotal%d",j);
    
    hTotal[j] = new TH2F(buf1," Number of primary particles ",
			 numberOfSectors[j-1],1,numberOfSectors[j-1],
			 numberOfRings[j-1],1,numberOfRings[j-1]);
  }   
  gDirectory = cwd;
 
       
  if(fNevents == 0) fNevents=fRunLoader->TreeE()->GetEntries(); 
  cout<<" fNevents "<<fNevents<<endl;
   for(Int_t ievent=0;ievent<fNevents;ievent++)
    { 
      fRunLoader->GetEvent(ievent) ;

      cout<<" ievent "<<ievent<<endl;
    for (Int_t i=0; i<5; i++)
        hTotal[i+1]->Reset();
      
      retval = gime->LoadDigits("READ"); 
      if (retval)
	{
	  Error("Exec","Error occured while loading digits. Exiting.");
	  return;
	}
      
      AliFMD * fFMD = (AliFMD *) gAlice->GetDetector("FMD");
      TClonesArray *fReconParticles=fFMD->ReconParticles();
      TClonesArray *fDigits=fFMD->Digits();
 
      TTree* treeD = gime->TreeD();
      if (treeD == 0x0)
	{
	  Error("Exec","Can not get Tree with Digits. Nothing to reconstruct - Exiting");
	  return;
	}
      
      TBranch *brDigits=0;
	    
      brDigits=treeD->GetBranch("FMD");
      cout<<" brDigits "<<brDigits<<endl;
      if (brDigits) {
	brDigits->SetAddress(&fDigits);
	//        fFMD->SetHitsAddressBranch(brHits);
      }else{
	cerr<<"EXEC Branch FMD digits not found"<<endl;
	return;
      } 
	  
      if(gime->TreeR()==0) gime->MakeTree("R");

      //Make branches
      fFMD->MakeBranch("R");

      
      Int_t zeroADC=6;
 
      AliFMDdigit  *fmdDigit;
       if (fFMD)
	{
	  gime->TreeD()->GetEvent(0); 
	  	  
	  Int_t nDigits=fDigits->GetEntries();
	  cout<<" nDigits "<<nDigits<<endl;
	  Int_t recParticles[6];
	  Int_t nRecPart=0 ;
	   Int_t zeroPads=0;
	   Int_t numberOfPads=0; //To avoid warning
	   Int_t pedestal;
	   Float_t channelWidth=(22400*50)/1024;
	   for (Int_t digit=0;digit<nDigits;digit++) 
	     {
	       fmdDigit=(AliFMDdigit*)fDigits->UncheckedAt(digit);    
	       ivol=fmdDigit->Volume();
	       iSector=fmdDigit->NumberOfSector();
	       iRing=fmdDigit->NumberOfRing();
	       pedestal=Int_t(gRandom->Gaus(500,250));
	       padADC= fmdDigit->ADCsignal()
		 -Int_t(Float_t(pedestal)/channelWidth);
	       if (padADC<0) padADC=0;
              hTotal[ivol]->Fill(iSector,iRing,padADC);
 	     } //digit loop
	   Int_t rmin=0; Int_t rmax=0; //To avoid warning
	   Int_t smin=0; Int_t smax=0; //To avoid warning
	   AliHeader *header = fRunLoader->GetHeader();
	   AliGenEventHeader* genHeader = header->GenEventHeader();
	   TArrayF *o = new TArrayF(3); 
	   genHeader->PrimaryVertex(*o);
	   Float_t zVertex=o->At(2);
 	   for (ivol=0; ivol<knumVolumes; ivol++)
	     {
               Float_t ring2number=Float_t (numberOfRings[ivol])/
                 (rout[ivol]-rin[ivol]);
               Float_t realZ=zVertex+z[ivol];
               theta=TMath::ATan(rout[ivol]/TMath::Abs(realZ));
               etain = - TMath::Log( TMath::Tan(theta/2.));
               theta=TMath::ATan(rin[ivol]/TMath::Abs(realZ));
               etaout=- TMath::Log( TMath::Tan(theta/2.));
               numberOfEtaIntervals[ivol]=(etaout-etain)*10-1;
               eta=etain;
               for (Int_t e1=0;e1<=numberOfEtaIntervals[ivol];e1++) 
                 {
                   theta = 2.*TMath::ATan (TMath::Exp (-eta));
                   Float_t radmin = TMath::Abs(realZ) * (TMath::Tan (theta));
                   rmax= Int_t ( (radmin-rin[ivol])*ring2number+0.5);
                   cout<<ivol<<" "<<" eta "<<eta<<" radmin "<<radmin<<

                     " Rmax "<<rmax<<" "<<endl;;
                   eta=eta+0.1;
                   theta = 2.*TMath::ATan (TMath::Exp (-eta));
                   rad = TMath::Abs(realZ) * (TMath::Tan (theta));
                   rmin=Int_t( (rad-rin[ivol])*ring2number+0.5);
                   cout<<"eta "<<eta<<" rad "<<rad<<" Rmin "<<rmin<<endl;
                   //      if(ivol==2&&e1==13) rmin=0;
                   zeroPads=0;
                   smin=0;
                   smax=numberOfSectors[ivol]; 
                   numberOfPads=(rmax-rmin)*(smax-smin);
                   for (Int_t iring=rmin; iring<rmax; iring++) 
                     {
                       for 
                         (Int_t isector=0;
                          isector<numberOfSectors[ivol]; 
                          isector++) 
                         {
			   if(hTotal[ivol+1]->GetBinContent(isector+1,iring+1)
                            <zeroADC) zeroPads++;}

                     } //ring
                   Float_t numberOfPads=Float_t(smax-smin)*Float_t(rmax-rmin);

                   cout<<" zero "<<zeroPads++<<" pads "<<numberOfPads;
                   Double_t lambda=-TMath::Log(Double_t(zeroPads)/numberOfPads);
                   Int_t fRecon=(lambda*numberOfPads+0.5);
                   
                   Float_t zerosRatio= 
                     (Float_t)zeroPads/(Float_t)numberOfPads;
                   cout<<" zerosRatio "<<zerosRatio<<" recon "<<fRecon<<endl;
                   recParticles[0]=ivol+1;
                   recParticles[1]=smin;
                   recParticles[2]=smax;
                   recParticles[3]=rmin;
                   recParticles[4]=rmax;
                   recParticles[5]= fRecon;
                   new((*fReconParticles)[nRecPart++]) 
                     AliFMDReconstParticles(recParticles);             


		 } // eta
	     } // volume
	   
	}//if FMD
       gime->TreeR()->Reset();
       gime->TreeR()->Fill(); 
       gime->WriteRecPoints("OVERWRITE");
    } //event loop
  cout<<"\nAliFMDReconstruction::Exec finished"<<endl;
}