//-----------------------------------------------------------
// File and Version Information:
// $Id$
//
// Description:
//      Implementation of class TpcLaserTask
//      see TpcLaserTask.h for details
//
// Environment:
//      Software developed for the PANDA Detector at FAIR.
//
// Author List:
//      Felix Boehmer        TUM            (original author)
//
//
//-----------------------------------------------------------


// This Class' Header ---------------------------------------
#include "TpcNoiseTask.h"

// Collaborating Class Headers --------
#include "FairRootManager.h"
#include "FairRunAna.h"
#include "FairRuntimeDb.h"
#include "TClonesArray.h"
#include "TpcPrimaryCluster.h"
#include "TVector3.h"
#include "TMath.h"
#include "TError.h"
#include "TpcDigiPar.h"
#include "TpcGas.h"
#include "TpcPadPlane.h"

#include <iostream>
#include <string>
#include "TRandom3.h"


TpcNoiseTask::TpcNoiseTask()
  : FairTask("TPC Noise Generator")
{
 
}

TpcNoiseTask::~TpcNoiseTask()
{
  ;  
}

InitStatus
TpcNoiseTask::Init()
{
  //Get ROOT Manager
  FairRootManager* ioman= FairRootManager::Instance();

  if(ioman==0)
    {
      Error("TpcNoiseTask::Init","RootManager not instantiated!");
      return kERROR;
    }
  // Get input collection
  fprimArray=(TClonesArray*) ioman->GetObject("TpcPrimaryCluster");
  
  if(fprimArray==0)
    {
      Error("TpcNoiseTask::Init","PrimaryElectron-array not found!");
      return kERROR;
    }

  //clear input array of any real "physical" hits
  fprimArray->Delete();

  fGas=fpar->getGas();

   //calculate number of voxels:
  unsigned int nPads = fpar->getPadPlane()->GetNPads();
  double rate = fpar->getRate() * 1.0E6;
  double dz = fpar->getZMax() - fpar->getZGem();  //cm
  double vDrift = fGas->VDrift()*1.0E-9; //cm/s
  double tDrift = dz/vDrift;
  unsigned int nSamples = tDrift * rate;
  fVox = nSamples * nPads;
  std::cout<<"***** TpcNoiseTask: Normalizing to "
	   <<fVox<<" voxels in the TPC"<<std::endl;

  return kSUCCESS;
}



void 
TpcNoiseTask::SetParContainers() {

  std::cout<<"TpcNoiseTask::SetParContainers"<<std::endl;
  std::cout.flush();

  // Get run and runtime database
  FairRun* run = FairRun::Instance();
  if ( ! run ) Fatal("SetParContainers", "No analysis run");

  FairRuntimeDb* db = run->GetRuntimeDb();
  if ( ! db ) Fatal("SetParContainers", "No runtime database");

  // Get Tpc digitisation parameter container
  fpar = (TpcDigiPar*) db->getContainer("TpcDigiPar");
  if (! fpar ) Fatal("SetParContainers", "TpcDigiPar not found");
  
  
}



void
TpcNoiseTask::Exec(Option_t* opt)
{  
 
  
  //Int_t nPrim = fprimArray->GetEntriesFast();
  int nNoise=(int)floor(fOcc*fVox);
  std::cout<<"nNoise: "    <<nNoise<<std::endl;
     
  TRandom3 randm(0);
  TVector3 pos(1,0,0);

  // charge W is given in eV -> convert deposited Energy from keV to eV
  double b=1000.*fmeanEnergy;
  unsigned int totalNoise(0);
  while(nNoise>0){
    // position:
    double z=randm.Uniform(fpar->getZGem(),fpar->getZMax());
    double r=randm.Uniform(fpar->getRMin(),fpar->getRMax());
    double phi=randm.Uniform(0,2*TMath::Pi());
    pos.SetZ(z);pos.SetPerp(r);pos.SetPhi(phi);
    // charge W is given in eV -> has been convert to keV above
    unsigned int q=(unsigned int)ceil(randm.Exp(b)/fGas->W());
    totalNoise+=q;
    unsigned int nPrim = fprimArray->GetEntriesFast();
    new((*fprimArray)[nPrim]) TpcPrimaryCluster(0,q,pos,9999,1,-1);
    
    nNoise--;
    if(nNoise%1000 == 0) {
      std::cout<<". ";
      std::cout.flush();
    }

  }
  std::cout<<" created "<< totalNoise <<" noise electrons"<<std::endl;
     
}
    
ClassImp(TpcNoiseTask)