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

// Panda Headers ----------------------

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

// C/C++ Headers ----------------------
#include <algorithm>
#include <iostream>
#include <assert.h>

// Collaborating Class Headers --------
#include "CbmRootManager.h"
#include "TClonesArray.h"
#include "Track.h"
#include "TpcCluster.h"
#include "TpcPlanarRecoHit.h"

#include "LSLTrackRep.h"
#include "RecoHitFactory.h"
#include "Kalman.h"
#include "FitterExceptions.h"
#include "TH1D.h"
#include "TFile.h"
#include "TGeoTrack.h"
#include "TGeoManager.h"
#include "TLorentzVector.h"
#include "DetPlane.h"

// Class Member definitions -----------


KalmanTask::KalmanTask()
  : CbmTask("Kalman Filter"), _persistence(kFALSE)
{
  _trackBranchName = "TrackPreFit";
}


KalmanTask::~KalmanTask()
{
  if(_pH!=NULL)delete _pH;
  if(_chi2H!=NULL)delete _chi2H;
}

InitStatus
KalmanTask::Init()
{
  //Get ROOT Manager
  CbmRootManager* ioman= CbmRootManager::Instance();

  if(ioman==0)
    {
      Error("KalmanTask::Init","RootManager not instantiated!");
      return kERROR;
    }
  
  // Get input collection
  _trackArray=(TClonesArray*) ioman->GetObject(_trackBranchName);
  
  if(_trackArray==0)
    {
      Error("KalmanTask::Init","track-array not found!");
      return kERROR;
    }
  

  // Build hit factory -----------------------------
  _theRecoHitFactory = new RecoHitFactory();
  TClonesArray* ar=(TClonesArray*) ioman->GetObject("TpcCluster");
   if(ar==0){
     Error("KalmanTask::Init","TpcCluster array not found");
   }
   else{ 
     _theRecoHitFactory->addProducer(2,new RecoHitProducer<TpcCluster,TpcPlanarRecoHit>(ar));
   }
 

  // setup histograms
  _pH=new TH1D("pH","p",100,0.4,0.6);
  _chi2H=new TH1D("chi2H","chi2",100,0,20);
  _massV0=new TH1D("massV0","massV0",100,0,5);
  _massETAC=new TH1D("massEta","massEta",100,2.5,3.5);

  return kSUCCESS;
}


void
KalmanTask::Exec(Option_t* opt)
{
  std::cout<<"KalmanTask::Exec"<<std::endl;
  // Reset output Array
  //if(_trackArray==0) Fatal("Kalman::Exec)","No TrackArray");
  // _trackArray->Delete();

  Int_t ntracks=_trackArray->GetEntriesFast();
  
  if(ntracks>20){
    std::cout<<"ntracks="<<ntracks<<" Evil Event! skipping"<<std::endl;
    return;
  }

  // Fitting ---------------- can go to another task!
  Kalman fitter;

  std::vector<TLorentzVector*> particles;
  std::vector<int> signs;
  
  for(Int_t itr=0;itr<ntracks;++itr){
    std::cout<<"starting track"<<itr<<std::endl;
    Track* trk=(Track*)_trackArray->At(itr);
    // Load RecoHits 
	try {
	  trk->addHitVector(_theRecoHitFactory->createMany(trk->getCand()));
	  std::cout<<trk->getNumHits()<<" hits in track "
			   <<itr<<std::endl;
    }
	catch(FitterException& e) {
	  std::cout << e.what() << std::endl;
	  throw e;
	}
    // Start Fitter
    try{
      std::cout<<"starting fit"<<std::endl;
      fitter.processTrack(trk);
    }
    catch (FitterException e){
      std::cout<<e.what()<<std::endl;
    }

    // Print Track Parameters after fit
    if(trk->getTrackRep(0)->getStatusFlag()==0){
      //trk->getTrackRep(0)->Print();
      DetPlane plane(TVector3(0,0,0.1),TVector3(1,0,0),TVector3(0,1,0));
      TVector3 p3=trk->getTrackRep(0)->getMom(plane);
      double p=trk->getMom().Mag();
      _pH->Fill(p);
      
      TLorentzVector* p4=new TLorentzVector();
      p4->SetXYZM(p3.X(),p3.Y(),p3.Z(),0.493677);
      particles.push_back(p4);
      signs.push_back(trk->getTrackRep(0)->getCharge());

      double chi2=trk->getChiSqu();
      _chi2H->Fill(chi2);

    }

  }

  std::cout<<"Fitting done"<<std::endl;
  if(particles.size()>20)return;
  std::cout<<"Starting Analysis"<<std::endl;

  std::vector<TLorentzVector> V0s;
  // try to reconstruct V0s
  for(int i=0;i<particles.size();++i){
    for(int j=i+1;j<particles.size();++j){
      TLorentzVector v0=*(particles[i])+*(particles[j]);
      V0s.push_back(v0);
      if(signs[i]!=signs[j]){
	_massV0->Fill(v0.M());
      }
    }
    delete particles[i];
  }

  double mphi=1.020;

  // try to build a etac
  for(int i=0;i<V0s.size();++i){
    if(fabs(V0s[i].M()-mphi)>0.03)continue;
    for(int j=i+1;j<V0s.size();++j){
      if(fabs(V0s[j].M()-mphi)>0.03)continue;
      TLorentzVector v0=(V0s[i])+(V0s[j]);
      _massETAC->Fill(v0.M());
    }
  }

  V0s.clear();
  signs.clear();
  particles.clear();

  return;
}

void 
KalmanTask::WriteHistograms(const TString& filename){
  TFile* file = new TFile(filename,"UPDATE");
  file->mkdir("Kalman");
  file->cd("Kalman");

  _pH->Write();
  delete _pH;
  _pH=NULL;

  _chi2H->Write();
  delete _chi2H;
  _chi2H=NULL;

  _massV0->Write();
  delete _massV0;
  _massV0=NULL;

  _massETAC->Write();
  delete _massETAC;
  _massETAC=NULL;

  file->Close();
  delete file;
}


ClassImp(KalmanTask)