/* Copyright (C) 2010-2020 Frankfurt Institute for Advanced Studies, Goethe-Universitaet Frankfurt, Frankfurt
   SPDX-License-Identifier: GPL-3.0-only
   Authors: I.Kisel,  S.Gorbunov, Igor Kulakov [committer], Maxim Zyzak */

/*
 *====================================================================
 *
 *  CBM Level 1 Reconstruction 
 *  
 *  Authors: I.Kisel,  S.Gorbunov
 *
 *  e-mail : ikisel@kip.uni-heidelberg.de 
 *
 *====================================================================
 *
 *  L1 Monte Carlo information
 *
 *====================================================================
 */

#include "CbmL1MCTrack.h"

#include "CbmL1.h"
#include "CbmL1Constants.h"

#include "L1Algo/L1Algo.h"
#include "L1Algo/L1StsHit.h"

CbmL1MCTrack::CbmL1MCTrack(double mass_, double q_, TVector3 vr, TLorentzVector vp, int _ID, int _mother_ID, int _pdg)
  : mass(mass_)
  , q(q_)
  , p(0)
  , x(0)
  , y(0)
  , z(0)
  , px(0)
  , py(0)
  , pz(0)
  , time(0)
  , ID(_ID)
  , iFile(0)
  , iEvent(0)
  , mother_ID(_mother_ID)
  , pdg(_pdg)
  , Points()
  , StsHits()
  , nMCContStations(0)
  , nHitContStations(0)
  , maxNStaMC(0)
  , maxNSensorMC(0)
  , maxNStaHits(0)
  , nStations(0)
  , nMCStations(0)
  , isReconstructable(0)
  , isAdditional()
  , rTracks()
  , tTracks()
{
  x  = vr.X();
  y  = vr.Y();
  z  = vr.Z();
  px = vp.Px();
  py = vp.Py();
  pz = vp.Pz();
  p  = sqrt(fabs(px * px + py * py + pz * pz));
};

// CbmL1MCTrack::CbmL1MCTrack(TmpMCPoints &mcPoint, TVector3 vr, TLorentzVector vp, int ID, int mother_ID):
//      ID(_ID), mother_ID(_mother_ID)
// {
//   mass = mcPoint->mass;
//   q = mcPoint->q;
//   pdg  = mcPoint->pdg;
//
//   x = vr.X();
//   y = vr.Y();
//   z = vr.Z();
//   px = vp.Px();
//   py = vp.Py();
//   pz = vp.Pz();
//   p = sqrt( fabs(px*px + py*py + pz*pz ));
// };

void CbmL1MCTrack::Init()
{
  CbmL1* L1 = CbmL1::Instance();
  // get stsHits
  StsHits.clear();
  for (unsigned int iP = 0; iP < Points.size(); iP++) {
    CbmL1MCPoint* point = &(L1->vMCPoints[Points[iP]]);
    for (unsigned int iH = 0; iH < point->hitIds.size(); iH++) {
      const int iih = point->hitIds[iH];
      if (std::find(StsHits.begin(), StsHits.end(), iih) == StsHits.end()) StsHits.push_back(iih);
    }
  }

  CalculateMCCont();
  CalculateHitCont();
  CalculateMaxNStaMC();
  CalculateMaxNStaHits();
  CalculateIsReconstructable();
}  // void CbmL1MCTrack::Init()


float CbmL1MCTrack::Fraction_MC()
{
  //     if ( Points.size() == 0 ) return 0;

  CbmL1* L1   = CbmL1::Instance();
  int counter = 0;
  for (unsigned int iP = 0; iP < Points.size(); iP++) {
    if (L1->vMCPoints_in_Time_Slice[Points[iP]] > 0) counter++;
  };
  return (Points.size() > 0) ? float(counter) / float(Points.size()) : 0;
}


void CbmL1MCTrack::CalculateMCCont()
{
  CbmL1* L1 = CbmL1::Instance();

  int nPoints     = Points.size();
  nMCContStations = 0;
  int istaold = -1, ncont = 0;
  for (int ih = 0; ih < nPoints; ih++) {
    CbmL1MCPoint& h = L1->vMCPoints[Points[ih]];
    int ista        = h.iStation;
    if (ista - istaold == 1) ncont++;
    else if (ista - istaold > 1) {
      if (nMCContStations < ncont) nMCContStations = ncont;
      ncont = 1;
    }
    if (ista <= istaold) continue;  // backward direction
    istaold = ista;
  }
  if (nMCContStations < ncont) nMCContStations = ncont;
};  // void CbmL1MCTrack::CalculateMCCont()

void CbmL1MCTrack::CalculateHitCont()
{
  CbmL1* L1    = CbmL1::Instance();
  L1Algo* algo = L1->algo;

  int nhits        = StsHits.size();
  nHitContStations = 0;
  int istaold = -1, ncont = 0;
  {
    for (int ih = 0; ih < nhits; ih++) {
      int jh            = StsHits[ih];
      const L1StsHit& h = (*algo->vStsHits)[jh];
      int ista          = (*algo->vSFlag)[h.f] / 4;

      if (ista - istaold == 1) ncont++;
      else if (ista - istaold > 1) {
        if (nHitContStations < ncont) nHitContStations = ncont;
        ncont = 1;
      }

      if (!(ista >= istaold)) {  // tracks going in backward direction are not reconstructable
        nHitContStations = 0;
        return;
      }
      if (ista == istaold) continue;  // backward direction
      istaold = ista;
    }
  }
  if (nHitContStations < ncont) nHitContStations = ncont;


};  // void CbmL1MCTrack::CalculateHitCont()

void CbmL1MCTrack::CalculateMaxNStaHits()
{
  CbmL1* L1 = CbmL1::Instance();

  maxNStaHits         = 0;
  nStations           = 0;
  int lastSta         = -1;
  int cur_maxNStaHits = 0;
  for (unsigned int iH = 0; iH < StsHits.size(); iH++) {
    CbmL1HitStore& sh = L1->vHitStore[StsHits[iH]];
    if (sh.iStation == lastSta) { cur_maxNStaHits++; }
    else {                             // new station
      if (!(sh.iStation > lastSta)) {  // tracks going in backward direction are not reconstructable
        maxNStaHits = 0;
        return;
      }
      if (cur_maxNStaHits > maxNStaHits) maxNStaHits = cur_maxNStaHits;
      cur_maxNStaHits = 1;
      lastSta         = sh.iStation;
      nStations++;
    }
  };
  if (cur_maxNStaHits > maxNStaHits) maxNStaHits = cur_maxNStaHits;
  //   cout << pdg << " " << p << " " << StsHits.size() << " > " << maxNStaHits << endl;
};  // void CbmL1MCTrack::CalculateHitCont()

void CbmL1MCTrack::CalculateMaxNStaMC()
{
  CbmL1* L1 = CbmL1::Instance();

  maxNStaMC         = 0;
  maxNSensorMC      = 0;
  nMCStations       = 0;
  int lastSta       = -1;
  float lastz       = -1;
  int cur_maxNStaMC = 0, cur_maxNSensorMC = 0;
  for (unsigned int iH = 0; iH < Points.size(); iH++) {
    CbmL1MCPoint& mcP = L1->vMCPoints[Points[iH]];
    if (mcP.iStation == lastSta) cur_maxNStaMC++;
    else {  // new station
      if (cur_maxNStaMC > maxNStaMC) maxNStaMC = cur_maxNStaMC;
      cur_maxNStaMC = 1;
      lastSta       = mcP.iStation;
      nMCStations++;
    }

    if (mcP.z == lastz)  // TODO: works incorrect because of different z
      cur_maxNSensorMC++;
    else {  // new z
      if (cur_maxNSensorMC > maxNSensorMC) maxNSensorMC = cur_maxNSensorMC;
      cur_maxNSensorMC = 1;
      lastz            = mcP.z;
    }
  };
  if (cur_maxNStaMC > maxNStaMC) maxNStaMC = cur_maxNStaMC;
  if (cur_maxNSensorMC > maxNSensorMC) maxNSensorMC = cur_maxNSensorMC;
  //   cout << pdg << " " << p << " " << Points.size() << " > " << maxNStaMC << " " << maxNSensorMC << endl;
};  // void CbmL1MCTrack::CalculateMaxNStaMC()


void CbmL1MCTrack::CalculateIsReconstructable()
{
  CbmL1* L1 = CbmL1::Instance();

  bool f = 1;

  // reject very slow tracks from analysis
  f &= (p > CbmL1Constants::MinRecoMom);
  // detected at least in 4 stations
  //   f &= (nMCContStations >= 4);

  // maximul 4 layers for a station.
  //   f &= (maxNStaHits <= 4);
  f &= (maxNStaMC <= 4);
  //   f &= (maxNSensorMC <= 1);
  if (L1->fPerformance == 4)
    isReconstructable = f & (nMCContStations >= CbmL1Constants::MinNStations) & (Fraction_MC() > 0.5);
  if (L1->fPerformance == 3) isReconstructable = f & (nMCContStations >= CbmL1Constants::MinNStations);  // L1-MC
  if (L1->fPerformance == 2) isReconstructable = f & (nStations >= CbmL1Constants::MinNStations);  // QA definition
  if (L1->fPerformance == 1)
    isReconstructable = f & (nHitContStations >= CbmL1Constants::MinNStations);  // L1 definition

  if (Points.size() > 0) {
    isAdditional = f & (nHitContStations == nStations) & (nMCContStations == nStations) & (nMCStations == nStations)
                   & (nHitContStations >= 3) & (L1->vMCPoints[Points[0]].iStation == 0);
    isAdditional &= !isReconstructable;
  }
  else
    isAdditional = 0;
};  // bool CbmL1MCTrack::IsReconstructable()