/**
 * \file LitTrackSelection.h
 *
 * \brief Implementation of the track selection algorithms.
 *
 * \author Andrey Lebedev <andrey.lebedev@gsi.de>
 * \date 2010
 *
 */
#ifndef LITTRACKSELECTION_H_
#define LITTRACKSELECTION_H_

#include "LitScalTrack.h"

#include <vector>
#include <set>
#include <utility>
#include <functional>
#include <algorithm>

using std::sort;
using std::pair;
using std::set;
using std::equal_range;

namespace lit {
namespace parallel {


void DoSortNofHits(
      vector<LitScalTrack*>& tracks)
{
   sort(tracks.begin(), tracks.end(), CompareLitScalTrackNofHitsMore());

   unsigned int maxNofHits = tracks.front()->GetNofHits();
   unsigned int minNofHits = tracks.back()->GetNofHits();

   for (unsigned int iNofHits = minNofHits; iNofHits <= maxNofHits; iNofHits++) {
      LitScalTrack value;
      value.SetNofHits(iNofHits);

      pair<vector<LitScalTrack*>::iterator, vector<LitScalTrack*>::iterator > bounds;
      bounds = equal_range(tracks.begin(), tracks.end(), &value, CompareLitScalTrackNofHitsMore());

      if(bounds.first == bounds.second) { continue; }

      sort(bounds.first, bounds.second, CompareLitScalTrackChiSqOverNdfLess());
   }
}

void DoSortLastStation(
      vector<LitScalTrack*>& tracks)
{
   sort(tracks.begin(), tracks.end(), CompareLitScalTrackLastStationIdMore());

   unsigned int maxPlaneId = tracks.front()->GetLastStationId();
   unsigned int minPlaneId = tracks.back()->GetLastStationId();

   for (unsigned int iPlaneId = minPlaneId; iPlaneId <= maxPlaneId; iPlaneId++) {
      LitScalTrack value;
      value.SetLastStationId(iPlaneId);

      pair<vector<LitScalTrack*>::iterator, vector<LitScalTrack*>::iterator > bounds;
      bounds = equal_range(tracks.begin(), tracks.end(), &value, CompareLitScalTrackLastStationIdMore());

      if(bounds.first == bounds.second) { continue; }

      sort(bounds.first, bounds.second, CompareLitScalTrackChiSqOverNdfLess());
   }
}

void DoSortChiSqOverNDF(
      vector<LitScalTrack*>& tracks)
{
   sort(tracks.begin(), tracks.end(), CompareLitScalTrackChiSqOverNdfLess());
}


void DoSelectSharedHits(
      vector<LitScalTrack*>& tracks)
{
   static const unsigned int NOF_SHARED_HITS = 3;
   if (tracks.empty()) return;

   DoSortNofHits(tracks);

   set<int> hitsId;
//   const int STRIPSTART = 100000;
//   const int TRDSTART = 1000000;

   unsigned int nofTracks = tracks.size();
   for (unsigned int iTrack = 0; iTrack < nofTracks; iTrack++) {
      LitScalTrack* track = tracks[iTrack];

      if (!track->IsGood()) { continue; }

      int nofSharedHits = 0;
      int nofHits = track->GetNofHits();
      for(unsigned int iHit = 0; iHit < nofHits; iHit++) {
         int hitId = track->GetHit(iHit)->refId;
        // LitHitType type = track->GetHit(iHit)->GetType();
        // LitSystemId sysId = track->GetHit(iHit)->GetSystem();
        // if (type == kLITSTRIPHIT) { hitId += STRIPSTART; }
        // if (sysId == kLITTRD) { hitId += TRDSTART; }
         if(hitsId.find(hitId) != hitsId.end()) {
            nofSharedHits++;
            if (nofSharedHits > NOF_SHARED_HITS) {
               track->IsGood(false);
               break;
            }
         }
      }

      if (!track->IsGood()) { continue; }

      for(int iHit = 0; iHit < nofHits; iHit++) {
         int hitId = track->GetHit(iHit)->refId;
         //LitHitType type = track->GetHit(iHit)->GetType();
         //LitSystemId detId = track->GetHit(iHit)->GetSystem();
        // if (type == kLITSTRIPHIT) { hitId += STRIPSTART; }
        // if (detId == kLITTRD) { hitId += TRDSTART; }
         hitsId.insert(hitId);
      }
   }
   hitsId.clear();
}

} // namespace parallel
} // namespace lit
#endif /* LITTRACKSELECTION_H_ */