/**
*  $Id: CbmRichRingFinderIdeal.cxx,v 1.5 2006/02/01 13:16:58 hoehne Exp $
*
*  Class  : CbmRichRingFinderIdeal
*  Description: This is the implementation of the Ideal RichRingFinder. This
*               takes the Rich hits and associates them with the MC Track.
*
*  Author : Supriya Das
*  E-mail : S.Das@gsi.de
*
*/
#include "CbmRichRingFinderIdeal.h"

#include "CbmRichHit.h"
#include "CbmRichRing.h"
#include "CbmRichPoint.h"
#include "CbmMCTrack.h"
#include "FairRootManager.h"

#include "TClonesArray.h"

#include <iostream>
#include <map>

using std::cout;
using std::endl;
using std::map;


CbmRichRingFinderIdeal::CbmRichRingFinderIdeal():
   fRichPoints(NULL),
   fMcTracks(NULL)
{

}

CbmRichRingFinderIdeal::~CbmRichRingFinderIdeal()
{

}

void CbmRichRingFinderIdeal::Init()
{
   FairRootManager* ioman = FairRootManager::Instance();
   if (NULL == ioman) {Fatal("CbmRichRingFinderIdeal::Init","RootManager is NULL!");}

   fMcTracks  = (TClonesArray*) ioman->GetObject("MCTrack");
   if (NULL == fMcTracks) {Fatal("CbmRichRingFinderIdeal::Init","No MCTrack array!");}

   fRichPoints  = (TClonesArray*) ioman->GetObject("RichPoint");
   if (NULL == fRichPoints) {Fatal("CbmRichRingFinderIdeal::Init","No RichPoint array!");}
}

Int_t CbmRichRingFinderIdeal::DoFind(
      TClonesArray* hitArray,
      TClonesArray* projArray,
		TClonesArray* ringArray)
{
   if ( NULL == hitArray) {
      cout << "-E- CbmRichRingFinderIdeal::DoFind, RichHit array missing!" << endl;
      return -1;
   }

   if ( NULL == ringArray ) {
      cout << "-E- CbmRichRingFinderIdeal::DoFind, Ring array missing!" << endl;
      return -1;
   }

   // Create STL map from MCtrack index to number of valid RichHits
   map<Int_t, Int_t> hitMap;
   Int_t nRichHits = hitArray->GetEntriesFast();
   for (Int_t iHit = 0; iHit < nRichHits; iHit++) {
      CbmRichHit* pRhit = (CbmRichHit*) hitArray->At(iHit);
      if ( NULL == pRhit ) continue;
      Int_t ptIndex = pRhit->GetRefId();
      if (ptIndex < 0) continue; // fake or background hit
      CbmRichPoint* pMCpt = (CbmRichPoint*) (fRichPoints->At(ptIndex));
      if ( NULL == pMCpt ) continue;
      Int_t mcTrackIndex = pMCpt->GetTrackID();
      if ( mcTrackIndex < 0 ) continue;
      CbmMCTrack* pMCtr = (CbmMCTrack*) fMcTracks->At(mcTrackIndex);
      if ( NULL == pMCtr ) continue;
      if ( pMCtr->GetPdgCode() != 50000050) continue; // select only Cherenkov photons
      Int_t motherId = pMCtr->GetMotherId();
      hitMap[motherId]++;
   }

   // Create STL map from MCTrack index to RichRing index
   map<Int_t, Int_t> ringMap;

   // Create RICHRings for MCTracks
   Int_t nRings  = 0; // number of RichRings
   Int_t nMCTracks = fMcTracks->GetEntriesFast();
   for (Int_t iMCTrack = 0; iMCTrack < nMCTracks; iMCTrack++) {
      CbmMCTrack* pMCtr = (CbmMCTrack*) fMcTracks->At(iMCTrack);
      if ( NULL == pMCtr ) continue;

      new((*ringArray)[nRings]) CbmRichRing();
      ringMap[iMCTrack] = nRings++;
   }

   // Loop over RichHits. Get corresponding MCPoint and MCTrack index
   for (Int_t iHit = 0; iHit < nRichHits; iHit++) {
      CbmRichHit* pRhit = (CbmRichHit*) hitArray->At(iHit);
      if ( NULL == pRhit ) continue;

      Int_t ptIndex = pRhit->GetRefId();

      if (ptIndex < 0) continue;// fake or background hit
      CbmRichPoint* pMCpt = (CbmRichPoint*) fRichPoints->At(ptIndex);
      if ( NULL == pMCpt ) continue;

      Int_t mcTrackIndex = pMCpt->GetTrackID();
      if ( mcTrackIndex < 0) continue;
      CbmMCTrack* pMCtr = (CbmMCTrack*) fMcTracks->At(mcTrackIndex);
      if ( NULL == pMCtr ) continue;
      if ( pMCtr->GetPdgCode() != 50000050) continue;
      Int_t motherId = pMCtr->GetMotherId();

      if (motherId < 0 || motherId > nMCTracks) continue;

      if (ringMap.find(motherId) == ringMap.end()) continue;

      Int_t ringIndex = ringMap[motherId];

      CbmRichRing* pRing = (CbmRichRing*) ringArray->At(ringIndex);
      if ( NULL == pRing ) continue;

      pRing->AddHit(iHit); // attach the hit to the ring
   }

   cout << "-I- CbmRichRingFinderIdeal: all " << nMCTracks << ", rec. " << nRings << endl;

   return nRings;
}