//
// Initialize the links between tracks and silicon hits and intersections
// after the track block and svx data blocks have been made.
// This block is off be default.  To get it, use makeTrackLinks set t
//
// This block needs the track block to have been requested, and then also
// SvxDataBlock
//
// Aaron Dominguez (LBL) 6 Nov 2002
//

#include "Stntuple/obj/TStnEvent.hh"
#include "Stntuple/obj/TStnDataBlock.hh"
#include "Stntuple/obj/TStnTrackBlock.hh"
#include "Stntuple/obj/TSvxDataBlock.hh"
#include "Stntuple/obj/TStnTrackLinkBlock.hh"
#include "Stntuple/mod/InitStntupleDataBlocks.hh"
#include "Stntuple/mod/SiHitLookup.hh"

#include "TrackingObjects/SiData/SiHit.hh"
#include "TrackingObjects/SiData/SiHitSet.hh"
#include "TrackingObjects/Tracks/CdfTrack.hh"
#include "SiliconGeometry/SiDigiCode.hh"
#include "TrackingUserHL/Utility/CorrectedHitLocations.hh"
#include "STLExtensions/VectIndexedMap.hh"
#include "AbsEnv/AbsEnv.hh"

#include "TVector3.h"

#include <vector>
#include <algorithm>

Int_t StntupleTrackLinkBlockLinks(TStnDataBlock* Block, AbsEvent* Event, int Mode) {
  // First get the various blocks.  If not there, bail out
  TStnTrackBlock*     tdata;
  tdata = (TStnTrackBlock* )     Block->GetEvent()->GetDataBlock("TrackBlock");
  if (! tdata) return -1;

  TStnTrackLinkBlock* tlink;
  tlink = (TStnTrackLinkBlock* ) Block->GetEvent()->GetDataBlock("TrackLinkBlock");
  if (! tlink) return -1;

  TSvxDataBlock*      sdata;
  sdata = (TSvxDataBlock* )      Block->GetEvent()->GetDataBlock("SvxDataBlock");
  if (! sdata) return -1;

  EventRecord::ConstIterator it(Event,"SiHitSet");
  if (! it.is_valid()) { // No hit list.  Go home
    return -1;
  }
  SiHitSet_ch sh(it);
  

  // Loop over Pasha's tracks and make links to SvxDataBlock and/or SiIsectBlock
  tlink->SiHitLinkTrk()->Init(tdata->NTracks());
  for (int itrk=0; itrk<tdata->NTracks(); ++itrk) {
    const CdfTrack *t=tdata->Track(itrk)->GetCdfTrack();
    if (!t) continue;

    // Loop over any silicon hits on this track and make cross links
    if ( sh->contents().size()>0 ) {
      tlink->SiHitLinkTrk()->InitLinks(itrk);
      for (CdfTrack::SiHitIterator si=t->beginSIHits(); si!=t->endSIHits(); ++si){
	// Dig out the index into the TClonesArray of TStnSiHits
	SiDigiCode digi=(*si)->getSiDigiCode();
	SiHitSet::const_digi_iterator di=sh->contents().find(digi);

	if ( di != sh->contents().end()) {
	  SiHitSet::const_iterator i = std::find((*di).second.begin(),(*di).second.end(),
						 (*si));
	  if (i != (*di).second.end()) {
	    int index = sh->index(di,i).vectorIndex();
	    int vecsize = (*di).second.size();

	    if (index>=0 && index<vecsize) { // We finally have the correct SiHit index!
	      SiHitLookup* sdata_fid = (SiHitLookup*) sdata->fId;
	      int ihit = sdata_fid->map[digi][index]; // Index into TClonesArray.
	      tlink->SiHitLinkTrk()->Add(itrk,ihit);

	      // Correct the hit's global location for wafer bows & misalignments
	      CorrectedHitLocations corrHit(*t, **si);
	      sdata->SiHit(ihit)->fGlobal = TVector3(corrHit.getHitGlobal().x(),
						     corrHit.getHitGlobal().y(),
						     corrHit.getHitGlobal().z());
	    }
	  }
	}
      }
    }
    
    // Loop over any track intersections is now done in StntupleSiIsectBlockLinks
    // for speed and convenience.
  }
  return 0;
}