#ifndef STNTUPLE_PHOTON_TPhotonUtil_hh
#define STNTUPLE_PHOTON_TPhotonUtil_hh

class TStnTrack;
class TStnPhoton;
class TStnPhotonBlock;
class TStnElectron;
class TStnJet;
class TStnEvent;
class TStnTrackBlock;
class TStnTriggerBlock;
class TClonesArray;

class TPhotonUtil: public TObject {

public:

  // match a L2 cluster to a detector eta and phi
  // pass is L2 pass number
  // clusOrIso = 0 = return index to TTl2d::Cluster(i)
  // clusOrIso = 1 = return index to TTl2d::ClusterIso(i)
  static Int_t L2ClusterMatch(Double_t eta, Double_t phi, 
			      TStnTriggerBlock* trigBlock,
			      int pass = 1, int clusOrIso = 0);

  // Correct photon quantites for a new z vertex.  Track list is needed for
  // Track iso, can be retrieved from TrackBlock or set to NULL (iso=999.0)
  static Int_t      SetPhotonZ(TStnPhoton* pho, Double_t z = 0, 
			       TClonesArray* trackList = NULL);
  static Int_t      SetAllPhotonZ(TStnEvent* event, Double_t z = 0);

  //add PPR energy and other corrections for 5.3.3
  // only call this once since it modifies the PhotonBlock contents
  static Int_t      CorrectPhotonEnergy(TStnEvent* event);

  // fix the isolation energy correction vs the number of vertices
  // only for dev_242 and dev_243_01
  // only call this once since it modifies the PhotonBlock contents
  static Int_t      CorrectPhotonIsolation(TStnEvent* event);

  static Double_t   TrkIsoSum1(TStnTrack*    track, 
			       TClonesArray* trackList,
			       Double_t      cone  = 0.4,
			       Double_t      dz    = 5.0, 
			       TStnTrack*    skipTrack = NULL);

  static Double_t   TrkIsoSum0(Double_t phi, Double_t eta, Double_t z, 
			       TClonesArray* trackList,
			       Double_t      cone  = 0.4,
			       Double_t      dz    = 5.0, 
			       TStnTrack*    skipTrack = NULL);

  static Int_t      DumpPhotons(TStnEvent* event, Float_t PhotonEt=0.0);

  static Double_t   ExpectedHadEm(Double_t energy);

  // deltax between expected CPR hit and nearest track
  static Double_t   CprTrack(TStnPhoton* pho, TStnTrackBlock* tblk);

  // returns true if a good vertex was found
  // return false and z=0 if no vertex, false and z=vertex if |z|>60cm.
  // nv12=nzv withclass>12 for jet corr
  static Bool_t     SelectVertex(TStnEvent* event, Float_t& z, Int_t& nv12, 
			int minClass = 12, bool useVxprimToo = false);

  // find matching object
  static TStnJet*      MatchJet(TStnEvent* event, TStnPhoton* pho);
  static TStnElectron* MatchElectron(TStnEvent* event, TStnPhoton* pho);
  static TStnElectron* MatchPhoenixElectron(TStnEvent* event, TStnPhoton* pho);
  static TStnElectron* MatchPhoenixElectron(TStnEvent* event, TStnElectron* ele);
  static TStnPhoton*   MatchPhoton(TStnEvent* event, TStnElectron* pho);

  // number of Phoenix hits in trajectory for a TStnElectron from TPhoenixBlock
  static Int_t        PhoenixHits(TStnEvent* event, TStnElectron* pele, 
				  Int_t& nHit, Int_t& nHitPhi);
  static TStnTrack*   PhoenixTrack(TStnEvent* event, TStnElectron* pele);

  // give this routine an uncorr jet Et and it returns 
  // an array of 15 smeared fake photon Et's and weights
  // for(int i=0; i<15; i++) hist.Fill(quantity such as bgEt[i], bgWht[i]);
  // uses numbers from Helen from 7/2004 (for gen4, dev_240), verified 2/2005
  // mode =0 for central value, -1 for -1sigma, +1 for +1sigma
  static void PhoBgWeights(Float_t jetEt, Float_t* bgEt, Float_t* bgWht, 
			   int mode=0);

  // find the distance to the edge of the hit CPR2 pad
  // zCPR= CDFz at CPR, phiGlobal=CDF phi
  // returns distance to center of nearest pad
  static Int_t cp2_close_pad( Float_t zCPR,  Float_t phiGlobal, 
			      Float_t &delx, Float_t &delz);

  ClassDef(TPhotonUtil,0)
};

#endif