/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                          *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/*
 $Id$ 
*/
/*
 $Log$
 Revision 1.9.8.4  2003/06/13 16:31:00  nilsen
 Introducing a backward incompatibility to hit files created before June 12
 2002. The enterance hit is no longer recorded. The starting position of
 every hit is used instead. Added GetPositionL0 to AliITShit, fixed up
 AliITSmodule to use starting location of hit and not enterance hits, and
 StepManager in AliITSvPPRasymm no longer records enterence hit to hit file.

*/
#include <TArrayI.h>

#include <stdlib.h>

#include "AliRun.h"
#include "AliITS.h"
#include "AliITShit.h"
#include "AliITSmodule.h"
#include "AliITSgeom.h"

ClassImp(AliITSmodule)

//_______________________________________________________________________
//
// Impementation of class AliITSmodule
//
// created by: A. Bouchm, W. Peryt, S. Radomski, P. Skowronski 
//             R. Barbers, B. Batyunia, B. S. Nilsen
// ver 1.0     CERN 16.09.1999
//_______________________________________________________________________
//________________________________________________________________________
// 
// Constructors and deconstructor
//________________________________________________________________________
//
AliITSmodule::AliITSmodule() {
    // constructor

    fHitsM       = 0;
    fTrackIndex  = 0;
    fHitIndex    = 0;
    fITS         = 0;

}
//_________________________________________________________________________
AliITSmodule::AliITSmodule(Int_t index) {
  // constructor

    fIndex      = index;
    fHitsM      = new TObjArray();
    fTrackIndex = new TArrayI(16);
    fHitIndex   = new TArrayI(16);
    fITS        = (AliITS*)(gAlice->GetDetector("ITS"));
}
//__________________________________________________________________________
AliITSmodule::~AliITSmodule() {
    // The destructor for AliITSmodule. Before destoring AliITSmodule
    // we must first destroy all of it's members.

    if(fHitsM){
      fHitsM->Delete();
      delete fHitsM;
      fHitsM = 0;
    } // end if
    delete fTrackIndex;
    delete fHitIndex;
    fITS = 0; // We don't delete this pointer since it is just a copy.
}
//____________________________________________________________________________
AliITSmodule::AliITSmodule(const AliITSmodule &source){
////////////////////////////////////////////////////////////////////////
//     Copy Constructor 
////////////////////////////////////////////////////////////////////////
  Error("AliITSmodule","AliITSmodule class has not to be copied! Exit.");
  exit(1);
}
//_____________________________________________________________________________
AliITSmodule& AliITSmodule::operator=(const AliITSmodule &source){
////////////////////////////////////////////////////////////////////////
//    Assignment operator 
////////////////////////////////////////////////////////////////////////
  Error("AliITSmodule","AliITSmodule class has not to be copied! Exit.");
  exit(1);
  return *this; // fake return neded on Sun
}
//_________________________________________________________________________
// 
// Hits management
//__________________________________________________________________________
Int_t AliITSmodule::AddHit(AliITShit* hit,Int_t t,Int_t h) {
// Hits management

  //printf("AddHit: beginning hit %p t h %d %d\n",hit,t,h);
    fHitsM->AddLast(new AliITShit(*hit));
    Int_t fNhitsM = fHitsM->GetEntriesFast();
    if(fNhitsM-1>=fTrackIndex->GetSize()){ // need to expand the TArrayI
      fTrackIndex->Set(fNhitsM+64);
    } // end if
    if(fNhitsM-1>=fHitIndex->GetSize()){ // need to expand the TArrayI
      fHitIndex->Set(fNhitsM+64);
    } // end if
    (*fTrackIndex)[fNhitsM-1] = t;
    (*fHitIndex)[fNhitsM-1]   = h;
    return fNhitsM;
}
//___________________________________________________________________________
Double_t AliITSmodule::PathLength(Int_t index,AliITShit *itsHit1,
				  AliITShit *itsHit2){
  // path lenght
   Float_t  x1g,y1g,z1g;   
   Float_t  x2g,y2g,z2g;
   Double_t s;

   itsHit1->GetPositionG(x1g,y1g,z1g);
   itsHit2->GetPositionG(x2g,y2g,z2g);

   s = TMath::Sqrt( ((Double_t)(x2g-x1g)*(Double_t)(x2g-x1g)) +
		    ((Double_t)(y2g-y1g)*(Double_t)(y2g-y1g)) +
		    ((Double_t)(z2g-z1g)*(Double_t)(z2g-z1g))  );
   return s;
}
//___________________________________________________________________________
void AliITSmodule::PathLength(Int_t index,
			      Float_t x,Float_t y,Float_t z,
			      Int_t status,Int_t &nseg,
			      Float_t &x1,Float_t &y1,Float_t &z1,
			      Float_t &dx1,Float_t &dy1,Float_t &dz1,
			      Int_t &flag){
  // path length
    static Float_t x0,y0,z0;

    if ((status&0x0002)!=0){ // entering
	x0 = x;
	y0 = y;
	z0 = z;
	nseg = 0;
	flag = 1;
    }else{
	x1 = x0;
	y1 = y0;
	z1 = z0;
	dx1 = x-x1;
	dy1 = y-y1;
	dz1 = z-z1;
	nseg++;
	if ((status&0x0004)!=0) flag = 0; //exiting
	if ((status&0x0001)!=0) flag = 2; // inside
	else flag = 2; //inside ?
	x0 = x;
	y0 = y;
	z0 = z;
    } // end if
}
//___________________________________________________________________________
Bool_t AliITSmodule::LineSegmentL(Int_t hitindex,Double_t &a,Double_t &b,
				  Double_t &c,Double_t &d,
				  Double_t &e,Double_t &f,Double_t &de){
  // line segment
    AliITShit *h1;
    Double_t t;

    if(hitindex>= fHitsM->GetEntriesFast()) return kFALSE;

    h1 = (AliITShit *) (fHitsM->At(hitindex));
    if(h1->StatusEntering()){ // if track entering volume, get index for next
	                      // step
	return kFALSE;
    } // end if StatusEntering()
    // else stepping
    de = h1->GetIonization();
    h1->GetPositionL0(a,c,e,t);
    h1->GetPositionL(b,d,f);
    b = b - a;
    d = d - c;
    f = f - e;
    return kTRUE;
}
//___________________________________________________________________________
Bool_t AliITSmodule::LineSegmentG(Int_t hitindex,Double_t &a,Double_t &b,
				  Double_t &c,Double_t &d,
				  Double_t &e,Double_t &f,Double_t &de){
  // line segment
    AliITShit *h1;
    Double_t t;

    if(hitindex>= fHitsM->GetEntriesFast()) return kFALSE;

    h1 = (AliITShit *) (fHitsM->At(hitindex));
    if(h1->StatusEntering()){ // if track entering volume, get index for next
	                      // step
	return kFALSE;
    } // end if StatusEntering()
    // else stepping
    de = h1->GetIonization();
    h1->GetPositionG0(a,c,e,t);
    h1->GetPositionG(b,d,f);
    b = b - a;
    d = d - c;
    f = f - e;
    return kTRUE;
}
//___________________________________________________________________________
Bool_t AliITSmodule::LineSegmentL(Int_t hitindex,Double_t &a,Double_t &b,
				  Double_t &c,Double_t &d,
				  Double_t &e,Double_t &f,
				  Double_t &de,Int_t &track){
  // line segmente
    AliITShit *h1;
    Double_t t;

    if(hitindex>= fHitsM->GetEntriesFast()) return kFALSE;

    h1 = (AliITShit *) (fHitsM->At(hitindex));
    if(h1->StatusEntering()){ // if track entering volume, get index for next
	                      // step
	track = h1->GetTrack();
	return kFALSE;
    } // end if StatusEntering()
    // else stepping
    de = h1->GetIonization();
    h1->GetPositionL0(a,c,e,t);
    h1->GetPositionL(b,d,f);
    b = b - a;
    d = d - c;
    f = f - e;
    track = h1->GetTrack();
    return kTRUE;
}
//___________________________________________________________________________
Bool_t AliITSmodule::LineSegmentG(Int_t hitindex,Double_t &a,Double_t &b,
				  Double_t &c,Double_t &d,
				  Double_t &e,Double_t &f,
				  Double_t &de,Int_t &track){
  // line segment
    AliITShit *h1;
    Double_t t;

    if(hitindex>= fHitsM->GetEntriesFast()) return kFALSE;

    h1 = (AliITShit *) (fHitsM->At(hitindex));
    if(h1->StatusEntering()){ // if track entering volume, get index for next
	                      // step
	track = h1->GetTrack();
	return kFALSE;
    } // end if StatusEntering()
    // else stepping
    de = h1->GetIonization();
    h1->GetPositionG0(a,c,e,t);
    h1->GetPositionG(b,d,f);
    b = b - a;
    d = d - c;
    f = f - e;
    track = h1->GetTrack();
    return kTRUE;
}
//______________________________________________________________________
Bool_t AliITSmodule::MedianHitG(AliITShit *h1,AliITShit *h2,
				Float_t &x,Float_t &y,Float_t &z){
    // Computes the mean hit location for a set of hits that make up a track
    // passing through a volume. Returns kFALSE untill the the track leaves
    // the volume.
    // median hit
   AliITSgeom *gm = fITS->GetITSgeom();
   Float_t x1l=0.,y1l=0.,z1l=0.;
   Float_t x2l=0.,y2l=0.,z2l=0.;
   Float_t xMl,yMl=0,zMl;
   Float_t l[3], g[3];

   h1->GetPositionG(x1l,y1l,z1l);
   h2->GetPositionG(x2l,y2l,z2l);

   if((y2l*y1l)<0.) {
     xMl = (-y1l / (y2l-y1l))*(x2l-x1l) + x1l;
     zMl = (-y1l / (y2l-y1l))*(z2l-z1l) + z1l;
   } else {
     xMl = 0.5*(x1l+x2l);
     zMl = 0.5*(z1l+z2l);
   }

   l[0] = xMl;
   l[1] = yMl;
   l[2] = zMl;
   gm->LtoG(h1->GetModule(),l,g);
   x = g[0];
   y = g[1];
   z = g[2];
   return kTRUE;
}
//___________________________________________________________________________
void AliITSmodule::MedianHitG(Int_t index,
			      Float_t hitx1,Float_t hity1,Float_t hitz1,
			      Float_t hitx2,Float_t hity2,Float_t hitz2,
			      Float_t &xMg, Float_t &yMg, Float_t &zMg){
  // median hit
   AliITSgeom *gm = fITS->GetITSgeom();
   Float_t x1l,y1l,z1l;
   Float_t x2l,y2l,z2l;
   Float_t xMl,yMl=0,zMl;
   Float_t l[3], g[3];

   g[0] = hitx1;
   g[1] = hity1;
   g[2] = hitz1;
   gm->GtoL(index,g,l);
   x1l = l[0];
   y1l = l[1];
   z1l = l[2];

   g[0] = hitx2;
   g[1] = hity2;
   g[2] = hitz2;
   gm->GtoL(index,g,l);
   x2l = l[0];
   y2l = l[1];
   z2l = l[2];

   if((y2l*y1l)<0.) {
     xMl = (-y1l / (y2l-y1l))*(x2l-x1l) + x1l;
     zMl = (-y1l / (y2l-y1l))*(z2l-z1l) + z1l;
   } else {
     xMl = 0.5*(x1l+x2l);
     zMl = 0.5*(z1l+z2l);
   }

   l[0] = xMl;
   l[1] = yMl;
   l[2] = zMl;
   gm->LtoG(index,l,g);
   xMg = g[0];
   yMg = g[1];
   zMg = g[2];
}
//___________________________________________________________________________
Bool_t AliITSmodule::MedianHitL( AliITShit *itsHit1, 
	       	    	     AliITShit *itsHit2, 
	       		     Float_t &xMl, Float_t &yMl, Float_t &zMl){
  // median hit
   Float_t x1l,y1l,z1l;
   Float_t x2l,y2l,z2l;

   itsHit1->GetPositionL(x1l,y1l,z1l);
   itsHit2->GetPositionL(x2l,y2l,z2l);

   yMl = 0.0;
   if((y2l*y1l)<0.) {
     xMl = (-y1l / (y2l-y1l))*(x2l-x1l) + x1l;
     zMl = (-y1l / (y2l-y1l))*(z2l-z1l) + z1l;	     
   } else {
     xMl = 0.5*(x1l+x2l);
     zMl = 0.5*(z1l+z2l);
   }
   return kTRUE;
}
//___________________________________________________________________________
void AliITSmodule::MedianHit(Int_t index,
			     Float_t xg,Float_t yg,Float_t zg,
			     Int_t status,
			     Float_t &xMg,Float_t &yMg,Float_t &zMg,
			     Int_t &flag){
  // median hit
   static Float_t x1,y1,z1;

   if ((status&0x0002)!=0){ // entering
       x1 = xg;
       y1 = yg;
       z1 = zg;
       flag = 1;
   } else if ((status&0x0004)!=0){ // exiting
       MedianHitG(index,x1,y1,z1,xg,yg,zg,xMg,yMg,zMg);
       flag = 0;
   } // end if
   else  flag = 1;
}
//___________________________________________________________________________
void AliITSmodule::GetID(Int_t &lay,Int_t &lad,Int_t &det){
  // get ID
	fITS->GetITSgeom()->GetModuleId(fIndex,lay,lad,det);
	return ;
}