/****************************************************************************
 *           Origin: I.Belikov, CERN, Jouri.Belikov@cern.ch                 *
 ****************************************************************************/

#if !defined(__CINT__) || defined(__MAKECINT__)
  #include <iostream.h>
  #include "AliTPCParam.h"
  #include "AliTPCtracker.h"
  #include "AliTPCpidESD.h"
  #include "AliRun.h"
  #include "AliMagF.h"
  #include "AliRunLoader.h"
  #include "AliTPCLoader.h"
  #include "AliESDpid.h"
  #include "AliESD.h"

  #include "TFile.h"
  #include "TStopwatch.h"
#endif

extern AliRun *gAlice;

Int_t AliTPCFindTracks(Int_t nev=5) {

   cerr<<"Looking for tracks...\n";

   if (gAlice) {
     delete gAlice->GetRunLoader();
     delete gAlice;
     gAlice = 0x0;
   }

   AliRunLoader *rl = AliRunLoader::Open("galice.root");
   if (rl == 0x0) {
      cerr<<"Can not open session"<<endl;
      return 1;
   }

   AliTPCLoader *tpcl = (AliTPCLoader*)rl->GetLoader("TPCLoader");
   if (tpcl == 0x0) {
      cerr<<"Can not get TPC Loader"<<endl;
      return 1;
   }
   
   if (rl->LoadgAlice()) {
      cerr<<"Error occured while loading gAlice"<<endl;
      return 1;
   }

   AliKalmanTrack::SetConvConst(
     1000/0.299792458/rl->GetAliRun()->Field()->SolenoidField()
   );

   rl->CdGAFile();
   AliTPCParam *dig=(AliTPCParam *)gDirectory->Get("75x40_100x60_150x60");
   if (!dig) { 
        cerr<<"TPC parameters have not been found !\n";
        return 1;
   }

   //rl->UnloadgAlice();   

   tpcl->LoadRecPoints("read");

   if (nev>rl->GetNumberOfEvents()) nev=rl->GetNumberOfEvents();
    
   TFile *ef=TFile::Open("AliESDtpc.root","RECREATE");
   if ((!ef)||(!ef->IsOpen())) {
      cerr<<"Can't AliESDtpc.root !\n"; return 1;
   }
   TStopwatch timer;
   Int_t rc=0;
   AliTPCtracker tracker(dig);
   //An instance of the TPC PID maker
   Double_t parTPC[]={45.0,0.08,10.}; // normalization constants,
                                      // see AliTPCpidESD class
   AliTPCpidESD tpcPID(parTPC);
   for (Int_t i=0;i<nev;i++){
     printf("Processing event %d\n",i);
     AliESD *event=new AliESD(); 
     rl->GetEvent(i);

     TTree *in=tpcl->TreeR();
     if (!in) {
        cerr<<"Can't get clusters tree !\n";
        return 4;
     }

     tracker.LoadClusters(in);
     rc=tracker.Clusters2Tracks(event);
     tpcPID.MakePID(event);                 // Preliminary PID
     AliESDpid::MakePID(event);             // for the ITS tracker
     tracker.UnloadClusters();

     if (rc==0) {
        Char_t ename[100]; 
        sprintf(ename,"%d",i);
        ef->cd();
        if (!event->Write(ename)) rc++;
     } 
     if (rc) {
        cerr<<"Something bad happened...\n";
     }
     delete event;
   }

   timer.Stop(); timer.Print();
 
   ef->Close();

   delete dig; //Thanks to Mariana Bondila

   delete rl;

   return rc;
}