///////////////////////////////////////////////////////////////////////////////
// export CTEQ6_DATA=/home/murat/4.10.4/cteq6/data
//
// assume that we're not changing Pt's, just eta's
///////////////////////////////////////////////////////////////////////////////
TStnAna*              x     = 0;
TChain*               chain = 0;
TStnGeneratorModule*  m_pyt = 0;
TTauMcAnaModule*      m_tmc = 0;
TG3Pythia6*           py    = 0;
TInterpreter*         ti    = 0;

void pythia_ana(const char* Process, 
		Int_t       PdfSet, 
		Int_t       NEvents = 1000, 
		Int_t       SaveHist = 1) {
//-----------------------------------------------------------------------------
//  use Pythia to generate input events, talk to Pythia to select a process
//  known channels: "wtaunu"
//-----------------------------------------------------------------------------
  char   script[200], script_dir[50] = "Electroweak/pythia/scripts";

  py = TG3Pythia6::Instance();
  ti = gInterpreter;

  sprintf(script,"%s/%s/%s.C",gSystem->Getenv("SRT_LOCAL"),script_dir,Process);
  if (strcmp(Process,"wtaunu") == 0) {
//-----------------------------------------------------------------------------
//  initialize W -> tau nu process
//-----------------------------------------------------------------------------
    ti->ExecuteMacro(script);
  }
  else if (strcmp(Process,"wenu") == 0) {
    ti->ExecuteMacro(script);
    py->SetMSTP(111, 0);	// turn off fragmentation
  }
  else if (strcmp(Process,"wmunu") == 0) {
    ti->ExecuteMacro(script);
    py->SetMSTP(111, 0);	// turn off fragmentation
  }
  else if (strcmp(Process,"zee") == 0) {
    ti->ExecuteMacro(script);
    py->SetMSTP(111, 0);	// turn off fragmentation
  }
  else if (strcmp(Process,"zmumu") == 0) {
    ti->ExecuteMacro(script);
    py->SetMSTP(111, 0);	// turn off fragmentation
  }
  else {
    printf(" unknown process: %s, exit\n",Process);
    return;
  }
//-----------------------------------------------------------------------------
// PDF's: 10000*MSTP(52)+MSTP(51), for CTEQ6   : 30200-30241
//                                     CTEQ5L  : 24046
//                                     MRST2003: 40001-40002
//-----------------------------------------------------------------------------
  int mstp_52 = PdfSet/10000;
  int mstp_51 = PdfSet%10000;

  py->SetMSTP(52,mstp_52);		// use CTEQ6
  py->SetMSTP(51,mstp_51);	        // best fit function
//-----------------------------------------------------------------------------
  m_pyt = new TStnGeneratorModule(py);
  m_tmc = new TTauMcAnaModule();

  chain = new TChain("STNTUPLE");
  x     = new TStnAna();

  x->SetInputModule(m_pyt);
  x->AddModule(m_tmc,0);	// no filtering


  //  m_pyt->SetEnergy(1960.); // - this is the default
//-----------------------------------------------------------------------------
// passing values using env
//-----------------------------------------------------------------------------
  const char* var;
  var = gSystem->Getenv("MIN_LOOSE_ELE_PT");
  if (var) m_tmc->SetMinLooseElePt (atof(var));
  var = gSystem->Getenv("MAX_LOOSE_ELE_ETA");
  if (var) m_tmc->SetMaxLooseEleEta(atof(var));

  var = gSystem->Getenv("MIN_TIGHT_ELE_PT");
  if (var) m_tmc->SetMinTightElePt (atof(var));
  var = gSystem->Getenv("MAX_TIGHT_ELE_ETA");
  if (var) m_tmc->SetMaxTightEleEta(atof(var));

  var = gSystem->Getenv("MIN_TIGHT_MUO_PT");
  if (var) m_tmc->SetMinTightMuoPt (atof(var));
  var = gSystem->Getenv("MAX_TIGHT_MUO_ETA");
  if (var) m_tmc->SetmaxTightMuoEta(atof(var));

  var = gSystem->Getenv("MIN_LOOSE_MUO_PT");
  if (var) m_tmc->SetMinLooseMuoPt (atof(var));
  var = gSystem->Getenv("MAX_LOOSE_MUO_ETA");
  if (var) m_tmc->SetMaxLooseMuoEta(atof(var));

  var = gSystem->Getenv("MIN_TIGHT_TAU_PT");
  if (var) m_tmc->SetMinTightTauPt (atof(var));
  var = gSystem->Getenv("MAX_TIGHT_TAU_ETA");
  if (var) m_tmc->SetMaxTightTauEta(atof(var));

  var = gSystem->Getenv("MIN_LOOSE_TAU_PT");
  if (var) m_tmc->SetMinLooseTauPt (atof(var));
  var = gSystem->Getenv("MAX_LOOSE_TAU_ETA");
  if (var) m_tmc->SetMaxLooseTauEta(atof(var));
//-----------------------------------------------------------------------------
// run
//-----------------------------------------------------------------------------
  x->Run(NEvents);

  if (SaveHist) {
    x->SaveHist(Form("%s.pythia_ana.%05i.%i.root",Process,PdfSet,NEvents));
  }
}