/**************************************************************************
 * 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:  $ */
#include <Riostream.h>
#include "AliLog.h"
#include "TStarLight.h"
#include "starlight.h"
#include "upcevent.h"
#include "AliRunLoader.h"
#include "AliGenEventHeader.h"
#include "AliGenStarLight.h"

ClassImp(AliGenStarLight);

AliGenStarLight::AliGenStarLight()
  : AliGenMC()
  , fSLgenerator(NULL) {
}
//----------------------------------------------------------------------
AliGenStarLight::AliGenStarLight(Int_t npart)
  : AliGenMC(npart)
  , fSLgenerator(new TStarLight("TStarLight",
				"StarLight UPC Event Generator",
				""))  // no config file name  
{
  //
}
//----------------------------------------------------------------------
AliGenStarLight::~AliGenStarLight() {
  if (NULL != fSLgenerator) delete fSLgenerator;
  fSLgenerator = NULL;
}
void AliGenStarLight::ImportConfigurationFromFile(const char* filename) {
  if (NULL == fSLgenerator) {
    AliFatal("AliGenStarLight class not constructed properly. ");
    return;
  }
  fSLgenerator->ImportConfigurationFromFile(filename);
}
void AliGenStarLight::SetParameter(const char* line) {
  if (NULL == fSLgenerator) {
    AliFatal("AliGenStarLight class not constructed properly. ");
    return;
  }
  fSLgenerator->SetParameter(line);
}
//----------------------------------------------------------------------
void AliGenStarLight::Init() {
  if (NULL == fSLgenerator) {
    AliFatal("AliGenStarLight class not constructed properly. ");
    return;
  }
  fSLgenerator->InitStarLight();
}
//----------------------------------------------------------------------
void AliGenStarLight::Generate() {
  Float_t vpos[4] = { 0, 0, 0, 0 };
  if (fVertexSmear == kPerEvent) {
    Vertex(); // get vertex
    for (Int_t i=0; i<3; ++i)
      vpos[i] = fVertex[i];
    vpos[3] = fTime;
  }

  Int_t   nt(0);     // number of tracks
  Bool_t  genOK(kFALSE);  
  // generate events until all constraints are fulfilled
  for (Int_t trials=0; !genOK && trials < 100*1000; ++trials) {
    fSLgenerator->GenerateEvent();
    fSLgenerator->BoostEvent();
    fSLgenerator->ImportParticles(&fParticles, "ALL");
    
    genOK = kTRUE;
    for (Long64_t i(0), n(fParticles.GetEntries()); i<n && genOK; ++i) {
      const TParticle *part(dynamic_cast<TParticle*>(fParticles.At(i)));
      if (NULL == part) {
	AliFatal("NULL == part");
	return;
      }
      genOK = 
	(part->Theta() >= fThetaMin) &&	(part->Theta() <  fThetaMax) &&
	(part->Phi()   >= fPhiMin)   &&	(part->Phi()   <  fPhiMax)   &&
	(part->Y()     >= fYMin)     &&	(part->Y()     <  fYMax)     &&
	(part->P()     >= fPMin)     &&	(part->P()     <  fPMax)     &&
	(part->Pt()    >= fPtMin)    &&	(part->Pt()    <  fPtMax);
    }
    if (kFALSE == genOK) continue;
    
    fNprimaries = 0;
    for (Long64_t i(0), n(fParticles.GetEntries()); i<n; ++i) {
      const TParticle *part(dynamic_cast<TParticle*>(fParticles.At(i)));	
      if (NULL == part) {
	AliFatal("NULL == part");
	return;
      }
      const Int_t   iparent(-1);
      const Float_t polar[3] = { 0, 0, 0 };
      const Float_t weight(trials+1);
      PushTrack(fTrackIt, iparent, part->GetPdgCode(), 
		part->Px(), part->Py(), part->Pz(), part->Energy(),
		vpos[0],    vpos[1],    vpos[2],    vpos[3],
		polar[0],   polar[1],   polar[2], 
		kPPrimary, nt, weight, part->GetStatusCode());
      AliInfo(Form("weight=%.0f nt=%d fTrackIt=%d statusCode=%d",
		   weight, nt, fTrackIt, part->GetStatusCode()));
      part->Print();
      KeepTrack(nt);
      ++fNprimaries;
    }
    fParticles.Clear();
  }
  if (kFALSE == genOK)
    AliFatal("Maximum number of trials reached");

  AliGenEventHeader* header = new AliGenEventHeader("SL");
  const TArrayF vertexPosition(3, vpos);
  header->SetPrimaryVertex(vertexPosition);
  header->SetInteractionTime(vpos[3]);
  header->SetNProduced(nt);
  AddHeader(header);
  SetHighWaterMark(nt);
  AliRunLoader::Instance()->CdGAFile();
}