#include <yanjun/YanjunAnalyzer/interface/YanjunAnalyzer.h>


YanjunAnalyzer::YanjunAnalyzer(const edm::ParameterSet& iConfig)

{
   //now do what ever initialization is needed

  nEvents   = 0;
  nFourM    = 0;
}


YanjunAnalyzer::~YanjunAnalyzer()
{
  
   // do anything here that needs to be done at desctruction time
   // (e.g. close files, deallocate resources etc.)
   

}


//
// member functions
//

// ------------ method called to for each event  ------------
void
YanjunAnalyzer::analyze(const edm::Event& iEvent, const edm::EventSetup& iSetup)
{
   using namespace edm;

   nEvents++;

   // using reco::TrackCollection;

   bool keepEvent   = false;

   int nMuon = 0;

   bool isFourM = false;
// get gen particle candidates
   edm::Handle<GenParticleCollection> genCandidates;
   iEvent.getByLabel("genParticles", genCandidates);
   float eta = 0.;
   for ( GenParticleCollection::const_iterator mcIter=genCandidates->begin(); mcIter!=genCandidates->end(); ++mcIter ) {
     
    // Muons:
     if ( mcIter->pdgId() == 13 || mcIter->pdgId() == -13) {
       // Mother is a Z
       if ( mcIter->mother()->pdgId() == 23 ) {
	
	 // In fiducial volume:
	 if ( mcIter->eta() > -2.4 && mcIter->eta() < 2.4 ) nMuon++;



       }
     }
     
   }
   
   if (nMuon > 3) {
     isFourM = true;
     nFourM++;
   }

   
   
// #ifdef THIS_IS_AN_EVENT_EXAMPLE
//    Handle<ExampleData> pIn;
//    iEvent.getByLabel("example",pIn);
// #endif
   
// #ifdef THIS_IS_AN_EVENTSETUP_EXAMPLE
//    ESHandle<SetupData> pSetup;
//    iSetup.get<SetupRecord>().get(pSetup);
// #endif
}


// ------------ method called once each job just before starting event loop  ------------
void YanjunAnalyzer::beginJob(const edm::EventSetup&)
{
}

// ------------ method called once each job just after ending the event loop  ------------
void 
YanjunAnalyzer::endJob() {
  std::cout << "Number of events read " << nEvents << std::endl;
  std::cout << "Four muons:   "
	    << " =  "    << nFourM  << std::endl;
  
}

//define this as a plug-in
DEFINE_FWK_MODULE(YanjunAnalyzer);