// system include files
#include <atomic>
#include <memory>
#include <cmath>
#include <iostream>
#include <sstream>
#include <fstream>

// user include files
#include "FWCore/Framework/interface/Frameworkfwd.h"
#include "FWCore/Framework/interface/stream/EDFilter.h"
#include "FWCore/Framework/interface/Event.h"
#include "FWCore/Framework/interface/EventSetup.h"
#include "FWCore/Framework/interface/Run.h"
#include "FWCore/Framework/interface/LuminosityBlock.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"
#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "FWCore/ParameterSet/interface/ConfigurationDescriptions.h"
#include "FWCore/Common/interface/TriggerNames.h"

#include "DataFormats/Common/interface/Handle.h"
#include "DataFormats/Common/interface/Ref.h"
#include "DataFormats/Common/interface/TriggerResults.h"
#include "DataFormats/HLTReco/interface/TriggerEvent.h"
#include "DataFormats/MuonReco/interface/Muon.h"
#include "DataFormats/MuonReco/interface/MuonFwd.h"

#include "HLTrigger/HLTcore/interface/HLTConfigProvider.h"
#include "Calibration/IsolatedParticles/interface/CaloPropagateTrack.h"

#include "MagneticField/Engine/interface/MagneticField.h"
#include "MagneticField/Records/interface/IdealMagneticFieldRecord.h"
#include "Geometry/CaloGeometry/interface/CaloGeometry.h"
#include "Geometry/Records/interface/CaloGeometryRecord.h"

//#define EDM_ML_DEBUG
//
// class declaration
//

namespace alCaHEMuonFilter {
  struct Counters {
    Counters() : nAll_(0), nGood_(0), nFinal_(0) {}
    mutable std::atomic<unsigned int> nAll_, nGood_, nFinal_;
  };
}  // namespace alCaHEMuonFilter

class AlCaHEMuonFilter : public edm::stream::EDFilter<edm::GlobalCache<alCaHEMuonFilter::Counters> > {
public:
  explicit AlCaHEMuonFilter(edm::ParameterSet const&, const alCaHEMuonFilter::Counters* count);
  ~AlCaHEMuonFilter() override;

  static std::unique_ptr<alCaHEMuonFilter::Counters> initializeGlobalCache(edm::ParameterSet const&) {
    return std::make_unique<alCaHEMuonFilter::Counters>();
  }

  bool filter(edm::Event&, edm::EventSetup const&) override;
  void endStream() override;
  static void globalEndJob(const alCaHEMuonFilter::Counters* counters);
  static void fillDescriptions(edm::ConfigurationDescriptions& descriptions);

private:
  void beginRun(edm::Run const&, edm::EventSetup const&) override;
  void endRun(edm::Run const&, edm::EventSetup const&) override;

  // ----------member data ---------------------------
  HLTConfigProvider hltConfig_;
  unsigned int nRun_, nAll_, nGood_, nFinal_;
  const std::vector<std::string> trigNames_;
  const std::string processName_;
  const edm::InputTag triggerResults_, labelMuon_;
  const bool pfCut_;
  const double trackIsoCut_, caloIsoCut_, pfIsoCut_, muonptCut_, muonetaCut_;
  const int preScale_;
  const edm::EDGetTokenT<edm::TriggerResults> tok_trigRes_;
  const edm::EDGetTokenT<reco::MuonCollection> tok_Muon_;
  const edm::ESGetToken<CaloGeometry, CaloGeometryRecord> tok_geom_;
  const edm::ESGetToken<MagneticField, IdealMagneticFieldRecord> tok_magField_;
};

//
// constants, enums and typedefs
//

//
// static data member definitions
//

//
// constructors and destructor
//
AlCaHEMuonFilter::AlCaHEMuonFilter(edm::ParameterSet const& iConfig, const alCaHEMuonFilter::Counters* count)
    : nRun_(0),
      nAll_(0),
      nGood_(0),
      nFinal_(0),
      trigNames_(iConfig.getParameter<std::vector<std::string> >("triggers")),
      processName_(iConfig.getParameter<std::string>("processName")),
      triggerResults_(iConfig.getParameter<edm::InputTag>("triggerResultLabel")),
      labelMuon_(iConfig.getParameter<edm::InputTag>("muonLabel")),
      pfCut_(iConfig.getParameter<bool>("pfCut")),
      trackIsoCut_(iConfig.getParameter<double>("trackIsolationCut")),
      caloIsoCut_(iConfig.getParameter<double>("caloIsolationCut")),
      pfIsoCut_(iConfig.getParameter<double>("pfIsolationCut")),
      muonptCut_(iConfig.getParameter<double>("muonPtCut")),
      muonetaCut_(iConfig.getParameter<double>("muonEtaCut")),
      preScale_(iConfig.getParameter<int>("preScale") > 0 ? iConfig.getParameter<int>("preScale") : 1),
      tok_trigRes_(consumes<edm::TriggerResults>(triggerResults_)),
      tok_Muon_(consumes<reco::MuonCollection>(labelMuon_)),
      tok_geom_(esConsumes<CaloGeometry, CaloGeometryRecord>()),
      tok_magField_(esConsumes<MagneticField, IdealMagneticFieldRecord>()) {
  // load the parameters and define tokens for access

  edm::LogVerbatim("HEMuon") << "Parameters read from config file \n"
                             << "Process " << processName_ << "  Prescale " << preScale_ << "  Isolation Cuts "
                             << trackIsoCut_ << ":" << caloIsoCut_ << "\n";
  for (unsigned int k = 0; k < trigNames_.size(); ++k)
    edm::LogVerbatim("HEMuon") << "Trigger[" << k << "] " << trigNames_[k] << "\n";
}  // AlCaHEMuonFilter::AlCaHEMuonFilter  constructor

AlCaHEMuonFilter::~AlCaHEMuonFilter() {}

//
// member functions
//

// ------------ method called on each new Event  ------------
bool AlCaHEMuonFilter::filter(edm::Event& iEvent, edm::EventSetup const& iSetup) {
  bool accept(false);
  ++nAll_;
#ifdef EDM_ML_DEBUG
  edm::LogVerbatim("HEMuon") << "AlCaHEMuonFilter::Run " << iEvent.id().run() << " Event " << iEvent.id().event()
                             << " Luminosity " << iEvent.luminosityBlock() << " Bunch " << iEvent.bunchCrossing()
                             << std::endl;
#endif
  //Step1: Find if the event passes one of the chosen triggers
  /////////////////////////////TriggerResults
  edm::Handle<edm::TriggerResults> triggerResults = iEvent.getHandle(tok_trigRes_);
  if (triggerResults.isValid()) {
    bool ok(false);
    std::vector<std::string> modules;
    const edm::TriggerNames& triggerNames = iEvent.triggerNames(*triggerResults);
    const std::vector<std::string>& triggerNames_ = triggerNames.triggerNames();
    for (unsigned int iHLT = 0; iHLT < triggerResults->size(); iHLT++) {
      int hlt = triggerResults->accept(iHLT);
      for (unsigned int i = 0; i < trigNames_.size(); ++i) {
        if (triggerNames_[iHLT].find(trigNames_[i]) != std::string::npos) {
          if (hlt > 0) {
            ok = true;
          }
#ifdef EDM_ML_DEBUG
          edm::LogVerbatim("HEMuon") << "AlCaHEMuonFilter::Trigger " << triggerNames_[iHLT] << " Flag " << hlt << ":"
                                     << ok << std::endl;
#endif
        }
      }
    }
    if (ok) {
      //Step2: Get geometry/B-field information
      //Get magnetic field
      const MagneticField* bField = &(iSetup.getData(tok_magField_));
      const CaloGeometry* geo = &(iSetup.getData(tok_geom_));

      // Relevant blocks from iEvent
      edm::Handle<reco::MuonCollection> muonHandle = iEvent.getHandle(tok_Muon_);
#ifdef EDM_ML_DEBUG
      edm::LogVerbatim("HEMuon") << "AlCaHEMuonFilter::Muon Handle " << muonHandle.isValid();
#endif
      if (muonHandle.isValid()) {
        for (reco::MuonCollection::const_iterator RecMuon = muonHandle->begin(); RecMuon != muonHandle->end();
             ++RecMuon) {
#ifdef EDM_ML_DEBUG
          edm::LogVerbatim("HEMuon") << "AlCaHEMuonFilter::Muon:Track " << RecMuon->track().isNonnull()
                                     << " innerTrack " << RecMuon->innerTrack().isNonnull() << " outerTrack "
                                     << RecMuon->outerTrack().isNonnull() << " globalTrack "
                                     << RecMuon->globalTrack().isNonnull() << std::endl;
#endif
          if ((RecMuon->track().isNonnull()) && (RecMuon->innerTrack().isNonnull()) &&
              (RecMuon->outerTrack().isNonnull()) && (RecMuon->globalTrack().isNonnull())) {
            bool ptCut = RecMuon->pt() < muonptCut_;
            bool etaCut = fabs(RecMuon->eta()) < muonetaCut_;
            if (ptCut || etaCut)
              continue;

            const reco::Track* pTrack = (RecMuon->innerTrack()).get();
            spr::propagatedTrackID trackID = spr::propagateCALO(pTrack, geo, bField, false);
#ifdef EDM_ML_DEBUG
            edm::LogVerbatim("HEMuon") << "AlCaHEMuonFilter::Propagate: ECAL " << trackID.okECAL << " to HCAL "
                                       << trackID.okHCAL << std::endl;
#endif
            double trackIso = RecMuon->isolationR03().sumPt;
            double caloIso = RecMuon->isolationR03().emEt + RecMuon->isolationR03().hadEt;
            double isolR04 =
                ((RecMuon->pfIsolationR04().sumChargedHadronPt +
                  std::max(0.,
                           RecMuon->pfIsolationR04().sumNeutralHadronEt + RecMuon->pfIsolationR04().sumPhotonEt -
                               (0.5 * RecMuon->pfIsolationR04().sumPUPt))) /
                 RecMuon->pt());
            bool isoCut = (pfCut_) ? (isolR04 < pfIsoCut_) : ((trackIso < trackIsoCut_) && (caloIso < caloIsoCut_));
            if ((trackID.okECAL) && (trackID.okHCAL) && isoCut) {
              accept = true;
              break;
            }
          }
        }
      }
    }
  }
  // Step 4:  Return the acceptance flag
  if (accept) {
    ++nGood_;
    if (((nGood_ - 1) % preScale_) != 0) {
      accept = false;
    } else {
      ++nFinal_;
    }
  }
  return accept;

}  // AlCaHEMuonFilter::filter

// ------------ method called once each job just after ending the event loop  ------------
void AlCaHEMuonFilter::endStream() {
  globalCache()->nAll_ += nAll_;
  globalCache()->nGood_ += nGood_;
  globalCache()->nFinal_ += nFinal_;
}

void AlCaHEMuonFilter::globalEndJob(const alCaHEMuonFilter::Counters* count) {
  edm::LogVerbatim("HEMuon") << "Selects " << count->nFinal_ << " out of " << count->nGood_ << " good events out of "
                             << count->nAll_ << " total # of events\n";
}

// ------------ method called when starting to processes a run  ------------
void AlCaHEMuonFilter::beginRun(edm::Run const& iRun, edm::EventSetup const& iSetup) {
  bool changed(false);
  bool flag = hltConfig_.init(iRun, iSetup, processName_, changed);
  edm::LogVerbatim("HEMuon") << "Run[" << nRun_ << "] " << iRun.run() << " hltconfig.init " << flag << std::endl;
}

// ------------ method called when ending the processing of a run  ------------
void AlCaHEMuonFilter::endRun(edm::Run const& iRun, edm::EventSetup const&) {
  edm::LogVerbatim("HEMuon") << "endRun[" << nRun_ << "] " << iRun.run() << "\n";
  nRun_++;
}

// ------------ method fills 'descriptions' with the allowed parameters for the module  ------------
void AlCaHEMuonFilter::fillDescriptions(edm::ConfigurationDescriptions& descriptions) {
  //The following says we do not know what parameters are allowed so do no validation
  // Please change this to state exactly what you do use, even if it is no parameters
  edm::ParameterSetDescription desc;
  std::vector<std::string> triggers = {"HLT_IsoMu", "HLT_Mu"};
  desc.add<std::string>("processName", "HLT");
  desc.add<edm::InputTag>("triggerResultLabel", edm::InputTag("TriggerResults", "", "HLT"));
  desc.add<edm::InputTag>("muonLabel", edm::InputTag("muons"));
  desc.add<std::vector<std::string> >("triggers", triggers);
  desc.add<double>("muonPtCut", 5.0);
  desc.add<double>("muonEtaCut", 1.305);
  desc.add<bool>("pfCut", true);
  desc.add<double>("pfIsolationCut", 0.15);
  desc.add<double>("trackIsolationCut", 3.0);
  desc.add<double>("caloIsolationCut", 5.0);
  desc.add<int>("preScale", 1);
  descriptions.add("alcaHEMuonFilter", desc);
}

//define this as a plug-in
#include "FWCore/Framework/interface/MakerMacros.h"
DEFINE_FWK_MODULE(AlCaHEMuonFilter);