// -*- C++ -*-
//
// Package:    PF_PU_AssoMap
// Class:      PF_PU_FirstVertexTracks
//
/**\class PF_PU_AssoMap PF_PU_FirstVertexTracks.cc CommonTools/RecoUtils/plugins/PF_PU_FirstVertexTracks.cc

  Description: Produces collection of tracks associated to the first vertex based on the pf_pu Association Map
*/
//
// Original Author:  Matthias Geisler
//         Created:  Wed Apr 18 14:48:37 CEST 2012
// $Id: PF_PU_FirstVertexTracks.cc,v 1.1 2012/11/21 09:57:30 mgeisler Exp $
//
//
#include "CommonTools/RecoUtils/interface/PF_PU_FirstVertexTracks.h"

// system include files
#include <vector>
#include <string>

// user include files
#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "DataFormats/Common/interface/Handle.h"
#include "DataFormats/Common/interface/OneToManyWithQualityGeneric.h"
#include "DataFormats/Common/interface/View.h"

#include "DataFormats/TrackReco/interface/TrackBase.h"
#include "DataFormats/EgammaCandidates/interface/GsfElectron.h"
#include "DataFormats/EgammaCandidates/interface/GsfElectronFwd.h"
#include "DataFormats/BeamSpot/interface/BeamSpot.h"

//
// constants, enums and typedefs
//

using namespace edm;
using namespace std;
using namespace reco;

typedef vector<pair<TrackRef, int> > TrackQualityPairVector;

//
// static data member definitions
//

//
// constructors and destructor
//
PF_PU_FirstVertexTracks::PF_PU_FirstVertexTracks(const edm::ParameterSet& iConfig) {
  //now do what ever other initialization is needed

  input_AssociationType_ = iConfig.getParameter<edm::InputTag>("AssociationType");

  token_TrackToVertexAssMap_ = mayConsume<TrackToVertexAssMap>(iConfig.getParameter<InputTag>("AssociationMap"));
  token_VertexToTrackAssMap_ = mayConsume<VertexToTrackAssMap>(iConfig.getParameter<InputTag>("AssociationMap"));

  token_generalTracksCollection_ = consumes<TrackCollection>(iConfig.getParameter<InputTag>("TrackCollection"));

  token_VertexCollection_ = mayConsume<VertexCollection>(iConfig.getParameter<InputTag>("VertexCollection"));

  input_MinQuality_ = iConfig.getParameter<int>("MinQuality");

  //register your products

  if (input_AssociationType_.label() == "TracksToVertex") {
    produces<TrackCollection>("T2V");
  } else {
    if (input_AssociationType_.label() == "VertexToTracks") {
      produces<TrackCollection>("V2T");
    } else {
      if (input_AssociationType_.label() == "Both") {
        produces<TrackCollection>("T2V");
        produces<TrackCollection>("V2T");
      } else {
        std::cout << "No correct InputTag for AssociationType!" << std::endl;
        std::cout << "Won't produce any TrackCollection!" << std::endl;
      }
    }
  }
}

//
// member functions
//

// ------------ method called to produce the data  ------------
void PF_PU_FirstVertexTracks::produce(edm::StreamID, edm::Event& iEvent, const edm::EventSetup& iSetup) const {
  unique_ptr<TrackCollection> t2v_firstvertextracks(new TrackCollection());
  unique_ptr<TrackCollection> v2t_firstvertextracks(new TrackCollection());

  bool t2vassmap = false;
  bool v2tassmap = false;

  //get the input vertex<->general track association map
  Handle<TrackToVertexAssMap> t2vAM;
  Handle<VertexToTrackAssMap> v2tAM;

  string asstype = input_AssociationType_.label();

  if ((asstype == "TracksToVertex") || (asstype == "Both")) {
    if (iEvent.getByToken(token_TrackToVertexAssMap_, t2vAM)) {
      t2vassmap = true;
    }
  }

  if ((asstype == "VertexToTracks") || (asstype == "Both")) {
    if (iEvent.getByToken(token_VertexToTrackAssMap_, v2tAM)) {
      v2tassmap = true;
    }
  }

  if (!t2vassmap && !v2tassmap) {
    cout << "No input collection could be found" << endl;
    return;
  }

  //get the input track collection
  Handle<TrackCollection> input_trckcollH;
  iEvent.getByToken(token_generalTracksCollection_, input_trckcollH);

  if (t2vassmap) {
    const TrackQualityPairVector trckcoll = t2vAM->begin()->val;

    //get the tracks associated to the first vertex and store them in a track collection
    for (unsigned int trckcoll_ite = 0; trckcoll_ite < trckcoll.size(); trckcoll_ite++) {
      float quality = trckcoll[trckcoll_ite].second;

      if (quality >= input_MinQuality_) {
        TrackRef AMtrkref = trckcoll[trckcoll_ite].first;

        for (unsigned int index_input_trck = 0; index_input_trck < input_trckcollH->size(); index_input_trck++) {
          TrackRef input_trackref = TrackRef(input_trckcollH, index_input_trck);

          if (trackMatch(*AMtrkref, *input_trackref)) {
            t2v_firstvertextracks->push_back(*AMtrkref);
            break;
          }
        }
      }
    }

    iEvent.put(std::move(t2v_firstvertextracks), "T2V");
  }

  if (v2tassmap) {
    //get the input vertex collection
    Handle<VertexCollection> input_vtxcollH;
    iEvent.getByToken(token_VertexCollection_, input_vtxcollH);

    VertexRef firstVertexRef(input_vtxcollH, 0);

    VertexToTrackAssMap::const_iterator v2t_ite;

    for (v2t_ite = v2tAM->begin(); v2t_ite != v2tAM->end(); v2t_ite++) {
      TrackRef AMtrkref = v2t_ite->key;

      for (unsigned int index_input_trck = 0; index_input_trck < input_trckcollH->size(); index_input_trck++) {
        TrackRef input_trackref = TrackRef(input_trckcollH, index_input_trck);

        if (trackMatch(*AMtrkref, *input_trackref)) {
          for (unsigned v_ite = 0; v_ite < (v2t_ite->val).size(); v_ite++) {
            VertexRef vtxref = (v2t_ite->val)[v_ite].first;
            float quality = (v2t_ite->val)[v_ite].second;

            if ((vtxref == firstVertexRef) && (quality >= input_MinQuality_)) {
              v2t_firstvertextracks->push_back(*AMtrkref);
            }
          }
        }
      }
    }

    iEvent.put(std::move(v2t_firstvertextracks), "V2T");
  }
}

bool PF_PU_FirstVertexTracks::trackMatch(const Track& track1, const Track& track2) const {
  return ((track1).eta() == (track2).eta() && (track1).phi() == (track2).phi() && (track1).chi2() == (track2).chi2() &&
          (track1).ndof() == (track2).ndof() && (track1).p() == (track2).p());
}

// ------------ method fills 'descriptions' with the allowed parameters for the module  ------------
void PF_PU_FirstVertexTracks::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;

  using namespace edm;
  desc.add<InputTag>("AssociationType");
  desc.add<InputTag>("AssociationMap");
  desc.add<InputTag>("TrackCollection");
  desc.add<InputTag>("VertexCollection");
  desc.add<int>("MinQuality");

  descriptions.addDefault(desc);
}

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