/*
 *  See header file for a description of this class.
 *
 *  \author G. Mila - INFN Torino
 */

#include "DQM/DTMonitorModule/interface/DTCalibValidation.h"

// Framework
#include "FWCore/Framework/interface/Event.h"
#include "FWCore/Framework/interface/EventSetup.h"
#include "FWCore/Framework/interface/ESHandle.h"
#include "FWCore/ServiceRegistry/interface/Service.h"
#include "DQMServices/Core/interface/DQMStore.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"

//Geometry
#include "Geometry/DTGeometry/interface/DTGeometry.h"

//RecHit
#include "DataFormats/DTRecHit/interface/DTRecSegment4DCollection.h"
#include "DataFormats/DTRecHit/interface/DTRecHitCollection.h"

#include <iterator>

using namespace edm;
using namespace std;

DTCalibValidation::DTCalibValidation(const ParameterSet& pset)
    : muonGeomToken_(esConsumes<edm::Transition::BeginRun>()) {
  parameters = pset;

  //FR the following was previously in the beginJob

  // the name of the rechits collection at step 1
  recHits1DToken_ =
      consumes<DTRecHitCollection>(edm::InputTag(parameters.getUntrackedParameter<string>("recHits1DLabel")));
  // the name of the 2D segments
  segment2DToken_ =
      consumes<DTRecSegment2DCollection>(edm::InputTag(parameters.getUntrackedParameter<string>("segment2DLabel")));
  // the name of the 4D segments
  segment4DToken_ =
      consumes<DTRecSegment4DCollection>(edm::InputTag(parameters.getUntrackedParameter<string>("segment4DLabel")));
  // the counter of segments not used to compute residuals
  wrongSegment = 0;
  // the counter of segments used to compute residuals
  rightSegment = 0;
  // the analysis type
  detailedAnalysis = parameters.getUntrackedParameter<bool>("detailedAnalysis", false);

  nevent = 0;
}

DTCalibValidation::~DTCalibValidation() {
  //FR the following was previously in the endJob

  LogVerbatim("DTCalibValidation") << "Segments used to compute residuals: " << rightSegment;
  LogVerbatim("DTCalibValidation") << "Segments not used to compute residuals: " << wrongSegment;
}

void DTCalibValidation::dqmBeginRun(const edm::Run& run, const edm::EventSetup& setup) {
  // get the geometry
  dtGeom = &setup.getData(muonGeomToken_);
}

void DTCalibValidation::analyze(const edm::Event& event, const edm::EventSetup& setup) {
  ++nevent;
  LogTrace("DTCalibValidation") << "[DTCalibValidation] Analyze #Run: " << event.id().run() << " #Event: " << nevent;

  // RecHit mapping at Step 1 -------------------------------
  map<DTWireId, vector<DTRecHit1DPair> > recHitsPerWire_1S;

  // RecHit mapping at Step 2 ------------------------------
  map<DTWireId, vector<DTRecHit1D> > recHitsPerWire_2S;

  if (detailedAnalysis) {
    LogTrace("DTCalibValidation") << "  -- DTRecHit S1: begin analysis:";
    // Get the rechit collection from the event
    Handle<DTRecHitCollection> dtRecHits;
    event.getByToken(recHits1DToken_, dtRecHits);
    recHitsPerWire_1S = map1DRecHitsPerWire(dtRecHits.product());

    LogTrace("DTCalibValidation") << "  -- DTRecHit S2: begin analysis:";
    // Get the 2D rechits from the event
    Handle<DTRecSegment2DCollection> segment2Ds;
    event.getByToken(segment2DToken_, segment2Ds);
    recHitsPerWire_2S = map1DRecHitsPerWire(segment2Ds.product());
  }

  // RecHit mapping at Step 3 ---------------------------------
  LogTrace("DTCalibValidation") << "  -- DTRecHit S3: begin analysis:";
  // Get the 4D rechits from the event
  Handle<DTRecSegment4DCollection> segment4Ds;
  event.getByToken(segment4DToken_, segment4Ds);
  map<DTWireId, vector<DTRecHit1D> > recHitsPerWire_3S = map1DRecHitsPerWire(segment4Ds.product());

  // Loop over all 4D segments
  for (DTRecSegment4DCollection::const_iterator segment = segment4Ds->begin(); segment != segment4Ds->end();
       ++segment) {
    if (detailedAnalysis) {
      LogTrace("DTCalibValidation") << "Anlysis on recHit at step 1";
      compute(dtGeom, (*segment), recHitsPerWire_1S, 1);

      LogTrace("DTCalibValidation") << "Anlysis on recHit at step 2";
      compute(dtGeom, (*segment), recHitsPerWire_2S, 2);
    }

    LogTrace("DTCalibValidation") << "Anlysis on recHit at step 3";
    compute(dtGeom, (*segment), recHitsPerWire_3S, 3);
  }
}

// Return a map between DTRecHit1DPair and wireId
map<DTWireId, vector<DTRecHit1DPair> > DTCalibValidation::map1DRecHitsPerWire(
    const DTRecHitCollection* dt1DRecHitPairs) {
  map<DTWireId, vector<DTRecHit1DPair> > ret;

  for (DTRecHitCollection::const_iterator rechit = dt1DRecHitPairs->begin(); rechit != dt1DRecHitPairs->end();
       ++rechit) {
    ret[(*rechit).wireId()].push_back(*rechit);
  }

  return ret;
}

// Return a map between DTRecHit1D at S2 and wireId
map<DTWireId, vector<DTRecHit1D> > DTCalibValidation::map1DRecHitsPerWire(const DTRecSegment2DCollection* segment2Ds) {
  map<DTWireId, vector<DTRecHit1D> > ret;

  // Loop over all 2D segments
  for (DTRecSegment2DCollection::const_iterator segment = segment2Ds->begin(); segment != segment2Ds->end();
       ++segment) {
    vector<DTRecHit1D> component1DHits = (*segment).specificRecHits();
    // Loop over all component 1D hits
    for (vector<DTRecHit1D>::const_iterator hit = component1DHits.begin(); hit != component1DHits.end(); ++hit) {
      ret[(*hit).wireId()].push_back(*hit);
    }
  }
  return ret;
}

// Return a map between DTRecHit1D at S3 and wireId
map<DTWireId, std::vector<DTRecHit1D> > DTCalibValidation::map1DRecHitsPerWire(
    const DTRecSegment4DCollection* segment4Ds) {
  map<DTWireId, vector<DTRecHit1D> > ret;
  // Loop over all 4D segments
  for (DTRecSegment4DCollection::const_iterator segment = segment4Ds->begin(); segment != segment4Ds->end();
       ++segment) {
    // Get component 2D segments
    vector<const TrackingRecHit*> segment2Ds = (*segment).recHits();
    // Loop over 2D segments:
    for (vector<const TrackingRecHit*>::const_iterator segment2D = segment2Ds.begin(); segment2D != segment2Ds.end();
         ++segment2D) {
      // Get 1D component rechits
      vector<const TrackingRecHit*> hits = (*segment2D)->recHits();
      // Loop over them
      for (vector<const TrackingRecHit*>::const_iterator hit = hits.begin(); hit != hits.end(); ++hit) {
        const DTRecHit1D* hit1D = dynamic_cast<const DTRecHit1D*>(*hit);
        ret[hit1D->wireId()].push_back(*hit1D);
      }
    }
  }

  return ret;
}

// Find the RecHit closest to the segment4D
template <typename type>
const type* DTCalibValidation::findBestRecHit(const DTLayer* layer,
                                              DTWireId wireId,
                                              const vector<type>& recHits,
                                              const float segmDist) {
  float res = 99999;
  const type* theBestRecHit = nullptr;
  // Loop over RecHits within the cell
  for (typename vector<type>::const_iterator recHit = recHits.begin(); recHit != recHits.end(); ++recHit) {
    float distTmp = recHitDistFromWire(*recHit, layer);
    if (fabs(distTmp - segmDist) < res) {
      res = fabs(distTmp - segmDist);
      theBestRecHit = &(*recHit);
    }
  }  // End of loop over RecHits within the cell

  return theBestRecHit;
}

// Compute the distance from wire (cm) of a hits in a DTRecHit1DPair
float DTCalibValidation::recHitDistFromWire(const DTRecHit1DPair& hitPair, const DTLayer* layer) {
  return fabs(hitPair.localPosition(DTEnums::Left).x() - hitPair.localPosition(DTEnums::Right).x()) / 2.;
}

// Compute the distance from wire (cm) of a hits in a DTRecHit1D
float DTCalibValidation::recHitDistFromWire(const DTRecHit1D& recHit, const DTLayer* layer) {
  return fabs(recHit.localPosition().x() - layer->specificTopology().wirePosition(recHit.wireId().wire()));
}

// Compute the position (cm) of a hits in a DTRecHit1DPair
float DTCalibValidation::recHitPosition(
    const DTRecHit1DPair& hitPair, const DTLayer* layer, const DTChamber* chamber, float segmentPos, int sl) {
  // Get the layer and the wire position
  GlobalPoint hitPosGlob_right = layer->toGlobal(hitPair.localPosition(DTEnums::Right));
  LocalPoint hitPosInChamber_right = chamber->toLocal(hitPosGlob_right);
  GlobalPoint hitPosGlob_left = layer->toGlobal(hitPair.localPosition(DTEnums::Left));
  LocalPoint hitPosInChamber_left = chamber->toLocal(hitPosGlob_left);

  float recHitPos = -1;
  if (sl != 2) {
    if (fabs(hitPosInChamber_left.x() - segmentPos) < fabs(hitPosInChamber_right.x() - segmentPos))
      recHitPos = hitPosInChamber_left.x();
    else
      recHitPos = hitPosInChamber_right.x();
  } else {
    if (fabs(hitPosInChamber_left.y() - segmentPos) < fabs(hitPosInChamber_right.y() - segmentPos))
      recHitPos = hitPosInChamber_left.y();
    else
      recHitPos = hitPosInChamber_right.y();
  }

  return recHitPos;
}

// Compute the position (cm) of a hits in a  DTRecHit1D
float DTCalibValidation::recHitPosition(
    const DTRecHit1D& recHit, const DTLayer* layer, const DTChamber* chamber, float segmentPos, int sl) {
  // Get the layer and the wire position
  GlobalPoint recHitPosGlob = layer->toGlobal(recHit.localPosition());
  LocalPoint recHitPosInChamber = chamber->toLocal(recHitPosGlob);

  float recHitPos = -1;
  if (sl != 2)
    recHitPos = recHitPosInChamber.x();
  else
    recHitPos = recHitPosInChamber.y();

  return recHitPos;
}

// Compute the residuals
template <typename type>
void DTCalibValidation::compute(const DTGeometry* dtGeom,
                                const DTRecSegment4D& segment,
                                const std::map<DTWireId, std::vector<type> >& recHitsPerWire,
                                int step) {
  bool computeResidual = true;

  // Get all 1D RecHits at step 3 within the 4D segment
  vector<DTRecHit1D> recHits1D_S3;

  // Get 1D RecHits at Step 3 and select only events with
  // 8 hits in phi and 4 hits in theta (if any)
  const DTChamberRecSegment2D* phiSeg = segment.phiSegment();
  if (phiSeg) {
    vector<DTRecHit1D> phiRecHits = phiSeg->specificRecHits();
    if (phiRecHits.size() != 8) {
      LogTrace("DTCalibValidation") << "[DTCalibValidation] Phi segments has: " << phiRecHits.size()
                                    << " hits, skipping";  // FIXME: info output
      computeResidual = false;
    }
    copy(phiRecHits.begin(), phiRecHits.end(), back_inserter(recHits1D_S3));
  }
  if (!phiSeg) {
    LogTrace("DTCalibValidation") << " [DTCalibValidation] 4D segment has not the phi segment! ";
    computeResidual = false;
  }

  if (segment.dimension() == 4) {
    const DTSLRecSegment2D* zSeg = segment.zSegment();
    if (zSeg) {
      vector<DTRecHit1D> zRecHits = zSeg->specificRecHits();
      if (zRecHits.size() != 4) {
        LogTrace("DTCalibValidation") << "[DTCalibValidation] Theta segments has: " << zRecHits.size()
                                      << " hits, skipping";  // FIXME: info output
        computeResidual = false;
      }
      copy(zRecHits.begin(), zRecHits.end(), back_inserter(recHits1D_S3));
    }
    if (!zSeg) {
      LogTrace("DTCalibValidation") << " [DTCalibValidation] 4D segment has not the z segment! ";
      computeResidual = false;
    }
  }

  if (!computeResidual)
    ++wrongSegment;
  if (computeResidual) {
    ++rightSegment;
    // Loop over 1D RecHit inside 4D segment
    for (vector<DTRecHit1D>::const_iterator recHit1D = recHits1D_S3.begin(); recHit1D != recHits1D_S3.end();
         ++recHit1D) {
      const DTWireId wireId = (*recHit1D).wireId();

      // Get the layer and the wire position
      const DTLayer* layer = dtGeom->layer(wireId);
      float wireX = layer->specificTopology().wirePosition(wireId.wire());

      // Extrapolate the segment to the z of the wire
      // Get wire position in chamber RF
      // (y and z must be those of the hit to be coherent in the transf. of RF in case of rotations of the layer alignment)
      LocalPoint wirePosInLay(wireX, (*recHit1D).localPosition().y(), (*recHit1D).localPosition().z());
      GlobalPoint wirePosGlob = layer->toGlobal(wirePosInLay);
      const DTChamber* chamber = dtGeom->chamber((*recHit1D).wireId().layerId().chamberId());
      LocalPoint wirePosInChamber = chamber->toLocal(wirePosGlob);

      // Segment position at Wire z in chamber local frame
      LocalPoint segPosAtZWire = segment.localPosition() + segment.localDirection() * wirePosInChamber.z() /
                                                               cos(segment.localDirection().theta());

      // Compute the distance of the segment from the wire
      int sl = wireId.superlayer();
      float SegmDistance = -1;
      if (sl == 1 || sl == 3) {
        // RPhi SL
        SegmDistance = fabs(wirePosInChamber.x() - segPosAtZWire.x());
        LogTrace("DTCalibValidation") << "SegmDistance: " << SegmDistance;
      } else if (sl == 2) {
        // RZ SL
        SegmDistance = fabs(segPosAtZWire.y() - wirePosInChamber.y());
        LogTrace("DTCalibValidation") << "SegmDistance: " << SegmDistance;
      }
      if (SegmDistance > 2.1)
        LogTrace("DTCalibValidation") << "  Warning: dist segment-wire: " << SegmDistance;

      // Look for RecHits in the same cell
      if (recHitsPerWire.find(wireId) == recHitsPerWire.end()) {
        LogTrace("DTCalibValidation") << "   No RecHit found at Step: " << step << " in cell: " << wireId;
      } else {
        const vector<type>& recHits = recHitsPerWire.at(wireId);
        LogTrace("DTCalibValidation") << "   " << recHits.size() << " RecHits, Step " << step
                                      << " in channel: " << wireId;

        // Get the layer
        const DTLayer* layer = dtGeom->layer(wireId);
        // Find the best RecHits
        const type* theBestRecHit = findBestRecHit(layer, wireId, recHits, SegmDistance);
        // Compute the distance of the recHit from the wire
        float recHitWireDist = recHitDistFromWire(*theBestRecHit, layer);
        LogTrace("DTCalibValidation") << "recHitWireDist: " << recHitWireDist;

        // Compute the residuals
        float residualOnDistance = recHitWireDist - SegmDistance;
        LogTrace("DTCalibValidation") << "WireId: " << wireId << "  ResidualOnDistance: " << residualOnDistance;
        float residualOnPosition = -1;
        float recHitPos = -1;
        if (sl == 1 || sl == 3) {
          recHitPos = recHitPosition(*theBestRecHit, layer, chamber, segPosAtZWire.x(), sl);
          residualOnPosition = recHitPos - segPosAtZWire.x();
        } else {
          recHitPos = recHitPosition(*theBestRecHit, layer, chamber, segPosAtZWire.y(), sl);
          residualOnPosition = recHitPos - segPosAtZWire.y();
        }
        LogTrace("DTCalibValidation") << "WireId: " << wireId << "  ResidualOnPosition: " << residualOnPosition;

        // Fill the histos
        if (sl == 1 || sl == 3)
          fillHistos(wireId.superlayerId(),
                     SegmDistance,
                     residualOnDistance,
                     (wirePosInChamber.x() - segPosAtZWire.x()),
                     residualOnPosition,
                     step);
        else
          fillHistos(wireId.superlayerId(),
                     SegmDistance,
                     residualOnDistance,
                     (wirePosInChamber.y() - segPosAtZWire.y()),
                     residualOnPosition,
                     step);
      }
    }
  }
}

void DTCalibValidation::bookHistograms(DQMStore::IBooker& ibooker,
                                       edm::Run const& iRun,
                                       edm::EventSetup const& iSetup) {
  //FR substitute the DQMStore instance by ibooker
  ibooker.setCurrentFolder("DT/DTCalibValidation");

  DTSuperLayerId slId;

  // Loop over all the chambers
  vector<const DTChamber*>::const_iterator ch_it = dtGeom->chambers().begin();
  vector<const DTChamber*>::const_iterator ch_end = dtGeom->chambers().end();
  for (; ch_it != ch_end; ++ch_it) {
    vector<const DTSuperLayer*>::const_iterator sl_it = (*ch_it)->superLayers().begin();
    vector<const DTSuperLayer*>::const_iterator sl_end = (*ch_it)->superLayers().end();
    // Loop over the SLs
    for (; sl_it != sl_end; ++sl_it) {
      slId = (*sl_it)->id();

      int firstStep = 1;
      if (!detailedAnalysis)
        firstStep = 3;
      // Loop over the 3 steps
      for (int step = firstStep; step <= 3; ++step) {
        LogTrace("DTCalibValidation") << "   Booking histos for SL: " << slId;

        // Compose the chamber name
        stringstream wheel;
        wheel << slId.wheel();
        stringstream station;
        station << slId.station();
        stringstream sector;
        sector << slId.sector();
        stringstream superLayer;
        superLayer << slId.superlayer();
        // Define the step
        stringstream Step;
        Step << step;

        string slHistoName = "_STEP" + Step.str() + "_W" + wheel.str() + "_St" + station.str() + "_Sec" + sector.str() +
                             "_SL" + superLayer.str();

        ibooker.setCurrentFolder("DT/DTCalibValidation/Wheel" + wheel.str() + "/Station" + station.str() + "/Sector" +
                                 sector.str());
        // Create the monitor elements
        vector<MonitorElement*> histos;
        // Note the order matters
        histos.push_back(ibooker.book1D(
            "hResDist" + slHistoName, "Residuals on the distance from wire (rec_hit - segm_extr) (cm)", 200, -0.4, 0.4));
        histos.push_back(
            ibooker.book2D("hResDistVsDist" + slHistoName,
                           "Residuals on the distance (cm) from wire (rec_hit - segm_extr) vs distance  (cm)",
                           100,
                           0,
                           2.5,
                           200,
                           -0.4,
                           0.4));
        if (detailedAnalysis) {
          histos.push_back(ibooker.book1D("hResPos" + slHistoName,
                                          "Residuals on the position from wire (rec_hit - segm_extr) (cm)",
                                          200,
                                          -0.4,
                                          0.4));
          histos.push_back(
              ibooker.book2D("hResPosVsPos" + slHistoName,
                             "Residuals on the position (cm) from wire (rec_hit - segm_extr) vs distance  (cm)",
                             200,
                             -2.5,
                             2.5,
                             200,
                             -0.4,
                             0.4));
        }

        histosPerSL[make_pair(slId, step)] = histos;
      }
    }
  }
}

// Fill a set of histograms for a given SL
void DTCalibValidation::fillHistos(
    DTSuperLayerId slId, float distance, float residualOnDistance, float position, float residualOnPosition, int step) {
  // FIXME: optimization of the number of searches
  vector<MonitorElement*> histos = histosPerSL[make_pair(slId, step)];
  histos[0]->Fill(residualOnDistance);
  histos[1]->Fill(distance, residualOnDistance);
  if (detailedAnalysis) {
    histos[2]->Fill(residualOnPosition);
    histos[3]->Fill(position, residualOnPosition);
  }
}

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