#ifndef CALOISOCORRECTION_H
#define CALOISOCORRECTION_H

/*
-----------------------------------------------------------------------
CaloIsoCorrection: computes corrected EtconeXX variables for electrons and photons

authors:   Mike Hance <michael.hance@cern.ch>
           Dominick Olivito <olivito@cern.ch>

This namespace contains functions for computing corrections for 
    the EtconeXX isolation variables, to account for energy leakage and pileup effects.  
    User functions are defined in this header file,
    while internal methods are defined in CaloIsoCorrection.cxx.
    
for more information:
https://twiki.cern.ch/twiki/bin/view/AtlasProtected/CaloIsolationCorrections

-----------------------------------------------------------------------
usage examples:

#include "CaloIsoCorrection.h"

// to get the nPV pileup corrected variables for electrons (similar for photons):
float EtconeXX_npv_corrected =   CaloIsoCorrection::GetNPVCorrectedIsolation(nPV,
                                                                            etaS2,
                                                                            radius,
                                                                            is_mc,
                                                                            Etcone_value,
                                                                            CaloIsoCorrection::ELECTRON);

// to get the error on the nPV pileup corrected variables for electrons (similar for photons):
float EtconeXX_npv_corrected_error =   CaloIsoCorrection::GetNPVCorrectedIsolationError(nPV,
                                                                                        etaS2,
                                                                                        radius,
                                                                                        is_mc,
                                                                                        Etcone_value,
                                                                                        CaloIsoCorrection::ELECTRON);

// to get the pt corrected isolation variables (similar for electrons):
float EtconeXX_pt_corrected = CaloIsoCorrection::GetPtCorrectedIsolation(energy,
                                                                         etaS2,
                                                                         etaPointing,
                                                                         etaCluster,
                                                                         radius,
                                                                         is_mc,
                                                                         Etcone_value,
                                                                         isConversion,
                                                                         CaloIsoCorrection::PHOTON);
                                                                               
// to get the error on the data-derived corrections (similar for electrons):
float EtconeXX_pt_corrected_error = CaloIsoCorrection::GetPtCorrectedIsolationError(energy,
                                                                                    etaS2,
                                                                                    etaPointing,
                                                                                    etaCluster,
                                                                                    radius,
                                                                                    is_mc,
                                                                                    CaloIsoCorrection::PHOTON);
                                                                              
-----------------------------------------------------------------------

The input variables are the following.  Variable names in the D3PDs are given in (parantheses)
    and are similar for electrons and photons unless otherwise noted.
    
    - nPV: number of primary vertices (corrections were derived requiring >= 2 tracks/vertex in 2011 data)
    
    - Etcone40: (ph_Etcone40) *** in MeV!
    - Etcone40_ED_corrected: ED corrected version of Etcone40 (ph_Etcone40_ED_corrected) *** in Mev!
    
    - energy: cluster energy (ph_cl_E) *** in MeV!
    - etaS2: eta in the 2nd calo sampling (ph_etas2)
    - etaPointing: pointing eta -> from 1st and 2nd calo samplings (ph_etap)
    - etaCluster: cluster eta (ph_cl_eta)
    - radius: radius of the input EtconeXX variable.  Can be given as, e.g., .20 or 20
    - is_mc: set to true if running on MC
    - Etcone_value: value of uncorrected EtconeXX variable (ph_EtconeXX) *** in MeV!
    - isConversion: photons only: conversion flag (ph_isConv)
    - parttype: ELECTRON or PHOTON, enum defined below
    
    *** energies must be in MeV!
    
-----------------------------------------------------------------------
*/

namespace CaloIsoCorrection{

  typedef enum { ELECTRON=0, PHOTON=1 } ParticleType;

  // ------------------------------------------------------------
  // --------------------- user methods -------------------------
  // ------------------------------------------------------------

  // ------------------------------------------------------------
  // ---------------- nPV pileup corrections --------------------
  
  float GetNPVCorrectedIsolation(unsigned int nPV,
                                 float etaS2,
                                 float radius,
                                 bool is_mc,
                                 float Etcone_value,
                                 ParticleType parttype = ELECTRON);
  
  // ------------------------------------------------------------
  // --------- energy density (ED) pileup corrections -----------
  // - equivalent to "EtconeXX_ED_corrected" variables
  
  float GetEDCorrectedIsolation(float Etcone40,
                                float Etcone40_ED_corrected,
                                float radius,
                                float Etcone_value,
                                ParticleType parttype = ELECTRON);
  
  // --------------------------------------------------------
  // --------------- pT leakage corrections -----------------
  // - equivalent to "EtconeXX_pt_corrected" variables
  
  float GetPtCorrectedIsolation(float energy,
                                float etaS2,
                                float etaPointing,
                                float etaCluster,
                                float radius,
                                bool is_mc,
                                float Etcone_value,
                                bool isConversion = false,
                                ParticleType parttype = ELECTRON);
  
  // --------------------------------------------------------
  // --------- pT leakage + nPV pileup corrections ----------
  
  float GetPtNPVCorrectedIsolation(unsigned int nPV,
                                   float energy,
                                   float etaS2,
                                   float etaPointing,
                                   float etaCluster,
                                   float radius,
                                   bool is_mc,
                                   float Etcone_value,
                                   bool isConversion = false,
                                   ParticleType parttype = ELECTRON);
  
  // -----------------------------------------------------------------
  // ----- pT leakage + energy density (ED) pileup corrections -------
  // - equivalent to "EtconeXX_corrected" variables
  
  float GetPtEDCorrectedIsolation(float Etcone40,
                                  float Etcone40_ED_corrected,
                                  float energy,
                                  float etaS2,
                                  float etaPointing,
                                  float etaCluster,
                                  float radius,
                                  bool is_mc,
                                  float Etcone_value,
                                  bool isConversion = false,
                                  ParticleType parttype = ELECTRON);
  
  // ---------------------------------------------------------
  // ----------- errors on nPV pileup corrections ------------
  
  // to get the error on the data-derived corrections
  float GetNPVCorrectedIsolationError(unsigned int nPV,
                                      float etaS2,
                                      float radius,
                                      bool is_mc,
                                      ParticleType parttype = ELECTRON);
  
  // ---------------------------------------------------------
  // ----------- errors on pT leakage corrections ------------
  
  // to get the error on the data-derived corrections
  float GetPtCorrectedIsolationError(float energy,
                                     float etaS2,
                                     float etaPointing,
                                     float etaCluster,
                                     float radius,
                                     bool is_mc,
                                     ParticleType parttype = ELECTRON);
  
}
#endif