////////////////////////////////////////////////////////////////////////
/// \struct OscProb::EigenPoint
///
/// \brief Struct to organise eigensystems for caching
///
/// This struct allows for comparisons of eigensystems based on
/// the neutrino energy, nu-nubar status, path density and Z/A.
///
/// \author Joao Coelho - jcoelho\@apc.in2p3.fr
////////////////////////////////////////////////////////////////////////

#ifndef EIGENPOINT_H
#define EIGENPOINT_H

#include "Definitions.h"
#include "NuPath.h"

namespace OscProb {

  struct EigenPoint {
  
    /// Constructor
    EigenPoint(int numNus=3, double e = 0, NuPath p = NuPath(0,0), bool n=false);
    
    /// Set eigensystem parameters
    void SetVars(double e = 0, NuPath p = NuPath(0,0), bool n=false);
    
    double fEnergy; ///< Neutrino energy
    NuPath fPath;   ///< Neutrino path
    bool fNubar;    ///< Nu-Nubar flag
    double fNE;     ///< Energy-density

    void SetNE(); ///< Set energy-density
    
    bool operator < (const EigenPoint &rhs) const;  ///< Comparison operator
    bool operator == (const EigenPoint &rhs) const; ///< Identity operator
    
    vectorD fEval;  ///< Eigenvalues to be cached
    matrixC fEvec;  ///< Eigenvectors to be cached

  };

}

namespace std {

  template <>
  struct hash<OscProb::EigenPoint> {
    auto operator()(const OscProb::EigenPoint &ep) const -> size_t {
      return hash<double>()(ep.fNE) ^ hash<double>()(ep.fPath.zoa);
    }
  };

}

#endif