penalty.h

#pragma once

#include "mpicontroller.h"
#include "externalpotential.h"
#include "reactioncoordinate.h"
#include "aux/table_1d.h"

namespace Faunus::Energy {

class Penalty : public EnergyTerm
{
  private:
    const Space& spc;
    std::string penalty_function_filename;
    std::string histogram_filename;
    bool overwrite_penalty = true; // overwrite input penalty function?
    void loadPenaltyFunction(const std::string& filename);
    void toDisk(); 
    void initializePenaltyFunction(const json& j);
    void to_json(json& j) const override;
    virtual void updatePenalty(const std::vector<double>& coordinate);

  protected:
    typedef typename std::shared_ptr<ReactionCoordinate::ReactionCoordinateBase> Tcoord;
    bool verbose = false;           
    bool avoid_energy_drift = true; 
    size_t number_of_reaction_coordinates = 0; 
    size_t update_counter = 0;                 
    size_t number_of_steps_between_updates;    
    size_t penalty_function_exchange_counter = 0;
    size_t samplings;
    double sum_of_energy_increments = 0; 
    double energy_increment_scaling_factor = 1.0;       
    double energy_increment = 0.0;                      
    std::vector<Tcoord> reaction_coordinates_functions; 
    std::vector<double> latest_coordinate; 

    Table<unsigned int> histogram;      
    Table<double> penalty_energy;       
    void logBarrierInformation() const; 

  public:
    Penalty(const json& j, const Space& spc);
    ~Penalty() override; 
    double energy(const Change& change) override;
    void sync(EnergyTerm* other, const Change& change) override;
    void streamPenaltyFunction(std::ostream& stream) const;
    void streamHistogram(std::ostream& stream) const;
};

#ifdef ENABLE_MPI

class PenaltyMPI : public Penalty
{
  private:
    const MPI::Controller& mpi;
    Eigen::VectorXi weights; 
    Eigen::VectorXd buffer;  
    void updatePenalty(const std::vector<double>& coordinate)
        override;                   
    void averagePenaltyFunctions(); 
  public:
    PenaltyMPI(const json& j, Space& spc, const MPI::Controller& mpi);
};
#endif

} // namespace Faunus::Energy