//  ************************************************************************************************
//
//  BornAgain: simulate and fit reflection and scattering
//
//! @file      Fit/Minimizer/IMinimizer.h
//! @brief     Defines interface IMinimizer.
//!
//! @homepage  http://www.bornagainproject.org
//! @license   GNU General Public License v3 or higher (see COPYING)
//! @copyright Forschungszentrum Jülich GmbH 2018
//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
//
//  ************************************************************************************************

#ifndef BORNAGAIN_FIT_MINIMIZER_IMINIMIZER_H
#define BORNAGAIN_FIT_MINIMIZER_IMINIMIZER_H

#include "Fit/Minimizer/MinimizerResult.h"
#include "Fit/Minimizer/Types.h"
#include <string>

namespace mumufit {
class Parameters;
}

//! Abstract base class for all kind minimizers.

class IMinimizer {
public:
    IMinimizer();
    virtual ~IMinimizer();

    IMinimizer(const IMinimizer& other) = delete;
    IMinimizer& operator=(const IMinimizer& other) = delete;

    //! Returns name of the minimizer.
    virtual std::string minimizerName() const = 0;

    //! Return name of the minimization algorithm.
    virtual std::string algorithmName() const = 0;

    //! Runs minimization.
    virtual mumufit::MinimizerResult minimize_scalar(fcn_scalar_t, mumufit::Parameters);
    //! Runs minimization.
    virtual mumufit::MinimizerResult minimize_residual(fcn_residual_t, mumufit::Parameters);

    //! Clears resources (parameters) for consecutives minimizations.
    virtual void clear() {}

    //! Returns minimum function value.
    virtual double minValue() const;

    //! Sets option string to the minimizer.
    virtual void setOptions(const std::string& options);

#ifndef SWIG
    //! Returns true if minimizer computations are residual-based, false otherwise.
    virtual bool requiresResiduals()
    {
        return false;
    }
#endif // SWIG
};

#endif // BORNAGAIN_FIT_MINIMIZER_IMINIMIZER_H
