#ifndef TMinuitMinimizer_hxx_seen
#define TMinuitMinimizer_hxx_seen

#include <TObject.h>

#include "IMinimizer.hxx"
#include <TMinuit.h>

namespace COMET {
    class TMinuitMinimizer;
};

/// A Concrete IMinimizer using a gradient minimization routine (see \ref
/// minimization). This uses Minuit.  The primary difference between this and
/// the ISimplexMinimizer is that this uses the "MINIMIZE" option which
/// requires the gradient.  For a smooth function, this can do better than
/// SIMPLEX, but if the function isn't smooth, it does much worse.  See a
/// reference book like "Numerical Recipes" for a detailed discussion of
/// fitting methods.
class COMET::TMinuitMinimizer : public COMET::IMinimizer, public TMinuit {
public:
    using IMinimizer::GetParameter;
    using TMinuit::GetParameter;

    TMinuitMinimizer(IMinimizerFunc& func);
    virtual ~TMinuitMinimizer() { }

    /// Override TMinuit virtual member function to provide our
    /// own minimizing function.
    Int_t  Eval(Int_t npar, Double_t *grad,
                Double_t &fval, Double_t *par, Int_t flag);

    
    /// Get the current estimated value of a parameter.
    virtual double GetParameter(int i) const;

    /// Get the i,j element of the covariance matrix
    virtual double GetCovariance(int i, int j) const;

    /// Get the current minimum value of the function.
    virtual double GetMinimum(void) const;
    
    /// Get the status of the last optimization.
    virtual int GetStatus(void) const;

    /// Set the precision for the minimum to be found.
    virtual void SetPrecision(double accuracy);

    /// Set the printing level of Minuit's output.
    virtual Int_t SetPrintLevel(int printLevel);

protected:
    /// Minimize using Minuit.
    virtual int Minimize(int npar, double *par);

private: 
    /// The minimum value found by the last call to Minimize.
    double fMinimum;

    /// The status of the last call to Minimize.
    int fStatus;

};

#endif