//
//  Copyright (C) 2013 Paolo Tosco
//
//  Copyright (C) 2004-2006 Rational Discovery LLC
//
//   @@ All Rights Reserved @@
//  This file is part of the RDKit.
//  The contents are covered by the terms of the BSD license
//  which is included in the file license.txt, found at the root
//  of the RDKit source tree.
//
#ifndef __RD_MMFFTORSIONCONSTRAINT_H__
#define __RD_MMFFTORSIONCONSTRAINT_H__
#include <iostream>
#include <ForceField/Contrib.h>

namespace ForceFields {
  namespace MMFF {

    //! A dihedral angle range constraint modelled after a TorsionContrib
    class TorsionConstraintContrib : public ForceFieldContrib {
    public:
      TorsionConstraintContrib() : d_at1Idx(-1), d_at2Idx(-1), d_at3Idx(-1), d_at4Idx(-1) {};
      //! Constructor
      /*!
      \param owner          pointer to the owning ForceField
      \param idx1           index of atom1 in the ForceField's positions
      \param idx2           index of atom2 in the ForceField's positions
      \param idx3           index of atom3 in the ForceField's positions
      \param idx4           index of atom4 in the ForceField's positions
      \param minDihedralDeg minimum dihedral angle
      \param maxDihedralDeg maximum dihedral angle
      \param forceConst     force Constant
	
      */
      TorsionConstraintContrib(ForceField *owner, unsigned int idx1,
        unsigned int idx2, unsigned int idx3, unsigned int idx4,
        double minDihedralDeg, double maxDihedralDeg, double forceConst);
      TorsionConstraintContrib(ForceField *owner, unsigned int idx1,
        unsigned int idx2, unsigned int idx3, unsigned int idx4,
        bool relative, double minDihedralDeg, double maxDihedralDeg,
        double forceConst);

      ~TorsionConstraintContrib() {
      }
      double getEnergy(double *pos) const;

      void getGrad(double *pos, double *grad) const;
      virtual TorsionConstraintContrib *copy() const { return new TorsionConstraintContrib(*this); };
    private:
      int d_at1Idx, d_at2Idx, d_at3Idx, d_at4Idx; //!< indices of atoms forming the dihedral angle
      double d_minDihedralDeg, d_maxDihedralDeg;        //!< rest amplitudes of the dihedral angle
      double d_forceConstant;  //!< force constant of the angle constraint

    };
  }
}
#endif
