/* -*- mia-c++  -*-
 *
 * This file is part of MIA - a toolbox for medical image analysis
 * Copyright (c) Leipzig, Madrid 1999-2017 Gert Wollny
 *
 * MIA is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with MIA; if not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef mia_core_regmodel_hh
#define mia_core_regmodel_hh

#include <mia/core/factory.hh>

NS_MIA_BEGIN

struct EXPORT_CORE regmodel_type {
       static const char *type_descr;
};

/**
   @cond INTERNAL
   \ingroup traits
   \brief a trait to provide some information about the registration objects
*/
template <int Dim>
struct RegistrationTraits {
       typedef void need_to_declare_RegistrationTraits_for_DIM;
       typedef need_to_declare_RegistrationTraits_for_DIM Data;
       typedef need_to_declare_RegistrationTraits_for_DIM Force;
       typedef need_to_declare_RegistrationTraits_for_DIM Transformation;
};
/// @endcond

/**
   \ingroup registration
   \brief Base class for PDE model based registrations

   Generic base class template for PDE based image registration models.

   \tparam Dim dimension of registration model
*/
template <int Dim>
class TRegModel : public CProductBase
{
public:
       /// Imaga data type for the registration model
       typedef typename RegistrationTraits<Dim>::Data Data;

       /// gradient force data type for the registration model
       typedef typename RegistrationTraits<Dim>::Force Force;

       /// transformation type for the registrationmodel
       typedef typename RegistrationTraits<Dim>::Transformation Transformation;

       /// plug-in helper type for search path evaluation
       typedef regmodel_type plugin_type;

       /// plug-in helper type for search path evaluation
       typedef Data plugin_data;

       TRegModel();
       virtual ~TRegModel();

       /**
          PDE solver for the registration model
          \param[in] b force the gradient force of the cost function
          \param[in,out] x estimated transformation direction that can be further optimized
          by a line search
          \remark the naming needs to be reviewed,
       */
       void solve (const Force& b, Transformation& x) const;

       /**
          \returns the scaling applied to the gradient force
          \remark why is this needed?
       */
       float get_force_scale() const;
private:
       virtual void do_solve(const Force& b, Transformation& x) const = 0;
       virtual float do_get_force_scale() const;
};

//
// implementation part of the registration model
//

template <int Dim>
TRegModel<Dim>::TRegModel()
{
}

template <int Dim>
TRegModel<Dim>::~TRegModel()
{
}

template <int Dim>
void TRegModel<Dim>::solve (const Force& b, Transformation& x) const
{
       do_solve(b, x);
}

template <int Dim>
float TRegModel<Dim>::get_force_scale() const
{
       return do_get_force_scale();
}

template <int Dim>
float  TRegModel<Dim>::do_get_force_scale() const
{
       return 1.0f;
}

NS_MIA_END

#endif
