// -*- c++ -*- (enables emacs c++ mode)
//===========================================================================
//
// Copyright (C) 2004-2009 Yves Renard
//
// This file is a part of GETFEM++
//
// Getfem++  is  free software;  you  can  redistribute  it  and/or modify it
// under  the  terms  of the  GNU  Lesser General Public License as published
// by  the  Free Software Foundation;  either version 2.1 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 Lesser General Public
// License for more details.
// You  should  have received a copy of the GNU Lesser General Public License
// along  with  this program;  if not, write to the Free Software Foundation,
// Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
//
// As a special exception, you  may use  this file  as it is a part of a free
// software  library  without  restriction.  Specifically,  if   other  files
// instantiate  templates  or  use macros or inline functions from this file,
// or  you compile this  file  and  link  it  with other files  to produce an
// executable, this file  does  not  by itself cause the resulting executable
// to be covered  by the GNU Lesser General Public License.  This   exception
// does not  however  invalidate  any  other  reasons why the executable file
// might be covered by the GNU Lesser General Public License.
//
//===========================================================================
// To be corrected : dependencies. The mesh fem using this fem will not
//                   depend on the mesh fem arguments.

/**@file getfem_mesh_fem_product.h
   @author Yves Renard <Yves.Renard@insa-lyon.fr>,
   @author Julien Pommier <Julien.Pommier@insa-toulouse.fr>
   @date April 8, 2005.
   @brief A kind of product of two mesh_fems. Specific for Xfem enrichment.
*/

#ifndef GETFEM_MESH_FEM_PRODUCT_H__
#define GETFEM_MESH_FEM_PRODUCT_H__

#include "getfem_mesh_fem.h"

namespace getfem {
  
  class fem_product : public virtual_fem {
    pfem pfems[2];
    size_type cv, xfem_index;
    dal::bit_vector enriched_dof1;
    
  public:

    fem_product(pfem pf1_, pfem pf2_, size_type i, size_type xfi,
		const dal::bit_vector &nn)
      : cv(i), xfem_index(xfi),  enriched_dof1(nn)
    { pfems[0] = pf1_; pfems[1] = pf2_; init(); }
    void init();
    void valid();
    void base_value(const base_node &x, base_tensor &t) const;
    void grad_base_value(const base_node &x, base_tensor &t) const;
    void hess_base_value(const base_node &x, base_tensor &t) const;

    void real_base_value(const fem_interpolation_context& c, 
			 base_tensor &t, bool = true) const;    
    void real_grad_base_value(const fem_interpolation_context& c, 
			      base_tensor &t, bool = true) const;
    void real_hess_base_value(const fem_interpolation_context& c, 
			      base_tensor &t, bool = true) const;
    
  };


  class mesh_fem_product : public mesh_fem {
  protected :
    const mesh_fem &mf1, &mf2;

    mutable std::vector<pfem> build_methods;
    mutable bool is_adapted;
    size_type xfem_index;
    dal::bit_vector enriched_dof;
    void clear_build_methods();

  public :
    void adapt(void);
    void update_from_context(void) const { is_adapted = false; touch(); }
    void clear(void);
    
    size_type memsize() const
    { return mesh_fem::memsize(); /* + ... */ }
    
    mesh_fem_product(const mesh_fem &me1, const mesh_fem &me2)
      : mesh_fem(me1.linked_mesh()), mf1(me1), mf2(me2)
    { is_adapted = false; xfem_index = reserve_xfem_index(); }
    void set_enrichment(const dal::bit_vector &nn)
    { enriched_dof = nn; adapt(); }
    
    ~mesh_fem_product() { clear_build_methods(); }
  };


}  /* end of namespace getfem.                                            */

#endif
  
