/*
 Copyright (C) 2014 Eugenio Gianniti <eugenio.gianniti@mail.polimi.it>

 This program 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
 this program; if not, see <http://www.gnu.org/licenses/>.
*/

#include <dolfin.h>
#include "mesh.h"
#include "meshfunction.h"
#include "dolfin_compat.h"

DEFUN_DLD (MeshFunction, args, nargout, "-*- texinfo -*-\n\
@deftypefn {Function File} {[@var{meshfunc}]} = \
MeshFunction (@var{Mesh}, @var{filename})\n\
@deftypefnx {Function File} {[@var{meshfunc}]} = \
MeshFunction (@var{type}, @var{Mesh}, @var{filename})\n\
@deftypefnx {Function File} {[@var{meshfunc}]} = \
MeshFunction (@var{type}, @var{Mesh}, @var{dim}, @var{value}) \n\
Initialize a meshfunction with the values contained in a file.\n\
The output @var{meshfunc} is an object which contains a representation of the \
meshfunction in @var{filename} which can be used to mark subdomains or \
facets where Dirichlet boundary conditions are to be applied.\n\
Optionally, you can set a label identifying the @var{type} of markers, \
in order to use @var{meshfunc} to mark subdomains in BilinearForm or \
LinearForm. Three labels are recognized: ""dx"" for cell markers, \
""ds"" for exterior facets and ""dS"" for interior facets.\n\
With the third invocation listed above it is possible to initialize \
a meshfunction of topological dimension @var{dim} on @var{Mesh}, setting all \
of its values to @var{value}, which is an integer.\n\
@seealso{DirichletBC, save, BilinearForm, LinearForm, mark}\n\
@end deftypefn")
{

  int nargin = args.length ();
  octave_value retval;

  if (nargin < 2 || nargin > 4 || nargout > 1)
    { print_usage (); }
  else
    {
      if (! mesh_type_loaded)
        {
          mesh::register_type ();
          mesh_type_loaded = true;
          mlock ();
        }

      if (! meshfunction_type_loaded)
        {
          meshfunction::register_type ();
          meshfunction_type_loaded = true;
          mlock ();
        }

      octave_idx_type offset = 0;
      std::string label;

      if (args(0).is_string ())
        {
          label = args(0).string_value ();
          offset = 1;
        }

      if (args(0 + offset).type_id () == mesh::static_type_id ())
        {
          mesh const & msh_arg =
            static_cast<mesh const &> (args(0 + offset).get_rep ());

          if (args(1 + offset).is_string ())
            {
              std::string filename = args(1 + offset).string_value ();
              if (!error_state)
                {
                  SHARED_PTR <dolfin::Mesh const> const &
                    pmsh = msh_arg.get_pmsh ();

                  try
                    { retval = new meshfunction (label, pmsh, filename); }
                  catch (std::runtime_error &)
                    { error ("error reading file"); }
                }
            }
          else if (args(1 + offset).is_real_scalar () &&
                   args(2 + offset).is_real_scalar ())
            {
              std::size_t dim = args(1 + offset).ulong_value ();
              std::size_t value = args(2 + offset).ulong_value ();

              if (!error_state)
                {
                  SHARED_PTR <dolfin::Mesh const> const &
                    pmsh = msh_arg.get_pmsh ();

                  retval = new meshfunction (label, pmsh, dim, value);
                }
            }
          else
            { error ("invalid input arguments"); }
        }
      else
        { error ("invalid input arguments"); }
    }

  return retval;
}