// Copyright (C) 2007, 2008, 2009 EPITA Research and Development Laboratory (LRDE)
//
// This file is part of Olena.
//
// Olena 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, version 2 of the License.
//
// Olena 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 Olena.  If not, see <http://www.gnu.org/licenses/>.
//
// As a special exception, you may use this file as part of a free
// software project 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 General Public License.  This
// exception does not however invalidate any other reasons why the
// executable file might be covered by the GNU General Public License.

#ifndef MLN_ACCU_COUNT_ADJACENT_VERTICES_HH
# define MLN_ACCU_COUNT_ADJACENT_VERTICES_HH

/// \file
///
/// Define an accumulator that counts the vertices adjacent to a
/// set of p_edges psites.

# include <mln/accu/internal/base.hh>
# include <mln/core/concept/meta_accumulator.hh>
# include <mln/pw/image.hh>
# include <mln/util/pix.hh>

namespace mln
{

  namespace accu
  {

    /// \brief Accumulator class counting the number of vertices
    /// adjacent to a set of mln::p_edges_psite (i.e., a set of
    /// edges).
    ///
    /// The type to be count is mln::util::pix< pw::image<F, S> >
    /// where \p F and \p S are the parameters of this class.
    ///
    /// This accumulator is used by mln::closing_area_on_vertices and
    /// mln::opening_area_on_vertices.
    ///
    /// \ingroup modaccuimages
    //
    template <typename F, typename S>
    struct count_adjacent_vertices
      : public mln::accu::internal::base< unsigned,
					  count_adjacent_vertices<F,S> >
    {
      typedef mln::util::pix< pw::image<F,S> > argument;

      count_adjacent_vertices();

      /// Manipulators.
      /// \{
      void init();
      void take(const argument& arg);
      void take(const count_adjacent_vertices<F,S>& other);

      /// Force the value of the counter to \a c.
      void set_value(unsigned c);
      /// \}

      /// Get the value of the accumulator.
      unsigned to_result() const;

      /// Return whether this accu can return a result.
      bool is_valid() const;

    protected:
      /// Update the value of the counter.
      void update_ ();

    protected:
      /// The value of the counter.
      unsigned count__;
      /// The set of adjacent vertices.
      std::set<unsigned> vertices_;
    };


    namespace meta
    {

      /// Meta accumulator for count_adjacent_vertices.
      struct count_adjacent_vertices
	: public Meta_Accumulator< count_adjacent_vertices >
      {
	template <typename F, typename S>
	  struct with
	  {
	    typedef accu::count_adjacent_vertices<F,S> ret;
	  };
      };

    } // end of namespace mln::accu::meta


# ifndef MLN_INCLUDE_ONLY

    template <typename F, typename S>
    inline
    count_adjacent_vertices<F,S>::count_adjacent_vertices()
    {
      init();
    }

    template <typename F, typename S>
    inline
    void
    count_adjacent_vertices<F,S>::init()
    {
      vertices_.clear();
      update_();
    }

    template <typename F, typename S>
    inline
    void
    count_adjacent_vertices<F,S>::take(const argument& arg)
    {
      vertices_.insert(arg.p().v1());
      vertices_.insert(arg.p().v2());
      update_();
    }

    template <typename F, typename S>
    inline
    void
    count_adjacent_vertices<F,S>::take(const count_adjacent_vertices<F,S>& other)
    {
      vertices_.insert (other.vertices_.begin(), other.vertices_.end());
      update_();
    }

    template <typename F, typename S>
    inline
    unsigned
    count_adjacent_vertices<F,S>::to_result() const
    {
      return count__;
    }

    template <typename F, typename S>
    inline
    void
    count_adjacent_vertices<F,S>::set_value(unsigned c)
    {
      count__ = c;
      /// Reset the other member.
      vertices_.clear();
    }

    template <typename F, typename S>
    inline
    void
    count_adjacent_vertices<F,S>::update_()
    {
      count__ = vertices_.size();
    }

    template <typename F, typename S>
    inline
    bool
    count_adjacent_vertices<F,S>::is_valid() const
    {
      return true;
    }

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::accu

} // end of namespace mln


#endif // ! MLN_ACCU_COUNT_ADJACENT_VERTICES_HH