// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
#include <config.h>

#include <dune/geometry/genericgeometry/subtopologies.hh>

namespace Dune
{

  namespace GenericGeometry
  {

    // size
    // ----

    unsigned int size ( unsigned int topologyId, int dim, int codim )
    {
      assert( (dim >= 0) && (topologyId < numTopologies( dim )) );
      assert( (0 <= codim) && (codim <= dim) );

      if( codim > 0 )
      {
        const unsigned int baseId = baseTopologyId( topologyId, dim );
        const unsigned int m = size( baseId, dim-1, codim-1 );

        if( isPrism( topologyId, dim ) )
        {
          const unsigned int n = (codim < dim ? size( baseId, dim-1, codim ) : 0);
          return n + 2*m;
        }
        else
        {
          assert( isPyramid( topologyId, dim ) );
          const unsigned int n = (codim < dim ? size( baseId, dim-1, codim ) : 1);
          return m+n;
        }
      }
      else
        return 1;
    }



    // subTopologyId
    // -------------

    unsigned int subTopologyId ( unsigned int topologyId, int dim, int codim, unsigned int i )
    {
      assert( i < size( topologyId, dim, codim ) );
      const int mydim = dim - codim;

      if( codim > 0 )
      {
        const unsigned int baseId = baseTopologyId( topologyId, dim );
        const unsigned int m = size( baseId, dim-1, codim-1 );

        if( isPrism( topologyId, dim ) )
        {
          const unsigned int n = (codim < dim ? size( baseId, dim-1, codim ) : 0);
          if( i < n )
            return subTopologyId( baseId, dim-1, codim, i ) | ((unsigned int)prismConstruction << (mydim - 1));
          else
            return subTopologyId( baseId, dim-1, codim-1, (i < n+m ? i-n : i-(n+m)) );
        }
        else
        {
          assert( isPyramid( topologyId, dim ) );
          if( i < m )
            return subTopologyId( baseId, dim-1, codim-1, i );
          else if( codim < dim )
            return subTopologyId( baseId, dim-1, codim, i-m ) | ((unsigned int)pyramidConstruction << (mydim - 1));
          else
            return 0u;
        }
      }
      else
        return topologyId;
    }



    // subTopologyNumbering
    // --------------------

    void subTopologyNumbering ( unsigned int topologyId, int dim, int codim, unsigned int i, int subcodim,
                                unsigned int *beginOut, unsigned int *endOut )
    {
      assert( (codim >= 0) && (subcodim >= 0) && (codim + subcodim <= dim) );
      assert( i < size( topologyId, dim, codim ) );
      assert( (endOut - beginOut) == size( subTopologyId( topologyId, dim, codim, i ), dim-codim, subcodim ) );

      if( codim == 0 )
      {
        for( unsigned int j = 0; (beginOut + j) != endOut; ++j )
          *(beginOut + j) = j;
      }
      else if( subcodim == 0 )
      {
        assert( endOut = beginOut + 1 );
        *beginOut = i;
      }
      else
      {
        const unsigned int baseId = baseTopologyId( topologyId, dim );

        const unsigned int m = size( baseId, dim-1, codim-1 );

        const unsigned int mb = size( baseId, dim-1, codim+subcodim-1 );
        const unsigned int nb = (codim + subcodim < dim ? size( baseId, dim-1, codim+subcodim ) : 0);

        if( isPrism( topologyId, dim ) )
        {
          const unsigned int n = size( baseId, dim-1, codim );
          if( i < n )
          {
            const unsigned int subId = subTopologyId( baseId, dim-1, codim, i );

            unsigned int *beginBase = beginOut;
            if( codim + subcodim < dim )
            {
              beginBase = beginOut + size( subId, dim-codim-1, subcodim );
              subTopologyNumbering( baseId, dim-1, codim, i, subcodim, beginOut, beginBase );
            }

            const unsigned int ms = size( subId, dim-codim-1, subcodim-1 );
            subTopologyNumbering( baseId, dim-1, codim, i, subcodim-1, beginBase, beginBase+ms );
            for( unsigned int j = 0; j < ms; ++j )
            {
              *(beginBase+j) += nb;
              *(beginBase+j+ms) = *(beginBase+j) + mb;
            }
          }
          else
          {
            const unsigned int s = (i < n+m ? 0 : 1);
            subTopologyNumbering( baseId, dim-1, codim-1, i-(n+s*m), subcodim, beginOut, endOut );
            for( unsigned int *it = beginOut; it != endOut; ++it )
              *it += nb + s*mb;
          }
        }
        else
        {
          assert( isPyramid( topologyId, dim ) );

          if( i < m )
            subTopologyNumbering( baseId, dim-1, codim-1, i, subcodim, beginOut, endOut );
          else
          {
            const unsigned int subId = subTopologyId( baseId, dim-1, codim, i-m );
            const unsigned int ms = size( subId, dim-codim-1, subcodim-1 );

            subTopologyNumbering( baseId, dim-1, codim, i-m, subcodim-1, beginOut, beginOut+ms );
            if( codim+subcodim < dim )
            {
              subTopologyNumbering( baseId, dim-1, codim, i-m, subcodim, beginOut+ms, endOut );
              for( unsigned int *it = beginOut + ms; it != endOut; ++it )
                *it += mb;
            }
            else
              *(beginOut + ms) = mb;
          }
        }
      }
    }

  } // namespace GenericGeometry

} // namespace Dune
