/* Copyright 2007 ENSEIRB, INRIA & CNRS
**
** This file is part of the Scotch software package for static mapping,
** graph partitioning and sparse matrix ordering.
**
** This software is governed by the CeCILL-C license under French law
** and abiding by the rules of distribution of free software. You can
** use, modify and/or redistribute the software under the terms of the
** CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
** URL: "http://www.cecill.info".
** 
** As a counterpart to the access to the source code and rights to copy,
** modify and redistribute granted by the license, users are provided
** only with a limited warranty and the software's author, the holder of
** the economic rights, and the successive licensors have only limited
** liability.
** 
** In this respect, the user's attention is drawn to the risks associated
** with loading, using, modifying and/or developing or reproducing the
** software by the user in light of its specific status of free software,
** that may mean that it is complicated to manipulate, and that also
** therefore means that it is reserved for developers and experienced
** professionals having in-depth computer knowledge. Users are therefore
** encouraged to load and test the software's suitability as regards
** their requirements in conditions enabling the security of their
** systems and/or data to be ensured and, more generally, to use and
** operate it in the same conditions as regards security.
** 
** The fact that you are presently reading this means that you have had
** knowledge of the CeCILL-C license and that you accept its terms.
*/
/************************************************************/
/**                                                        **/
/**   NAME       : metis_graph_order.c                     **/
/**                                                        **/
/**   AUTHOR     : Francois PELLEGRINI                     **/
/**                                                        **/
/**   FUNCTION   : This module is the compatibility        **/
/**                library for the MeTiS ordering          **/
/**                routines.                               **/
/**                                                        **/
/**   DATES      : # Version 5.0  : from : 08 sep 2006     **/
/**                                 to     07 jun 2007     **/
/**                                                        **/
/************************************************************/

/*
**  The defines and includes.
*/

#define LIBRARY

#include "common.h"
#include "scotch.h"
#include "metis.h"                                /* Our "metis.h" file */

/************************************/
/*                                  */
/* These routines are the C API for */
/* MeTiS graph ordering routines.   */
/*                                  */
/************************************/

/*
**
*/

void
METIS_EdgeND (
const int * const           n,
const int * const           xadj,
const int * const           adjncy,
const int * const           numflag,
const int * const           options,
int * const                 perm,
int * const                 iperm)
{
  METIS_NodeWND (n, xadj, adjncy, NULL, numflag, options, perm, iperm);
}

/*
**
*/

void
METIS_NodeND (
const int * const           n,
const int * const           xadj,
const int * const           adjncy,
const int * const           numflag,
const int * const           options,
int * const                 perm,
int * const                 iperm)
{
  METIS_NodeWND (n, xadj, adjncy, NULL, numflag, options, perm, iperm);
}

/*
**
*/

void
METIS_NodeWND (
const int * const           n,
const int * const           xadj,
const int * const           adjncy,
const int * const           vwgt,
const int * const           numflag,
const int * const           options,
int * const                 perm,
int * const                 iperm)
{
  SCOTCH_Graph        grafdat;                    /* Scotch graph object to interface with libScotch    */
  SCOTCH_Ordering     ordedat;                    /* Scotch ordering object to interface with libScotch */
  SCOTCH_Strat        stradat;

  if (sizeof (SCOTCH_Num) != sizeof (int)) {
    SCOTCH_errorPrint ("METIS_*ND (as of SCOTCH): SCOTCH_Num type should equate to int");
    return;
  }

  SCOTCH_graphInit (&grafdat);

  if (SCOTCH_graphBuild (&grafdat,
                         *numflag, *n, xadj, xadj + 1, vwgt, NULL,
                         xadj[*n] - *numflag, adjncy, NULL) == 0) {
    SCOTCH_stratInit (&stradat);
#ifdef SCOTCH_DEBUG_ALL
    if (SCOTCH_graphCheck (&grafdat) == 0)        /* TRICK: next instruction called only if graph is consistent */
#endif /* SCOTCH_DEBUG_ALL */
    {
      if (SCOTCH_graphOrderInit (&grafdat, &ordedat, iperm, perm, /* MeTiS and Scotch have opposite definitions for (inverse) permutations */
                                 NULL, NULL, NULL) == 0) {
        SCOTCH_graphOrderCompute (&grafdat, &ordedat, &stradat);
        SCOTCH_graphOrderExit    (&grafdat, &ordedat);
      }
    }
    SCOTCH_stratExit (&stradat);
  }
  SCOTCH_graphExit (&grafdat);
}