/* Copyright 2014,2018,2019,2025,2026 IPB, Universite de Bordeaux, 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       : test_scotch_graph_order.c               **/
/**                                                        **/
/**   AUTHOR     : Francois PELLEGRINI                     **/
/**                                                        **/
/**   FUNCTION   : This module tests the operation of      **/
/**                the SCOTCH_graphOrderCompute*()         **/
/**                routines.                               **/
/**                                                        **/
/**   DATES      : # Version 6.0  : from : 05 aug 2014     **/
/**                                 to   : 01 sep 2019     **/
/**                # Version 7.0  : from : 04 jul 2025     **/
/**                                 to   : 11 apr 2026     **/
/**                                                        **/
/************************************************************/

/*
**  The defines and includes.
*/

#include <stdio.h>
#if (((defined __STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)) || (defined HAVE_STDINT_H))
#include <stdint.h>
#endif /* (((defined __STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)) || (defined HAVE_STDINT_H)) */
#include <stdlib.h>
#include <string.h>

#include "../libscotch/module.h"
#include "../libscotch/common.h"

#include "scotch.h"

/*************************************/
/*                                   */
/* The consistency checking routine. */
/*                                   */
/*************************************/

/* This routine checks that the produced
** permutation and inverse permutation are
** inverses of each other.
** It exits on error.
*/

static
void
checkOrder (
const SCOTCH_Num            baseval,
const SCOTCH_Num            vertnbr,
const SCOTCH_Num * const    permtab,
const SCOTCH_Num * const    peritab)
{
  SCOTCH_Num          vertnum;

  const SCOTCH_Num                  vertnnd = vertnbr + baseval;

  for (vertnum = 0; vertnum < vertnbr; vertnum ++) {  /* Un-based traversal */
    SCOTCH_Num          perival;
    SCOTCH_Num          permval;

    permval = permtab[vertnum];
    if ((permval <  baseval) ||
        (permval >= vertnnd))
      SCOTCH_errorPrint ("checkOrder: invalid permutation value");

    perival = peritab[vertnum];
    if ((perival <  baseval) ||
        (perival >= vertnnd))
      SCOTCH_errorPrint ("checkOrder: invalid inverse permutation value");

    if (peritab[permval - baseval] != (vertnum + baseval))
      SCOTCH_errorPrint ("checkOrder: invalid permutation pair");
  }
}

/*********************/
/*                   */
/* The main routine. */
/*                   */
/*********************/

int
main (
int                 argc,
char *              argv[])
{
  FILE *              fileptr;
  SCOTCH_Graph        grafdat;
  SCOTCH_Ordering     ordedat;
  SCOTCH_Strat        stradat;
  SCOTCH_Num          baseval;
  SCOTCH_Num          vertnbr;
  SCOTCH_Num          vertnum;
  SCOTCH_Num          listnbr;
  SCOTCH_Num          listnum;
  SCOTCH_Num *        listtab;
  SCOTCH_Num *        peritab;
  SCOTCH_Num *        permtab;
  int                 o;

  SCOTCH_errorProg (argv[0]);

  if (argc != 2) {
    SCOTCH_errorPrint ("usage: %s graph_file", argv[0]);
    exit (EXIT_FAILURE);
  }

  o = 0;                                          /* Assume everything will be all right */

  if (SCOTCH_graphInit (&grafdat) != 0) {         /* Initialize source graph */
    SCOTCH_errorPrint ("main: cannot initialize graph");
    exit (EXIT_FAILURE);
  }

  if ((fileptr = fopen (argv[1], "r")) == NULL) {
    SCOTCH_errorPrint ("main: cannot open file (1)");
    exit (EXIT_FAILURE);
  }

  if (SCOTCH_graphLoad (&grafdat, fileptr, -1, 0) != 0) { /* Read source graph */
    SCOTCH_errorPrint ("main: cannot load graph");
    exit (EXIT_FAILURE);
  }

  fclose (fileptr);

  SCOTCH_graphData (&grafdat, &baseval, &vertnbr, NULL, NULL, NULL, NULL, NULL, NULL, NULL);

  listnbr = (vertnbr + 1) / 2;                    /* Only keep half of the vertices in induced graph */
  if ((listtab = malloc (listnbr * sizeof (SCOTCH_Num))) == NULL) {
    SCOTCH_errorPrint ("main: out of memory (1)");
    exit (EXIT_FAILURE);
  }
  for (listnum = 0, vertnum = baseval + (listnbr / 4); /* Keep only middle half of the vertices */
       listnum < listnbr; listnum ++, vertnum ++)
    listtab[listnum] = vertnum;

  if (((peritab = malloc (vertnbr * sizeof (SCOTCH_Num))) == NULL) ||
      ((permtab = malloc (vertnbr * sizeof (SCOTCH_Num))) == NULL)) {
    SCOTCH_errorPrint ("main: out of memory (2)");
    exit (EXIT_FAILURE);
  }

  if ((fileptr = tmpfile ()) == NULL) {           /* Open temporary file for resulting output */
    SCOTCH_errorPrint ("main: cannot open file (2)");
    exit (EXIT_FAILURE);
  }

  if (SCOTCH_stratInit (&stradat) != 0) {         /* Initialize ordering strategy */
    SCOTCH_errorPrint ("main: cannot initialize strategy");
    exit (EXIT_FAILURE);
  }

  if (SCOTCH_graphOrderInit (&grafdat, &ordedat, permtab, peritab, NULL, NULL, NULL) != 0) { /* Initialize ordering */
    SCOTCH_errorPrint ("main: cannot initialize ordering (1)");
    exit (EXIT_FAILURE);
  }

  if (SCOTCH_graphOrderCompute (&grafdat, &ordedat, &stradat) != 0) {
    SCOTCH_errorPrint ("main: cannot order graph");
    exit (EXIT_FAILURE);
  }

  if (SCOTCH_graphOrderCheck (&grafdat, &ordedat) != 0) {
    SCOTCH_errorPrint ("main: invalid ordering (1)");
    exit (EXIT_FAILURE);
  }

  checkOrder (baseval, vertnbr, permtab, peritab); /* Double check permutation validity and bijectivity */

  o |= SCOTCH_graphOrderSave     (&grafdat, &ordedat, fileptr); /* Test ordering data output routines */
  o |= SCOTCH_graphOrderSaveMap  (&grafdat, &ordedat, fileptr);
  o |= SCOTCH_graphOrderSaveTree (&grafdat, &ordedat, fileptr);
  if (o != 0)
    exit (EXIT_FAILURE);

  SCOTCH_graphOrderExit (&grafdat, &ordedat);     /* Free computed ordering */

  if (SCOTCH_graphOrderInit (&grafdat, &ordedat, permtab, peritab, NULL, NULL, NULL) != 0) { /* Initialize ordering again */
    SCOTCH_errorPrint ("main: cannot initialize ordering (2)");
    exit (EXIT_FAILURE);
  }

  if (SCOTCH_graphOrderComputeList (&grafdat, &ordedat, listnbr, listtab, &stradat) != 0) {
    SCOTCH_errorPrint ("main: cannot order induced graph");
    exit (EXIT_FAILURE);
  }

  if (SCOTCH_graphOrderCheck (&grafdat, &ordedat) != 0) {
    SCOTCH_errorPrint ("main: invalid ordering (2)");
    exit (EXIT_FAILURE);
  }

  o |= SCOTCH_graphOrderSave     (&grafdat, &ordedat, fileptr); /* Test ordering data output routines */
  o |= SCOTCH_graphOrderSaveMap  (&grafdat, &ordedat, fileptr);
  o |= SCOTCH_graphOrderSaveTree (&grafdat, &ordedat, fileptr);
  if (o != 0)
    exit (EXIT_FAILURE);

  fclose (fileptr);

  SCOTCH_graphOrderExit (&grafdat, &ordedat);

  free (permtab);
  free (peritab);
  free (listtab);
  SCOTCH_stratExit (&stradat);
  SCOTCH_graphExit (&grafdat);

  exit (EXIT_SUCCESS);
}
