static const char help[] = "Test ParMETIS handling of negative weights.\n\n";

/* Test contributed by John Fettig */

/*
 * This file implements two tests for a bug reported in ParMETIS. These tests are not expected to pass without the
 * patches in the PETSc distribution of ParMetis. See parmetis.py
 *
 *
 * The bug was reported upstream, but has received no action so far.
 *
 * http://glaros.dtc.umn.edu/gkhome/node/837
 *
 */

#include <petscsys.h>
#include <parmetis.h>

#define PetscCallPARMETIS(...) \
  do { \
    int metis_ierr = __VA_ARGS__; \
    PetscCheck(metis_ierr != METIS_ERROR_INPUT, PETSC_COMM_SELF, PETSC_ERR_LIB, "ParMETIS error due to wrong inputs and/or options"); \
    PetscCheck(metis_ierr != METIS_ERROR_MEMORY, PETSC_COMM_SELF, PETSC_ERR_LIB, "ParMETIS error due to insufficient memory"); \
    PetscCheck(metis_ierr != METIS_ERROR, PETSC_COMM_SELF, PETSC_ERR_LIB, "ParMETIS general error"); \
  } while (0)

int main(int argc, char *argv[])
{
  PetscBool   flg;
  PetscMPIInt rank, size;
  idx_t       ni, isize, *vtxdist, *xadj, *adjncy, *vwgt, *part;
  idx_t       wgtflag = 0, numflag = 0, ncon = 1, ndims = 3, edgecut = 0;
  idx_t       options[5];
  PetscReal  *xyz;
  real_t     *sxyz, *tpwgts, ubvec[1];
  MPI_Comm    comm;
  FILE       *fp;
  char        fname[PETSC_MAX_PATH_LEN], prefix[PETSC_MAX_PATH_LEN] = "";
  size_t      red;

  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &argv, NULL, help));
#if defined(PETSC_USE_64BIT_INDICES)
  PetscCall(PetscPrintf(PETSC_COMM_WORLD, "This example only works with 32-bit indices\n"));
  PetscCall(PetscFinalize());
  return 0;
#endif
  MPI_Comm_rank(PETSC_COMM_WORLD, &rank);
  MPI_Comm_size(PETSC_COMM_WORLD, &size);

  PetscOptionsBegin(PETSC_COMM_WORLD, NULL, "Parmetis test options", "");
  PetscCall(PetscOptionsString("-prefix", "Path and prefix of test file", "", prefix, prefix, sizeof(prefix), &flg));
  PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must specify -prefix");
  PetscOptionsEnd();

  PetscCall(PetscMalloc1(size + 1, &vtxdist));

  PetscCall(PetscSNPrintf(fname, sizeof(fname), "%s.%d.graph", prefix, rank));

  PetscCall(PetscFOpen(PETSC_COMM_SELF, fname, "r", &fp));

  red = fread(vtxdist, sizeof(idx_t), size + 1, fp);
  PetscCheck(red == (size_t)(size + 1), PETSC_COMM_SELF, PETSC_ERR_SYS, "Unable to read from data file");

  ni = vtxdist[rank + 1] - vtxdist[rank];

  PetscCall(PetscMalloc1(ni + 1, &xadj));

  red = fread(xadj, sizeof(idx_t), ni + 1, fp);
  PetscCheck(red == (size_t)(ni + 1), PETSC_COMM_SELF, PETSC_ERR_SYS, "Unable to read from data file");

  PetscCall(PetscMalloc1(xadj[ni], &adjncy));

  for (PetscInt i = 0; i < ni; i++) {
    red = fread(&adjncy[xadj[i]], sizeof(idx_t), xadj[i + 1] - xadj[i], fp);
    PetscCheck(red == (size_t)(xadj[i + 1] - xadj[i]), PETSC_COMM_SELF, PETSC_ERR_SYS, "Unable to read from data file");
  }

  PetscCall(PetscFClose(PETSC_COMM_SELF, fp));

  PetscCall(PetscSNPrintf(fname, sizeof(fname), "%s.%d.graph.xyz", prefix, rank));
  PetscCall(PetscFOpen(PETSC_COMM_SELF, fname, "r", &fp));

  PetscCall(PetscMalloc3(ni * ndims, &xyz, ni, &part, size, &tpwgts));
  PetscCall(PetscMalloc1(ni * ndims, &sxyz));

  red = fread(xyz, sizeof(PetscReal), ndims * ni, fp);
  PetscCheck(red == (size_t)(ndims * ni), PETSC_COMM_SELF, PETSC_ERR_SYS, "Unable to read from data file");
  for (PetscInt i = 0; i < ni * ndims; i++) sxyz[i] = (size_t)xyz[i];

  PetscCall(PetscFClose(PETSC_COMM_SELF, fp));

  vwgt = NULL;

  for (PetscInt i = 0; i < size; i++) tpwgts[i] = 1. / size;
  isize = size;

  ubvec[0]   = 1.05;
  options[0] = 0;
  options[1] = 2;
  options[2] = 15;
  options[3] = 0;
  options[4] = 0;

  PetscCallMPI(MPI_Comm_dup(MPI_COMM_WORLD, &comm));
  PetscCallPARMETIS(ParMETIS_V3_PartGeomKway(vtxdist, xadj, adjncy, vwgt, NULL, &wgtflag, &numflag, &ndims, sxyz, &ncon, &isize, tpwgts, ubvec, options, &edgecut, part, &comm));
  PetscCallMPI(MPI_Comm_free(&comm));

  PetscCall(PetscFree(vtxdist));
  PetscCall(PetscFree(xadj));
  PetscCall(PetscFree(adjncy));
  PetscCall(PetscFree3(xyz, part, tpwgts));
  PetscCall(PetscFree(sxyz));
  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   build:
      requires: parmetis

   test:
      nsize: 2
      requires: parmetis datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
      args: -prefix ${DATAFILESPATH}/parmetis-test/testnp2

   test:
      suffix: 2
      nsize: 4
      requires: parmetis datafilespath !complex double !defined(PETSC_USE_64BIT_INDICES)
      args: -prefix ${DATAFILESPATH}/parmetis-test/testnp4

TEST*/