static char help[] = "Tests ISSortGlobal().\n\n";

#include <petscis.h>

int main(int argc, char **argv)
{
  IS          is;
  PetscInt    n, i, first, last, nmax = 100;
  PetscMPIInt rank;
  PetscRandom randsizes, randvalues;
  PetscReal   r;
  PetscInt   *keys, *keyscopy, *keyseven, *keyssorted;
  PetscLayout map, mapeven;
  PetscBool   sorted;
  MPI_Comm    comm;

  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &argv, NULL, help));
  comm = MPI_COMM_WORLD;
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  PetscOptionsBegin(comm, "", "Parallel Sort Test Options", "IS");
  PetscCall(PetscOptionsBoundedInt("-nmax", "Maximum number of keys per process", "ex11.c", nmax, &nmax, NULL, 0));
  PetscOptionsEnd();

  PetscCall(PetscRandomCreate(comm, &randsizes));
  PetscCall(PetscRandomSetInterval(randsizes, 0., PetscMax(nmax, 1)));
  PetscCall(PetscRandomSetOptionsPrefix(randsizes, "sizes_"));
  PetscCall(PetscRandomSetFromOptions(randsizes));

  PetscCall(PetscRandomCreate(comm, &randvalues));
  PetscCall(PetscRandomSetOptionsPrefix(randvalues, "values_"));
  PetscCall(PetscRandomSetFromOptions(randvalues));

  PetscCall(PetscRandomGetValueReal(randsizes, &r));
  n = (PetscInt)PetscMin(r, nmax);
  PetscCall(PetscRandomSetInterval(randsizes, 0., 1.));
  PetscCall(PetscRandomGetValueReal(randsizes, &r));
  first = PETSC_INT_MIN + 1 + (PetscInt)((PETSC_INT_MAX - 1) * r);
  PetscCall(PetscRandomGetValueReal(randsizes, &r));
  last = first + (PetscInt)((PETSC_INT_MAX - 1) * r);

  PetscCall(PetscRandomSetInterval(randvalues, first, last));
  PetscCall(PetscMalloc3(n, &keys, n, &keyscopy, n, &keyssorted));
  for (i = 0; i < n; i++) {
    PetscCall(PetscRandomGetValueReal(randvalues, &r));
    keys[i] = keyscopy[i] = (PetscInt)r;
  }
  PetscCall(ISCreateGeneral(comm, n, keys, PETSC_USE_POINTER, &is));
  PetscCall(ISViewFromOptions(is, NULL, "-keys_view"));

  PetscCall(ISGetLayout(is, &map));
  PetscCall(PetscLayoutCreateFromSizes(map->comm, PETSC_DECIDE, map->N, 1, &mapeven));
  PetscCall(PetscLayoutSetUp(mapeven));
  PetscCall(PetscMalloc1(mapeven->n, &keyseven));

  PetscCall(PetscParallelSortInt(map, mapeven, keys, keyseven));
  PetscCall(PetscParallelSortedInt(mapeven->comm, mapeven->n, keyseven, &sorted));
  PetscCheck(sorted, mapeven->comm, PETSC_ERR_PLIB, "PetscParallelSortInt() failed to sort");
  for (i = 0; i < n; i++) PetscCheck(keys[i] == keyscopy[i], PETSC_COMM_SELF, PETSC_ERR_PLIB, "PetscParallelSortInt() modified input array");

  PetscCall(PetscParallelSortInt(map, map, keys, keyssorted));
  PetscCall(PetscParallelSortedInt(map->comm, map->n, keyssorted, &sorted));
  PetscCheck(sorted, mapeven->comm, PETSC_ERR_PLIB, "PetscParallelSortInt() failed to sort");
  for (i = 0; i < n; i++) PetscCheck(keys[i] == keyscopy[i], PETSC_COMM_SELF, PETSC_ERR_PLIB, "PetscParallelSortInt() modified input array");

  PetscCall(PetscParallelSortInt(map, map, keys, keys));
  PetscCall(PetscParallelSortedInt(map->comm, map->n, keys, &sorted));
  PetscCheck(sorted, mapeven->comm, PETSC_ERR_PLIB, "PetscParallelSortInt() failed to sort");
  /* TODO */
#if 0
  PetscCall(ISSortGlobal(is));
#endif

  PetscCall(PetscFree(keyseven));
  PetscCall(PetscLayoutDestroy(&mapeven));
  PetscCall(ISDestroy(&is));
  PetscCall(PetscFree3(keys, keyscopy, keyssorted));
  PetscCall(PetscRandomDestroy(&randvalues));
  PetscCall(PetscRandomDestroy(&randsizes));

  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   test:
      requires: !defined(PETSC_USE_REAL___FP16)
      nsize: {{1 2 3 4 5}}
      args: -nmax {{0 1 5 10 100}}
      output_file: output/empty.out

TEST*/