//EpetraMap_To_TpetraMap: takes in Epetra_Map object, converts it to its equivalent Tpetra::Map object,
//and returns an RCP pointer to this Tpetra::Map
Teuchos::RCP<const Tpetra_Map> Petra::EpetraMap_To_TpetraMap(const Teuchos::RCP<const Epetra_Map>& epetraMap_,
                                                      const Teuchos::RCP<const Teuchos::Comm<int> >& commT_)
{
  const std::size_t numElements = Teuchos::as<std::size_t>(epetraMap_->NumMyElements());
  const auto indexBase = Teuchos::as<GO>(epetraMap_->IndexBase());
  if (epetraMap_->DistributedGlobal() || epetraMap_->Comm().NumProc() == Teuchos::OrdinalTraits<int>::one()) {
    Teuchos::Array<Tpetra_GO> indices(numElements);
    int *epetra_indices = epetraMap_->MyGlobalElements();
    for(LO i=0; i < numElements; i++)
       indices[i] = epetra_indices[i];
    const Tpetra::global_size_t computeGlobalElements = Teuchos::OrdinalTraits<Tpetra::global_size_t>::invalid();
    return Teuchos::rcp(new Tpetra_Map(computeGlobalElements, indices, indexBase, commT_));
  } else {
    return Teuchos::rcp(new Tpetra_Map(numElements, indexBase, commT_, Tpetra::LocallyReplicated));
  }
}
TEUCHOS_UNIT_TEST(PdQuickGridDiscretization_MPI_np2, SimpleTensorProductMeshTest) {

  Teuchos::RCP<Epetra_Comm> comm;
  comm = rcp(new Epetra_MpiComm(MPI_COMM_WORLD));

  int numProcs = comm->NumProc();
  int rank     = comm->MyPID();

  TEST_COMPARE(numProcs, ==, 2);

  if(numProcs != 2){
     std::cerr << "Unit test runtime ERROR: utPeridigm_PdQuickGridDiscretization_MPI_np2 only makes sense on 2 processors" << std::endl;
     return;
  }

  RCP<ParameterList> discParams = rcp(new ParameterList);

  // create a 2x2x2 discretization
  // specify a spherical neighbor search with the horizon a tad longer than the mesh spacing
  discParams->set("Type", "PdQuickGrid");
  discParams->set("NeighborhoodType", "Spherical");
  ParameterList& quickGridParams = discParams->sublist("TensorProduct3DMeshGenerator");
  quickGridParams.set("Type", "PdQuickGrid");
  quickGridParams.set("X Origin", 0.0);
  quickGridParams.set("Y Origin", 0.0);
  quickGridParams.set("Z Origin", 0.0);
  quickGridParams.set("X Length", 1.0);
  quickGridParams.set("Y Length", 1.0);
  quickGridParams.set("Z Length", 1.0);
  quickGridParams.set("Number Points X", 2);
  quickGridParams.set("Number Points Y", 2);
  quickGridParams.set("Number Points Z", 2);

  // initialize the horizon manager and set the horizon to 0.501
  ParameterList blockParameterList;
  ParameterList& blockParams = blockParameterList.sublist("My Block");
  blockParams.set("Block Names", "block_1");
  blockParams.set("Horizon", 0.501);
  PeridigmNS::HorizonManager::self().loadHorizonInformationFromBlockParameters(blockParameterList);

  // create the discretization
  RCP<PdQuickGridDiscretization> discretization =
    rcp(new PdQuickGridDiscretization(comm, discParams));

  // sanity check, calling with a dimension other than 1 or 3 should throw an exception
  TEST_THROW(discretization->getGlobalOwnedMap(0), Teuchos::Exceptions::InvalidParameter);
  TEST_THROW(discretization->getGlobalOwnedMap(2), Teuchos::Exceptions::InvalidParameter);
  TEST_THROW(discretization->getGlobalOwnedMap(4), Teuchos::Exceptions::InvalidParameter);

  // basic checks on the 1d map
  Teuchos::RCP<const Epetra_BlockMap> map = discretization->getGlobalOwnedMap(1);
  TEST_ASSERT(map->NumGlobalElements() == 8);
  TEST_ASSERT(map->NumMyElements() == 4);
  TEST_ASSERT(map->ElementSize() == 1);
  TEST_ASSERT(map->IndexBase() == 0);
  TEST_ASSERT(map->UniqueGIDs() == true);
  int* myGlobalElements = map->MyGlobalElements();
  if(rank == 0){
    TEST_ASSERT(myGlobalElements[0] == 0);
    TEST_ASSERT(myGlobalElements[1] == 2);
    TEST_ASSERT(myGlobalElements[2] == 4);
    TEST_ASSERT(myGlobalElements[3] == 6);
  }
  if(rank == 1){
    TEST_ASSERT(myGlobalElements[0] == 5);
    TEST_ASSERT(myGlobalElements[1] == 7);
    TEST_ASSERT(myGlobalElements[2] == 1);
    TEST_ASSERT(myGlobalElements[3] == 3);
  }

  // check the 1d overlap map
  // for this simple discretization, everything should be ghosted on both processors
  Teuchos::RCP<const Epetra_BlockMap> overlapMap = discretization->getGlobalOverlapMap(1);
  TEST_ASSERT(overlapMap->NumGlobalElements() == 16);
  TEST_ASSERT(overlapMap->NumMyElements() == 8);
  TEST_ASSERT(overlapMap->ElementSize() == 1);
  TEST_ASSERT(overlapMap->IndexBase() == 0);
  TEST_ASSERT(overlapMap->UniqueGIDs() == false);
  myGlobalElements = overlapMap->MyGlobalElements();
  if(rank == 0){
    TEST_ASSERT(myGlobalElements[0] == 0);
    TEST_ASSERT(myGlobalElements[1] == 2);
    TEST_ASSERT(myGlobalElements[2] == 4);
    TEST_ASSERT(myGlobalElements[3] == 6);
    TEST_ASSERT(myGlobalElements[4] == 1);
    TEST_ASSERT(myGlobalElements[5] == 3);
    TEST_ASSERT(myGlobalElements[6] == 5);
    TEST_ASSERT(myGlobalElements[7] == 7);
  }
  if(rank == 1){
    TEST_ASSERT(myGlobalElements[0] == 5);
    TEST_ASSERT(myGlobalElements[1] == 7);
    TEST_ASSERT(myGlobalElements[2] == 1);
    TEST_ASSERT(myGlobalElements[3] == 3);
    TEST_ASSERT(myGlobalElements[4] == 0);
    TEST_ASSERT(myGlobalElements[5] == 2);
    TEST_ASSERT(myGlobalElements[6] == 4);
    TEST_ASSERT(myGlobalElements[7] == 6);
  }

  // same checks for 3d map
  map = discretization->getGlobalOwnedMap(3);
  TEST_ASSERT(map->NumGlobalElements() == 8);
  TEST_ASSERT(map->NumMyElements() == 4);
  TEST_ASSERT(map->ElementSize() == 3);
  TEST_ASSERT(map->IndexBase() == 0);
  TEST_ASSERT(map->UniqueGIDs() == true);
  myGlobalElements = map->MyGlobalElements();
  if(rank == 0){
    TEST_ASSERT(myGlobalElements[0] == 0);
    TEST_ASSERT(myGlobalElements[1] == 2);
    TEST_ASSERT(myGlobalElements[2] == 4);
    TEST_ASSERT(myGlobalElements[3] == 6);
  }
  if(rank == 1){
    TEST_ASSERT(myGlobalElements[0] == 5);
    TEST_ASSERT(myGlobalElements[1] == 7);
    TEST_ASSERT(myGlobalElements[2] == 1);
    TEST_ASSERT(myGlobalElements[3] == 3);
  }

  // check the 3d overlap map
  // for this simple discretization, everything should be ghosted on both processors
  overlapMap = discretization->getGlobalOverlapMap(3);
  TEST_ASSERT(overlapMap->NumGlobalElements() == 16);
  TEST_ASSERT(overlapMap->NumMyElements() == 8);
  TEST_ASSERT(overlapMap->ElementSize() == 3);
  TEST_ASSERT(overlapMap->IndexBase() == 0);
  TEST_ASSERT(overlapMap->UniqueGIDs() == false);
  myGlobalElements = overlapMap->MyGlobalElements();
  if(rank == 0){
    TEST_ASSERT(myGlobalElements[0] == 0);
    TEST_ASSERT(myGlobalElements[1] == 2);
    TEST_ASSERT(myGlobalElements[2] == 4);
    TEST_ASSERT(myGlobalElements[3] == 6);
    TEST_ASSERT(myGlobalElements[4] == 1);
    TEST_ASSERT(myGlobalElements[5] == 3);
    TEST_ASSERT(myGlobalElements[6] == 5);
    TEST_ASSERT(myGlobalElements[7] == 7);
  }
  if(rank == 1){
    TEST_ASSERT(myGlobalElements[0] == 5);
    TEST_ASSERT(myGlobalElements[1] == 7);
    TEST_ASSERT(myGlobalElements[2] == 1);
    TEST_ASSERT(myGlobalElements[3] == 3);
    TEST_ASSERT(myGlobalElements[4] == 0);
    TEST_ASSERT(myGlobalElements[5] == 2);
    TEST_ASSERT(myGlobalElements[6] == 4);
    TEST_ASSERT(myGlobalElements[7] == 6);
  }

  // check the bond map
  // the horizon was chosen such that each point should have three neighbors
  // note that if the NeighborhoodType parameter is not set to Spherical, this will fail
  Teuchos::RCP<const Epetra_BlockMap> bondMap = discretization->getGlobalBondMap();
  TEST_ASSERT(bondMap->NumGlobalElements() == 8);
  TEST_ASSERT(bondMap->NumMyElements() == 4);
  TEST_ASSERT(bondMap->IndexBase() == 0);
  TEST_ASSERT(bondMap->UniqueGIDs() == true);
  myGlobalElements = bondMap->MyGlobalElements();
  if(rank == 0){
    TEST_ASSERT(myGlobalElements[0] == 0);
    TEST_ASSERT(myGlobalElements[1] == 2);
    TEST_ASSERT(myGlobalElements[2] == 4);
    TEST_ASSERT(myGlobalElements[3] == 6);
  }
  if(rank == 1){
    TEST_ASSERT(myGlobalElements[0] == 5);
    TEST_ASSERT(myGlobalElements[1] == 7);
    TEST_ASSERT(myGlobalElements[2] == 1);
    TEST_ASSERT(myGlobalElements[3] == 3);
  }
  TEST_ASSERT(discretization->getNumBonds() == 4*3);

  // check the initial positions
  // all three coordinates are contained in a single vector
  Teuchos::RCP<Epetra_Vector> initialX = discretization->getInitialX();
  TEST_ASSERT(initialX->MyLength() == 4*3);
  TEST_ASSERT(initialX->GlobalLength() == 8*3);
  if(rank == 0){
    TEST_FLOATING_EQUALITY((*initialX)[0],  0.25, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[1],  0.25, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[2],  0.25, 1.0e-16);
 
    TEST_FLOATING_EQUALITY((*initialX)[3],  0.25, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[4],  0.75, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[5],  0.25, 1.0e-16);

    TEST_FLOATING_EQUALITY((*initialX)[6],  0.25, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[7],  0.25, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[8],  0.75, 1.0e-16);

    TEST_FLOATING_EQUALITY((*initialX)[9],  0.25, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[10], 0.75, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[11], 0.75, 1.0e-16);
  }
  if(rank == 1){
    TEST_FLOATING_EQUALITY((*initialX)[0],  0.75, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[1],  0.25, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[2],  0.75, 1.0e-16);

    TEST_FLOATING_EQUALITY((*initialX)[3],  0.75, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[4],  0.75, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[5],  0.75, 1.0e-16);

    TEST_FLOATING_EQUALITY((*initialX)[6],  0.75, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[7],  0.25, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[8],  0.25, 1.0e-16);

    TEST_FLOATING_EQUALITY((*initialX)[9],  0.75, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[10], 0.75, 1.0e-16);
    TEST_FLOATING_EQUALITY((*initialX)[11], 0.25, 1.0e-16);
  }

  // check cell volumes
  Teuchos::RCP<Epetra_Vector> volume = discretization->getCellVolume();
  TEST_ASSERT(volume->MyLength() == 4);
  TEST_ASSERT(volume->GlobalLength() == 8);
  for(int i=0 ; i<volume->MyLength() ; ++i)
    TEST_FLOATING_EQUALITY((*volume)[i], 0.125, 1.0e-16);

  // check the neighbor lists
  Teuchos::RCP<PeridigmNS::NeighborhoodData> neighborhoodData = discretization->getNeighborhoodData();
  TEST_ASSERT(neighborhoodData->NumOwnedPoints() == 4);
  int* ownedIds = neighborhoodData->OwnedIDs();
  TEST_ASSERT(ownedIds[0] == 0);
  TEST_ASSERT(ownedIds[1] == 1);
  TEST_ASSERT(ownedIds[2] == 2);
  TEST_ASSERT(ownedIds[3] == 3);
  TEST_ASSERT(neighborhoodData->NeighborhoodListSize() == 16);
  int* neighborhood = neighborhoodData->NeighborhoodList();
  int* neighborhoodPtr = neighborhoodData->NeighborhoodPtr();
  // remember, these are local IDs on each processor, 
  // which includes both owned and ghost nodes (confusing!)
  if(rank == 0){
    TEST_ASSERT(neighborhoodPtr[0] == 0);
    TEST_ASSERT(neighborhood[0]    == 3);
    TEST_ASSERT(neighborhood[1]    == 4);
    TEST_ASSERT(neighborhood[2]    == 1);
    TEST_ASSERT(neighborhood[3]    == 2);

    TEST_ASSERT(neighborhoodPtr[1] == 4);
    TEST_ASSERT(neighborhood[4]    == 3);
    TEST_ASSERT(neighborhood[5]    == 0);
    TEST_ASSERT(neighborhood[6]    == 5);
    TEST_ASSERT(neighborhood[7]    == 3);

    TEST_ASSERT(neighborhoodPtr[2] == 8);
    TEST_ASSERT(neighborhood[8]    == 3);
    TEST_ASSERT(neighborhood[9]    == 0);
    TEST_ASSERT(neighborhood[10]   == 6);
    TEST_ASSERT(neighborhood[11]   == 3);

    TEST_ASSERT(neighborhoodPtr[3] == 12);
    TEST_ASSERT(neighborhood[12]   == 3);
    TEST_ASSERT(neighborhood[13]   == 1);
    TEST_ASSERT(neighborhood[14]   == 2);
    TEST_ASSERT(neighborhood[15]   == 7);
  }
  if(rank == 1){
    TEST_ASSERT(neighborhoodPtr[0] == 0);
    TEST_ASSERT(neighborhood[0]    == 3);
    TEST_ASSERT(neighborhood[1]    == 2);
    TEST_ASSERT(neighborhood[2]    == 6);
    TEST_ASSERT(neighborhood[3]    == 1);

    TEST_ASSERT(neighborhoodPtr[1] == 4);
    TEST_ASSERT(neighborhood[4]    == 3);
    TEST_ASSERT(neighborhood[5]    == 3);
    TEST_ASSERT(neighborhood[6]    == 0);
    TEST_ASSERT(neighborhood[7]    == 7);

    TEST_ASSERT(neighborhoodPtr[2] == 8);
    TEST_ASSERT(neighborhood[8]    == 3);
    TEST_ASSERT(neighborhood[9]    == 4);
    TEST_ASSERT(neighborhood[10]   == 3);
    TEST_ASSERT(neighborhood[11]   == 0);

    TEST_ASSERT(neighborhoodPtr[3] == 12);
    TEST_ASSERT(neighborhood[12]   == 3);
    TEST_ASSERT(neighborhood[13]   == 2);
    TEST_ASSERT(neighborhood[14]   == 5);
    TEST_ASSERT(neighborhood[15]   == 1);
  }
}