//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt for details.
//  This software is distributed WITHOUT ANY WARRANTY; without even
//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
//  PURPOSE.  See the above copyright notice for more information.
//
//  Copyright 2014 National Technology & Engineering Solutions of Sandia, LLC (NTESS).
//  Copyright 2014 UT-Battelle, LLC.
//  Copyright 2014 Los Alamos National Security.
//
//  Under the terms of Contract DE-NA0003525 with NTESS,
//  the U.S. Government retains certain rights in this software.
//
//  Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
//  Laboratory (LANL), the U.S. Government retains certain rights in
//  this software.
//============================================================================

#include <vtkm/Pair.h>
#include <vtkm/Types.h>
#include <vtkm/VecTraits.h>

#include <vtkm/testing/Testing.h>

namespace
{

//general pair test
template <typename T, typename U>
void PairTest()
{
  {
    using P = vtkm::Pair<T, U>;

    // Pair types should preserve the trivial properties of their components.
    // This insures that algorithms like std::copy will optimize fully.
    VTKM_TEST_ASSERT(std::is_trivial<T>::value &&
                       std::is_trivial<U>::value == std::is_trivial<P>::value,
                     "PairType's triviality differs from ComponentTypes.");
  }

  //test that all the constructors work properly
  {
    vtkm::Pair<T, U> no_params_pair;
    no_params_pair.first = TestValue(12, T());
    no_params_pair.second = TestValue(34, U());
    vtkm::Pair<T, U> copy_constructor_pair(no_params_pair);
    vtkm::Pair<T, U> assignment_pair = no_params_pair;

    VTKM_TEST_ASSERT((no_params_pair == copy_constructor_pair),
                     "copy constructor doesn't match default constructor");
    VTKM_TEST_ASSERT(!(no_params_pair != copy_constructor_pair), "operator != is working properly");

    VTKM_TEST_ASSERT((no_params_pair == assignment_pair),
                     "assignment constructor doesn't match default constructor");
    VTKM_TEST_ASSERT(!(no_params_pair != assignment_pair), "operator != is working properly");
  }

  //now lets give each item in the pair some values and do some in depth
  //comparisons
  T a = TestValue(56, T());
  U b = TestValue(78, U());

  //test the constructors now with real values
  {
    vtkm::Pair<T, U> pair_ab(a, b);
    vtkm::Pair<T, U> copy_constructor_pair(pair_ab);
    vtkm::Pair<T, U> assignment_pair = pair_ab;
    vtkm::Pair<T, U> make_p = vtkm::make_Pair(a, b);

    VTKM_TEST_ASSERT(!(pair_ab != pair_ab), "operator != isn't working properly for vtkm::Pair");
    VTKM_TEST_ASSERT((pair_ab == pair_ab), "operator == isn't working properly for vtkm::Pair");

    VTKM_TEST_ASSERT((pair_ab == copy_constructor_pair),
                     "copy constructor doesn't match pair constructor");
    VTKM_TEST_ASSERT((pair_ab == assignment_pair),
                     "assignment constructor doesn't match pair constructor");

    VTKM_TEST_ASSERT(copy_constructor_pair.first == a, "first field not set right");
    VTKM_TEST_ASSERT(assignment_pair.second == b, "second field not set right");

    VTKM_TEST_ASSERT((pair_ab == make_p), "make_pair function doesn't match pair constructor");
  }

  //test the ordering operators <, >, <=, >=
  {
    //in all cases pair_ab2 is > pair_ab. these verify that if the second
    //argument of the pair is different we respond properly
    U b2(b);
    vtkm::VecTraits<U>::SetComponent(b2, 0, vtkm::VecTraits<U>::GetComponent(b2, 0) + 1);

    vtkm::Pair<T, U> pair_ab2(a, b2);
    vtkm::Pair<T, U> pair_ab(a, b);

    VTKM_TEST_ASSERT((pair_ab2 >= pair_ab), "operator >= failed");
    VTKM_TEST_ASSERT((pair_ab2 >= pair_ab2), "operator >= failed");

    VTKM_TEST_ASSERT((pair_ab2 > pair_ab), "operator > failed");
    VTKM_TEST_ASSERT(!(pair_ab2 > pair_ab2), "operator > failed");

    VTKM_TEST_ASSERT(!(pair_ab2 < pair_ab), "operator < failed");
    VTKM_TEST_ASSERT(!(pair_ab2 < pair_ab2), "operator < failed");

    VTKM_TEST_ASSERT(!(pair_ab2 <= pair_ab), "operator <= failed");
    VTKM_TEST_ASSERT((pair_ab2 <= pair_ab2), "operator <= failed");

    VTKM_TEST_ASSERT(!(pair_ab2 == pair_ab), "operator == failed");
    VTKM_TEST_ASSERT((pair_ab2 != pair_ab), "operator != failed");

    T a2(a);
    vtkm::VecTraits<T>::SetComponent(a2, 0, vtkm::VecTraits<T>::GetComponent(a2, 0) + 1);
    vtkm::Pair<T, U> pair_a2b(a2, b);
    //this way can verify that if the first argument of the pair is different
    //we respond properly
    VTKM_TEST_ASSERT((pair_a2b >= pair_ab), "operator >= failed");
    VTKM_TEST_ASSERT((pair_a2b >= pair_a2b), "operator >= failed");

    VTKM_TEST_ASSERT((pair_a2b > pair_ab), "operator > failed");
    VTKM_TEST_ASSERT(!(pair_a2b > pair_a2b), "operator > failed");

    VTKM_TEST_ASSERT(!(pair_a2b < pair_ab), "operator < failed");
    VTKM_TEST_ASSERT(!(pair_a2b < pair_a2b), "operator < failed");

    VTKM_TEST_ASSERT(!(pair_a2b <= pair_ab), "operator <= failed");
    VTKM_TEST_ASSERT((pair_a2b <= pair_a2b), "operator <= failed");

    VTKM_TEST_ASSERT(!(pair_a2b == pair_ab), "operator == failed");
    VTKM_TEST_ASSERT((pair_a2b != pair_ab), "operator != failed");
  }
}

template <typename FirstType>
struct DecideSecondType
{
  template <typename SecondType>
  void operator()(const SecondType&) const
  {
    PairTest<FirstType, SecondType>();
  }
};

struct DecideFirstType
{
  template <typename T>
  void operator()(const T&) const
  {
    //T is our first type for vtkm::Pair, now to figure out the second type
    vtkm::testing::Testing::TryTypes(DecideSecondType<T>(), vtkm::TypeListTagField());
  }
};

void TestPair()
{
  //we want to test each combination of standard vtkm types in a
  //vtkm::Pair, so to do that we dispatch twice on TryTypes. We could
  //dispatch on all types, but that gets excessively large and takes a
  //long time to compile (although it runs fast). Instead, just select
  //a subset of non-trivial combinations.
  vtkm::testing::Testing::TryTypes(DecideFirstType(), vtkm::TypeListTagCommon());
}

} // anonymous namespace

int UnitTestPair(int, char* [])
{
  return vtkm::testing::Testing::Run(TestPair);
}