/*
 *  Copyright 2008-2013 NVIDIA Corporation
 *  Modifications Copyright© 2019-2025 Advanced Micro Devices, Inc. All rights reserved.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#include <thrust/pair.h>
#include <thrust/sequence.h>
#include <thrust/sort.h>

#include <unittest/unittest.h>

struct make_pair_functor
{
  template <typename T1, typename T2>
  THRUST_HOST_DEVICE thrust::pair<T1, T2> operator()(const T1& x, const T2& y)
  {
    return thrust::make_pair(x, y);
  } // end operator()()
}; // end make_pair_functor

template <typename T>
struct TestPairStableSortByKey
{
  void operator()(const size_t n)
  {
    using P = thrust::pair<T, T>;

    // host arrays
    thrust::host_vector<T> h_p1 = unittest::random_integers<T>(n);
    thrust::host_vector<T> h_p2 = unittest::random_integers<T>(n);
    thrust::host_vector<P> h_pairs(n);

    thrust::host_vector<int> h_values(n);
    thrust::sequence(h_values.begin(), h_values.end());

    // zip up pairs on the host
    thrust::transform(h_p1.begin(), h_p1.end(), h_p2.begin(), h_pairs.begin(), make_pair_functor());

    // device arrays
    thrust::device_vector<P> d_pairs    = h_pairs;
    thrust::device_vector<int> d_values = h_values;

    // sort on the host
    thrust::stable_sort_by_key(h_pairs.begin(), h_pairs.end(), h_values.begin());

    // sort on the device
    thrust::stable_sort_by_key(d_pairs.begin(), d_pairs.end(), d_values.begin());

    ASSERT_EQUAL_QUIET(h_pairs, d_pairs);
    ASSERT_EQUAL(h_values, d_values);
  }
};
VariableUnitTest<TestPairStableSortByKey, unittest::type_list<unittest::int8_t, unittest::int16_t, unittest::int32_t>>
  TestPairStableSortByKeyInstance;
