/*
 *  Copyright 2008-2013 NVIDIA Corporation
 *  Modifications Copyright© 2019 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/device_vector.h>
#include <thrust/functional.h>
#include <thrust/host_vector.h>
#include <thrust/iterator/discard_iterator.h>
#include <thrust/iterator/retag.h>
#include <thrust/merge.h>
#include <thrust/sort.h>
#include <thrust/unique.h>

#include "test_header.hpp"

TESTS_DEFINE(MergeByKeyTests, FullTestsParams);
TESTS_DEFINE(PrimitiveMergeByKeyTests, NumericalTestsParams);

TEST(MergeByKeyTests, UsingHip)
{
    ASSERT_EQ(THRUST_DEVICE_SYSTEM, THRUST_DEVICE_SYSTEM_HIP);
}

TYPED_TEST(MergeByKeyTests, MergeByKeySimple)
{
    using Vector   = typename TestFixture::input_type;
    using Iterator = typename Vector::iterator;

    Vector a_key(3), a_val(3), b_key(4), b_val(4);

    a_key[0] = 0;
    a_key[1] = 2;
    a_key[2] = 4;
    a_val[0] = 13;
    a_val[1] = 7;
    a_val[2] = 42;

    b_key[0] = 0;
    b_key[1] = 3;
    b_key[2] = 3;
    b_key[3] = 4;
    b_val[0] = 42;
    b_val[1] = 42;
    b_val[2] = 7;
    b_val[3] = 13;

    Vector ref_key(7), ref_val(7);
    ref_key[0] = 0;
    ref_val[0] = 13;
    ref_key[1] = 0;
    ref_val[1] = 42;
    ref_key[2] = 2;
    ref_val[2] = 7;
    ref_key[3] = 3;
    ref_val[3] = 42;
    ref_key[4] = 3;
    ref_val[4] = 7;
    ref_key[5] = 4;
    ref_val[5] = 42;
    ref_key[6] = 4;
    ref_val[6] = 13;

    Vector result_key(7), result_val(7);

    thrust::pair<Iterator, Iterator> ends = thrust::merge_by_key(a_key.begin(),
                                                                 a_key.end(),
                                                                 b_key.begin(),
                                                                 b_key.end(),
                                                                 a_val.begin(),
                                                                 b_val.begin(),
                                                                 result_key.begin(),
                                                                 result_val.begin());

    EXPECT_EQ(result_key.end(), ends.first);
    EXPECT_EQ(result_val.end(), ends.second);
    ASSERT_EQ(ref_key, result_key);
    ASSERT_EQ(ref_val, result_val);
}

template <typename InputIterator1,
          typename InputIterator2,
          typename InputIterator3,
          typename InputIterator4,
          typename OutputIterator1,
          typename OutputIterator2>
thrust::pair<OutputIterator1, OutputIterator2> merge_by_key(my_system& system,
                                                            InputIterator1,
                                                            InputIterator1,
                                                            InputIterator2,
                                                            InputIterator2,
                                                            InputIterator3,
                                                            InputIterator4,
                                                            OutputIterator1 keys_result,
                                                            OutputIterator2 values_result)
{
    system.validate_dispatch();
    return thrust::make_pair(keys_result, values_result);
}

TEST(MergeByKeyTests, MergeByKeyDispatchExplicit)
{
    thrust::device_vector<int> vec(1);

    my_system sys(0);
    thrust::merge_by_key(sys,
                         vec.begin(),
                         vec.begin(),
                         vec.begin(),
                         vec.begin(),
                         vec.begin(),
                         vec.begin(),
                         vec.begin(),
                         vec.begin());

    ASSERT_EQ(true, sys.is_valid());
}

template <typename InputIterator1,
          typename InputIterator2,
          typename InputIterator3,
          typename InputIterator4,
          typename OutputIterator1,
          typename OutputIterator2>
thrust::pair<OutputIterator1, OutputIterator2> merge_by_key(my_tag,
                                                            InputIterator1,
                                                            InputIterator1,
                                                            InputIterator2,
                                                            InputIterator2,
                                                            InputIterator3,
                                                            InputIterator4,
                                                            OutputIterator1 keys_result,
                                                            OutputIterator2 values_result)
{
    *keys_result = 13;
    return thrust::make_pair(keys_result, values_result);
}

TEST(MergeByKeyTests, MergeByKeyDispatchImplicit)
{
    thrust::device_vector<int> vec(1);

    thrust::merge_by_key(thrust::retag<my_tag>(vec.begin()),
                         thrust::retag<my_tag>(vec.begin()),
                         thrust::retag<my_tag>(vec.begin()),
                         thrust::retag<my_tag>(vec.begin()),
                         thrust::retag<my_tag>(vec.begin()),
                         thrust::retag<my_tag>(vec.begin()),
                         thrust::retag<my_tag>(vec.begin()),
                         thrust::retag<my_tag>(vec.begin()));

    ASSERT_EQ(13, vec.front());
}

TYPED_TEST(PrimitiveMergeByKeyTests, TestMergeByKeyWithRandomData)
{
    using T = typename TestFixture::input_type;

    const std::vector<size_t> sizes = get_sizes();
    for(auto size : sizes)
    {
        thrust::host_vector<T> random_keys = get_random_data<unsigned short int>(size, 0, 255);
        thrust::host_vector<T> random_vals = get_random_data<unsigned short int>(size, 0, 255);

        size_t denominators[]   = {1, 2, 3, 4, 5, 6, 7, 8, 9};
        size_t num_denominators = sizeof(denominators) / sizeof(size_t);

        for(size_t i = 0; i < num_denominators; ++i)
        {
            size_t size_a = size / denominators[i];

            thrust::host_vector<T> h_a_keys(random_keys.begin(), random_keys.begin() + size_a);
            thrust::host_vector<T> h_b_keys(random_keys.begin() + size_a, random_keys.end());

            thrust::host_vector<T> h_a_vals(random_vals.begin(), random_vals.begin() + size_a);
            thrust::host_vector<T> h_b_vals(random_vals.begin() + size_a, random_vals.end());

            thrust::stable_sort(h_a_keys.begin(), h_a_keys.end());
            thrust::stable_sort(h_b_keys.begin(), h_b_keys.end());

            thrust::device_vector<T> d_a_keys = h_a_keys;
            thrust::device_vector<T> d_b_keys = h_b_keys;

            thrust::device_vector<T> d_a_vals = h_a_vals;
            thrust::device_vector<T> d_b_vals = h_b_vals;

            thrust::host_vector<T> h_result_keys(size);
            thrust::host_vector<T> h_result_vals(size);

            thrust::device_vector<T> d_result_keys(size);
            thrust::device_vector<T> d_result_vals(size);

            thrust::pair<typename thrust::host_vector<T>::iterator,
                         typename thrust::host_vector<T>::iterator>
                h_end;

            thrust::pair<typename thrust::device_vector<T>::iterator,
                         typename thrust::device_vector<T>::iterator>
                d_end;

            h_end = thrust::merge_by_key(h_a_keys.begin(),
                                         h_a_keys.end(),
                                         h_b_keys.begin(),
                                         h_b_keys.end(),
                                         h_a_vals.begin(),
                                         h_b_vals.begin(),
                                         h_result_keys.begin(),
                                         h_result_vals.begin());
            h_result_keys.erase(h_end.first, h_result_keys.end());
            h_result_vals.erase(h_end.second, h_result_vals.end());

            d_end = thrust::merge_by_key(d_a_keys.begin(),
                                         d_a_keys.end(),
                                         d_b_keys.begin(),
                                         d_b_keys.end(),
                                         d_a_vals.begin(),
                                         d_b_vals.begin(),
                                         d_result_keys.begin(),
                                         d_result_vals.begin());
            d_result_keys.erase(d_end.first, d_result_keys.end());
            d_result_vals.erase(d_end.second, d_result_vals.end());

            thrust::host_vector<T> d_result_keys_h = d_result_keys;
            thrust::host_vector<T> d_result_vals_h = d_result_vals;

            ASSERT_EQ(h_result_keys, d_result_keys_h);
            ASSERT_EQ(h_result_vals, d_result_vals_h);
        }
    }
}

TYPED_TEST(PrimitiveMergeByKeyTests, MergeByKeyToDiscardIterator)
{
    using T = typename TestFixture::input_type;

    const std::vector<size_t> sizes = get_sizes();
    for(auto size : sizes)
    {
        thrust::host_vector<T> h_a_keys = get_random_data<T>(
            size, std::numeric_limits<T>::min(), std::numeric_limits<T>::max());
        thrust::host_vector<T> h_b_keys = get_random_data<T>(
            size, std::numeric_limits<T>::min(), std::numeric_limits<T>::max());

        thrust::host_vector<T> h_a_vals = get_random_data<T>(
            size, std::numeric_limits<T>::min(), std::numeric_limits<T>::max());
        thrust::host_vector<T> h_b_vals = get_random_data<T>(
            size, std::numeric_limits<T>::min(), std::numeric_limits<T>::max());

        thrust::stable_sort(h_a_keys.begin(), h_a_keys.end());
        thrust::stable_sort(h_b_keys.begin(), h_b_keys.end());

        thrust::device_vector<T> d_a_keys = h_a_keys;
        thrust::device_vector<T> d_b_keys = h_b_keys;

        thrust::device_vector<T> d_a_vals = h_a_vals;
        thrust::device_vector<T> d_b_vals = h_b_vals;

        typedef thrust::pair<thrust::discard_iterator<>, thrust::discard_iterator<>> discard_pair;

        discard_pair h_result = thrust::merge_by_key(h_a_keys.begin(),
                                                     h_a_keys.end(),
                                                     h_b_keys.begin(),
                                                     h_b_keys.end(),
                                                     h_a_vals.begin(),
                                                     h_b_vals.begin(),
                                                     thrust::make_discard_iterator(),
                                                     thrust::make_discard_iterator());

        discard_pair d_result = thrust::merge_by_key(d_a_keys.begin(),
                                                     d_a_keys.end(),
                                                     d_b_keys.begin(),
                                                     d_b_keys.end(),
                                                     d_a_vals.begin(),
                                                     d_b_vals.begin(),
                                                     thrust::make_discard_iterator(),
                                                     thrust::make_discard_iterator());

        thrust::discard_iterator<> reference(2 * size);

        ASSERT_EQ(reference, h_result.first);
        ASSERT_EQ(reference, h_result.second);
        ASSERT_EQ(reference, d_result.first);
        ASSERT_EQ(reference, d_result.second);
    }
}

TYPED_TEST(PrimitiveMergeByKeyTests, MergeByKeyDescending)
{
    using T = typename TestFixture::input_type;

    const std::vector<size_t> sizes = get_sizes();
    for(auto size : sizes)
    {
        thrust::host_vector<T> random_keys = get_random_data<unsigned short int>(size, 0, 255);
        thrust::host_vector<T> random_vals = get_random_data<unsigned short int>(size, 0, 255);

        size_t denominators[]   = {1, 2, 3, 4, 5, 6, 7, 8, 9};
        size_t num_denominators = sizeof(denominators) / sizeof(size_t);

        for(size_t i = 0; i < num_denominators; ++i)
        {
            size_t size_a = size / denominators[i];

            thrust::host_vector<T> h_a_keys(random_keys.begin(), random_keys.begin() + size_a);
            thrust::host_vector<T> h_b_keys(random_keys.begin() + size_a, random_keys.end());

            thrust::host_vector<T> h_a_vals(random_vals.begin(), random_vals.begin() + size_a);
            thrust::host_vector<T> h_b_vals(random_vals.begin() + size_a, random_vals.end());

            thrust::stable_sort(h_a_keys.begin(), h_a_keys.end(), thrust::greater<T>());
            thrust::stable_sort(h_b_keys.begin(), h_b_keys.end(), thrust::greater<T>());

            thrust::device_vector<T> d_a_keys = h_a_keys;
            thrust::device_vector<T> d_b_keys = h_b_keys;

            thrust::device_vector<T> d_a_vals = h_a_vals;
            thrust::device_vector<T> d_b_vals = h_b_vals;

            thrust::host_vector<T> h_result_keys(size);
            thrust::host_vector<T> h_result_vals(size);

            thrust::device_vector<T> d_result_keys(size);
            thrust::device_vector<T> d_result_vals(size);

            thrust::pair<typename thrust::host_vector<T>::iterator,
                         typename thrust::host_vector<T>::iterator>
                h_end;

            thrust::pair<typename thrust::device_vector<T>::iterator,
                         typename thrust::device_vector<T>::iterator>
                d_end;

            h_end = thrust::merge_by_key(h_a_keys.begin(),
                                         h_a_keys.end(),
                                         h_b_keys.begin(),
                                         h_b_keys.end(),
                                         h_a_vals.begin(),
                                         h_b_vals.begin(),
                                         h_result_keys.begin(),
                                         h_result_vals.begin(),
                                         thrust::greater<T>());
            h_result_keys.erase(h_end.first, h_result_keys.end());
            h_result_vals.erase(h_end.second, h_result_vals.end());

            d_end = thrust::merge_by_key(d_a_keys.begin(),
                                         d_a_keys.end(),
                                         d_b_keys.begin(),
                                         d_b_keys.end(),
                                         d_a_vals.begin(),
                                         d_b_vals.begin(),
                                         d_result_keys.begin(),
                                         d_result_vals.begin(),
                                         thrust::greater<T>());
            d_result_keys.erase(d_end.first, d_result_keys.end());
            d_result_vals.erase(d_end.second, d_result_vals.end());

            ASSERT_EQ(h_result_keys, d_result_keys);
            ASSERT_EQ(h_result_vals, d_result_vals);
        }
    }
}