/*
 *  Copyright 2008-2013 NVIDIA Corporation
 *  Modifications Copyright© 2019-2023 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/iterator/iterator_traits.h>
#include <thrust/iterator/retag.h>
#include <thrust/swap.h>
#include <thrust/system/cpp/memory.h>

#include "test_header.hpp"

TESTS_DEFINE(SwapRangesTests, FullTestsParams);
TESTS_DEFINE(PrimitiveSwapRangesTests, NumericalTestsParams);

TEST(SwapRangesTests, UsingHip)
{
    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    ASSERT_EQ(THRUST_DEVICE_SYSTEM, THRUST_DEVICE_SYSTEM_HIP);
}

template <typename ForwardIterator1, typename ForwardIterator2>
ForwardIterator2
swap_ranges(my_system& system, ForwardIterator1, ForwardIterator1, ForwardIterator2 first2)
{
    system.validate_dispatch();
    return first2;
}

TEST(SwapRangesTests, SwapRangesDispatchExplicit)
{
    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    thrust::device_vector<int> vec(1);

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

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

template <typename ForwardIterator1, typename ForwardIterator2>
ForwardIterator2 swap_ranges(my_tag, ForwardIterator1, ForwardIterator1, ForwardIterator2 first2)
{
    *first2 = 13;
    return first2;
}

TEST(SwapRangesTests, SwapRangesDispatchImplicit)
{
    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    thrust::device_vector<int> vec(1);

    thrust::swap_ranges(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(SwapRangesTests, SwapRangesSimple)
{
    using Vector = typename TestFixture::input_type;
    using Policy = typename TestFixture::execution_policy;

    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    Vector v1(5);
    v1[0] = 0;
    v1[1] = 1;
    v1[2] = 2;
    v1[3] = 3;
    v1[4] = 4;

    Vector v2(5);
    v2[0] = 5;
    v2[1] = 6;
    v2[2] = 7;
    v2[3] = 8;
    v2[4] = 9;

    thrust::swap_ranges(Policy{}, v1.begin(), v1.end(), v2.begin());

    ASSERT_EQ(v1[0], 5);
    ASSERT_EQ(v1[1], 6);
    ASSERT_EQ(v1[2], 7);
    ASSERT_EQ(v1[3], 8);
    ASSERT_EQ(v1[4], 9);

    ASSERT_EQ(v2[0], 0);
    ASSERT_EQ(v2[1], 1);
    ASSERT_EQ(v2[2], 2);
    ASSERT_EQ(v2[3], 3);
    ASSERT_EQ(v2[4], 4);
}

TYPED_TEST(PrimitiveSwapRangesTests, SwapRanges)
{
    using T = typename TestFixture::input_type;

    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    const std::vector<size_t> sizes        = get_sizes();
    T                         error_margin = T(0.01);

    for(auto size : get_sizes())
    {
        SCOPED_TRACE(testing::Message() << "with size= " << size);

        for(auto seed : get_seeds())
        {
            SCOPED_TRACE(testing::Message() << "with seed= " << seed);

            thrust::host_vector<T> a1 = get_random_data<T>(
                size,
                std::numeric_limits<T>::min(),
                std::numeric_limits<T>::max(),
                seed
            );
            thrust::host_vector<T> a2 = get_random_data<T>(
                size,
                std::numeric_limits<T>::min(),
                std::numeric_limits<T>::max(),
                seed + seed_value_addition
            );

            thrust::host_vector<T>   h1 = a1;
            thrust::host_vector<T>   h2 = a2;
            thrust::device_vector<T> d1 = a1;
            thrust::device_vector<T> d2 = a2;

            thrust::swap_ranges(h1.begin(), h1.end(), h2.begin());
            thrust::swap_ranges(d1.begin(), d1.end(), d2.begin());

            thrust::host_vector<T> d1_h = d1;
            thrust::host_vector<T> d2_h = d2;

            for(size_t i = 0; i < size; i++)
            {
                ASSERT_NEAR(h1[i], a2[i], error_margin);
                ASSERT_NEAR(d1_h[i], a2[i], error_margin);
                ASSERT_NEAR(h2[i], a1[i], error_margin);
                ASSERT_NEAR(d2_h[i], a1[i], error_margin);
            }
        }
    }
}

struct type_with_swap
{
    inline __host__ __device__ type_with_swap()
        : m_x()
        , m_swapped(false)
    {
    }

    inline __host__ __device__ type_with_swap(int x)
        : m_x(x)
        , m_swapped(false)
    {
    }

    inline __host__ __device__ type_with_swap(int x, bool s)
        : m_x(x)
        , m_swapped(s)
    {
    }

    inline __host__ __device__ type_with_swap(const type_with_swap& other)
        : m_x(other.m_x)
        , m_swapped(other.m_swapped)
    {
    }

    inline __host__ __device__ bool operator==(const type_with_swap& other) const
    {
        return m_x == other.m_x && m_swapped == other.m_swapped;
    }

    type_with_swap& operator=(const type_with_swap&) = default;

    int  m_x;
    bool m_swapped;
};

inline __host__ __device__ void swap(type_with_swap& a, type_with_swap& b)
{
    thrust::swap(a.m_x, b.m_x);
    a.m_swapped = true;
    b.m_swapped = true;
}

template <class T, class H>
void inline careful_assert(T first, H second)
{
    bool cond = (first == second);
    ASSERT_EQ(cond, true);
}

TEST(SwapRangesTests, SwapRangesUserSwap)
{
    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());
    
    thrust::host_vector<type_with_swap> h_A(3, type_with_swap(0));
    thrust::host_vector<type_with_swap> h_B(3, type_with_swap(1));

    thrust::device_vector<type_with_swap> d_A = h_A;
    thrust::device_vector<type_with_swap> d_B = h_B;

    // check that nothing is yet swapped
    type_with_swap ref = type_with_swap(0, false);

    ASSERT_EQ(ref, h_A[0]);
    ASSERT_EQ(ref, h_A[1]);
    ASSERT_EQ(ref, h_A[2]);

    careful_assert(ref, d_A[0]);
    careful_assert(ref, d_A[1]);
    careful_assert(ref, d_A[2]);

    ref = type_with_swap(1, false);

    ASSERT_EQ(ref, h_B[0]);
    ASSERT_EQ(ref, h_B[1]);
    ASSERT_EQ(ref, h_B[2]);

    careful_assert(ref, d_B[0]);
    careful_assert(ref, d_B[1]);
    careful_assert(ref, d_B[2]);

    // swap the ranges

    thrust::swap_ranges(h_A.begin(), h_A.end(), h_B.begin());
    thrust::swap_ranges(d_A.begin(), d_A.end(), d_B.begin());

    // check that things were swapped
    ref = type_with_swap(1, true);

    ASSERT_EQ(ref, h_A[0]);
    ASSERT_EQ(ref, h_A[1]);
    ASSERT_EQ(ref, h_A[2]);

    careful_assert(ref, d_A[0]);
    careful_assert(ref, d_A[1]);
    careful_assert(ref, d_A[2]);

    ref = type_with_swap(0, true);

    ASSERT_EQ(ref, h_B[0]);
    ASSERT_EQ(ref, h_B[1]);
    ASSERT_EQ(ref, h_B[2]);

    careful_assert(ref, d_B[0]);
    careful_assert(ref, d_B[1]);
    careful_assert(ref, d_B[2]);
}