/*
 *  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/pair.h>
#include <thrust/scan.h>
#include <thrust/transform.h>

#include "test_header.hpp"

TESTS_DEFINE(PairScanVariablesTests, NumericalTestsParams);

struct make_pair_functor
{
    template <typename T1, typename T2>
    __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

struct add_pairs
{
    template <typename Pair1, typename Pair2>
    __host__ __device__ Pair1 operator()(const Pair1& x, const Pair2& y)
    {
        return thrust::make_pair(x.first + y.first, x.second + y.second);
    } // end operator()
}; // end add_pairs

// TODO: Workaround, for issue:
// issue 127
struct maximum_pairs
{
    template <typename Pair1, typename Pair2>
    __host__ __device__ Pair1 operator()(const Pair1& x, const Pair2& y)
    {
        //bool b = x.first < y.first || (!(y.first < x.first) && x.second < y.second);
        //return b ? y : x;
        return x.first < y.first || (!(y.first < x.first) && x.second < y.second) ? y : x;
    } // end operator()
}; // end maximum_pairs

TYPED_TEST(PairScanVariablesTests, TestPairScan)
{
    using T = typename TestFixture::input_type;

    const std::vector<size_t> sizes = get_sizes();
    for(auto size : sizes)
    {
        typedef thrust::pair<T, T> P;

        thrust::host_vector<T> h_p1 = get_random_data<T>(
            size, std::numeric_limits<T>::min(), std::numeric_limits<T>::max());
        thrust::host_vector<T> h_p2 = get_random_data<T>(
            size, std::numeric_limits<T>::min(), std::numeric_limits<T>::max());
        thrust::host_vector<P> h_pairs(size);
        thrust::host_vector<P> h_output(size);

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

        thrust::device_vector<T> d_p1    = h_p1;
        thrust::device_vector<T> d_p2    = h_p2;
        thrust::device_vector<P> d_pairs = h_pairs;
        thrust::device_vector<P> d_output(size);

        P init = thrust::make_pair(13, 13);

        // scan with plus
        thrust::inclusive_scan(h_pairs.begin(), h_pairs.end(), h_output.begin(), add_pairs());
        thrust::inclusive_scan(d_pairs.begin(), d_pairs.end(), d_output.begin(), add_pairs());
        ASSERT_EQ_QUIET(h_output, d_output);

        // scan with maximum
        // TODO: Workaround
        thrust::inclusive_scan(h_pairs.begin(),
                               h_pairs.end(),
                               h_output.begin(),
                               maximum_pairs() /*thrust::maximum<P>()*/);
        thrust::inclusive_scan(d_pairs.begin(),
                               d_pairs.end(),
                               d_output.begin(),
                               maximum_pairs() /*thrust::maximum<P>()*/);
        ASSERT_EQ_QUIET(h_output, d_output);

        // scan with plus
        thrust::exclusive_scan(h_pairs.begin(), h_pairs.end(), h_output.begin(), init, add_pairs());
        thrust::exclusive_scan(d_pairs.begin(), d_pairs.end(), d_output.begin(), init, add_pairs());
        ASSERT_EQ_QUIET(h_output, d_output);

        // scan with maximum
        // TODO: Workaround
        thrust::exclusive_scan(h_pairs.begin(),
                               h_pairs.end(),
                               h_output.begin(),
                               init,
                               maximum_pairs() /*thrust::maximum<P>()*/);
        thrust::exclusive_scan(d_pairs.begin(),
                               d_pairs.end(),
                               d_output.begin(),
                               init,
                               maximum_pairs() /*thrust::maximum<P>()*/);
        ASSERT_EQ_QUIET(h_output, d_output);
    }
}