// MIT License
//
// Copyright (c) 2017-2020 Advanced Micro Devices, Inc. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// SOFTWARE.

#include "common_test_header.hpp"

// required rocprim headers
#include <rocprim/iterator/arg_index_iterator.hpp>
#include <rocprim/device/device_reduce.hpp>

// required test headers
#include "test_seed.hpp"
#include "test_utils.hpp"


// Params for tests
template<class InputType>
struct RocprimArgIndexIteratorParams
{
    using input_type = InputType;
};

template<class Params>
class RocprimArgIndexIteratorTests : public ::testing::Test
{
public:
    using input_type = typename Params::input_type;
    const bool debug_synchronous = false;
};

typedef ::testing::Types<
    RocprimArgIndexIteratorParams<int>,
    RocprimArgIndexIteratorParams<unsigned int>,
    RocprimArgIndexIteratorParams<unsigned long>,
    RocprimArgIndexIteratorParams<float>
> RocprimArgIndexIteratorTestsParams;

TYPED_TEST_SUITE(RocprimArgIndexIteratorTests, RocprimArgIndexIteratorTestsParams);

TYPED_TEST(RocprimArgIndexIteratorTests, Equal)
{
    int device_id = test_common_utils::obtain_device_from_ctest();
    SCOPED_TRACE(testing::Message() << "with device_id= " << device_id);
    HIP_CHECK(hipSetDevice(device_id));

    using T = typename TestFixture::input_type;
    using Iterator = typename rocprim::arg_index_iterator<T*>;

    for (size_t seed_index = 0; seed_index < random_seeds_count + seed_size; seed_index++)
    {
        unsigned int seed_value = seed_index < random_seeds_count  ? rand() : seeds[seed_index - random_seeds_count];
        SCOPED_TRACE(testing::Message() << "with seed= " << seed_value);

        std::vector<T> input = test_utils::get_random_data<T>(5, 1, 200, seed_value);

        Iterator x(input.data());
        Iterator y = x;
        for(size_t i = 0; i < 5; i++)
        {
            ASSERT_EQ(x[i].key, i);
            ASSERT_EQ(x[i].value, input[i]);
        }
        ASSERT_EQ(x[2].value, input[2]);

        x += 2;
        for(size_t i = 0; i < 2; i++)
        {
            y++;
        }
        ASSERT_EQ(x, y);
    }
}

struct arg_min
{
    template<
        class Key,
        class Value
    >
    ROCPRIM_HOST_DEVICE inline
    constexpr rocprim::key_value_pair<Key, Value>
    operator()(const rocprim::key_value_pair<Key, Value>& a,
               const rocprim::key_value_pair<Key, Value>& b) const
    {
        return ((b.value < a.value) || ((a.value == b.value) && (b.key < a.key))) ? b : a;
    }
};

TYPED_TEST(RocprimArgIndexIteratorTests, ReduceArgMinimum)
{
    int device_id = test_common_utils::obtain_device_from_ctest();
    SCOPED_TRACE(testing::Message() << "with device_id= " << device_id);
    HIP_CHECK(hipSetDevice(device_id));

    using T = typename TestFixture::input_type;
    using Iterator = typename rocprim::arg_index_iterator<T*>;
    using key_value = typename Iterator::value_type;
    using difference_type = typename Iterator::difference_type;
    const bool debug_synchronous = false;

    const size_t size = 1024;

    hipStream_t stream = 0; // default

    for (size_t seed_index = 0; seed_index < random_seeds_count + seed_size; seed_index++)
    {
        unsigned int seed_value = seed_index < random_seeds_count  ? rand() : seeds[seed_index - random_seeds_count];
        SCOPED_TRACE(testing::Message() << "with seed= " << seed_value);

        // Generate data
        std::vector<T> input = test_utils::get_random_data<T>(size, 1, 200, seed_value);
        std::vector<key_value> output(1);

        T * d_input;
        key_value * d_output;
        HIP_CHECK(test_common_utils::hipMallocHelper(&d_input, input.size() * sizeof(T)));
        HIP_CHECK(test_common_utils::hipMallocHelper(&d_output, output.size() * sizeof(key_value)));
        HIP_CHECK(
            hipMemcpy(
                d_input, input.data(),
                input.size() * sizeof(T),
                hipMemcpyHostToDevice
            )
        );
        HIP_CHECK(hipDeviceSynchronize());

        Iterator d_iter(d_input);

        arg_min reduce_op;
        const key_value max(std::numeric_limits<difference_type>::max(), std::numeric_limits<T>::max());

        // Calculate expected results on host
        Iterator x(input.data());
        key_value expected = std::accumulate(x, x + size, max, reduce_op);

        // temp storage
        size_t temp_storage_size_bytes;
        void * d_temp_storage = nullptr;
        // Get size of d_temp_storage
        HIP_CHECK(
            rocprim::reduce(
                d_temp_storage, temp_storage_size_bytes,
                d_iter, d_output, max, input.size(),
                reduce_op, stream, debug_synchronous
            )
        );

        // temp_storage_size_bytes must be >0
        ASSERT_GT(temp_storage_size_bytes, 0);

        // allocate temporary storage
        HIP_CHECK(test_common_utils::hipMallocHelper(&d_temp_storage, temp_storage_size_bytes));
        HIP_CHECK(hipDeviceSynchronize());

        // Run
        HIP_CHECK(
            rocprim::reduce(
                d_temp_storage, temp_storage_size_bytes,
                d_iter, d_output, max, input.size(),
                reduce_op, stream, debug_synchronous
            )
        );
        HIP_CHECK(hipGetLastError());
        HIP_CHECK(hipDeviceSynchronize());

        // Copy output to host
        HIP_CHECK(
            hipMemcpy(
                output.data(), d_output,
                output.size() * sizeof(key_value),
                hipMemcpyDeviceToHost
            )
        );
        HIP_CHECK(hipDeviceSynchronize());

        // Check if output values are as expected
        auto diff = std::abs(test_utils::precision_threshold<T>::percentage * expected.value);
        if(std::is_integral<T>::value) diff = 0;
        ASSERT_EQ(output[0].key, expected.key);
        ASSERT_NEAR(output[0].value, expected.value, diff);

        hipFree(d_input);
        hipFree(d_output);
        hipFree(d_temp_storage);
    }
}