// MIT License
//
// Copyright (c) 2017-2022 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
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#include <iostream>
#include <chrono>
#include <vector>
#include <locale>
#include <string>
#include <limits>

// Google Benchmark
#include "benchmark/benchmark.h"
// CmdParser
#include "cmdparser.hpp"
#include "benchmark_utils.hpp"

// HIP API
#include <hip/hip_runtime.h>

// rocPRIM
#include <rocprim/rocprim.hpp>

#define HIP_CHECK(condition)         \
  {                                   \
    hipError_t error = condition;    \
    if(error != hipSuccess){         \
        std::cout << "HIP error: " << error << " line: " << __LINE__ << std::endl; \
        exit(error); \
    } \
  }

#ifndef DEFAULT_N
const size_t DEFAULT_N = 1024 * 1024 * 32;
#endif

namespace rp = rocprim;

namespace
{

constexpr unsigned int warmup_size = 2;
constexpr size_t min_size = 30000;
constexpr std::array<size_t, 8> segment_counts{ 10, 100, 1000, 2500, 5000, 7500, 10000, 100000 };
constexpr std::array<size_t, 4> segment_lengths{30, 256, 3000, 300000};
}


template<class Key>
void run_sort_keys_benchmark(benchmark::State& state,
                             size_t num_segments,
                             size_t mean_segment_length,
                             size_t target_size,
                             hipStream_t stream)
{
    using offset_type = int;
    using key_type = Key;

    std::vector<offset_type> offsets;
    offsets.push_back(0);

    static constexpr int seed = 716;
    std::default_random_engine gen(seed);

    std::normal_distribution<double> segment_length_dis(static_cast<double>(mean_segment_length),
                                                        0.1 * mean_segment_length);

    size_t offset = 0;
    for(size_t segment_index = 0; segment_index < num_segments;)
    {
        const double segment_length_candidate = std::round(segment_length_dis(gen));
        if (segment_length_candidate < 0)
        {
            continue;
        }
        const offset_type segment_length = static_cast<offset_type>(segment_length_candidate);
        offset += segment_length;
        offsets.push_back(offset);
        ++segment_index;
    }
    const size_t size = offset;
    const size_t segments_count = offsets.size() - 1;

    std::vector<key_type> keys_input;
    if(std::is_floating_point<key_type>::value)
    {
        keys_input = get_random_data<key_type>(
            size,
            static_cast<key_type>(-1000),
            static_cast<key_type>(1000)
        );
    }
    else
    {
        keys_input = get_random_data<key_type>(
            size,
            std::numeric_limits<key_type>::min(),
            std::numeric_limits<key_type>::max()
        );
    }
    size_t batch_size = 1;
    if(size < target_size)
    {
        batch_size = (target_size + size - 1) / size;
    }

    offset_type * d_offsets;
    HIP_CHECK(hipMalloc(&d_offsets, offsets.size() * sizeof(offset_type)));
    HIP_CHECK(
        hipMemcpy(
            d_offsets, offsets.data(),
            offsets.size() * sizeof(offset_type),
            hipMemcpyHostToDevice
        )
    );

    key_type * d_keys_input;
    key_type * d_keys_output;
    HIP_CHECK(hipMalloc(&d_keys_input, size * sizeof(key_type)));
    HIP_CHECK(hipMalloc(&d_keys_output, size * sizeof(key_type)));
    HIP_CHECK(
        hipMemcpy(
            d_keys_input, keys_input.data(),
            size * sizeof(key_type),
            hipMemcpyHostToDevice
        )
    );

    void * d_temporary_storage = nullptr;
    size_t temporary_storage_bytes = 0;
    HIP_CHECK(
        rp::segmented_radix_sort_keys(
            d_temporary_storage, temporary_storage_bytes,
            d_keys_input, d_keys_output, size,
            segments_count, d_offsets, d_offsets + 1,
            0, sizeof(key_type) * 8,
            stream, false
        )
    );

    HIP_CHECK(hipMalloc(&d_temporary_storage, temporary_storage_bytes));
    HIP_CHECK(hipDeviceSynchronize());

    // Warm-up
    for(size_t i = 0; i < warmup_size; i++)
    {
        HIP_CHECK(
            rp::segmented_radix_sort_keys(
                d_temporary_storage, temporary_storage_bytes,
                d_keys_input, d_keys_output, size,
                segments_count, d_offsets, d_offsets + 1,
                0, sizeof(key_type) * 8,
                stream, false
            )
        );
    }
    HIP_CHECK(hipDeviceSynchronize());

    for (auto _ : state)
    {
        auto start = std::chrono::high_resolution_clock::now();

        for(size_t i = 0; i < batch_size; i++)
        {
            HIP_CHECK(
                rp::segmented_radix_sort_keys(
                    d_temporary_storage, temporary_storage_bytes,
                    d_keys_input, d_keys_output, size,
                    segments_count, d_offsets, d_offsets + 1,
                    0, sizeof(key_type) * 8,
                    stream, false
                )
            );
        }
        HIP_CHECK(hipDeviceSynchronize());

        auto end = std::chrono::high_resolution_clock::now();
        auto elapsed_seconds =
            std::chrono::duration_cast<std::chrono::duration<double>>(end - start);
        state.SetIterationTime(elapsed_seconds.count());
    }
    state.SetBytesProcessed(state.iterations() * batch_size * size * sizeof(key_type));
    state.SetItemsProcessed(state.iterations() * batch_size * size);

    HIP_CHECK(hipFree(d_temporary_storage));
    HIP_CHECK(hipFree(d_offsets));
    HIP_CHECK(hipFree(d_keys_input));
    HIP_CHECK(hipFree(d_keys_output));
}

template<class Key, class Value>
void run_sort_pairs_benchmark(benchmark::State& state,
                              size_t num_segments,
                              size_t mean_segment_length,
                              size_t target_size,
                              hipStream_t stream)
{
    using offset_type = int;
    using key_type = Key;
    using value_type = Value;

    // Generate data
    std::vector<offset_type> offsets;
    offsets.push_back(0);

    static constexpr int seed = 716;
    std::default_random_engine gen(seed);

    std::normal_distribution<double> segment_length_dis(static_cast<double>(mean_segment_length),
                                                        0.1 * mean_segment_length);

    size_t offset = 0;
    for(size_t segment_index = 0; segment_index < num_segments;)
    {
        const double segment_length_candidate = std::round(segment_length_dis(gen));
        if (segment_length_candidate < 0)
        {
            continue;
        }
        const offset_type segment_length = static_cast<offset_type>(segment_length_candidate);
        offset += segment_length;
        offsets.push_back(offset);
        ++segment_index;
    }
    const size_t size = offset;
    const size_t segments_count = offsets.size() - 1;

    std::vector<key_type> keys_input;
    if(std::is_floating_point<key_type>::value)
    {
        keys_input = get_random_data<key_type>(
            size,
            static_cast<key_type>(-1000),
            static_cast<key_type>(1000)
        );
    }
    else
    {
        keys_input = get_random_data<key_type>(
            size,
            std::numeric_limits<key_type>::min(),
            std::numeric_limits<key_type>::max()
        );
    }
    size_t batch_size = 1;
    if(size < target_size)
    {
        batch_size = (target_size + size - 1) / size;
    }

    std::vector<value_type> values_input(size);
    std::iota(values_input.begin(), values_input.end(), 0);

    offset_type * d_offsets;
    HIP_CHECK(hipMalloc(&d_offsets, (segments_count + 1) * sizeof(offset_type)));
    HIP_CHECK(
        hipMemcpy(
            d_offsets, offsets.data(),
            (segments_count + 1) * sizeof(offset_type),
            hipMemcpyHostToDevice
        )
    );

    key_type * d_keys_input;
    key_type * d_keys_output;
    HIP_CHECK(hipMalloc(&d_keys_input, size * sizeof(key_type)));
    HIP_CHECK(hipMalloc(&d_keys_output, size * sizeof(key_type)));
    HIP_CHECK(
        hipMemcpy(
            d_keys_input, keys_input.data(),
            size * sizeof(key_type),
            hipMemcpyHostToDevice
        )
    );

    value_type * d_values_input;
    value_type * d_values_output;
    HIP_CHECK(hipMalloc(&d_values_input, size * sizeof(value_type)));
    HIP_CHECK(hipMalloc(&d_values_output, size * sizeof(value_type)));
    HIP_CHECK(
        hipMemcpy(
            d_values_input, values_input.data(),
            size * sizeof(value_type),
            hipMemcpyHostToDevice
        )
    );

    void * d_temporary_storage = nullptr;
    size_t temporary_storage_bytes = 0;
    HIP_CHECK(
        rp::segmented_radix_sort_pairs(
            d_temporary_storage, temporary_storage_bytes,
            d_keys_input, d_keys_output, d_values_input, d_values_output, size,
            segments_count, d_offsets, d_offsets + 1,
            0, sizeof(key_type) * 8,
            stream, false
        )
    );

    HIP_CHECK(hipMalloc(&d_temporary_storage, temporary_storage_bytes));
    HIP_CHECK(hipDeviceSynchronize());

    // Warm-up
    for(size_t i = 0; i < warmup_size; i++)
    {
        HIP_CHECK(
            rp::segmented_radix_sort_pairs(
                d_temporary_storage, temporary_storage_bytes,
                d_keys_input, d_keys_output, d_values_input, d_values_output, size,
                segments_count, d_offsets, d_offsets + 1,
                0, sizeof(key_type) * 8,
                stream, false
            )
        );
    }
    HIP_CHECK(hipDeviceSynchronize());

    for (auto _ : state)
    {
        auto start = std::chrono::high_resolution_clock::now();

        for(size_t i = 0; i < batch_size; i++)
        {
            HIP_CHECK(
                rp::segmented_radix_sort_pairs(
                    d_temporary_storage, temporary_storage_bytes,
                    d_keys_input, d_keys_output, d_values_input, d_values_output, size,
                    segments_count, d_offsets, d_offsets + 1,
                    0, sizeof(key_type) * 8,
                    stream, false
                )
            );
        }
        HIP_CHECK(hipDeviceSynchronize());

        auto end = std::chrono::high_resolution_clock::now();
        auto elapsed_seconds =
            std::chrono::duration_cast<std::chrono::duration<double>>(end - start);
        state.SetIterationTime(elapsed_seconds.count());
    }
    state.SetBytesProcessed(
        state.iterations() * batch_size * size * (sizeof(key_type) + sizeof(value_type))
    );
    state.SetItemsProcessed(state.iterations() * batch_size * size);

    HIP_CHECK(hipFree(d_temporary_storage));
    HIP_CHECK(hipFree(d_offsets));
    HIP_CHECK(hipFree(d_keys_input));
    HIP_CHECK(hipFree(d_keys_output));
    HIP_CHECK(hipFree(d_values_input));
    HIP_CHECK(hipFree(d_values_output));
}

template<class KeyT>
void add_sort_keys_benchmarks(std::vector<benchmark::internal::Benchmark *> &benchmarks,
                              hipStream_t stream,
                              size_t max_size,
                              size_t min_size,
                              size_t target_size)
{
    std::string name = Traits<KeyT>::name();
    for(const auto segment_count : segment_counts)
    {
        for(const auto segment_length : segment_lengths)
        {
            const auto number_of_elements = segment_count * segment_length;
            if(number_of_elements > max_size || number_of_elements < min_size)
            {
                continue;
            }
            benchmarks.push_back(
                benchmark::RegisterBenchmark(
                    (std::string("sort_keys<") + name + ">(" + std::to_string(segment_count) +
                        " segments with length ~" + std::to_string(segment_length) +")").c_str(),
                    [=](benchmark::State &state) { run_sort_keys_benchmark<KeyT>(state, segment_count, segment_length, target_size, stream); }
                )
            );
        }
    }
}

template<class KeyT, class ValueT>
void add_sort_pairs_benchmarks(std::vector<benchmark::internal::Benchmark *> &benchmarks,
                               hipStream_t stream,
                               size_t max_size,
                               size_t min_size,
                               size_t target_size)
{
    std::string key_name = Traits<KeyT>::name();
    std::string value_name = Traits<ValueT>::name();
    for(const auto segment_count : segment_counts)
    {
        for(const auto segment_length : segment_lengths)
        {
            const auto number_of_elements = segment_count * segment_length;
            if(number_of_elements > max_size || number_of_elements < min_size)
            {
                continue;
            }
            benchmarks.push_back(
                benchmark::RegisterBenchmark(
                    (std::string("sort_pairs<") + key_name + ", " + value_name + ">(" + std::to_string(segment_count) +
                        " segments with length ~" + std::to_string(segment_length) +")").c_str(),
                    [=](benchmark::State &state) { run_sort_pairs_benchmark<KeyT, ValueT>(state, segment_count, segment_length, target_size, stream); }
                )
            );
        }
    }
}

int main(int argc, char *argv[])
{
    cli::Parser parser(argc, argv);
    parser.set_optional<size_t>("size", "size", DEFAULT_N, "number of values");
    parser.set_optional<int>("trials", "trials", -1, "number of iterations");
    parser.run_and_exit_if_error();

    // Parse argv
    benchmark::Initialize(&argc, argv);
    const size_t size = parser.get<size_t>("size");
    const int trials = parser.get<int>("trials");

    // HIP
    hipStream_t stream = 0; // default

    // Benchmark info
    add_common_benchmark_info();
    benchmark::AddCustomContext("size", std::to_string(size));

    // Add benchmarks
    std::vector<benchmark::internal::Benchmark*> benchmarks;
    add_sort_keys_benchmarks<float>(benchmarks, stream, size, min_size, size / 2);
    add_sort_keys_benchmarks<double>(benchmarks, stream, size, min_size, size / 2);
    add_sort_keys_benchmarks<int8_t>(benchmarks, stream, size, min_size, size / 2);
    add_sort_keys_benchmarks<uint8_t>(benchmarks, stream, size, min_size, size / 2);
    add_sort_keys_benchmarks<rocprim::half>(benchmarks, stream, size, min_size, size / 2);
    add_sort_keys_benchmarks<int>(benchmarks, stream, size, min_size, size / 2);

    using custom_float2 = custom_type<float, float>;
    using custom_double2 = custom_type<double, double>;
    add_sort_pairs_benchmarks<int, float>(benchmarks, stream, size, min_size, size / 2);
    add_sort_pairs_benchmarks<long long, double>(benchmarks, stream, size, min_size, size / 2);
    add_sort_pairs_benchmarks<int8_t, int8_t>(benchmarks, stream, size, min_size, size / 2);
    add_sort_pairs_benchmarks<uint8_t, uint8_t>(benchmarks, stream, size, min_size, size / 2);
    add_sort_pairs_benchmarks<rocprim::half, rocprim::half>(benchmarks, stream, size, min_size, size / 2);
    add_sort_pairs_benchmarks<int, custom_float2>(benchmarks, stream, size, min_size, size / 2);
    add_sort_pairs_benchmarks<long long, custom_double2>(benchmarks, stream, size, min_size, size / 2);

    // Use manual timing
    for(auto& b : benchmarks)
    {
        b->UseManualTime();
        b->Unit(benchmark::kMillisecond);
    }

    // Force number of iterations
    if(trials > 0)
    {
        for(auto& b : benchmarks)
        {
            b->Iterations(trials);
        }
    }

    // Run benchmarks
    benchmark::RunSpecifiedBenchmarks();
    return 0;
}