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#ifndef ROCPRIM_BENCHMARK_DETAIL_BENCHMARK_DEVICE_MERGE_SORT_BLOCK_SORT_PARALLEL_HPP_
#define ROCPRIM_BENCHMARK_DETAIL_BENCHMARK_DEVICE_MERGE_SORT_BLOCK_SORT_PARALLEL_HPP_

#include <cstddef>
#include <string>
#include <vector>

// Google Benchmark
#include <benchmark/benchmark.h>

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

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

#include "benchmark_utils.hpp"

namespace rp = rocprim;

constexpr const char* get_block_sort_method_name(rocprim::block_sort_algorithm alg)
{
    switch(alg)
    {
        case rocprim::block_sort_algorithm::merge_sort: return "merge_sort";
        case rocprim::block_sort_algorithm::bitonic_sort:
            return "bitonic_sort";
        case rocprim::block_sort_algorithm::stable_merge_sort:
            return "stable_merge_sort";
            // Not using `default: ...` because it kills effectiveness of -Wswitch
    }
    return "unknown_algorithm";
}

template<typename Config>
std::string config_name()
{
    const rocprim::detail::merge_sort_block_sort_config_params config = Config();
    return "{bs:" + std::to_string(config.block_sort_config.block_size)
           + ",ipt:" + std::to_string(config.block_sort_config.items_per_thread)
           + ",method:" + std::string(get_block_sort_method_name(config.block_sort_method)) + "}";
}

template<>
inline std::string config_name<rocprim::default_config>()
{
    return "default_config";
}

template<typename Key    = int,
         typename Value  = rocprim::empty_type,
         typename Config = rocprim::default_config>
struct device_merge_sort_block_sort_benchmark : public config_autotune_interface
{
    std::string name() const override
    {
        using namespace std::string_literals;
        return bench_naming::format_name("{lvl:device,algo:merge_sort_block_sort,key_type:"
                                         + std::string(Traits<Key>::name())
                                         + ",value_type:" + std::string(Traits<Value>::name())
                                         + ",cfg:" + config_name<Config>() + "}");
    }

    static constexpr unsigned int batch_size  = 10;
    static constexpr unsigned int warmup_size = 5;

    // keys benchmark
    template<typename val = Value>
    auto do_run(benchmark::State& state, size_t size, const hipStream_t stream) const ->
        typename std::enable_if<std::is_same<val, ::rocprim::empty_type>::value, void>::type
    {
        using key_type = Key;

        // Generate data
        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());
        }

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

        ::rocprim::less<key_type> lesser_op;
        rocprim::empty_type*      values_ptr = nullptr;
        unsigned int              items_per_block;
        // Warm-up
        for(size_t i = 0; i < warmup_size; i++)
        {
            HIP_CHECK(rp::detail::merge_sort_block_sort<Config>(d_keys_input,
                                                                d_keys_output,
                                                                values_ptr,
                                                                values_ptr,
                                                                size,
                                                                items_per_block,
                                                                lesser_op,
                                                                stream,
                                                                false));
        }
        HIP_CHECK(hipDeviceSynchronize());

        // HIP events creation
        hipEvent_t start, stop;
        HIP_CHECK(hipEventCreate(&start));
        HIP_CHECK(hipEventCreate(&stop));

        for(auto _ : state)
        {
            // Record start event
            HIP_CHECK(hipEventRecord(start, stream));

            for(size_t i = 0; i < batch_size; i++)
            {
                HIP_CHECK(rp::detail::merge_sort_block_sort<Config>(d_keys_input,
                                                                    d_keys_output,
                                                                    values_ptr,
                                                                    values_ptr,
                                                                    size,
                                                                    items_per_block,
                                                                    lesser_op,
                                                                    stream,
                                                                    false));
            }

            // Record stop event and wait until it completes
            HIP_CHECK(hipEventRecord(stop, stream));
            HIP_CHECK(hipEventSynchronize(stop));

            float elapsed_mseconds;
            HIP_CHECK(hipEventElapsedTime(&elapsed_mseconds, start, stop));
            state.SetIterationTime(elapsed_mseconds / 1000);
        }

        // Destroy HIP events
        HIP_CHECK(hipEventDestroy(start));
        HIP_CHECK(hipEventDestroy(stop));

        state.SetBytesProcessed(state.iterations() * batch_size * size * sizeof(key_type));
        state.SetItemsProcessed(state.iterations() * batch_size * size);

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

    // pairs benchmark
    template<typename val = Value>
    auto do_run(benchmark::State& state, size_t size, const hipStream_t stream) const ->
        typename std::enable_if<!std::is_same<val, ::rocprim::empty_type>::value, void>::type
    {
        using key_type   = Key;
        using value_type = Value;

        // Generate data
        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());
        }

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

        key_type* d_keys_input;
        key_type* d_keys_output;
        HIP_CHECK(hipMalloc(reinterpret_cast<void**>(&d_keys_input), size * sizeof(key_type)));
        HIP_CHECK(hipMalloc(reinterpret_cast<void**>(&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(reinterpret_cast<void**>(&d_values_input), size * sizeof(value_type)));
        HIP_CHECK(hipMalloc(reinterpret_cast<void**>(&d_values_output), size * sizeof(value_type)));
        HIP_CHECK(hipMemcpy(d_values_input,
                            values_input.data(),
                            size * sizeof(value_type),
                            hipMemcpyHostToDevice));

        ::rocprim::less<key_type> lesser_op;
        unsigned int              items_per_block;

        HIP_CHECK(hipDeviceSynchronize());

        // Warm-up
        for(size_t i = 0; i < warmup_size; i++)
        {

            HIP_CHECK(rp::detail::merge_sort_block_sort<Config>(d_keys_input,
                                                                d_keys_output,
                                                                d_values_input,
                                                                d_values_output,
                                                                size,
                                                                items_per_block,
                                                                lesser_op,
                                                                stream,
                                                                false));
        }
        HIP_CHECK(hipDeviceSynchronize());

        // HIP events creation
        hipEvent_t start, stop;
        HIP_CHECK(hipEventCreate(&start));
        HIP_CHECK(hipEventCreate(&stop));

        for(auto _ : state)
        {
            // Record start event
            HIP_CHECK(hipEventRecord(start, stream));

            for(size_t i = 0; i < batch_size; i++)
            {
                HIP_CHECK(rp::detail::merge_sort_block_sort<Config>(d_keys_input,
                                                                    d_keys_output,
                                                                    d_values_input,
                                                                    d_values_output,
                                                                    size,
                                                                    items_per_block,
                                                                    lesser_op,
                                                                    stream,
                                                                    false));
            }

            // Record stop event and wait until it completes
            HIP_CHECK(hipEventRecord(stop, stream));
            HIP_CHECK(hipEventSynchronize(stop));

            float elapsed_mseconds;
            HIP_CHECK(hipEventElapsedTime(&elapsed_mseconds, start, stop));
            state.SetIterationTime(elapsed_mseconds / 1000);
        }

        // Destroy HIP events
        HIP_CHECK(hipEventDestroy(start));
        HIP_CHECK(hipEventDestroy(stop));

        state.SetBytesProcessed(state.iterations() * batch_size * size
                                * (sizeof(key_type) + sizeof(value_type)));
        state.SetItemsProcessed(state.iterations() * batch_size * size);

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

    void run(benchmark::State& state, size_t size, hipStream_t stream) const override
    {
        do_run(state, size, stream);
    }
};

template<unsigned int                  BlockSize,
         rocprim::block_sort_algorithm Algo,
         typename Key,
         typename Value = rocprim::empty_type>
struct device_merge_sort_block_sort_benchmark_generator
{
    template<unsigned int ItemsPerThreadExponent>
    struct create_ipt
    {
        static constexpr unsigned int items_per_thread = 1u << ItemsPerThreadExponent;
        using generated_config
            = rocprim::detail::merge_sort_block_sort_config<BlockSize, items_per_thread, Algo>;

        void operator()(std::vector<std::unique_ptr<config_autotune_interface>>& storage)
        {
            storage.emplace_back(
                std::make_unique<
                    device_merge_sort_block_sort_benchmark<Key, Value, generated_config>>());
        }
    };

    static void create(std::vector<std::unique_ptr<config_autotune_interface>>& storage)
    {
        // Sort_items_per_block must be equal or larger than merge_items_per_block, so make
        // the items_per_thread at least as large so the sort_items_per_block
        // would be atleast 1024.
        static constexpr unsigned int min_items_per_thread_exponent
            = rocprim::Log2<(1024 / BlockSize)>::VALUE;

        // Very large block sizes don't work with large items_per_blocks since
        // shared memory is limited
        static constexpr unsigned int max_shared_memory = TUNING_SHARED_MEMORY_MAX;
        static constexpr unsigned int max_size_per_element
            = std::max(sizeof(Key) + sizeof(unsigned int), sizeof(Value));
        static constexpr unsigned int max_items_per_thread
            = max_shared_memory / (BlockSize * max_size_per_element);
        static constexpr unsigned int max_items_per_thread_exponent
            = rocprim::Log2<max_items_per_thread>::VALUE - 1;

        static_for_each<make_index_range<unsigned int,
                                         min_items_per_thread_exponent,
                                         max_items_per_thread_exponent>,
                        create_ipt>(storage);
    }
};

#endif // ROCPRIM_BENCHMARK_DETAIL_BENCHMARK_DEVICE_MERGE_SORT_BLOCK_SORT_PARALLEL_HPP_
