// MIT License
//
// Copyright (c) 2024-2025 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.

// Benchmark utils
#include "../../bench_utils/bench_utils.hpp"

// rocThrust
#include <thrust/device_vector.h>
#include <thrust/execution_policy.h>
#include <thrust/random.h>
#include <thrust/shuffle.h>

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

// STL
#include <cstdlib>
#include <functional>
#include <string>
#include <unordered_map>
#include <vector>

struct basic
{
  template <typename T, typename Policy>
  float64_t run(thrust::device_vector<T>& data, const std::string rng_engine, Policy policy)
  {
    auto do_engine = [&](auto&& engine_constructor) {
      bench_utils::gpu_timer d_timer;

      d_timer.start(0);
      thrust::shuffle(policy, data.begin(), data.end(), engine_constructor());
      d_timer.stop(0);

      return d_timer.get_duration();
    };

    if (rng_engine == "minstd")
    {
      return do_engine([] {
        return thrust::random::minstd_rand{};
      });
    }
    else if (rng_engine == "ranlux24")
    {
      return do_engine([] {
        return thrust::random::ranlux24{};
      });
    }
    else if (rng_engine == "ranlux48")
    {
      return do_engine([] {
        return thrust::random::ranlux48{};
      });
    }
    else if (rng_engine == "taus88")
    {
      return do_engine([] {
        return thrust::random::taus88{};
      });
    }

    return -1;
  }
};

template <class Benchmark, class T>
void run_benchmark(
  benchmark::State& state, const std::size_t elements, const std::string /*seed_type*/, const std::string rng_engine)
{
  // Benchmark object
  Benchmark benchmark{};

  // GPU times
  std::vector<double> gpu_times;

  // Generate input
  thrust::device_vector<T> data(elements);

  bench_utils::caching_allocator_t alloc{};
  thrust::detail::device_t policy{};

  for (auto _ : state)
  {
    float64_t duration = benchmark.template run<T>(data, rng_engine, policy(alloc));
    state.SetIterationTime(duration);
    gpu_times.push_back(duration);
  }

  // BytesProcessed include read and written bytes, so when the BytesProcessed/s are reported
  // it will actually be the global memory bandwidth gotten.
  state.SetBytesProcessed(state.iterations() * 2 * elements * sizeof(T));
  state.SetItemsProcessed(state.iterations() * elements);

  const double gpu_cv         = bench_utils::StatisticsCV(gpu_times);
  state.counters["gpu_noise"] = gpu_cv;
}

#define CREATE_BENCHMARK(T, RngEngine, Elements)                                                                \
  benchmark::RegisterBenchmark(                                                                                 \
    bench_utils::bench_naming::format_name(                                                                     \
      "{algo:shuffle,subalgo:" + name + ",input_type:" #T + ",rng_engine:" #RngEngine + ",elements:" #Elements) \
      .c_str(),                                                                                                 \
    run_benchmark<Benchmark, T>,                                                                                \
    Elements,                                                                                                   \
    seed_type,                                                                                                  \
    RngEngine)

#define BENCHMARK_RNG_ENGINE(type, rng_engine)                                              \
  CREATE_BENCHMARK(type, rng_engine, 1 << 16), CREATE_BENCHMARK(type, rng_engine, 1 << 20), \
    CREATE_BENCHMARK(type, rng_engine, 1 << 24), CREATE_BENCHMARK(type, rng_engine, 1 << 28)

#define BENCHMARK_TYPE(type)                                                    \
  BENCHMARK_RNG_ENGINE(type, "minstd"), BENCHMARK_RNG_ENGINE(type, "ranlux24"), \
    BENCHMARK_RNG_ENGINE(type, "ranlux48"), BENCHMARK_RNG_ENGINE(type, "taus88")

template <class Benchmark>
void add_benchmarks(
  const std::string& name, std::vector<benchmark::internal::Benchmark*>& benchmarks, const std::string seed_type)
{
  std::vector<benchmark::internal::Benchmark*> bs = {
    BENCHMARK_TYPE(int8_t),
    BENCHMARK_TYPE(int16_t),
    BENCHMARK_TYPE(int32_t),
    BENCHMARK_TYPE(int64_t)
#if THRUST_BENCHMARKS_HAVE_INT128_SUPPORT
      ,
    BENCHMARK_TYPE(int128_t)
#endif
  };

  benchmarks.insert(benchmarks.end(), bs.begin(), bs.end());
}

int main(int argc, char* argv[])
{
  cli::Parser parser(argc, argv);
  parser.set_optional<std::string>("name_format", "name_format", "human", "either: json,human,txt");
  parser.set_optional<std::string>("seed", "seed", "random", bench_utils::get_seed_message());
  parser.run_and_exit_if_error();

  // Parse argv
  benchmark::Initialize(&argc, argv);
  bench_utils::bench_naming::set_format(parser.get<std::string>("name_format")); /* either: json,human,txt */
  const std::string seed_type = parser.get<std::string>("seed");

  // Benchmark info
  bench_utils::add_common_benchmark_info();
  benchmark::AddCustomContext("seed", seed_type);

  // Add benchmark
  std::vector<benchmark::internal::Benchmark*> benchmarks;
  add_benchmarks<basic>("basic", benchmarks, seed_type);

  // Use manual timing
  for (auto& b : benchmarks)
  {
    b->UseManualTime();
    b->Unit(benchmark::kMicrosecond);
    b->MinTime(0.4); // in seconds
  }

  // Run benchmarks
  benchmark::RunSpecifiedBenchmarks(bench_utils::ChooseCustomReporter());

  // Finish
  benchmark::Shutdown();
  return 0;
}
