/*
 * Copyright (c) Advanced Micro Devices, Inc., or its affiliates.
 *
 * SPDX-License-Identifier: MIT
 */

#pragma once

#include "math_common.hh"
#include "math_special_values.hh"

#include <hip/hip_cooperative_groups.h>

namespace cg = cooperative_groups;

#define MATH_BINARY_KERNEL_DEF(func_name)                                                          \
  template <typename T, typename RT = T>                                                           \
  __global__ void func_name##_kernel(RT* const ys, const size_t num_xs, T* const x1s,              \
                                     T* const x2s) {                                               \
    const auto tid = cg::this_grid().thread_rank();                                                \
    const auto stride = cg::this_grid().size();                                                    \
                                                                                                   \
    for (size_t i = tid; i < num_xs; i += stride) {                                                \
      if constexpr (std::is_same_v<float, T>) {                                                    \
        ys[i] = func_name##f(x1s[i], x2s[i]);                                                      \
      } else if constexpr (std::is_same_v<double, T>) {                                            \
        ys[i] = func_name(x1s[i], x2s[i]);                                                         \
      }                                                                                            \
    }                                                                                              \
  }

template <typename T, typename TArg, typename RT, typename RTArg, typename ValidatorBuilder>
void BinaryFloatingPointBruteForceTest(kernel_sig<T, TArg, TArg> kernel,
                                       ref_sig<RT, RTArg, RTArg> ref_func,
                                       const ValidatorBuilder& validator_builder,
                                       const TArg a = std::numeric_limits<TArg>::lowest(),
                                       const TArg b = std::numeric_limits<TArg>::max()) {
  const auto [grid_size, block_size] = GetOccupancyMaxPotentialBlockSize(kernel);
  const uint64_t num_iterations = GetTestIterationCount();
  const auto max_batch_size =
      std::min(GetMaxAllowedDeviceMemoryUsage() / (sizeof(TArg) * 2 + sizeof(T)), num_iterations);
  LinearAllocGuard<TArg> x1s{LinearAllocs::hipHostMalloc, max_batch_size * sizeof(TArg)};
  LinearAllocGuard<TArg> x2s{LinearAllocs::hipHostMalloc, max_batch_size * sizeof(TArg)};

  MathTest math_test(kernel, max_batch_size);

  auto batch_size = max_batch_size;
  const auto num_threads = thread_pool.thread_count();
  for (uint64_t i = 0ul; i < num_iterations; i += batch_size) {
    batch_size = std::min<uint64_t>(max_batch_size, num_iterations - i);

    const auto min_sub_batch_size = batch_size / num_threads;
    const auto tail = batch_size % num_threads;

    auto base_idx = 0u;
    for (auto i = 0u; i < num_threads; ++i) {
      const auto sub_batch_size = min_sub_batch_size + (i < tail);
      thread_pool.Post([=, &x1s, &x2s] {
        const auto generator = [=] {
          static thread_local std::mt19937 rng(std::random_device{}());
          if constexpr (std::is_same_v<TArg, Float16>) {
            std::uniform_real_distribution<RefType_t<Float16>> unif_dist(-FLOAT16_MAX, FLOAT16_MAX);
            return static_cast<Float16>(unif_dist(rng));
          } else {
            std::uniform_real_distribution<RefType_t<TArg>> unif_dist(a, b);
            return static_cast<TArg>(unif_dist(rng));
          }
        };
        std::generate(x1s.ptr() + base_idx, x1s.ptr() + base_idx + sub_batch_size, generator);
        std::generate(x2s.ptr() + base_idx, x2s.ptr() + base_idx + sub_batch_size, generator);
      });
      base_idx += sub_batch_size;
    }

    thread_pool.Wait();

    math_test.Run(validator_builder, grid_size, block_size, ref_func, batch_size, x1s.ptr(),
                  x2s.ptr());
  }
}

template <typename T, typename TArg, typename RT, typename RTArg, typename ValidatorBuilder>
void BinaryFloatingPointSpecialValuesTest(kernel_sig<T, TArg, TArg> kernel,
                                          ref_sig<RT, RTArg, RTArg> ref_func,
                                          const ValidatorBuilder& validator_builder) {
  const auto [grid_size, block_size] = GetOccupancyMaxPotentialBlockSize(kernel);
  using SpecialValsType = std::conditional_t<std::is_same_v<TArg, Float16>, float, TArg>;
  const auto values = std::get<SpecialVals<SpecialValsType>>(kSpecialValRegistry);

  const auto size = values.size * values.size;
  LinearAllocGuard<TArg> x1s{LinearAllocs::hipHostMalloc, size * sizeof(TArg)};
  LinearAllocGuard<TArg> x2s{LinearAllocs::hipHostMalloc, size * sizeof(TArg)};

  for (auto i = 0u; i < values.size; ++i) {
    for (auto j = 0u; j < values.size; ++j) {
      x1s.ptr()[i * values.size + j] = values.data[i];
      x2s.ptr()[i * values.size + j] = values.data[j];
    }
  }

  MathTest math_test(kernel, size);
  math_test.template Run<false>(validator_builder, grid_size, block_size, ref_func, size, x1s.ptr(),
                                x2s.ptr());
}

template <typename T, typename TArg, typename RT, typename RTArg, typename ValidatorBuilder>
void BinaryFloatingPointTest(kernel_sig<T, TArg, TArg> kernel, ref_sig<RT, RTArg, RTArg> ref_func,
                             const ValidatorBuilder& validator_builder) {
  SECTION("Special values") {
    BinaryFloatingPointSpecialValuesTest(kernel, ref_func, validator_builder);
  }

  SECTION("Brute force") { BinaryFloatingPointBruteForceTest(kernel, ref_func, validator_builder); }
}

#define MATH_BINARY_WITHIN_ULP_TEST_DEF(kern_name, ref_func, sp_ulp, dp_ulp)                       \
  MATH_BINARY_KERNEL_DEF(kern_name)                                                                \
                                                                                                   \
  HIP_TEMPLATE_TEST_CASE(Unit_Device_##kern_name##_Accuracy_Positive, float, double) {             \
    using RT = RefType_t<TestType>;                                                                \
    RT (*ref)(RT, RT) = ref_func;                                                                  \
    const auto ulp = std::is_same_v<float, TestType> ? sp_ulp : dp_ulp;                            \
                                                                                                   \
    BinaryFloatingPointTest(kern_name##_kernel<TestType>, ref,                                     \
                            ULPValidatorBuilderFactory<TestType>(ulp));                            \
  }