// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// SPDX-FileCopyrightText: Copyright Contributors to the Kokkos project

#include <cstdio>
#include <sstream>
#include <iostream>

#include <Kokkos_Macros.hpp>
#ifdef KOKKOS_ENABLE_EXPERIMENTAL_CXX20_MODULES
import kokkos.core;
#else
#include <Kokkos_Core.hpp>
#endif

namespace Test {

namespace {
template <class T, int N>
class MyArray {
 public:
  T values[N];
  KOKKOS_INLINE_FUNCTION
  void operator+=(const MyArray& src) {
    for (int i = 0; i < N; i++) values[i] += src.values[i];
  }
};

template <class T, int N, class PolicyType, int S>
struct FunctorFor {
  double static_array[S];
  KOKKOS_INLINE_FUNCTION
  void operator()(const typename PolicyType::member_type& /*team*/) const {}
};
template <class T, int N, class PolicyType, int S>
struct FunctorReduce {
  double static_array[S];
  KOKKOS_INLINE_FUNCTION
  void operator()(const typename PolicyType::member_type& /*team*/,
                  MyArray<T, N>& lval) const {
    for (int j = 0; j < N; j++) lval.values[j] += 1 + lval.values[0];
  }
};
}  // namespace
}  // namespace Test

template <class T, int N>
struct Kokkos::reduction_identity<Test::MyArray<T, N>> {
  KOKKOS_FUNCTION static Test::MyArray<T, N> sum() {
    return Test::MyArray<T, N>{};
  }
};

namespace Test {

using policy_type = Kokkos::TeamPolicy<TEST_EXECSPACE>;
using policy_type_128_8 =
    Kokkos::TeamPolicy<TEST_EXECSPACE, Kokkos::LaunchBounds<128, 8>>;

// We need to special case for NVIDIA architectures which don't have space for
// 2048 threads ptxas warns and with errors as warning errors out: "ptxas error
// : Value of threads per SM for entry _ZN6... is out of range. .minnctapersm
// will be ignored" And yes I understand I am lying now with the name of the
// policy
#if defined(KOKKOS_ARCH_TURING75) || defined(KOKKOS_ARCH_AMPERE86) || \
    defined(KOKKOS_ARCH_AMPERE87) || defined(KOKKOS_ARCH_ADA89) ||    \
    defined(KOKKOS_ARCH_BLACKWELL120) || defined(KOKKOS_ARCH_BLACKWELL121)
using policy_type_1024_2 =
    Kokkos::TeamPolicy<TEST_EXECSPACE, Kokkos::LaunchBounds<1024, 1>>;
#else
using policy_type_1024_2 =
    Kokkos::TeamPolicy<TEST_EXECSPACE, Kokkos::LaunchBounds<1024, 2>>;
#endif

template <class T, int N, class PolicyType, int S>
void test_team_policy_max_recommended_static_size(int scratch_size) {
  PolicyType p = PolicyType(10000, Kokkos::AUTO, 4)
                     .set_scratch_size(0, Kokkos::PerTeam(scratch_size));
  int team_size_max_for = p.team_size_max(FunctorFor<T, N, PolicyType, S>(),
                                          Kokkos::ParallelForTag());
  int team_size_rec_for = p.team_size_recommended(
      FunctorFor<T, N, PolicyType, S>(), Kokkos::ParallelForTag());
  int team_size_max_reduce = p.team_size_max(
      FunctorReduce<T, N, PolicyType, S>(), Kokkos::ParallelReduceTag());
  MyArray<T, N> dummy;
  int team_size_max_reduce_reducer = p.team_size_max(
      FunctorReduce<T, N, PolicyType, S>(), Kokkos::Sum<MyArray<T, N>>{dummy},
      Kokkos::ParallelReduceTag());
  int team_size_rec_reduce = p.team_size_recommended(
      FunctorReduce<T, N, PolicyType, S>(), Kokkos::ParallelReduceTag());
  int team_size_rec_reduce_reducer = p.team_size_recommended(
      FunctorReduce<T, N, PolicyType, S>(), Kokkos::Sum<MyArray<T, N>>{dummy},
      Kokkos::ParallelReduceTag());

  ASSERT_GE(team_size_max_for, team_size_rec_for);
  ASSERT_GE(team_size_max_reduce, team_size_rec_reduce);
  ASSERT_GE(team_size_max_reduce_reducer, team_size_rec_reduce_reducer);
  ASSERT_GE(team_size_max_for, team_size_max_reduce);

  Kokkos::parallel_for(PolicyType(10000, team_size_max_for, 4)
                           .set_scratch_size(0, Kokkos::PerTeam(scratch_size)),
                       FunctorFor<T, N, PolicyType, S>());
  Kokkos::parallel_for(PolicyType(10000, team_size_rec_for, 4)
                           .set_scratch_size(0, Kokkos::PerTeam(scratch_size)),
                       FunctorFor<T, N, PolicyType, S>());
  MyArray<T, N> val;
  double n_leagues = 10000;

  Kokkos::parallel_reduce(
      PolicyType(n_leagues, team_size_max_reduce, 4)
          .set_scratch_size(0, Kokkos::PerTeam(scratch_size)),
      FunctorReduce<T, N, PolicyType, S>(), val);
  Kokkos::parallel_reduce(
      PolicyType(n_leagues, team_size_rec_reduce, 4)
          .set_scratch_size(0, Kokkos::PerTeam(scratch_size)),
      FunctorReduce<T, N, PolicyType, S>(), val);
  Kokkos::fence();
}

template <class T, int N, class PolicyType>
void test_team_policy_max_recommended(int scratch_size) {
  test_team_policy_max_recommended_static_size<T, N, PolicyType, 1>(
      scratch_size);
  // FIXME_SYCL prevent running out of total kernel argument size limit
#ifdef KOKKOS_ENABLE_SYCL
  test_team_policy_max_recommended_static_size<T, N, PolicyType, 100>(
      scratch_size);
#else
  test_team_policy_max_recommended_static_size<T, N, PolicyType, 1000>(
      scratch_size);
#endif
}

TEST(TEST_CATEGORY, team_policy_max_recommended) {
  int max_scratch_size = policy_type::scratch_size_max(0);
  test_team_policy_max_recommended<double, 2, policy_type>(0);
  test_team_policy_max_recommended<double, 2, policy_type>(max_scratch_size /
                                                           3);
  test_team_policy_max_recommended<double, 2, policy_type>(max_scratch_size);
  test_team_policy_max_recommended<double, 2, policy_type_128_8>(0);
  test_team_policy_max_recommended<double, 2, policy_type_128_8>(
      max_scratch_size / 3 / 8);
  test_team_policy_max_recommended<double, 2, policy_type_128_8>(
      max_scratch_size / 8);
  test_team_policy_max_recommended<double, 2, policy_type_1024_2>(0);
  test_team_policy_max_recommended<double, 2, policy_type_1024_2>(
      max_scratch_size / 3 / 2);
  test_team_policy_max_recommended<double, 2, policy_type_1024_2>(
      max_scratch_size / 2);

  test_team_policy_max_recommended<double, 16, policy_type>(0);
  test_team_policy_max_recommended<double, 16, policy_type>(max_scratch_size /
                                                            3);
  test_team_policy_max_recommended<double, 16, policy_type>(max_scratch_size);
  test_team_policy_max_recommended<double, 16, policy_type_128_8>(0);
  test_team_policy_max_recommended<double, 16, policy_type_128_8>(
      max_scratch_size / 3 / 8);
  test_team_policy_max_recommended<double, 16, policy_type_128_8>(
      max_scratch_size / 8);
  test_team_policy_max_recommended<double, 16, policy_type_1024_2>(0);
  test_team_policy_max_recommended<double, 16, policy_type_1024_2>(
      max_scratch_size / 3 / 2);
  test_team_policy_max_recommended<double, 16, policy_type_1024_2>(
      max_scratch_size / 2);
}

template <typename TeamHandleType, typename ReducerValueType>
struct MinMaxTeamLeagueRank {
  KOKKOS_FUNCTION void operator()(const TeamHandleType& team,
                                  ReducerValueType& update) const {
    int const x = team.league_rank();
    if (x < update.min_val) {
      update.min_val = x;
    }
    if (x > update.max_val) {
      update.max_val = x;
    }
  }
};

TEST(TEST_CATEGORY, team_policy_minmax_scalar_without_plus_equal_k) {
  using ExecSpace           = TEST_EXECSPACE;
  using ReducerType         = Kokkos::MinMax<int, Kokkos::HostSpace>;
  using ReducerValueType    = typename ReducerType::value_type;
  using DynamicScheduleType = Kokkos::Schedule<Kokkos::Dynamic>;
  using TeamPolicyType = Kokkos::TeamPolicy<ExecSpace, DynamicScheduleType>;
  using TeamHandleType = typename TeamPolicyType::member_type;

  static constexpr int num_teams = 17;
  ReducerValueType val;
  ReducerType reducer(val);

  TeamPolicyType p(num_teams, Kokkos::AUTO);
  MinMaxTeamLeagueRank<TeamHandleType, ReducerValueType> f1;

  Kokkos::parallel_reduce(p, f1, reducer);
  ASSERT_EQ(val.min_val, 0);
  ASSERT_EQ(val.max_val, num_teams - 1);
}

}  // namespace Test
