//@HEADER
// ************************************************************************
//
//                        Kokkos v. 4.0
//       Copyright (2022) National Technology & Engineering
//               Solutions of Sandia, LLC (NTESS).
//
// Under the terms of Contract DE-NA0003525 with NTESS,
// the U.S. Government retains certain rights in this software.
//
// Part of Kokkos, under the Apache License v2.0 with LLVM Exceptions.
// See https://kokkos.org/LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//@HEADER

#include <Kokkos_Core.hpp>

namespace TestConcept {

using ExecutionSpace = TEST_EXECSPACE;
using MemorySpace    = typename ExecutionSpace::memory_space;
using DeviceType     = typename ExecutionSpace::device_type;

static_assert(Kokkos::is_execution_space<ExecutionSpace>{});
static_assert(Kokkos::is_execution_space<ExecutionSpace const>{});
static_assert(!Kokkos::is_execution_space<ExecutionSpace &>{});
static_assert(!Kokkos::is_execution_space<ExecutionSpace const &>{});

static_assert(Kokkos::is_memory_space<MemorySpace>{});
static_assert(Kokkos::is_memory_space<MemorySpace const>{});
static_assert(!Kokkos::is_memory_space<MemorySpace &>{});
static_assert(!Kokkos::is_memory_space<MemorySpace const &>{});

static_assert(Kokkos::is_device<DeviceType>{});
static_assert(Kokkos::is_device<DeviceType const>{});
static_assert(!Kokkos::is_device<DeviceType &>{});
static_assert(!Kokkos::is_device<DeviceType const &>{});

static_assert(!Kokkos::is_device<ExecutionSpace>{});
static_assert(!Kokkos::is_device<MemorySpace>{});

static_assert(Kokkos::is_space<ExecutionSpace>{});
static_assert(Kokkos::is_space<MemorySpace>{});
static_assert(Kokkos::is_space<DeviceType>{});
static_assert(Kokkos::is_space<ExecutionSpace const>{});
static_assert(Kokkos::is_space<MemorySpace const>{});
static_assert(Kokkos::is_space<DeviceType const>{});
static_assert(!Kokkos::is_space<ExecutionSpace &>{});
static_assert(!Kokkos::is_space<MemorySpace &>{});
static_assert(!Kokkos::is_space<DeviceType &>{});

static_assert(Kokkos::is_execution_space_v<ExecutionSpace>);
static_assert(!Kokkos::is_execution_space_v<ExecutionSpace &>);

static_assert(
    std::is_same<float, Kokkos::Impl::remove_cvref_t<float const &>>{});
static_assert(std::is_same<int, Kokkos::Impl::remove_cvref_t<int &>>{});
static_assert(std::is_same<int, Kokkos::Impl::remove_cvref_t<int const>>{});
static_assert(std::is_same<float, Kokkos::Impl::remove_cvref_t<float>>{});

/*-------------------------------------------------
  begin test for team_handle concept

  Here we also provide a complete trait that follows the full concept specified
  in:
    https://github.com/kokkos/kokkos/blob/61d7db55fceac3318c987a291f77b844fd94c165/core/src/Kokkos_Concepts.hpp#L160
  but this is not used as implementation for performance reasons as discussed
  in: https://github.com/kokkos/kokkos/pull/5375
  ------------------------------------------------- */

template <typename T>
struct is_team_handle_complete_trait_check {
 private:
  struct TrivialFunctor {
    void operator()(double &) {}
  };
  using test_value_type = double;
  test_value_type lvalueForMethodsNeedingIt_;
  test_value_type *ptrForMethodsNeedingIt_;
  // we use Sum here but any other reducer can be used
  // since we just want something that meets the ReducerConcept
  using reduction_to_test_t = ::Kokkos::Sum<test_value_type>;

  // nested aliases
  template <class U>
  using ExecutionSpaceArchetypeAlias = typename U::execution_space;
  template <class U>
  using ScratchMemorySpaceArchetypeAlias = typename U::scratch_memory_space;

  // "indices" methods
  template <class U>
  using TeamRankArchetypeExpr = decltype(std::declval<U const &>().team_rank());

  template <class U>
  using TeamSizeArchetypeExpr = decltype(std::declval<U const &>().team_size());

  template <class U>
  using LeagueRankArchetypeExpr =
      decltype(std::declval<U const &>().league_rank());

  template <class U>
  using LeagueSizeArchetypeExpr =
      decltype(std::declval<U const &>().league_size());

  // scratch space
  template <class U>
  using TeamShmemArchetypeExpr =
      decltype(std::declval<U const &>().team_shmem());

  template <class U>
  using TeamScratchArchetypeExpr =
      decltype(std::declval<U const &>().team_scratch(0));

  template <class U>
  using ThreadScracthArchetypeExpr =
      decltype(std::declval<U const &>().thread_scratch(0));

  // collectives
  template <class U>
  using TeamBarrierArchetypeExpr =
      decltype(std::declval<U const &>().team_barrier());

  template <class U>
  using TeamBroadcastArchetypeExpr = decltype(
      std::declval<U const &>().team_broadcast(lvalueForMethodsNeedingIt_, 0));

  template <class U>
  using TeamBroadcastAcceptClosureArchetypeExpr =
      decltype(std::declval<U const &>().team_broadcast(
          TrivialFunctor{}, lvalueForMethodsNeedingIt_, 0));

  template <class U>
  using TeamReducedArchetypeExpr =
      decltype(std::declval<U const &>().team_reduce(
          std::declval<reduction_to_test_t>()));

  template <class U>
  using TeamScanArchetypeExpr = decltype(std::declval<U const &>().team_scan(
      lvalueForMethodsNeedingIt_, ptrForMethodsNeedingIt_));

 public:
  static constexpr bool value =
      Kokkos::is_detected_v<ExecutionSpaceArchetypeAlias, T> &&
      Kokkos::is_detected_v<ScratchMemorySpaceArchetypeAlias, T> &&
      //
      Kokkos::is_detected_exact_v<int, TeamRankArchetypeExpr, T> &&
      Kokkos::is_detected_exact_v<int, TeamSizeArchetypeExpr, T> &&
      Kokkos::is_detected_exact_v<int, LeagueRankArchetypeExpr, T> &&
      Kokkos::is_detected_exact_v<int, LeagueSizeArchetypeExpr, T> &&
      //
      Kokkos::is_detected_exact_v<
          Kokkos::detected_t<ScratchMemorySpaceArchetypeAlias, T> const &,
          TeamShmemArchetypeExpr, T> &&
      Kokkos::is_detected_exact_v<
          Kokkos::detected_t<ScratchMemorySpaceArchetypeAlias, T> const &,
          TeamScratchArchetypeExpr, T> &&
      Kokkos::is_detected_exact_v<
          Kokkos::detected_t<ScratchMemorySpaceArchetypeAlias, T> const &,
          ThreadScracthArchetypeExpr, T> &&
      //
      Kokkos::is_detected_exact_v<void, TeamBarrierArchetypeExpr, T> &&
      Kokkos::is_detected_exact_v<void, TeamBroadcastArchetypeExpr, T> &&
      Kokkos::is_detected_exact_v<void, TeamBroadcastAcceptClosureArchetypeExpr,
                                  T> &&
      Kokkos::is_detected_exact_v<void, TeamReducedArchetypeExpr, T> &&
      Kokkos::is_detected_exact_v<test_value_type, TeamScanArchetypeExpr, T>;
  constexpr operator bool() const noexcept { return value; }
};

template <class T>
inline constexpr bool is_team_handle_complete_trait_check_v =
    is_team_handle_complete_trait_check<T>::value;

// actual test begins here

/*
  FIXME_OPENMPTARGET
  https://github.com/kokkos/kokkos/blob/2d6cbad7e079eb45ae69ac6a59929d9fcf10409a/core/src/OpenMPTarget/Kokkos_OpenMPTarget_Exec.hpp#L860-L864

  FIXME_OPENACC
  OpenACCTeamMember is missing the following method:
    template <typename ReducerType>
    KOKKOS_INLINE_FUNCTION std::enable_if_t<is_reducer<ReducerType>::value>
    team_reduce(ReducerType const& reducer) const noexcept;
*/

#if !defined(KOKKOS_ENABLE_OPENMPTARGET) && !defined(KOKKOS_ENABLE_OPENACC)
using space_t  = TEST_EXECSPACE;
using policy_t = Kokkos::TeamPolicy<space_t>;
using member_t = typename policy_t::member_type;

// is_team_handle uses the actual core implementation
static_assert(Kokkos::is_team_handle<member_t>::value);
static_assert(Kokkos::is_team_handle_v<member_t>);
static_assert(Kokkos::is_team_handle_v<member_t const>);
static_assert(!Kokkos::is_team_handle_v<member_t &>);
static_assert(!Kokkos::is_team_handle_v<member_t const &>);
static_assert(!Kokkos::is_team_handle_v<member_t *>);
static_assert(!Kokkos::is_team_handle_v<member_t const *>);
static_assert(!Kokkos::is_team_handle_v<member_t *const>);

// is_team_handle_complete_trait_check uses the FULL trait class above
static_assert(is_team_handle_complete_trait_check<member_t>::value);
static_assert(is_team_handle_complete_trait_check_v<member_t>);
static_assert(is_team_handle_complete_trait_check_v<member_t const>);
static_assert(!is_team_handle_complete_trait_check_v<member_t &>);
static_assert(!is_team_handle_complete_trait_check_v<member_t const &>);
static_assert(!is_team_handle_complete_trait_check_v<member_t *>);
static_assert(!is_team_handle_complete_trait_check_v<member_t const *>);
static_assert(!is_team_handle_complete_trait_check_v<member_t *const>);
#endif

}  // namespace TestConcept