//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++03, c++11
// UNSUPPORTED: nvrtc
// UNSUPPORTED: windows

// cuda::mr::resource_ref properties

#define LIBCUDACXX_ENABLE_EXPERIMENTAL_MEMORY_RESOURCE

#include <cuda/memory_resource>

#include <cuda/std/cassert>
#include <cuda/std/cstdint>

template <class T>
struct property_with_value {
  using value_type = T;
};

template <class T>
struct property_without_value {};

struct Fake_alloc_base {
  void* object = nullptr;
  const cuda::mr::_Async_alloc_vtable* static_vtable = nullptr;
};

template <class... Properties>
struct resource {
  void* allocate(std::size_t, std::size_t) { return &_val; }

  void deallocate(void* ptr, std::size_t, std::size_t) {
    // ensure that we did get the right inputs forwarded
    _val = *static_cast<int*>(ptr);
  }

  void* allocate_async(std::size_t, std::size_t, cuda::stream_ref) {
    return &_val;
  }

  void deallocate_async(void* ptr, std::size_t, std::size_t, cuda::stream_ref) {
    // ensure that we did get the right inputs forwarded
    _val = *static_cast<int*>(ptr);
  }

  bool operator==(const resource& other) const { return _val == other._val; }
  bool operator!=(const resource& other) const { return _val != other._val; }

  int _val = 0;

  _LIBCUDACXX_TEMPLATE(class Property)
    (requires (!cuda::property_with_value<Property>) && _CUDA_VSTD::_One_of<Property, Properties...>) //
  friend void get_property(const resource&, Property) noexcept {}

  _LIBCUDACXX_TEMPLATE(class Property)
    (requires cuda::property_with_value<Property> && _CUDA_VSTD::_One_of<Property, Properties...>) //
  friend typename Property::value_type get_property(const resource& res, Property) noexcept {
    return res._val;
  }
};

template <class PropA, class PropB>
void test_conversion_from_resource_ref() {
  resource<PropA, PropB> input{42};
  cuda::mr::resource_ref<PropA, PropB> ref_input{input};

  { // lvalue
    cuda::mr::resource_ref<PropB> ref{ref_input};

    // Ensure that we properly "punch through" the resource ref
    const auto fake_orig = *reinterpret_cast<Fake_alloc_base*>(&ref_input);
    const auto fake_conv = *reinterpret_cast<Fake_alloc_base*>(&ref);
    assert(fake_orig.object == fake_conv.object);
    assert(fake_orig.static_vtable == fake_conv.static_vtable);

    // Ensure that we properly pass on the allocate function
    assert(input.allocate(0, 0) == ref.allocate(0, 0));

    // Ensure we are deallocating properly
    int expected_after_deallocate = 1337;
    ref.deallocate(static_cast<void*>(&expected_after_deallocate), 0, 0);
    assert(input._val == expected_after_deallocate);
  }

  { // prvalue
    cuda::mr::resource_ref<PropB> ref{
        cuda::mr::resource_ref<PropA, PropB>{input}};

    // Ensure that we properly "punch through" the resource ref
    const auto fake_orig = *reinterpret_cast<Fake_alloc_base*>(&ref_input);
    const auto fake_conv = *reinterpret_cast<Fake_alloc_base*>(&ref);
    assert(fake_orig.object == fake_conv.object);
    assert(fake_orig.static_vtable == fake_conv.static_vtable);

    // Ensure that we properly pass on the allocate function
    assert(input.allocate(0, 0) == ref.allocate(0, 0));

    // Ensure we are deallocating properly
    int expected_after_deallocate = 1337;
    ref.deallocate(static_cast<void*>(&expected_after_deallocate), 0, 0);
    assert(input._val == expected_after_deallocate);
  }
}

template <class PropA, class PropB>
void test_conversion_from_async_resource_ref() {
  resource<PropA, PropB> input{42};
  cuda::mr::async_resource_ref<PropA, PropB> ref_input{input};

  { // lvalue
    cuda::mr::resource_ref<PropB> ref{ref_input};

    // Ensure that we properly "punch through" the resource ref
    const auto fake_orig = reinterpret_cast<Fake_alloc_base*>(&ref_input);
    const auto fake_conv = reinterpret_cast<Fake_alloc_base*>(&ref);
    assert(fake_orig->object == fake_conv->object);
    assert(fake_orig->static_vtable == fake_conv->static_vtable);

    // Ensure that we properly pass on the allocate function
    assert(input.allocate(0, 0) == ref.allocate(0, 0));

    // Ensure we are deallocating properly
    int expected_after_deallocate = 1337;
    ref.deallocate(static_cast<void*>(&expected_after_deallocate), 0, 0);
    assert(input._val == expected_after_deallocate);
  }

  { // prvalue
    cuda::mr::resource_ref<PropB> ref{
        cuda::mr::async_resource_ref<PropA, PropB>{input}};

    // Ensure that we properly "punch through" the resource ref
    const auto fake_orig = reinterpret_cast<Fake_alloc_base*>(&ref_input);
    const auto fake_conv = reinterpret_cast<Fake_alloc_base*>(&ref);
    assert(fake_orig->object == fake_conv->object);
    assert(fake_orig->static_vtable == fake_conv->static_vtable);

    // Ensure that we properly pass on the allocate function
    assert(input.allocate(0, 0) == ref.allocate(0, 0));

    // Ensure we are deallocating properly
    int expected_after_deallocate = 1337;
    ref.deallocate(static_cast<void*>(&expected_after_deallocate), 0, 0);
    assert(input._val == expected_after_deallocate);
  }
}

int main(int, char**) {
    NV_IF_TARGET(NV_IS_HOST,(
        test_conversion_from_resource_ref<property_with_value<short>,
                                          property_with_value<int> >();
        test_conversion_from_resource_ref<property_with_value<short>,
                                          property_without_value<int> >();
        test_conversion_from_resource_ref<property_without_value<short>,
                                          property_without_value<int> >();

        test_conversion_from_async_resource_ref<property_with_value<short>,
                                                property_with_value<int> >();
        test_conversion_from_async_resource_ref<property_with_value<short>,
                                                property_without_value<int> >();
        test_conversion_from_async_resource_ref<property_without_value<short>,
                                                property_without_value<int> >();
    ))

    return 0;
}
