//===----------------------------------------------------------------------===//
//
// 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) 2024 NVIDIA CORPORATION & AFFILIATES.
//
//===----------------------------------------------------------------------===//
#ifndef LIBCXX_TEST_SUPPORT_TEST_RANGE_H
#define LIBCXX_TEST_SUPPORT_TEST_RANGE_H

#include <cuda/std/iterator>
#include <cuda/std/ranges>

#include "test_iterators.h"

struct sentinel
{
  template <class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I>, int> = 0>
  TEST_FUNC friend bool operator==(sentinel const&, I const&)
  {
    return true;
  }
  template <class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I>, int> = 0>
  TEST_FUNC friend bool operator==(I const&, sentinel const&)
  {
    return true;
  }
  template <class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I>, int> = 0>
  TEST_FUNC friend bool operator!=(sentinel const&, I const&)
  {
    return false;
  }
  template <class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I>, int> = 0>
  TEST_FUNC friend bool operator!=(I const&, sentinel const&)
  {
    return false;
  }
};

template <template <class...> class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I<int*>>, int> = 0>
struct test_range
{
  TEST_FUNC I<int*> begin()
  {
    return I<int*>{nullptr};
  }
  TEST_FUNC I<int const*> begin() const
  {
    return I<int const*>{nullptr};
  }
  TEST_FUNC sentinel end()
  {
    return sentinel{};
  }
  TEST_FUNC sentinel end() const
  {
    return sentinel{};
  }
};

template <template <class...> class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I<int*>>, int> = 0>
struct test_non_const_range
{
  TEST_FUNC I<int*> begin()
  {
    return I<int*>{nullptr};
  }
  TEST_FUNC sentinel end()
  {
    return sentinel{};
  }
};

template <template <class...> class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I<int*>>, int> = 0>
struct test_common_range
{
  TEST_FUNC I<int*> begin()
  {
    return I<int*>{nullptr};
  }
  TEST_FUNC I<int const*> begin() const
  {
    return I<int const*>{nullptr};
  }
  TEST_FUNC I<int*> end()
  {
    return I<int*>{nullptr};
  }
  TEST_FUNC I<int const*> end() const
  {
    return I<int const*>{nullptr};
  }
};

template <template <class...> class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I<int*>>, int> = 0>
struct test_non_const_common_range
{
  TEST_FUNC I<int*> begin()
  {
    return I<int*>{nullptr};
  }
  TEST_FUNC I<int*> end()
  {
    return I<int*>{nullptr};
  }
};

template <template <class...> class I, cuda::std::enable_if_t<cuda::std::input_or_output_iterator<I<int*>>, int> = 0>
struct test_view : cuda::std::ranges::view_base
{
  TEST_FUNC I<int*> begin()
  {
    return I<int*>{nullptr};
  }
  TEST_FUNC I<int const*> begin() const
  {
    return I<int const*>{nullptr};
  }
  TEST_FUNC sentinel end()
  {
    return sentinel{};
  }
  TEST_FUNC sentinel end() const
  {
    return sentinel{};
  }
};

struct BorrowedRange
{
  TEST_FUNC int* begin() const
  {
    return nullptr;
  }
  TEST_FUNC int* end() const
  {
    return nullptr;
  }
  TEST_FUNC BorrowedRange(BorrowedRange&&) = delete;
};

namespace cuda::std::ranges
{
template <>
inline constexpr bool enable_borrowed_range<BorrowedRange> = true;
} // namespace cuda::std::ranges

static_assert(!cuda::std::ranges::view<BorrowedRange>);
static_assert(cuda::std::ranges::borrowed_range<BorrowedRange>);

using BorrowedView = cuda::std::ranges::empty_view<int>;
static_assert(cuda::std::ranges::view<BorrowedView>);
static_assert(cuda::std::ranges::borrowed_range<BorrowedView>);

using NonBorrowedView = cuda::std::ranges::single_view<int>;
static_assert(cuda::std::ranges::view<NonBorrowedView>);
static_assert(!cuda::std::ranges::borrowed_range<NonBorrowedView>);

template <class Range>
inline constexpr bool simple_view =
  cuda::std::ranges::view<Range> && cuda::std::ranges::range<const Range>
  && cuda::std::same_as<cuda::std::ranges::iterator_t<Range>, cuda::std::ranges::iterator_t<const Range>>
  && cuda::std::same_as<cuda::std::ranges::sentinel_t<Range>, cuda::std::ranges::sentinel_t<const Range>>;

#endif // LIBCXX_TEST_SUPPORT_TEST_RANGE_H