//===----------------------------------------------------------------------===//
//
// 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.
//
//===----------------------------------------------------------------------===//

// cuda::std::ranges::end
// cuda::std::ranges::cend

#include <cuda/std/cassert>
#include <cuda/std/ranges>
#include <cuda/std/utility>

#include "test_iterators.h"
#include "test_macros.h"

using RangeEndT  = decltype(cuda::std::ranges::end);
using RangeCEndT = decltype(cuda::std::ranges::cend);

TEST_GLOBAL_VARIABLE int globalBuff[8] = {};

#if !TEST_COMPILER(MSVC, <, 19, 23)
// old MSVC has a bug where it doesn't properly handle rvalue arrays
static_assert(!cuda::std::is_invocable_v<RangeEndT, int (&&)[]>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, int (&&)[]>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, int (&&)[10]>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, int (&&)[10]>, "");
#endif // !TEST_COMPILER(MSVC, <, 19, 23)

static_assert(!cuda::std::is_invocable_v<RangeEndT, int (&)[]>, "");
static_assert(cuda::std::is_invocable_v<RangeEndT, int (&)[10]>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, int (&)[]>, "");
static_assert(cuda::std::is_invocable_v<RangeCEndT, int (&)[10]>, "");

struct Incomplete;
static_assert(!cuda::std::is_invocable_v<RangeEndT, Incomplete (&&)[]>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, Incomplete (&&)[42]>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, Incomplete (&&)[]>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, Incomplete (&&)[42]>, "");

struct EndMember
{
  int x;
  __host__ __device__ const int* begin() const;
  __host__ __device__ constexpr const int* end() const
  {
    return &x;
  }
};

// Ensure that we can't call with rvalues with borrowing disabled.
static_assert(cuda::std::is_invocable_v<RangeEndT, EndMember&>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndMember&&>, "");
static_assert(cuda::std::is_invocable_v<RangeEndT, EndMember const&>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndMember const&&>, "");
static_assert(cuda::std::is_invocable_v<RangeCEndT, EndMember&>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, EndMember&&>, "");
static_assert(cuda::std::is_invocable_v<RangeCEndT, EndMember const&>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, EndMember const&&>, "");

struct Different
{
  __host__ __device__ char* begin();
  __host__ __device__ sentinel_wrapper<char*>& end();
  __host__ __device__ short* begin() const;
  __host__ __device__ sentinel_wrapper<short*>& end() const;
};
__host__ __device__ constexpr bool testReturnTypes()
{
  {
    int* x[2] = {};
    unused(x);
    static_assert(cuda::std::same_as<decltype(cuda::std::ranges::end(x)), int**>, "");
    static_assert(cuda::std::same_as<decltype(cuda::std::ranges::cend(x)), int* const*>, "");
  }
  {
    int x[2][2] = {};
    unused(x);
    static_assert(cuda::std::same_as<decltype(cuda::std::ranges::end(x)), int(*)[2]>, "");
    static_assert(cuda::std::same_as<decltype(cuda::std::ranges::cend(x)), const int(*)[2]>, "");
  }
  {
    Different x{};
    unused(x);
    static_assert(cuda::std::same_as<decltype(cuda::std::ranges::end(x)), sentinel_wrapper<char*>>, "");
    static_assert(cuda::std::same_as<decltype(cuda::std::ranges::cend(x)), sentinel_wrapper<short*>>, "");
  }
  return true;
}

__host__ __device__ constexpr bool testArray()
{
  int a[2] = {};
  assert(cuda::std::ranges::end(a) == a + 2);
  assert(cuda::std::ranges::cend(a) == a + 2);

  int b[2][2] = {};
  assert(cuda::std::ranges::end(b) == b + 2);
  assert(cuda::std::ranges::cend(b) == b + 2);

  EndMember c[2] = {};
  assert(cuda::std::ranges::end(c) == c + 2);
  assert(cuda::std::ranges::cend(c) == c + 2);

  return true;
}

struct EndMemberReturnsInt
{
  __host__ __device__ int begin() const;
  __host__ __device__ int end() const;
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndMemberReturnsInt const&>, "");

struct EndMemberReturnsVoidPtr
{
  __host__ __device__ const void* begin() const;
  __host__ __device__ const void* end() const;
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndMemberReturnsVoidPtr const&>, "");

struct PtrConvertible
{
  __host__ __device__ operator int*() const;
};
struct PtrConvertibleEndMember
{
  __host__ __device__ PtrConvertible begin() const;
  __host__ __device__ PtrConvertible end() const;
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, PtrConvertibleEndMember const&>, "");

struct NoBeginMember
{
  __host__ __device__ constexpr const int* end();
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, NoBeginMember const&>, "");

struct NonConstEndMember
{
  int x;
  __host__ __device__ constexpr int* begin()
  {
    return nullptr;
  }
  __host__ __device__ constexpr int* end()
  {
    return &x;
  }
};
static_assert(cuda::std::is_invocable_v<RangeEndT, NonConstEndMember&>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, NonConstEndMember const&>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, NonConstEndMember&>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, NonConstEndMember const&>, "");

struct EnabledBorrowingEndMember
{
  __host__ __device__ constexpr int* begin() const
  {
    return nullptr;
  }
  __host__ __device__ constexpr int* end() const
  {
    return &globalBuff[0];
  }
};
namespace cuda
{
namespace std
{
namespace ranges
{
template <>
_CCCL_INLINE_VAR constexpr bool enable_borrowed_range<EnabledBorrowingEndMember> = true;
}
} // namespace std
} // namespace cuda
struct EndMemberFunction
{
  int x;
  __host__ __device__ constexpr const int* begin() const
  {
    return nullptr;
  }
  __host__ __device__ constexpr const int* end() const
  {
    return &x;
  }
  __host__ __device__ friend constexpr int* end(EndMemberFunction const&);
};

struct Empty
{};
struct EmptyEndMember
{
  __host__ __device__ Empty begin() const;
  __host__ __device__ Empty end() const;
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, EmptyEndMember const&>, "");

struct EmptyPtrEndMember
{
  Empty x;
  __host__ __device__ constexpr const Empty* begin() const
  {
    return nullptr;
  }
  __host__ __device__ constexpr const Empty* end() const
  {
    return &x;
  }
};

__host__ __device__ constexpr bool testEndMember()
{
  EndMember a{};
  assert(cuda::std::ranges::end(a) == &a.x);
  assert(cuda::std::ranges::cend(a) == &a.x);

  NonConstEndMember b{};
  assert(cuda::std::ranges::end(b) == &b.x);
  static_assert(!cuda::std::is_invocable_v<RangeCEndT, decltype((b))>, "");

  EnabledBorrowingEndMember c{};
  assert(cuda::std::ranges::end(cuda::std::move(c)) == &globalBuff[0]);
  assert(cuda::std::ranges::cend(cuda::std::move(c)) == &globalBuff[0]);

  EndMemberFunction d{};
  assert(cuda::std::ranges::end(d) == &d.x);
  assert(cuda::std::ranges::cend(d) == &d.x);

  EmptyPtrEndMember e{};
  assert(cuda::std::ranges::end(e) == &e.x);
  assert(cuda::std::ranges::cend(e) == &e.x);

  return true;
}

struct EndFunction
{
  int x;
  __host__ __device__ friend constexpr const int* begin(EndFunction const&)
  {
    return nullptr;
  }
  __host__ __device__ friend constexpr const int* end(EndFunction const& bf)
  {
    return &bf.x;
  }
};

static_assert(cuda::std::is_invocable_v<RangeEndT, EndFunction const&>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndFunction&&>, "");

static_assert(cuda::std::is_invocable_v<RangeEndT, EndFunction const&>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndFunction&&>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndFunction&>, "");
static_assert(cuda::std::is_invocable_v<RangeCEndT, EndFunction const&>, "");
static_assert(cuda::std::is_invocable_v<RangeCEndT, EndFunction&>, "");

struct EndFunctionReturnsInt
{
  __host__ __device__ friend constexpr int begin(EndFunctionReturnsInt const&);
  __host__ __device__ friend constexpr int end(EndFunctionReturnsInt const&);
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndFunctionReturnsInt const&>, "");

struct EndFunctionReturnsVoidPtr
{
  __host__ __device__ friend constexpr void* begin(EndFunctionReturnsVoidPtr const&);
  __host__ __device__ friend constexpr void* end(EndFunctionReturnsVoidPtr const&);
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndFunctionReturnsVoidPtr const&>, "");

struct EndFunctionReturnsEmpty
{
  __host__ __device__ friend constexpr Empty begin(EndFunctionReturnsEmpty const&);
  __host__ __device__ friend constexpr Empty end(EndFunctionReturnsEmpty const&);
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndFunctionReturnsEmpty const&>, "");

struct EndFunctionReturnsPtrConvertible
{
  __host__ __device__ friend constexpr PtrConvertible begin(EndFunctionReturnsPtrConvertible const&);
  __host__ __device__ friend constexpr PtrConvertible end(EndFunctionReturnsPtrConvertible const&);
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, EndFunctionReturnsPtrConvertible const&>, "");

struct NoBeginFunction
{
  __host__ __device__ friend constexpr const int* end(NoBeginFunction const&);
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, NoBeginFunction const&>, "");

struct EndFunctionByValue
{
  __host__ __device__ friend constexpr int* begin(EndFunctionByValue)
  {
    return nullptr;
  }
  __host__ __device__ friend constexpr int* end(EndFunctionByValue)
  {
    return &globalBuff[1];
  }
};
static_assert(!cuda::std::is_invocable_v<RangeCEndT, EndFunctionByValue>, "");

struct EndFunctionEnabledBorrowing
{
  __host__ __device__ friend constexpr int* begin(EndFunctionEnabledBorrowing)
  {
    return nullptr;
  }
  __host__ __device__ friend constexpr int* end(EndFunctionEnabledBorrowing)
  {
    return &globalBuff[2];
  }
};
namespace cuda
{
namespace std
{
namespace ranges
{
template <>
_CCCL_INLINE_VAR constexpr bool enable_borrowed_range<EndFunctionEnabledBorrowing> = true;
}
} // namespace std
} // namespace cuda

struct EndFunctionReturnsEmptyPtr
{
  Empty x;
  __host__ __device__ friend constexpr const Empty* begin(EndFunctionReturnsEmptyPtr const&)
  {
    return nullptr;
  }
  __host__ __device__ friend constexpr const Empty* end(EndFunctionReturnsEmptyPtr const& bf)
  {
    return &bf.x;
  }
};

struct EndFunctionWithDataMember
{
  int x;
  int end;
  __host__ __device__ friend constexpr const int* begin(EndFunctionWithDataMember const&)
  {
    return nullptr;
  }
  __host__ __device__ friend constexpr const int* end(EndFunctionWithDataMember const& bf)
  {
    return &bf.x;
  }
};

struct EndFunctionWithPrivateEndMember
{
  int y;
  __host__ __device__ friend constexpr const int* begin(EndFunctionWithPrivateEndMember const&)
  {
    return nullptr;
  }
  __host__ __device__ friend constexpr const int* end(EndFunctionWithPrivateEndMember const& bf)
  {
    return &bf.y;
  }

private:
  __host__ __device__ const int* end() const;
};

struct BeginMemberEndFunction
{
  int x;
  __host__ __device__ constexpr const int* begin() const
  {
    return nullptr;
  }
  __host__ __device__ friend constexpr const int* end(BeginMemberEndFunction const& bf)
  {
    return &bf.x;
  }
};

__host__ __device__ constexpr bool testEndFunction()
{
  const EndFunction a{};
  assert(cuda::std::ranges::end(a) == &a.x);
  assert(cuda::std::ranges::cend(a) == &a.x);
  EndFunction aa{};
  static_assert(!cuda::std::is_invocable_v<RangeEndT, decltype((aa))>, "");
  assert(cuda::std::ranges::cend(aa) == &aa.x);

  EndFunctionByValue b{};
  assert(cuda::std::ranges::end(b) == &globalBuff[1]);
  assert(cuda::std::ranges::cend(b) == &globalBuff[1]);

  EndFunctionEnabledBorrowing c{};
  assert(cuda::std::ranges::end(cuda::std::move(c)) == &globalBuff[2]);
  assert(cuda::std::ranges::cend(cuda::std::move(c)) == &globalBuff[2]);

  const EndFunctionReturnsEmptyPtr d{};
  assert(cuda::std::ranges::end(d) == &d.x);
  assert(cuda::std::ranges::cend(d) == &d.x);
  EndFunctionReturnsEmptyPtr dd{};
  static_assert(!cuda::std::is_invocable_v<RangeEndT, decltype((dd))>, "");
  assert(cuda::std::ranges::cend(dd) == &dd.x);

  const EndFunctionWithDataMember e{};
  assert(cuda::std::ranges::end(e) == &e.x);
  assert(cuda::std::ranges::cend(e) == &e.x);
  EndFunctionWithDataMember ee{};
  static_assert(!cuda::std::is_invocable_v<RangeEndT, decltype((ee))>, "");
  assert(cuda::std::ranges::cend(ee) == &ee.x);

  const EndFunctionWithPrivateEndMember f{};
  assert(cuda::std::ranges::end(f) == &f.y);
  assert(cuda::std::ranges::cend(f) == &f.y);
  EndFunctionWithPrivateEndMember ff{};
  static_assert(!cuda::std::is_invocable_v<RangeEndT, decltype((ff))>, "");
  assert(cuda::std::ranges::cend(ff) == &ff.y);

  const BeginMemberEndFunction g{};
  assert(cuda::std::ranges::end(g) == &g.x);
  assert(cuda::std::ranges::cend(g) == &g.x);
  BeginMemberEndFunction gg{};
  static_assert(!cuda::std::is_invocable_v<RangeEndT, decltype((gg))>, "");
  assert(cuda::std::ranges::cend(gg) == &gg.x);

  return true;
}
static_assert(noexcept(cuda::std::ranges::end(cuda::std::declval<int (&)[10]>())));
static_assert(noexcept(cuda::std::ranges::cend(cuda::std::declval<int (&)[10]>())));

// needs c++17's guaranteed copy elision
#if !TEST_COMPILER(MSVC2019) // broken noexcept
_CCCL_GLOBAL_CONSTANT struct NoThrowMemberEnd
{
  __host__ __device__ ThrowingIterator<int> begin() const;
  __host__ __device__ ThrowingIterator<int> end() const noexcept; // auto(t.end()) doesn't throw
} ntme;
static_assert(noexcept(cuda::std::ranges::end(ntme)), "");
static_assert(noexcept(cuda::std::ranges::cend(ntme)), "");

_CCCL_GLOBAL_CONSTANT struct NoThrowADLEnd
{
  __host__ __device__ ThrowingIterator<int> begin() const;
  __host__ __device__ friend ThrowingIterator<int> end(NoThrowADLEnd&) noexcept; // auto(end(t)) doesn't throw
  __host__ __device__ friend ThrowingIterator<int> end(const NoThrowADLEnd&) noexcept;
} ntae;
static_assert(noexcept(cuda::std::ranges::end(ntae)), "");
static_assert(noexcept(cuda::std::ranges::cend(ntae)), "");
#endif // !TEST_COMPILER(MSVC2019)

_CCCL_GLOBAL_CONSTANT struct NoThrowMemberEndReturnsRef
{
  __host__ __device__ ThrowingIterator<int> begin() const;
  __host__ __device__ ThrowingIterator<int>& end() const noexcept; // auto(t.end()) may throw
} ntmerr;
static_assert(!noexcept(cuda::std::ranges::end(ntmerr)), "");
static_assert(!noexcept(cuda::std::ranges::cend(ntmerr)), "");

_CCCL_GLOBAL_CONSTANT struct EndReturnsArrayRef
{
  __host__ __device__ auto begin() const noexcept -> int (&)[10];
  __host__ __device__ auto end() const noexcept -> int (&)[10];
} erar;
static_assert(noexcept(cuda::std::ranges::end(erar)), "");
static_assert(noexcept(cuda::std::ranges::cend(erar)), "");

#if TEST_STD_VER > 2017
// Test ADL-proofing.
struct Incomplete;
template <class T>
struct Holder
{
  T t;
};
static_assert(!cuda::std::is_invocable_v<RangeEndT, Holder<Incomplete>*>, "");
static_assert(!cuda::std::is_invocable_v<RangeEndT, Holder<Incomplete>*&>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, Holder<Incomplete>*>, "");
static_assert(!cuda::std::is_invocable_v<RangeCEndT, Holder<Incomplete>*&>, "");
#endif // TEST_STD_VER > 2017

int main(int, char**)
{
  static_assert(testReturnTypes(), "");

  testArray();
  static_assert(testArray(), "");

  testEndMember();
  static_assert(testEndMember(), "");

  testEndFunction();
  static_assert(testEndFunction(), "");

#if !TEST_COMPILER(MSVC2019) // broken noexcept
  unused(ntme);
  unused(ntae);
#endif // !TEST_COMPILER(MSVC2019)
  unused(ntmerr);
  unused(erar);

  return 0;
}