/*
 *  Copyright 2018 NVIDIA Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#pragma once

#include <thrust/detail/config.h>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header
#include <thrust/detail/type_deduction.h>
#include <thrust/type_traits/remove_cvref.h>

#include <tuple>
#include <type_traits>

THRUST_NAMESPACE_BEGIN

namespace detail
{

struct capture_as_dependency_fn
{
  template <typename Dependency>
  auto operator()(Dependency&& dependency) const THRUST_DECLTYPE_RETURNS(capture_as_dependency(THRUST_FWD(dependency)))
};

// Default implementation: universal forwarding.
template <typename Dependency>
auto capture_as_dependency(Dependency&& dependency) THRUST_DECLTYPE_RETURNS(THRUST_FWD(dependency))

  template <typename... Dependencies>
  auto capture_as_dependency(std::tuple<Dependencies...>& dependencies)
    THRUST_DECLTYPE_RETURNS(tuple_for_each(THRUST_FWD(dependencies), capture_as_dependency_fn{}))

      template <template <typename> class BaseSystem, typename... Dependencies>
      struct execute_with_dependencies : BaseSystem<execute_with_dependencies<BaseSystem, Dependencies...>>
{
private:
  using super_t = BaseSystem<execute_with_dependencies<BaseSystem, Dependencies...>>;

  std::tuple<remove_cvref_t<Dependencies>...> dependencies;

public:
  _CCCL_HOST execute_with_dependencies(super_t const& super, Dependencies&&... deps)
      : super_t(super)
      , dependencies(std::forward<Dependencies>(deps)...)
  {}

  template <typename... UDependencies>
  _CCCL_HOST execute_with_dependencies(super_t const& super, UDependencies&&... deps)
      : super_t(super)
      , dependencies(THRUST_FWD(deps)...)
  {}

  template <typename... UDependencies>
  _CCCL_HOST execute_with_dependencies(UDependencies&&... deps)
      : dependencies(THRUST_FWD(deps)...)
  {}

  template <typename... UDependencies>
  _CCCL_HOST execute_with_dependencies(super_t const& super, std::tuple<UDependencies...>&& deps)
      : super_t(super)
      , dependencies(std::move(deps))
  {}

  template <typename... UDependencies>
  _CCCL_HOST execute_with_dependencies(std::tuple<UDependencies...>&& deps)
      : dependencies(std::move(deps))
  {}

  std::tuple<remove_cvref_t<Dependencies>...> _CCCL_HOST extract_dependencies()
  {
    return std::move(dependencies);
  }

  // Rebinding.
  template <typename... UDependencies>
  _CCCL_HOST execute_with_dependencies<BaseSystem, UDependencies...> rebind_after(UDependencies&&... udependencies) const
  {
    return {capture_as_dependency(THRUST_FWD(udependencies))...};
  }

  // Rebinding.
  template <typename... UDependencies>
  _CCCL_HOST execute_with_dependencies<BaseSystem, UDependencies...>
  rebind_after(std::tuple<UDependencies...>& udependencies) const
  {
    return {capture_as_dependency(udependencies)};
  }
  template <typename... UDependencies>
  _CCCL_HOST execute_with_dependencies<BaseSystem, UDependencies...>
  rebind_after(std::tuple<UDependencies...>&& udependencies) const
  {
    return {capture_as_dependency(std::move(udependencies))};
  }
};

template <typename Allocator, template <typename> class BaseSystem, typename... Dependencies>
struct execute_with_allocator_and_dependencies
    : BaseSystem<execute_with_allocator_and_dependencies<Allocator, BaseSystem, Dependencies...>>
{
private:
  using super_t = BaseSystem<execute_with_allocator_and_dependencies<Allocator, BaseSystem, Dependencies...>>;

  std::tuple<remove_cvref_t<Dependencies>...> dependencies;
  Allocator alloc;

public:
  template <typename... UDependencies>
  _CCCL_HOST execute_with_allocator_and_dependencies(super_t const& super, Allocator a, UDependencies&&... deps)
      : super_t(super)
      , dependencies(THRUST_FWD(deps)...)
      , alloc(a)
  {}

  template <typename... UDependencies>
  _CCCL_HOST execute_with_allocator_and_dependencies(Allocator a, UDependencies&&... deps)
      : dependencies(THRUST_FWD(deps)...)
      , alloc(a)
  {}

  template <typename... UDependencies>
  _CCCL_HOST
  execute_with_allocator_and_dependencies(super_t const& super, Allocator a, std::tuple<UDependencies...>&& deps)
      : super_t(super)
      , dependencies(std::move(deps))
      , alloc(a)
  {}

  template <typename... UDependencies>
  _CCCL_HOST execute_with_allocator_and_dependencies(Allocator a, std::tuple<UDependencies...>&& deps)
      : dependencies(std::move(deps))
      , alloc(a)
  {}

  std::tuple<remove_cvref_t<Dependencies>...> _CCCL_HOST extract_dependencies()
  {
    return std::move(dependencies);
  }

  _CCCL_HOST typename std::add_lvalue_reference<Allocator>::type get_allocator()
  {
    return alloc;
  }

  // Rebinding.
  template <typename... UDependencies>
  _CCCL_HOST execute_with_allocator_and_dependencies<Allocator, BaseSystem, UDependencies...>
  rebind_after(UDependencies&&... udependencies) const
  {
    return {alloc, capture_as_dependency(THRUST_FWD(udependencies))...};
  }

  // Rebinding.
  template <typename... UDependencies>
  _CCCL_HOST execute_with_allocator_and_dependencies<Allocator, BaseSystem, UDependencies...>
  rebind_after(std::tuple<UDependencies...>& udependencies) const
  {
    return {alloc, capture_as_dependency(udependencies)};
  }
  template <typename... UDependencies>
  _CCCL_HOST execute_with_allocator_and_dependencies<Allocator, BaseSystem, UDependencies...>
  rebind_after(std::tuple<UDependencies...>&& udependencies) const
  {
    return {alloc, capture_as_dependency(std::move(udependencies))};
  }
};

template <template <typename> class BaseSystem, typename... Dependencies>
_CCCL_HOST std::tuple<remove_cvref_t<Dependencies>...>
extract_dependencies(thrust::detail::execute_with_dependencies<BaseSystem, Dependencies...>&& system)
{
  return std::move(system).extract_dependencies();
}
template <template <typename> class BaseSystem, typename... Dependencies>
_CCCL_HOST std::tuple<remove_cvref_t<Dependencies>...>
extract_dependencies(thrust::detail::execute_with_dependencies<BaseSystem, Dependencies...>& system)
{
  return std::move(system).extract_dependencies();
}

template <typename Allocator, template <typename> class BaseSystem, typename... Dependencies>
_CCCL_HOST std::tuple<remove_cvref_t<Dependencies>...> extract_dependencies(
  thrust::detail::execute_with_allocator_and_dependencies<Allocator, BaseSystem, Dependencies...>&& system)
{
  return std::move(system).extract_dependencies();
}
template <typename Allocator, template <typename> class BaseSystem, typename... Dependencies>
_CCCL_HOST std::tuple<remove_cvref_t<Dependencies>...> extract_dependencies(
  thrust::detail::execute_with_allocator_and_dependencies<Allocator, BaseSystem, Dependencies...>& system)
{
  return std::move(system).extract_dependencies();
}

template <typename System>
_CCCL_HOST std::tuple<> extract_dependencies(System&&)
{
  return std::tuple<>{};
}

} // namespace detail

THRUST_NAMESPACE_END