//
// Copyright (c) 2022 Klemens Morgenstern (klemens.morgenstern@gmx.net)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef BOOST_COBALT_DETAIL_DETACHED_HPP
#define BOOST_COBALT_DETAIL_DETACHED_HPP

#include <boost/cobalt/detail/exception.hpp>
#include <boost/cobalt/detail/forward_cancellation.hpp>
#include <boost/cobalt/detail/wrapper.hpp>
#include <boost/cobalt/detail/this_thread.hpp>
#include <boost/cobalt/op.hpp>

#include <boost/asio/cancellation_signal.hpp>

#include <boost/core/exchange.hpp>

#include <coroutine>
#include <optional>
#include <utility>
#include <boost/asio/bind_allocator.hpp>

namespace boost::cobalt
{

struct detached;

namespace detail
{

struct detached_promise
    : promise_memory_resource_base,
      promise_cancellation_base<asio::cancellation_slot, asio::enable_total_cancellation>,
      promise_throw_if_cancelled_base,
      enable_awaitables<detached_promise>,
      enable_await_allocator<detached_promise>,
      enable_await_executor<detached_promise>,
      enable_await_deferred
{
  using promise_cancellation_base<asio::cancellation_slot, asio::enable_total_cancellation>::await_transform;
  using promise_throw_if_cancelled_base::await_transform;
  using enable_awaitables<detached_promise>::await_transform;
  using enable_await_allocator<detached_promise>::await_transform;
  using enable_await_executor<detached_promise>::await_transform;
  using enable_await_deferred::await_transform;

  [[nodiscard]] detached get_return_object();

  std::suspend_never await_transform(
      cobalt::this_coro::reset_cancellation_source_t<asio::cancellation_slot> reset) noexcept
  {
    this->reset_cancellation_source(reset.source);
    return {};
  }

  using executor_type = executor;
  executor_type exec;
  const executor_type & get_executor() const {return exec;}

  template<typename ... Args>
  detached_promise(Args & ...args)
      :
#if !defined(BOOST_COBALT_NO_PMR)
        promise_memory_resource_base(detail::get_memory_resource_from_args(args...)),
#endif
        exec{detail::get_executor_from_args(args...)}
  {
  }

  std::suspend_never initial_suspend() noexcept {return {};}
  std::suspend_never final_suspend() noexcept {return {};}

  void return_void() {}
#if !defined(BOOST_NO_EXCEPTIONS)
  void unhandled_exception() { throw ; }
#endif
};

}

}

#endif //BOOST_COBALT_DETAIL_DETACHED_HPP