/*
 * Copyright (c) 2017-2023 zhllxt
 *
 * author   : zhllxt
 * email    : 37792738@qq.com
 * 
 * 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 __ASIO2_MQTT_AOP_UNSUBSCRIBE_HPP__
#define __ASIO2_MQTT_AOP_UNSUBSCRIBE_HPP__

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
#pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include <asio2/base/iopool.hpp>

#include <asio2/base/detail/function_traits.hpp>
#include <asio2/base/detail/util.hpp>

#include <asio2/mqtt/message.hpp>

namespace asio2::detail
{
	template<class caller_t, class args_t>
	class mqtt_aop_unsubscribe
	{
		friend caller_t;

	protected:
		// must be server
		template<class Message, class Response, bool IsClient = args_t::is_client>
		inline std::enable_if_t<!IsClient, void>
		_before_unsubscribe_callback(
			error_code& ec, std::shared_ptr<caller_t>& caller_ptr, caller_t* caller, mqtt::message& om,
			Message& msg, Response& rep)
		{
			detail::ignore_unused(ec, caller_ptr, caller, om, msg, rep);

			using message_type  [[maybe_unused]] = typename detail::remove_cvref_t<Message>;
			using response_type [[maybe_unused]] = typename detail::remove_cvref_t<Response>;

			rep.packet_id(msg.packet_id());

			mqtt::utf8_string_set& topic_filters = msg.topic_filters();

			topic_filters.for_each([&](/*mqtt::utf8_string*/auto& str)
			{
				auto[share_name, topic_filter] = mqtt::parse_topic_filter(str.data_view());

				if (!share_name.empty())
				{
					caller->shared_targets().erase(caller_ptr, share_name, topic_filter);
				}

				std::size_t removed = caller->subs_map().erase(topic_filter, caller->client_id());

				// The Payload contains a list of Reason Codes.
				// https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901194
				if constexpr (std::is_same_v<response_type, mqtt::v5::unsuback>)
				{
					if /**/ (topic_filter.empty())
						rep.add_reason_codes(detail::to_underlying(mqtt::error::topic_filter_invalid));
					else if (removed == 0)
						rep.add_reason_codes(detail::to_underlying(mqtt::error::no_subscription_existed));
					else
						rep.add_reason_codes(detail::to_underlying(mqtt::error::success));
				}
				else
				{
					std::ignore = removed;
				}
			});
		}

		template<class Message, class Response, bool IsClient = args_t::is_client>
		inline std::enable_if_t<IsClient, void>
		_before_unsubscribe_callback(
			error_code& ec, std::shared_ptr<caller_t>& caller_ptr, caller_t* caller, mqtt::message& om,
			Message& msg, Response& rep)
		{
			detail::ignore_unused(ec, caller_ptr, caller, om, msg, rep);

			ASIO2_ASSERT(false && "client should't recv the unsubscribe message");
		}

		// must be server
		inline void _before_user_callback_impl(
			error_code& ec, std::shared_ptr<caller_t>& caller_ptr, caller_t* caller, mqtt::message& om,
			mqtt::v3::unsubscribe& msg, mqtt::v3::unsuback& rep)
		{
			if (_before_unsubscribe_callback(ec, caller_ptr, caller, om, msg, rep); ec)
				return;
		}

		// must be server
		inline void _before_user_callback_impl(
			error_code& ec, std::shared_ptr<caller_t>& caller_ptr, caller_t* caller, mqtt::message& om,
			mqtt::v4::unsubscribe& msg, mqtt::v4::unsuback& rep)
		{
			if (_before_unsubscribe_callback(ec, caller_ptr, caller, om, msg, rep); ec)
				return;
		}

		// must be server
		inline void _before_user_callback_impl(
			error_code& ec, std::shared_ptr<caller_t>& caller_ptr, caller_t* caller, mqtt::message& om,
			mqtt::v5::unsubscribe& msg, mqtt::v5::unsuback& rep)
		{
			if (_before_unsubscribe_callback(ec, caller_ptr, caller, om, msg, rep); ec)
				return;
		}

		inline void _after_user_callback_impl(
			error_code& ec, std::shared_ptr<caller_t>& caller_ptr, caller_t* caller, mqtt::message& om,
			mqtt::v3::unsubscribe& msg, mqtt::v3::unsuback& rep)
		{
			detail::ignore_unused(ec, caller_ptr, caller, om, msg, rep);
		}

		inline void _after_user_callback_impl(
			error_code& ec, std::shared_ptr<caller_t>& caller_ptr, caller_t* caller, mqtt::message& om,
			mqtt::v4::unsubscribe& msg, mqtt::v4::unsuback& rep)
		{
			detail::ignore_unused(ec, caller_ptr, caller, om, msg, rep);
		}

		inline void _after_user_callback_impl(
			error_code& ec, std::shared_ptr<caller_t>& caller_ptr, caller_t* caller, mqtt::message& om,
			mqtt::v5::unsubscribe& msg, mqtt::v5::unsuback& rep)
		{
			detail::ignore_unused(ec, caller_ptr, caller, om, msg, rep);

		}
	};
}

#endif // !__ASIO2_MQTT_AOP_UNSUBSCRIBE_HPP__