/**
 * Copyright (c) 2022 Paul-Louis Ageneau
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef RTC_IMPL_POLL_SERVICE_H
#define RTC_IMPL_POLL_SERVICE_H

#include "pollinterrupter.hpp"
#include "socket.hpp"
#include "common.hpp"
#include "internals.hpp"

#if RTC_ENABLE_WEBSOCKET

#include <chrono>
#include <mutex>
#include <thread>
#include <unordered_map>
#include <functional>

namespace rtc::impl {

class PollService {
public:
	using clock = std::chrono::steady_clock;

	static PollService &Instance();

	PollService(const PollService &) = delete;
	PollService &operator=(const PollService &) = delete;
	PollService(PollService &&) = delete;
	PollService &operator=(PollService &&) = delete;

	void start();
	void join();

	enum class Direction { Both, In, Out };
	enum class Event { None, Error, Timeout, In, Out };

	struct Params {
		Direction direction;
		optional<clock::duration> timeout;
		std::function<void(Event)> callback;
	};

	void add(socket_t sock, Params params);
	void remove(socket_t sock);

private:
	PollService();
	~PollService();

	void prepare(std::vector<struct pollfd> &pfds, optional<clock::time_point> &next);
	void process(std::vector<struct pollfd> &pfds);
	void runLoop();

	struct SocketEntry {
		Params params;
		optional<clock::time_point> until;
	};

	using SocketMap = std::unordered_map<socket_t, SocketEntry>;
	unique_ptr<SocketMap> mSocks;

	std::recursive_mutex mMutex;
	std::thread mThread;
	bool mStopped;
	PollInterrupter mInterrupter;
};

std::ostream &operator<<(std::ostream &out, PollService::Direction direction);

} // namespace rtc::impl

#endif

#endif