/*
 * Copyright (C) 2019 Emeric Poupon
 *
 * This file is part of LMS.
 *
 * LMS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * LMS 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include <chrono>
#include <unordered_map>

#include <Wt/WDateTime.h>

#include "utils/NetAddress.hpp"
#include "utils/Exception.hpp"

namespace Auth
{
	class LoginThrottler
	{
		public:
			LoginThrottler(std::size_t maxEntries) : _maxEntries {maxEntries} {}

			// user must lock these calls to avoid races
			bool isClientThrottled(const boost::asio::ip::address& address) const;
			void onBadClientAttempt(const boost::asio::ip::address& address);
			void onGoodClientAttempt(const boost::asio::ip::address& address);

		private:
			void removeOutdatedEntries();

			const std::size_t _maxEntries;
			static constexpr std::size_t _maxBadConsecutiveAttemptCount {5};
			static constexpr std::chrono::seconds _throttlingDuration {3};

			struct AttemptInfo
			{
				Wt::WDateTime nextAttempt;
				std::size_t badConsecutiveAttemptCount{};
			};
			std::unordered_map<boost::asio::ip::address, AttemptInfo>	_attemptsInfo;
	};
} // Auth