/*
	This file is part of Fennix Kernel.

	Fennix Kernel 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.

	Fennix Kernel 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 Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/

#pragma once

#include <ratio>
#include <type_traits>

namespace std
{
	namespace chrono
	{
		template <class Rep, class Period = std::ratio<1>>
		class duration
		{
		private:
			Rep _rep;
			std::ratio<Period::num, Period::den> _period;

		public:
			using rep = Rep;
			using period = Period;

			constexpr duration() = default;
			duration(const duration &) = default;

			template <class Rep2>
			constexpr explicit duration(const Rep2 &r) { _rep = r; }

			template <class Rep2, class Period2>
			constexpr duration(const duration<Rep2, Period2> &d);

			duration &operator=(const duration &other) = default;

			constexpr Rep count() const { return _rep; }

			static constexpr duration zero() noexcept;
			static constexpr duration min() noexcept;
			static constexpr duration max() noexcept;
			constexpr std::common_type_t<duration> operator+() const;
			constexpr std::common_type_t<duration> operator-() const;

			constexpr duration operator++(int) { return duration(_rep++); }
			constexpr duration operator--(int) { return duration(_rep--); }

			constexpr duration &operator++()
			{
				++_rep;
				return *this;
			}

			constexpr duration &operator--()
			{
				--_rep;
				return *this;
			}

			constexpr duration &operator+=(const duration &d)
			{
				_rep += d.count();
				return *this;
			}

			constexpr duration &operator-=(const duration &d)
			{
				_rep -= d.count();
				return *this;
			}

			constexpr duration &operator*=(const Rep &rhs)
			{
				_rep *= rhs;
				return *this;
			}

			constexpr duration &operator/=(const Rep &rhs)
			{
				_rep /= rhs;
				return *this;
			}

			constexpr duration &operator%=(const Rep &rhs)
			{
				_rep %= rhs;
				return *this;
			}

			constexpr duration &operator%=(const duration &rhs)
			{
				_rep %= rhs.count();
				return *this;
			}
		};

		template <class Clock, class Duration = typename Clock::duration>
		class time_point;

		using nanoseconds = std::chrono::duration<int64_t, std::nano>;
		using microseconds = std::chrono::duration<int64_t, std::micro>;
		using milliseconds = std::chrono::duration<int64_t, std::milli>;
		using seconds = std::chrono::duration<int64_t>;
		using minutes = std::chrono::duration<int64_t, std::ratio<60>>;
		using hours = std::chrono::duration<int64_t, std::ratio<3600>>;
		using days = std::chrono::duration<int64_t, std::ratio<86400>>;
		using weeks = std::chrono::duration<int64_t, std::ratio<604800>>;
		using months = std::chrono::duration<int64_t, std::ratio<2629746>>;
		using years = std::chrono::duration<int64_t, std::ratio<31556952>>;

		template <class ToDuration, class Rep, class Period>
		constexpr ToDuration duration_cast(const std::chrono::duration<Rep, Period> &d)
		{
			typedef typename ToDuration::rep ToRep;
			typedef typename ToDuration::period ToPeriod;
			typedef std::ratio_divide<Period, ToPeriod> CF;
			typedef typename std::common_type<Rep, ToRep, intmax_t>::type CR;
			CR cr_count = static_cast<CR>(d.count());
			CR cr_num = static_cast<CR>(CF::num);
			CR cr_den = static_cast<CR>(CF::den);

			if constexpr (CF::num == 1 && CF::den == 1)
				return ToDuration(static_cast<ToRep>(cr_count));
			else if constexpr (CF::den == 1)
				return ToDuration(static_cast<ToRep>(cr_count * cr_num));
			else if constexpr (CF::num == 1)
				return ToDuration(static_cast<ToRep>(cr_count / cr_den));
			else
				return ToDuration(static_cast<ToRep>(cr_count * cr_num / cr_den));
		}
	}

	inline namespace literals
	{
		inline namespace chrono_literals
		{
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wliteral-suffix"
			constexpr std::chrono::hours operator""h(unsigned long long h)
			{
				return std::chrono::hours(h);
			}

			constexpr std::chrono::duration<long double, std::ratio<3600, 1>> operator""h(long double h)
			{
				return std::chrono::duration<long double, std::ratio<3600, 1>>(h);
			}

			constexpr std::chrono::minutes operator""min(unsigned long long m)
			{
				return std::chrono::minutes(m);
			}

			constexpr std::chrono::duration<long double, std::ratio<60, 1>> operator""min(long double m)
			{
				return std::chrono::duration<long double, std::ratio<60, 1>>(m);
			}

			constexpr std::chrono::seconds operator""s(unsigned long long s)
			{
				return std::chrono::seconds(s);
			}

			constexpr std::chrono::duration<long double> operator""s(long double s)
			{
				return std::chrono::duration<long double>(s);
			}

			constexpr std::chrono::milliseconds operator""ms(unsigned long long ms)
			{
				return std::chrono::milliseconds(ms);
			}

			constexpr std::chrono::duration<long double, std::milli> operator""ms(long double ms)
			{
				return std::chrono::duration<long double, std::milli>(ms);
			}

			constexpr std::chrono::microseconds operator""us(unsigned long long us)
			{
				return std::chrono::microseconds(us);
			}

			constexpr std::chrono::duration<long double, std::micro> operator""us(long double us)
			{
				return std::chrono::duration<long double, std::micro>(us);
			}

			constexpr std::chrono::nanoseconds operator""ns(unsigned long long ns)
			{
				return std::chrono::nanoseconds(ns);
			}

			constexpr std::chrono::duration<long double, std::nano> operator""ns(long double ns)
			{
				return std::chrono::duration<long double, std::nano>(ns);
			}
#pragma GCC diagnostic pop
		}
	}
}