/*! \file pisystemtime.h
 * \ingroup Core
 * \~\brief
 * \~english System time structs and methods
 * \~russian Типы и методы системного времени
*/
/*
	PIP - Platform Independent Primitives
	Time structs
	Ivan Pelipenko peri4ko@yandex.ru

	This program 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 3 of the License, or
	(at your option) any later version.

	This program 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 program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PISYSTEMTIME_H
#define PISYSTEMTIME_H


#include "pistring.h"


//! \ingroup Core
//! \~\brief
//! \~english System time with nanosecond precision.
//! \~russian Системное время с точностью до наносекунд.
class PIP_EXPORT PISystemTime {
public:
	
	//! \~english Contructs time with seconds and nanoseconds = 0
	//! \~russian Создает время с секундами и наносекундами = 0
	PISystemTime() {seconds = nanoseconds = 0;}
	
	//! \~english Contructs time with "s" seconds and "ns" nanoseconds
	//! \~russian Создает время с секундами "s" и наносекундами "ns"
	PISystemTime(int s, int ns) {seconds = s; nanoseconds = ns; checkOverflows();}
	
	
	//! \~english Returns time value in seconds
	//! \~russian Возвращает значение времени в секундах
	double toSeconds() const {return double(seconds) + nanoseconds / 1.e+9;}
	
	//! \~english Returns time value in milliseconds
	//! \~russian Возвращает значение времени в миллисекундах
	double toMilliseconds() const {return seconds * 1.e+3 + nanoseconds / 1.e+6;}
	
	//! \~english  Returns time value in microseconds
	//! \~russian Возвращает значение времени в микросекундах
	double toMicroseconds() const {return seconds * 1.e+6 + nanoseconds / 1.e+3;}
	
	//! \~english Returns time value in nanoseconds
	//! \~russian Возвращает значение времени в наносекундах
	double toNanoseconds() const {return seconds * 1.e+9 + double(nanoseconds);}
	
	
	//! \~english  Add to time "v" seconds
	//! \~russian Добавляет ко времени "v" секунд
	PISystemTime & addSeconds(double v) {*this += fromSeconds(v); return *this;}
	
	//! \~english Add to time "v" milliseconds
	//! \~russian Добавляет ко времени "v" миллисекунд
	PISystemTime & addMilliseconds(double v) {*this += fromMilliseconds(v); return *this;}
	
	//! \~english Add to time "v" microseconds
	//! \~russian Добавляет ко времени "v" микросекунд
	PISystemTime & addMicroseconds(double v) {*this += fromMicroseconds(v); return *this;}
	
	//! \~english Add to time "v" nanoseconds
	//! \~russian Добавляет ко времени "v" наносекунд
	PISystemTime & addNanoseconds(double v) {*this += fromNanoseconds(v); return *this;}
	
	
	//! \~english Sleep for this time
	//! \~russian Ожидать это время
	void sleep();
	
	//! \~english On *nix system assign current value to timespec struct
	//! \~russian На *nix системах присваивает время к timespec структуре
	void toTimespec(void * ts);
	
	//! \~english Returns copy of this time with absolutely values of s and ns
	//! \~russian Возвращает копию времени с модулем значения
	PISystemTime abs() const;
	
	//! \~english Returns sum of this time with "t"
	//! \~russian Возвращает сумму этого времени с "t"
	PISystemTime   operator +(const PISystemTime & t) const {PISystemTime tt(*this); tt.seconds += t.seconds; tt.nanoseconds += t.nanoseconds; tt.checkOverflows(); return tt;}
	
	//! \~english Returns difference between this time and "t"
	//! \~russian Возвращает разницу между этим временем и "t"
	PISystemTime   operator -(const PISystemTime & t) const {PISystemTime tt(*this); tt.seconds -= t.seconds; tt.nanoseconds -= t.nanoseconds; tt.checkOverflows(); return tt;}
	
	//! \~english Returns multiplication between this time and "t"
	//! \~russian Возвращает это временя умноженное на "t"
	PISystemTime   operator *(const double & v) const {return fromMilliseconds(toMilliseconds() * v);}
	
	//! \~english Returns division between this time and "t"
	//! \~russian Возвращает это временя поделённое на "t"
	PISystemTime   operator /(const double & v) const {return fromMilliseconds(toMilliseconds() / v);}
	
	//! \~english Add to time "t"
	//! \~russian Добавляет ко времени "t"
	PISystemTime & operator +=(const PISystemTime & t) {seconds += t.seconds; nanoseconds += t.nanoseconds; checkOverflows(); return *this;}
	
	//! \~english Subtract from time "t"
	//! \~russian Вычитает из времени "t"
	PISystemTime & operator -=(const PISystemTime & t) {seconds -= t.seconds; nanoseconds -= t.nanoseconds; checkOverflows(); return *this;}
	
	//! \~english Multiply time by "v"
	//! \~russian Умножает время на "v"
	PISystemTime & operator *=(const double & v) {*this = fromMilliseconds(toMilliseconds() * v); return *this;}
	
	//! \~english Divide time by "v"
	//! \~russian Делит время на "v"
	PISystemTime & operator /=(const double & v) {*this = fromMilliseconds(toMilliseconds() / v); return *this;}
	
	
	//! \~english Compare operator
	//! \~russian Оператор сравнения
	bool operator ==(const PISystemTime & t) const {return ((seconds == t.seconds) && (nanoseconds == t.nanoseconds));}
	
	//! \~english Compare operator
	//! \~russian Оператор сравнения
	bool operator !=(const PISystemTime & t) const {return ((seconds != t.seconds) || (nanoseconds != t.nanoseconds));}
	
	//! \~english Compare operator
	//! \~russian Оператор сравнения
	bool operator >(const PISystemTime & t) const {if (seconds == t.seconds) return nanoseconds > t.nanoseconds; return seconds > t.seconds;}
	
	//! \~english Compare operator
	//! \~russian Оператор сравнения
	bool operator <(const PISystemTime & t) const {if (seconds == t.seconds) return nanoseconds < t.nanoseconds; return seconds < t.seconds;}
	
	//! \~english Compare operator
	//! \~russian Оператор сравнения
	bool operator >=(const PISystemTime & t) const {if (seconds == t.seconds) return nanoseconds >= t.nanoseconds; return seconds >= t.seconds;}
	
	//! \~english Compare operator
	//! \~russian Оператор сравнения
	bool operator <=(const PISystemTime & t) const {if (seconds == t.seconds) return nanoseconds <= t.nanoseconds; return seconds <= t.seconds;}
	
	
	//! \~english Contructs time from seconds "v"
	//! \~russian Создает время из "v" секунд
	static PISystemTime fromSeconds(double v) {int s = piFloord(v); return PISystemTime(s, int((v - s) * 1000000000.));}
	
	//! \~english Contructs time from milliseconds "v"
	//! \~russian Создает время из "v" миллисекунд
	static PISystemTime fromMilliseconds(double v) {int s = piFloord(v / 1000.); return PISystemTime(s, int((v / 1000. - s) * 1000000000.));}
	
	//! \~english Contructs time from microseconds "v"
	//! \~russian Создает время из "v" микросекунд
	static PISystemTime fromMicroseconds(double v) {int s = piFloord(v / 1000000.); return PISystemTime(s, int((v / 1000000. - s) * 1000000000.));}
	
	//! \~english Contructs time from nanoseconds "v"
	//! \~russian Создает время из "v" наносекунд
	static PISystemTime fromNanoseconds(double v) {int s = piFloord(v / 1000000000.); return PISystemTime(s, int((v / 1000000000. - s) * 1000000000.));}
	
	//! \~english Returns current system time
	//! \~russian Возвращает текущее системное время
	static PISystemTime current(bool precise_but_not_system = false);
	
	//! \~english Seconds time part
	//! \~russian Секунды времени
	int seconds;
	
	//! \~english Nanoseconds time part
	//! \~russian Наносекунды времени
	int nanoseconds;
	
private:
	void checkOverflows() {while (nanoseconds >= 1000000000) {nanoseconds -= 1000000000; seconds++;} while (nanoseconds < 0) {nanoseconds += 1000000000; seconds--;}}
	
};

//! \relatesalso PICout
//! \~english \brief Output operator to PICout
//! \~russian \brief Оператор вывода в PICout
inline PICout operator <<(PICout s, const PISystemTime & v) {s.space(); s.saveAndSetControls(0); s << "(" << v.seconds << " s, " << v.nanoseconds << " ns)"; s.restoreControls(); return s;}




//! \ingroup Core
//! \~\brief
//! \~english Time measurements.
//! \~russian Измерение времени.
class PIP_EXPORT PITimeMeasurer {
public:
	PITimeMeasurer();
	
	/** \brief Set internal time mark to current system time
	 * \details This function used for set start time mark. Later
	 * you can find out elapsed time from this time mark to any
	 * moment of time with \a elapsed_s(), \a elapsed_m(),
	 * \a elapsed_u() or \a elapsed_n() functions.
	 * \sa \a elapsed_s(), \a elapsed_m(), \a elapsed_u(), \a elapsed_n() */
	void reset() {t_st = PISystemTime::current(true);}
	
	//! \brief Returns nanoseconds elapsed from last \a reset() execution or from timer measurer creation.
	double elapsed_n() const;

	//! \brief Returns microseconds elapsed from last \a reset() execution or from timer measurer creation.
	double elapsed_u() const;

	//! \brief Returns milliseconds elapsed from last \a reset() execution or from timer measurer creation.
	double elapsed_m() const;

	//! \brief Returns seconds elapsed from last \a reset() execution or from timer measurer creation.
	double elapsed_s() const;

	//! \brief Returns PISystemTime elapsed from last \a reset() execution or from timer measurer creation.
	PISystemTime elapsed() const;
	
	double reset_time_n() const {return t_st.toNanoseconds();}
	double reset_time_u() const {return t_st.toMicroseconds();}
	double reset_time_m() const {return t_st.toMilliseconds();}
	double reset_time_s() const {return t_st.toSeconds();}
	
	//! \brief Returns time mark of last \a reset() execution or timer measurer creation.
	PISystemTime reset_time() {return t_st;}
	
	//! \brief Returns nanoseconds representation of current system time.
	static double elapsed_system_n() {return PISystemTime::current(true).toNanoseconds();}

	//! \brief Returns microseconds representation of current system time.
	static double elapsed_system_u() {return PISystemTime::current(true).toMicroseconds();}

	//! \brief Returns milliseconds representation of current system time.
	static double elapsed_system_m() {return PISystemTime::current(true).toMilliseconds();}

	//! \brief Returns seconds representation of current system time.
	static double elapsed_system_s() {return PISystemTime::current(true).toSeconds();}

	//! \brief Returns time mark of current system time.
	static PISystemTime elapsed_system() {return PISystemTime::current(true);}
	
private:
	PISystemTime t_st, t_cur;
	
};

#endif // PITIME_H