#ifndef INCLUDED_C_TIMESPEC_H
#define INCLUDED_C_TIMESPEC_H

#ifndef INCLUDED_C_TYPES_H
#include <c_Types.h>
#endif /*INCLUDED_C_TYPES_H*/

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

#define C_NSEC_PER_USEC	1000L
#define C_USEC_PER_MSEC	1000L
#define C_MSEC_PER_SEC	1000L
#define C_NSEC_PER_MSEC	1000000L
#define C_USEC_PER_SEC	1000000L
#define C_NSEC_PER_SEC	1000000000L

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

C_STATIC_FORCE_INLINE
struct timespec c_timespec_normalise(struct timespec ts)
{
    while(ts.tv_nsec >= C_NSEC_PER_SEC)
    {
        ++(ts.tv_sec);
        ts.tv_nsec -= C_NSEC_PER_SEC;
    }

    while(ts.tv_nsec <= -C_NSEC_PER_SEC)
    {
        --(ts.tv_sec);
        ts.tv_nsec += C_NSEC_PER_SEC;
    }

    if(ts.tv_nsec < 0)
    {
        /* Negative nanoseconds isn't valid according to POSIX.
         * Decrement tv_sec and roll tv_nsec over.
        */

        --(ts.tv_sec);
        ts.tv_nsec = (C_NSEC_PER_SEC + ts.tv_nsec);
    }

    return ts;
}

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

C_STATIC_FORCE_INLINE
struct timespec c_timespec_add(struct timespec ts1, struct timespec ts2)
{
    /* Normalise inputs to prevent tv_nsec rollover if whole-second values
     * are packed in it.
    */
    ts1 = c_timespec_normalise(ts1);
    ts2 = c_timespec_normalise(ts2);

    ts1.tv_sec  += ts2.tv_sec;
    ts1.tv_nsec += ts2.tv_nsec;

    return c_timespec_normalise(ts1);
}

C_STATIC_FORCE_INLINE
struct timespec c_timespec_sub(struct timespec ts1, struct timespec ts2)
{
    /* Normalise inputs to prevent tv_nsec rollover if whole-second values
     * are packed in it.
    */
    ts1 = c_timespec_normalise(ts1);
    ts2 = c_timespec_normalise(ts2);

    ts1.tv_sec  -= ts2.tv_sec;
    ts1.tv_nsec -= ts2.tv_nsec;

    return c_timespec_normalise(ts1);
}

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */



C_STATIC_FORCE_INLINE
int c_timespec_cmp(struct timespec ts1, struct timespec ts2)
{
	ts1 = c_timespec_normalise(ts1);
	ts2 = c_timespec_normalise(ts2);

	if(ts1.tv_sec == ts2.tv_sec && ts1.tv_nsec == ts2.tv_nsec)
	{
		return 0;
	}
	else if((ts1.tv_sec > ts2.tv_sec)
		  || (ts1.tv_sec == ts2.tv_sec && ts1.tv_nsec > ts2.tv_nsec))
	{
		return 1;
	}
	else {
		return -1;
	}
}

C_STATIC_FORCE_INLINE
bool c_timespec_eq(struct timespec ts1, struct timespec ts2)
{
	ts1 = c_timespec_normalise(ts1);
	ts2 = c_timespec_normalise(ts2);

	return (ts1.tv_sec == ts2.tv_sec && ts1.tv_nsec == ts2.tv_nsec);
}

C_STATIC_FORCE_INLINE
bool c_timespec_gt(struct timespec ts1, struct timespec ts2)
{
	ts1 = c_timespec_normalise(ts1);
	ts2 = c_timespec_normalise(ts2);

	return (ts1.tv_sec > ts2.tv_sec || (ts1.tv_sec == ts2.tv_sec && ts1.tv_nsec > ts2.tv_nsec));
}

C_STATIC_FORCE_INLINE
bool c_timespec_ge(struct timespec ts1, struct timespec ts2)
{
	ts1 = c_timespec_normalise(ts1);
	ts2 = c_timespec_normalise(ts2);

	return (ts1.tv_sec > ts2.tv_sec || (ts1.tv_sec == ts2.tv_sec && ts1.tv_nsec >= ts2.tv_nsec));
}

C_STATIC_FORCE_INLINE
bool c_timespec_lt(struct timespec ts1, struct timespec ts2)
{
	ts1 = c_timespec_normalise(ts1);
	ts2 = c_timespec_normalise(ts2);

	return (ts1.tv_sec < ts2.tv_sec || (ts1.tv_sec == ts2.tv_sec && ts1.tv_nsec < ts2.tv_nsec));
}

C_STATIC_FORCE_INLINE
bool c_timespec_le(struct timespec ts1, struct timespec ts2)
{
	ts1 = c_timespec_normalise(ts1);
	ts2 = c_timespec_normalise(ts2);

	return (ts1.tv_sec < ts2.tv_sec || (ts1.tv_sec == ts2.tv_sec && ts1.tv_nsec <= ts2.tv_nsec));
}

C_STATIC_FORCE_INLINE
struct timespec c_timespec_min(struct timespec ts1, struct timespec ts2) {
    if(c_timespec_le(ts1, ts2)) {
        return ts1;
    } else {
        return ts2;
    }
}

C_STATIC_FORCE_INLINE
struct timespec c_timespec_max(struct timespec ts1, struct timespec ts2) {
	if(c_timespec_ge(ts1, ts2)) {
		return ts1;
	} else {
		return ts2;
	}
}

C_STATIC_FORCE_INLINE
struct timespec c_timespec_clamp(struct timespec ts, struct timespec min, struct timespec max) {
	if(c_timespec_gt(ts, max)) {
		return max;
	}
	if(c_timespec_lt(ts, min)) {
		return min;
	}
	return ts;
}


/* ------------------------------------------------------------------------------------------------------------------ */
/*  */


C_STATIC_FORCE_INLINE
struct timespec c_timespec_from_double(double s)
{
	struct timespec ts = {
		.tv_sec  = s,
		.tv_nsec = (s - (long)(s)) * C_NSEC_PER_SEC,
	};

	return c_timespec_normalise(ts);
}



C_STATIC_FORCE_INLINE
double c_timespec_to_double(struct timespec ts)
{
	return ((double)(ts.tv_sec) + ((double)(ts.tv_nsec) / C_NSEC_PER_SEC));
}


/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

C_STATIC_FORCE_INLINE
struct timespec c_timespec_from_timeval(struct timeval tv)
{
	struct timespec ts = {
		.tv_sec  = tv.tv_sec,
		.tv_nsec = tv.tv_usec * C_NSEC_PER_USEC
	};

	return c_timespec_normalise(ts);
}

C_STATIC_FORCE_INLINE
struct timeval c_timespec_to_timeval(struct timespec ts)
{
	ts = c_timespec_normalise(ts);

	struct timeval tv = {
		.tv_sec  = ts.tv_sec,
		.tv_usec = ts.tv_nsec / C_NSEC_PER_USEC,
	};

	return tv;
}

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

C_STATIC_FORCE_INLINE
struct timespec c_timespec_from_ms(long milliseconds)
{
	struct timespec ts = {
		.tv_sec  = (milliseconds / C_MSEC_PER_SEC),
		.tv_nsec = (milliseconds % C_MSEC_PER_SEC) * C_NSEC_PER_MSEC,
	};

	return c_timespec_normalise(ts);
}

C_STATIC_FORCE_INLINE
long c_timespec_to_ms(struct timespec ts)
{
	return (ts.tv_sec * C_MSEC_PER_SEC) + (ts.tv_nsec / C_NSEC_PER_MSEC);
}

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

struct timespec c_timespec_mod(struct timespec ts1, struct timespec ts2);

#endif /*INCLUDED_C_TIMESPEC_H*/