//
// Copyright 2011-2013 Ettus Research LLC
// Copyright 2018 Ettus Research, a National Instruments Company
//
// SPDX-License-Identifier: GPL-3.0-or-later
//

#include <uhd/types/time_spec.hpp>
#include <cmath> 

using namespace uhd;

/***********************************************************************
 * Time spec constructors
 **********************************************************************/
#define time_spec_init(full, frac) { \
    const int64_t _full = int64_t(full); \
    const double _frac = double(frac); \
    const int _frac_int = int(_frac); \
    _full_secs = _full + _frac_int; \
    _frac_secs = _frac - _frac_int; \
    if (_frac_secs < 0) {\
        _full_secs -= 1; \
        _frac_secs += 1; \
    } \
}

UHD_INLINE long long fast_llround(const double x){
    return (long long)(x + 0.5); // assumption of non-negativity
}

time_spec_t::time_spec_t(double secs){
    time_spec_init(0, secs);
}

time_spec_t::time_spec_t(int64_t full_secs, double frac_secs){
    time_spec_init(full_secs, frac_secs);
}

time_spec_t::time_spec_t(int64_t full_secs, long tick_count, double tick_rate){
    const double frac_secs = tick_count/tick_rate;
    time_spec_init(full_secs, frac_secs);
}

time_spec_t time_spec_t::from_ticks(long long ticks, double tick_rate){
    const long long rate_i = (long long)(tick_rate);
    const double rate_f = tick_rate - rate_i;
    const int64_t secs_full = int64_t(ticks/rate_i);
    const long long ticks_error = ticks - (secs_full*rate_i);
    const double ticks_frac = ticks_error - secs_full*rate_f;
    return time_spec_t(secs_full, ticks_frac/tick_rate);
}

/***********************************************************************
 * Time spec accessors
 **********************************************************************/
long time_spec_t::get_tick_count(double tick_rate) const{
    return long(fast_llround(this->get_frac_secs()*tick_rate));
}

long long time_spec_t::to_ticks(double tick_rate) const{
    const long long rate_i = (long long)(tick_rate);
    const double rate_f = tick_rate - rate_i;
    const long long ticks_full = this->get_full_secs()*rate_i;
    const double ticks_error = this->get_full_secs()*rate_f;
    const double ticks_frac = this->get_frac_secs()*tick_rate;
    return ticks_full + fast_llround(ticks_error + ticks_frac);
}

double time_spec_t::get_real_secs(void) const{
    return this->get_full_secs() + this->get_frac_secs();
}

/***********************************************************************
 * Time spec math overloads
 **********************************************************************/
time_spec_t &time_spec_t::operator+=(const time_spec_t &rhs){
    time_spec_init(
        this->get_full_secs() + rhs.get_full_secs(),
        this->get_frac_secs() + rhs.get_frac_secs()
    );
    return *this;
}

time_spec_t &time_spec_t::operator+=(double &rhs){
    double full_secs = std::trunc(rhs);
     time_spec_init(
         this->get_full_secs() + full_secs,
         this->get_frac_secs() + rhs - full_secs
    );
    return *this;
}

time_spec_t &time_spec_t::operator-=(const time_spec_t &rhs){
    time_spec_init(
        this->get_full_secs() - rhs.get_full_secs(),
        this->get_frac_secs() - rhs.get_frac_secs()
    );
    return *this;
}

time_spec_t &time_spec_t::operator-=(double &rhs) {
    double full_secs = std::trunc(rhs);
    time_spec_init(
        this->get_full_secs() - full_secs,
        this->get_frac_secs() - (rhs - full_secs)
    );
    return *this;
}

bool uhd::operator==(const time_spec_t &lhs, const time_spec_t &rhs){
    return
        lhs.get_full_secs() == rhs.get_full_secs() and
        lhs.get_frac_secs() == rhs.get_frac_secs()
    ;
}

bool uhd::operator<(const time_spec_t &lhs, const time_spec_t &rhs){
    return (
        (lhs.get_full_secs() < rhs.get_full_secs()) or (
        (lhs.get_full_secs() == rhs.get_full_secs()) and
        (lhs.get_frac_secs() < rhs.get_frac_secs())
    ));
}
