/*
PURPOSE:
    ( Clock clock )
PROGRAMMERS:
     ((Alex Lin) (NASA) (April 2009) (--) (c++ port)))
*/

#include <stdlib.h>

#include "trick/Clock.hh"
#include "trick/exec_proto.h"
#include "trick/release.h"

Trick::Clock * the_clock = NULL ;

/**
@details
-# Sets the global clock pointer to the current instance
*/
Trick::Clock::Clock(unsigned long long in_clock_tics_per_sec, std::string in_name) :
 name(in_name) ,
 clock_tics_per_sec(in_clock_tics_per_sec) ,
 rt_clock_ratio(1.0) ,
 sim_tic_ratio(1.0) ,
 ref_time_tics(0) { }

int Trick::Clock::set_global_clock() {
    the_clock = this ;
    return 0 ;
}

int Trick::Clock::calc_sim_time_ratio(int in_time_tic_value ) {
    sim_tic_ratio = in_time_tic_value / (double)clock_tics_per_sec ;
    return 0 ;
}

double Trick::Clock::get_rt_clock_ratio() {
    return rt_clock_ratio ;
}

int Trick::Clock::set_rt_clock_ratio(double in_rt_clock_ratio) {
    long long curr_time = clock_time() ;
    rt_clock_ratio = in_rt_clock_ratio ;
    clock_reset(curr_time) ;
    return 0 ;
}

int Trick::Clock::adjust_ref_time(long long in_tics) {
    ref_time_tics += (long long)(in_tics / ( rt_clock_ratio * sim_tic_ratio )) ;
    return 0 ;
}

int Trick::Clock::sync_to_wall_clock(double align_tic_mult, int tics_per_sec) {

    long long curr_time ;
    long long sync_time ;

    curr_time = wall_clock_time() ;
    sync_time = curr_time - ( curr_time % int(align_tic_mult * tics_per_sec / (rt_clock_ratio * sim_tic_ratio) ) ) +
     int(align_tic_mult * tics_per_sec / (rt_clock_ratio * sim_tic_ratio) ) ;
    set_reference(sync_time) ;
    return 0 ;
}

/**
@details
-# Get the hardware specific wall clock time
-# Subtract the simulation time to give a reference time.
-# Save the reference time.
*/
long long Trick::Clock::clock_time() {
    long long curr_time ;
    curr_time = wall_clock_time() ;
    return ((long long)((curr_time - ref_time_tics) * rt_clock_ratio * sim_tic_ratio));
}

/**
@details
-# Get the current real time.
-# While the current real time is less than the requested time
   -# Release the processor momentarily
   -# Get the current real time.
*/
long long Trick::Clock::clock_spin(long long req_time) {
    long long curr_time ;
    curr_time = clock_time() ;
    /* Perform spin loop to allow current time to catch up to requested time */
    while (curr_time < req_time) {
        curr_time = clock_time();
    }
    return curr_time ;
}

/**
@details
-# Call the hardware specific wall clock time
-# Subtract the reference time to give the elapsed real time.
-# return the elapsed real time.
*/
long long Trick::Clock::clock_reset(long long ref) {
    long long curr_time ;
    curr_time = wall_clock_time() ;
    ref_time_tics = curr_time - (long long)(ref / (rt_clock_ratio * sim_tic_ratio));
    return (long long)(ref_time_tics * sim_tic_ratio * rt_clock_ratio ) ;
}

/**
@details
-# Sets the clock's reference time to incoming value
*/
int Trick::Clock::set_reference(long long ref) {
    ref_time_tics = ref ;
    return 0 ;
}

/**
@details
-# Return the name of the clock
*/
const char * Trick::Clock::get_name() {
    return name.c_str() ;
}