// Filename:   Timer.cxx
// Timer class: provides a countdown timer with minutes and seconds
// Implementation

#include <iostream>
#include "Timer.h"

using namespace std;

const int secInMin = 60;          // number of seconds in minute

// The constructor
Timer::Timer(int minutes, int seconds)
{
   set(minutes, seconds);
}

// sets the minutes and seconds of timer
void Timer::set(int minutes, int seconds)
{
   theSeconds = minutes * secInMin + seconds;
   if (theSeconds < 0) {
      cerr << "Initialization must be non-negative. Timer at zero.\n";
      theSeconds = 0;
   }
}

// prints the minutes and seconds remaining
void Timer::print(ostream &os) const
{
   char fillCh;     // starting fill character

   os << theSeconds / secInMin << ":";
   os.width(2);
   fillCh = os.fill('0');
   os << theSeconds % secInMin;
   os.fill(fillCh);
}

// subtracts minutes and seconds from the timer
// maintains timer at no less than zero
void Timer::subtract(int minutes, int seconds)
{
   theSeconds -= (minutes * secInMin) + seconds;
   if (theSeconds < 0) {
      theSeconds = 0;
   } 
}

// returns whether timer has run out of time
// returns 1 if out of time, 0 if there is time remaining
int Timer::outOfTime( ) const
{
   return theSeconds == 0;
}

// prints t to ostream os
ostream & operator << (ostream & os, const Timer & t)
{
   t.print(os);
   return os;
}