//DISPLAY 12.2 Implementation File for DigitalTime
//Implementation file dtime.cpp (Your system may require some
//suffix other than .cpp): This is the IMPLEMENTATION of the ADT DigitalTime.
//The interface for the class DigitalTime is in the header file dtime.h.
#include <iostream>
#include <cctype>
#include <cstdlib>
#include "dtime.h"
using namespace std;

//These FUNCTION DECLARATIONS are for use in the definition of
//the overloaded input operator >>:

void readHour(istream& ins, int& theHour);
//Precondition: Next input in the stream ins is a time in 24-hour notation,
//like 9:45 or 14:45.
//Postcondition: theHour has been set to the hour part of the time.
//The colon has been discarded and the next input to be read is the minute.

void readMinute(istream& ins, int& theMinute);
//Reads the minute from the stream ins after readHour has read the hour.

int digitToInt(char c);
//Precondition: c is one of the digits '0' through '9'.
//Returns the integer for the digit; for example, digitToInt('3') returns 3.

bool operator ==(const DigitalTime& time1, const DigitalTime& time2)
{
    return (time1.hour == time2.hour && time1.minute == time2.minute);
}

//Uses iostream and cstdlib:
DigitalTime::DigitalTime(int theHour, int theMinute)
{
    if (theHour < 0 || theHour > 23 || theMinute < 0 || theMinute > 59)
    {
        cout << "Illegal argument to DigitalTime constructor.";
        exit(1);
    }

    else
    {
        hour = theHour;
        minute = theMinute;
    }
}
DigitalTime::DigitalTime( ) : hour(0), minute(0)
{
    //Body intentionally empty.
}


void DigitalTime::advance(int minutesAdded)
{
    int grossMinutes = minute + minutesAdded;
    minute = grossMinutes%60;

    int hourAdjustment = grossMinutes/60;
    hour = (hour + hourAdjustment)%24;
}

void DigitalTime::advance(int hoursAdded, int minutesAdded)
{
    hour = (hour + hoursAdded)%24;
    advance(minutesAdded);
}

//Uses iostream:
ostream& operator <<(ostream& outs, const DigitalTime& theObject)
{
    outs << theObject.hour << ':';
    if (theObject.minute < 10)
        outs << '0';
    outs << theObject.minute;
    return outs;
}

//Uses iostream:
istream& operator >>(istream& ins, DigitalTime& theObject)
{
    readHour(ins, theObject.hour);
    readMinute(ins, theObject.minute);
    return ins;
}

int digitToInt(char c)
{
    return ( static_cast<int>(c) - static_cast<int>('0') );
}

//Uses iostream, cctype, and cstdlib:
void readMinute(istream& ins, int& theMinute)
{
    char c1, c2;
    ins >> c1 >> c2;

    if (!(isdigit(c1) && isdigit(c2)))


    {
        cout << "Error illegal input to readMinute\n";
        exit(1);
    }

    theMinute = digitToInt(c1)*10 + digitToInt(c2);

    if (theMinute < 0 || theMinute > 59)
    {
        cout << "Error illegal input to readMinute\n";
        exit(1);
    }
}

//Uses iostream, cctype, and cstdlib:
void readHour(istream& ins, int& theHour)
{
    char c1, c2;
    ins >> c1 >> c2;
    if ( !( isdigit(c1) && (isdigit(c2) || c2 == ':' ) ) )
    {
        cout << "Error illegal input to readHour\n";
        exit(1);
    }

    if (isdigit(c1) && c2 == ':')
    {
        theHour = digitToInt(c1);
    }
    else //(isdigit(c1) && isdigit(c2))
    {
        theHour = digitToInt(c1)*10 + digitToInt(c2);
        ins >> c2;//discard ':'
        if (c2 != ':')
        {
            cout << "Error illegal input to readHour\n";
            exit(1);
        }
    }
    if ( theHour < 0 || theHour > 23 )
    {
        cout << "Error illegal input to readHour\n";
        exit(1);
    }
}