// Time.cpp

#include "Time.h"

using std::isspace;
using std::istream;

istream & operator>>(istream & in, Time & t)
{
    // variables for reading the hours and minutes (so we
    // can leave t unchanged in case of an error)
    int h = 99;
    int m = 99;

    // read hours after skipping whitespace
    in >> h;
    if (!in) return in; // no int in stream
    if (h < 0 || h > 23) {
        in.setstate(in.failbit);
        return in;
    }

    // read next char and make sure it's a colon
    char next_char = in.get();
    if (!in) return in;
    if (next_char != ':') {
        in.putback(next_char);
        in.setstate(in.failbit);
        return in;
    }

    // make sure next char is not whitespace
    next_char = in.peek();
    if (!in) return in;
    if (isspace(next_char)) {
        in.setstate(in.failbit);
        return in;
    }

    // read minutes
    in >> m;
    if (!in) return in;
    if (m < 0 || m > 59) {
        in.setstate(in.failbit);
        return in;
    }

    // all good (except possibly for the number of digits in
    // the hours and minutes)
    t.set(h, m);
    return in;
}