#!/usr/bin/perl -w
use strict;
use Date::Calc qw(Day_of_Year);

# Format of monkdays.txt
# marto:01-28:11-30
# <nick>:<join date mm-dd>:<birthdate mm-dd>

my $monkfile = "monkdays.txt";
my %monks;

open MONKS, "<$monkfile" or die "Ugh:$!\n";

while (<MONKS>) {
    chomp;
    my ($nick, $joined, $bday) = split(/:/, $_);
    $monks{$nick}{joined} = $joined;
    $monks{$nick}{bday} = $bday;

    # Calculate the julian day for each date, and add to hash
    $monks{$nick}{jday_joined} = Day_of_Year("2006", split(/-/, $joined));
    $monks{$nick}{jday_bday} = Day_of_Year("2006", split(/-/, $bday));

    # Now, calculate the delta (in days) between birthdate and joined date
    $monks{$nick}{delta}  =
                           ($monks{$nick}{jday_joined} > $monks{$nick}{jday_bday})
                         ? ($monks{$nick}{jday_joined} - $monks{$nick}{jday_bday})
                         : ($monks{$nick}{jday_bday} - $monks{$nick}{jday_joined});
}

close MONKS;


print "Total Monks with birthdays:", scalar (keys %monks), "\n\n";
print "Monks who joined within 10 days of their birthday:\n\n";
printf "%-20s %-10s %-10s %-5s", "Monk", "Joined", "Birthday", "Delta";
print "\n";

foreach my $monk (sort by_delta keys %monks) {
    last if $monks{$monk}{delta} > 10;
    printf "%-20s %-10s %-10s %-5s",
        "$monk",
        "$monks{$monk}{joined}",
        "$monks{$monk}{bday}",
        "$monks{$monk}{delta}";
    print "\n";
}

sub by_delta {
    return $monks{$a}{delta} <=> $monks{$b}{delta};
}