#!usr/bin/perl
#Script to parse dates with the following formats:
#Apr 8 1984, Apr 08 84, 4/8/84, 04/08/84, 08 Apr 1984

use warnings;
use strict;

#blah blah blah once
print "\n\n\n\n";
print "Date Converter, v1.0\n";
print "this program assumes that a year from 10 to 99 is in the 1900's\n";
print "and that a year from 00 to 09 is in the 2000's\n";
print "and will loop until you type 'q' to break out of it.\n";

#loop script forever, atbe
while (1)
{

#declare my vars and make sure they're empty
my ( $MM, $DD, $YY, $YYYY );

#take in date or q at command line and make text lowercase
print "please enter a date\n";
chomp (my $date = <>);
if ($date eq "q")
{
exit();
}
$date = lc ($date);

#run date entered thru series of regex filters, 
#and subsequently perform perly goodness on them.
#send result to output subroutine
    
if ($date =~ /[a-zA-Z]{3}\s\d{1,2}\s\d{2,4}/) #parse Apr 08 84 or Apr 8 1984
{
    my @dateparts = split (/\s/ , $date);
    $MM = $dateparts [0];
    $DD = $dateparts [1];
    $YY = $dateparts [2];
    if (10 <= $YY && $YY <= 99)
    {$YYYY = $YY + 1900}
    elsif (0 <= $YY && $YY <= 9)    
    {$YYYY = $YY + 2000}
    else {$YYYY = $YY}
    output ($MM, $DD, $YYYY);

}
elsif ($date =~ /\d{1,2}\/\d{1,2}\/\d{2}/) #parse 04/08/84 or 4/8/84
{
    my @dateparts = split (/\// , $date);
    $MM = $dateparts [0];
    $DD = $dateparts [1];
    $YY = $dateparts [2];
    if (10 <= $YY && $YY <= 99)
    {$YYYY = $YY + 1900}
    elsif (0 <= $YY && $YY <= 9)    
    {$YYYY = $YY + 2000}
    output ($MM, $DD, $YYYY);
} 
elsif ($date =~ /\d{1,2}\s([a-zA-Z]{3})\s\d{4}/) #parse 08 Apr 1984
{
    my @dateparts = split (/\s/ , $date);
    $DD = $dateparts [0];
    $MM = $dateparts [1];
    $YYYY = $dateparts [2];
    output ($MM, $DD, $YYYY);
} 
else #contingency plan
{
    print "\nyour entry is not in a format recognized by this script.\n";
    print "please use only the following:\nApr 8 1984, Apr 08 84, 4/8/84, 04/08/84, 08 Apr 1984, or 'q' to quit.\n\n";
}

#output subroutine
#take in $MM $DD $YYYY, parse $MM with %months
#and print "fullmonth day, year" to STDOUT
sub output {
my @outputdates = @_;
    my %months = (
        jan => "January",
        feb => "February",
        mar => "March",
        apr => "April",
        may => "May",
        jun => "June",
        jul => "July",
        aug => "August",
        sep => "September",
        oct => "October",
        nov => "November",
        dec => "December",
        1 => "January",
        2 => "February",
        3 => "March",
        4 => "April",
        5 => "May",
        6 => "June",
        7 => "July",
        8 => "August",
        9 => "September",
        10 => "October",
        11 => "November",
        12 => "December",
        '01' => "January",
        '02' => "February",
        '03' => "March",
        '04' => "April",
        '05' => "May",
        '06' => "June",
        '07' => "July",
        '08' => "August",
        '09' => "September"
);
    
    print "$months{$outputdates[0]} $outputdates[1], $outputdates[2]\n\n";
}
}