#!/usr/bin/env perl

use strict;
use warnings;
use Switch;
use Convert::Base32;

# Prompt user on which action they wish to take
print "[D]ecode or [E]ncode URN (default = D): ";
chomp (my $urn_format = <>);

# Execute appropriate function
switch (uc($urn_format)) {
	case "" { &urnDecode }
	case "D" { &urnDecode }
	case "E" { &urnEncode }
	else {print "Invalid option. Enter \"D\" to decode or \"E\" to encode."}
}

# Convert URN:SHA1 (base32) values to standard SHA1 (base16)
sub urnDecode {
	print "\nEnter URN to decode: ";
	chomp (my $urn_decode = <>);
	
	print "SHA1: " . decode_base32($urn_decode) . "\n";
}

# Convert SHA1 (base16) values to URN:SHA1 (base32)
sub urnEncode {
	print "\nEnter SHA1 to encode: ";
	chomp (my $urn_encode = <>);
	
	print "urn:sha1:" . uc(encode_base32(pack('H40', $urn_encode))) . "\n";
}

exit 0;