#!/usr/bin/perl -w
use strict;
use warnings;
use Crypt::Tea;

if (@ARGV != 3)
{
        print STDERR "Usage: $0 [-d|-e] [FILENAME] [KEY] \n";
        exit 1;
}

if (($ARGV[0] ne '-d') && ($ARGV[0] ne '-e'))
{
        print "Specify '-d' to decrypt or '-e' to encrypt\n";
  exit 1;
}

my ($action, $file, $key) = @ARGV;

open (my $fh, '<', $file) or die $!;
my @input = readline($fh) or die "readline failed: $!\n";

if ($action eq '-e')
{
        my @cryptedText = cryptText($key,$action,\@input);
        my $i = join("\n",@cryptedText); 
        print $i;
}

if ($action eq '-d')
{
        my @cryptedText = cryptText($key,$action,\@input);
        my $i  = join('',@cryptedText);
        print $i;
}

sub cryptText
{
        die if @_ != 3;
        my ($key,$action,$input) = @_;
        my @cryptedText;
        foreach my $text (@$input)
        {
                if ($action eq '-d')
                {
                        $text = decrypt($text,$key);
                }
                if ($action eq '-e')
                {
                        $text = encrypt($text,$key);
                }
                push (@cryptedText,$text);
        }
        return @cryptedText;
}