# ------------------------------------------------------------------
# Loaded Modules
# ------------------------------------------------------------------
use strict;
use warnings;
use Net::LDAP;
use Net::LDAP;
use Date::Manip;
use Email::Simple ();
use Email::Sender::Simple qw(sendmail);
use Email::Sender::Transport::SMTP ();
use Email::Simple::Creator ();

# ------------------------------------------------------------------
# smtp parameters
# ------------------------------------------------------------------
my $smtpserver = 'server';
my $smtpport = 25;
my $transport = Email::Sender::Transport::SMTP->new({
  host => $smtpserver,
  port => $smtpport,
});
my $sender_adr = "rumpel.stilzchen\@blablub.com";

# ------------------------------------------------------------------
# ldap parameters
# ------------------------------------------------------------------
my $ldap_srv = 'PDC';
my $ldap_usr = 'CN=bal.blub,OU=User,DC=foo,DC=com';
my $ldap_pwd = 'na so eins';
my $ldap_base_dir = 'dc=foo,dc=com';

# ------------------------------------------------------------------
# connect to ldap
# ------------------------------------------------------------------ 
my $ldap = Net::LDAP->new( $ldap_srv ) or die "$@";
my $mesg = $ldap->bind( $ldap_usr,
                        password => $ldap_pwd
                       );

# ------------------------------------------------------------------
# search LDAP database
# ------------------------------------------------------------------ 
$mesg = $ldap->search(  base=>$ldap_base_dir,
			filter => "(&(objectclass=*)(sn=*))");
			#filter=>"(name=*)",
my @entries = $mesg->entries;

foreach my $entry (@entries) {
	my $samACC     = $entry->get_value('samAccountName');
	my $name       = $entry->get_value('name');
	my $descr      = $entry->get_value('description');
	my $mail       = $entry->get_value('mail');
	my $expired    = readable_date($entry->get_value('accountExpires'));
	my $manager    = $entry->get_value('manager');
	&check_data($samACC, $name, $mail, $expired, $manager, $descr);
}

# ------------------------------------------------------------------
# Process data
# ------------------------------------------------------------------ 
sub check_data{
		my $date = ParseDate("today");
		my $newdate = DateCalc(ParseDate($_[3]), ParseDateDelta('- 2 days'));
		
		if ($newdate eq $date) {
		foreach my $contact ($_[4]){
			my $email  = Email::Simple->create(
			   header  => [
			   To      => $_[2],
			   From    => $sender_adr,
			   Subject => 'Konto Abgelaufen - Bitte Verlängern',
				      ],
			   body    => "Sehr geehrte Damen und Herren\n Der Zugang fue Account $_[1] $_[5] laeuft am $_[3] ab\n",
			);
		sendmail($email, { transport => $transport });
              }
	}
   	else {
   	print "Alles OK";
        }
}

# ------------------------------------------------------------------
# disconnect from ldap
# ------------------------------------------------------------------ 
$mesg = $ldap->unbind;   # take down session
 
# ------------------------------------------------------------------
# convert none readable date/time format to readable format
# ------------------------------------------------------------------  
sub readable_date {
    my $wintime = shift;
    my $unix_epoch = win_to_unix_epoch($wintime);
    my ($year, $month, $day,) = (localtime $unix_epoch)[5,4,3,2,1,0];
    $year  += 1900;
    $month += 1;
    ($month, $day) = map { sprintf '%02d', $_ } $month, $day;
    my $LastLogin = join('-', $year, $month, $day);
}

sub win_to_unix_epoch {
    # Actually hundreths of nanoseconds at this point...
    my $nanoseconds = shift;
    # Get seconds
    my $seconds = $nanoseconds / 10_000_000;
    # This magic number is the difference between Unix and Windows epoch.
    my $unix_epoch = $seconds - 11644473600;
    # Return the Unix epoch for use with localtime().
    return $unix_epoch;