#!/usr/local/bin/perl -w

#============================================================= -*-perl-*-
# courier-imap_postfix_last-login.pl
#========================================================================
# Version 0.0.1, 2015-06-04
#========================================================================

# Parsing is possible only for one year at time due to syslog date/time format limitation.
# The current year is hardcoded in the script.

use strict;

use Time::Local;
use POSIX qw(strftime);

my $logDir = '/var/log';

# Jun  4 15:15:40 hostname imapd: LOGIN, user=user@example.com, ip=[::1], port=[43029], protocol=IMAP
# Jun  4 15:15:46 hostname pop3d: LOGIN, user=user@example.com, ip=[::ffff:127.0.0.238], port=[15226]
my $REcourierLOGIN =
qr/^((\w{3})\s+(\d+) (\d{2}):(\d{2}):(\d{2})) \S+ (\S+): LOGIN, user=([^,]+),/;

# Jun  3 17:46:46 hostname postfix/smtpd[739497]: 9E9721E40254: client=127-0-0-2.example.com[127.0.0.2], sasl_method=LOGIN, sasl_username=user@example.com
# Jun  4 00:00:02 hostname postfix/smtpd[999616]: 7F3D91E40254: client=unknown[127.0.0.6], sasl_method=LOGIN, sasl_username=user@example.com
my $REpostfixSASL =
qr/^((\w{3})\s+(\d+) (\d{2}):(\d{2}):(\d{2})) \S+ postfix\/(\S+)\[\d+\]: [[:xdigit:]]+: client=[^,]+, sasl_method=[^,]+, sasl_username=(.+)$/;

my $currentYear = strftime "%Y", localtime(time);
my $filename = "-name maillog-$currentYear* ! -name maillog-${currentYear}01* -o -name maillog";

my %lastAccess;

my %month = (
    Jan => 1,
    Feb => 2,
    Mar => 3,
    Apr => 4,
    May => 5,
    Jun => 6,
    Jul => 7,
    Aug => 8,
    Sep => 9,
    Oct => 10,
    Nov => 11,
    Dec => 12,
);

open( LIST, "find $logDir $filename | sort |" )
  or die("Cannot fetch filelist: $!\n");

foreach my $file (<LIST>) {
    my $counter = 0;
    chomp $file;
    print "Processing $file ... ";

    open( MAILLOG, "zcat -f $file|" )
      or die("Cannot open $0: $!\n");

    while (<MAILLOG>) {
        ( index( $_, ': LOGIN, ' ) == -1 )
          && ( index( $_, ', sasl_username=' ) == -1 )
          && next;
        if ( /$REcourierLOGIN/ || /$REpostfixSASL/ ) {

            my $epoch =
              timelocal( $6, $5, $4, $3, $month{$2} - 1, $currentYear );

            if ( !defined( $lastAccess{$8}{'epoch'} )
                || $epoch > $lastAccess{$8}{'epoch'} )
            {
                $lastAccess{$8}{'time'}  = $1;
                $lastAccess{$8}{'epoch'} = $epoch;
            }

            $lastAccess{$8}{'count'}++;
            $lastAccess{$8}{'service'}{$7}++;
            $counter++;
            #print 'U';
        }
    }

    close(MAILLOG);
    print "matches: $counter\n";
}
close(LIST);

printf "\n%30s | %16s | %6s\n", "E-mail account", "Last access time",
  "Access count";

my $i = 77;
while ( $i-- ) { print "-" }
print "\n";

map {
    printf "%30s | %16s | %6d  (",
      $_, $lastAccess{$_}{'time'}, $lastAccess{$_}{'count'};
    my $time = $_;
    map { print " $_=$lastAccess{$time}{'service'}{$_}"; }
      sort keys %{ $lastAccess{$_}{'service'} };
    print " )\n";

    #my $epochTime = strftime "%b %e %H:%M:%S", localtime($lastAccess{$_}{'epoch'});
    #print $epochTime, "\n";

} sort keys %lastAccess;

beep();

exit;

sub beep {
    my $i = 0;
    $| = 1;
    while ( $i++ <= 2 ) { print "\a"; system("sleep .12"); }
    print "\a";
    $| = 0;
}