#!/usr/bin/perl

#############################################################################
#
# This script has been developed
# by Jesper Knudsen at http://sme.swerts-knudsen.dk
# And modified by Emmanuel Jooris at http://sme.firewall-services.com
#
# Revision History:
#
# January 18, 2006: Initial version
# June 06, 2008: Modification for add LearnAsHam and LearnInWL
# March 06, 2016: adding tmp and new subdir, tag filtering, improvements... JP Pialasse 
#############################################################################

use Sys::Hostname;
use Email::Simple;
use esmith::AccountsDB;
use esmith::ConfigDB;
use Digest::MD5 qw(md5 md5_hex md5_base64);
use File::Find;
use File::Copy;
use File::Copy::Recursive;
use File::Basename;
use File::Path;
use Encode qw/encode decode/;
use utf8;
 
my $hostname = hostname();

#Opening databases
my $adb = esmith::AccountsDB->open_ro()
   or die "Could not open AccountsDB ( reason : ".esmith::DB->error." )\n";
my $sadb = esmith::ConfigDB->open_ro()
   or die "Could not open ConfigurationDB ( reason : ".esmith::DB->error." )\n";

# some variables of interest
my $subjectTAG= $sadb->get_prop("spamassassin", "Subject");
my $tag= $sadb->get_prop("LearnAsSpam", "tag");
my $MessageRetentionTime =  $sadb->get_prop('spamassassin', '$MessageRetentionTime')|| "15";
my $DelayToMove =  $sadb->get_prop("LearnAsSpam", "DelayToMove") || $MessageRetentionTime ; # delay in day before moving files
$DelayToMove= $DelayToMove<$MessageRetentionTime ?  $DelayToMove : 0; # set 0 to disable
my $agesecs=60*60*24*$DelayToMove;      #converts $agedays to seconds
my $daysago=time-$agesecs;              #the time stamp of $agedays ago in seconds
my $daysago2=localtime($daysago);       #the time stamp of $agedays ago in words - mainly for printing
my $SpamLinks = $sadb->get_prop("LearnAsSpam", "SpamLinks") || "";
my @files;

#getting user list
my @users = $adb->users;
#adding admin
my @admin = $adb->get('admin');
push @users ,@admin;

# getting WL before running
open(SADB, "/home/e-smith/db/spamassassin");
binmode(SADB);
my $md5 = Digest::MD5->new->addfile(SADB)->b64digest;
close(SADB);

#Verbose mode
my $verbose= $sadb->get_prop("Learn", "Verbose") || "enabled";
my $outputfile=($verbose eq "disabled")? "/dev/null": '/tmp/LearnLog.txt';
my $LOG;
open ( $LOG, '+>', $outputfile) unless ($verbose eq "enabled");
# select new filehandle
select $LOG unless ($verbose eq "enabled");
my $currentuser;

# Running for every user
foreach my $user (@users) {
	my $firstname = $user->prop('FirstName');
	my $lastname = $user->prop('LastName');
	my $key = $user->key;
        # verification if user included or excluded
        my @include=  split(',',$sadb->get_prop("Learn", "Include")) if $sadb->get_prop("Learn", "Include");
        my @exclude=  split(',',$sadb->get_prop("Learn", "Exclude")) if $sadb->get_prop("Learn", "Exclude");
        next if ( (@exclude) and  @found = grep { $_ eq $key } @exclude );
        next unless ( ! (@include) or @found = grep { $_ eq $key } @include );

	$currentuser = sprintf("Checking for user (%s): %s %s\n", $key,$firstname, $lastname);
	print $currentuser unless ($verbose eq "active");

       my $MailDir = ($key eq "admin")? "/home/e-smith" .  "/Maildir" : "/home/e-smith/files/users/"  . $key . "/Maildir";

	my @modes = ("LearnAsSpam","LearnAsHam","LearnInWL");
	foreach my $mode (@modes) {
		# verificating mode is enabled
		if ($sadb->get_prop($mode, "status") ne "enabled") { next; }

		# getting dir name to search according to actual mode
		my $dirname = $sadb->get_prop($mode, "dir");
		if ( !(defined($dirname)) ) {
			Vact();print "Errors in DB, dir subkey not present for key $mode\n";
			next;
		}
		# adding heading periode if missing as this is an IMAP folder
		if ($sadb->get_prop($mode, "Uniq") eq "enabled") {
			$dirname= (substr($dirname, 0, 1) eq '.')? $dirname: ".$dirname";
		}

		#searching dir : fix to avoid to get multiple dir as default
		opendir(LOGDIR, $MailDir);
		my @logdirs = ($sadb->get_prop($mode, "Uniq") eq "enabled")? sort grep { /^$dirname$/ } readdir(LOGDIR) :sort grep { /$dirname/ } readdir(LOGDIR); 
		closedir(LOGDIR);

		($login,$pass,$uid,$gid) = getpwnam($key) or die "$key not in passwd file";
		# mk dir if not exist
		if (! @logdirs and ($sadb->get_prop($mode, "Uniq") eq "enabled"))	{
			Vact();print  "+->mkdir :". $MailDir . "/" . $dirname . "\n";
			foreach $a ('','/cur','/tmp','/new'){
				mkdir $MailDir . "/" . $dirname . "$a";
                        	chown $uid,$gid,$MailDir . "/" . $dirname . "$a";
			}
 		};
		
		my $junkdir = $MailDir . "/.junkmail"; 
		unless ( -d $junkdir ) {
                        Vact();print  "+->mkdir :". $junkdir . "\n";
                        foreach $a ('','/cur','/tmp','/new'){
                                mkdir $junkdir . "/" . "$a";
                                chown $uid,$gid,$junkdir . "/" . "$a";
                        }

                }

		# create junkmail links if necessary
		my $Spamlinks = $user->prop('SpamLinks') || "";
		if ($mode eq "LearnAsSpam" and ($SpamLinks or  $Spamlinks ) ) {
			$Spamlinks= $SpamLinks ?  $SpamLinks .",". $Spamlinks : $Spamlinks;
                        $Spamlinks =~ s/,$//;
			foreach $a (split(",",$Spamlinks)){
				$a=(substr($a, 0, 1) eq '.')? $a: ".$a";
				my $Link= $MailDir . "/" . $a;
				next if ( $Link eq ".." || $Link eq "." || $Link eq "" );
				next if ( -l $Link);
				if (-d $Link) {
					Vact(); print "+->move previous dir $Link  content to $junkdir\n";
					File::Copy::Recursive::dirmove($Link, $junkdir) or die "Can't move folder in place of our wanted link from %Link to $junkdir: $!";
                                        #side effect : ownership is lost
                                        @files = ( glob( $junkdir . '/cur/*' ),glob( $junkdir . '/new/*' ), glob( $junkdir . '/tmp/*' )  );
                                        chown $uid, $gid, @files;
				};
				if (! -e $Link) {
   					Vact(); print "+->create link $Link on $junkdir\n";
					symlink($junkdir, $Link) or die "Can't create symlink from $Link to $junkdir: $!";
				};
			}	
		}

                # moving junkmail content if we want to check it another time before deleting
		# sometime files will get there whithout any spamassassin check ( MUA moving it here)
                if ($mode eq "LearnAsSpam" and $sadb->get_prop($mode, "DeleteAfterLearn") eq "enabled" and  $DelayToMove >0) {
			my $SpamDir = $MailDir . "/" . $logdir . "/cur/";
			return unless (-e $SpamDir and -d $SpamDir);
                       @files=();
			find(\&wanted, $junkdir ."/cur" );
        		find(\&wanted, $junkdir ."/new" ) if ($sadb->get_prop($mode, "LearnNew") eq "enabled" or $sadb->get_prop($mode, "LearnNew") eq  "junkmail");
 			sub wanted {
        			$filesecs = (stat("$File::Find::dir/$_"))[9]; #GETS THE 9TH ELEMENT OF file STAT - THE MODIFIED TIME
        			$filesecs2=localtime($filesecs);
	        		if ($filesecs<$daysago && -f){ #-f=regular files
	                		push (@files,"$File::Find::dir/$_");
	                		push (@files,"$filesecs2");
	        		}
			}
			my %filehash=@files; #puts the array into a hash for easy printing.  Key=file, Value=date
			undef @files;
	       		foreach $filename (sort keys %filehash){
                	 	Vact(); print  "--> moving $filename       $filehash{$filename}\n";
                               	move $filename,"$MailDir/$dirname/cur" ;
			}
                }

	
		# loop through all matching directories
		foreach my $logdir (@logdirs) {
			#sa-learn here to avoid its loading for each files, when it can walk in directories on itself!
                        my $SpamDir = ($sadb->get_prop($mode, "LearnNew") eq "enabled")? $MailDir . "/" . $logdir : $MailDir . "/" . $logdir . "/cur/" ;
                        #taking action according to actual mode
                        my $counter = 0;
			find( { wanted => sub { -f && $_ =~ m/($logdir\/cur|$logdir\/new|$logdir\/tmp)/ && $counter++;}, no_chdir => 1, follow_fast => 1 }, $SpamDir );
			if ($mode eq "LearnAsSpam" and $counter>0) {
                                my $result = `/usr/bin/sa-learn --spam $SpamDir`;
				chomp($result); Vact(); printf("+Learning Spam from %s: %s\n",$logdir,$result);
                        }
                        elsif ($mode eq "LearnAsHam" and $counter>0) {
                                my $result = `/usr/bin/sa-learn --ham  $SpamDir`;
				chomp($result); Vact(); printf("+Learning Ham from %s: %s\n",$logdir,$result);
                         }

		   @list= ($sadb->get_prop($mode, "LearnNew") eq "enabled") ? ('/cur/','/new/'):('/cur/');
		   foreach $a (@list){
			my $SpamDir = $MailDir . "/" . $logdir . "$a";
			# list and sort file in dir
			opendir(SPAMDIR, $SpamDir);
			my @spamfiles = sort grep { /$hostname/ } readdir(SPAMDIR);
			closedir(SPAMDIR);

			#
			foreach my $spamfile (@spamfiles) {
				my $filetolearn = $SpamDir . $spamfile;
				my $filetolearnbash = $filetolearn;
				$filetolearnbash =~ s/;/\\;/g;
				$filetolearnbash =~ s/:/\\:/g;

				#taking action according to actual mode
				if ($mode eq "LearnInWL") {
					Vact(); printf("+Learning in WhiteList: %s\n",$filetolearnbash);
					`/usr/bin/LearnInWL.pl $filetolearnbash`;
				}
				# if we are in LearnAsSpam mode and DeleteAfterLearn is enabled delete message, else tagging a move message
				if ($mode eq "LearnAsSpam" and $sadb->get_prop($mode, "DeleteAfterLearn") eq "enabled") {
					`rm -f $filetolearn`;
				}
				else {
					if (defined($sadb->get_prop($mode, "tag"))) {
						# Opening, reading in one scalar and parsing mail
						$/=undef;
						open(MAILFILE,"<:encoding(UTF-8)",$filetolearn);
						my $emailbrut = <MAILFILE>;
						close(MAILFILE);
						$/="\n";
						my $email = Email::Simple->new($emailbrut);
						
						#changing subject (tagging), opening and writing new mail
						my $Subject= $email->header("Subject");
						if ( ($mode ne "LearnAsSpam") && ($sadb->get_prop($mode, "RemoveSPAMTag") eq "enabled") ) {
	 						for my $test  ( quotemeta $subjectTAG ,  quotemeta $tag) {
								($Subject= $Subject) =~ s/$test//;	
							}
							# we also remove Spam tag or client will move the mail again in spam dir
							$email->header_set("X-Spam-Flag",'NO');
                                                        $email->header_set("X-Spam-Level",'*');
                                                        $email->header_set("X-Spam-Status",'No, score=0.0 required=4.0 autolearn=disabled');
						}
						# encoding as MIME Q (not B)  with UTF8 as default.
						my $cleanTag= encode("MIME-Q",$sadb->get_prop($mode, "tag"));
						$email->header_set("Subject",$cleanTag.$Subject);
						open(MAILFILEWRITE,">","$filetolearn");
						print(MAILFILEWRITE $email->as_string);
						close(MAILFILEWRITE)
					}
					my $mvdir;
					if ($mode eq "LearnAsSpam") {
						$mvdir = $MailDir . "/.junkmail/cur/";
					}
					else {
						$mvdir = $MailDir . "/cur/";
					}
					`mv $filetolearn $mvdir`;
				}
			}
  		   }
		}
	}

} 

open(SADB, "/home/e-smith/db/spamassassin");
binmode(SADB);
my $newmd5 = Digest::MD5->new->addfile(SADB)->b64digest;
close(SADB);

# fix for bad ownership of bayes files
system('/bin/chown','spamd:spamd','/var/spool/spamd/.spamassassin/bayes_toks');

if ($newmd5 ne $md5) {
	`expand-template /etc/mail/spamassassin/local.cf`;
	`/usr/bin/systemctl restart spamassassin.service`;
	print "\n";
}

# restore STDOUT
select STDOUT;
# read log and print on STDOUT if mode active
if ($verbose eq "active"){ 
	seek $LOG, 0, 0;
	while (<$LOG>) {
		print $_;
	}
}		 
close($LOG) unless ($verbose eq "enabled");
unlink $outputfile unless ($verbose eq "disabled");

# sub to print the user line if something happen on active verbose mode
sub Vact() {
return unless ($verbose eq "active");
print $currentuser;
$currentuser="";
}