#
#
# This library of functions is used for filtering messages.
#


# processes approval decision.
#
# Arguments: 
#
# Subject, newsgroup, ShortDirectoryName, decision, comment

sub process_approval_decision {

  my $comment = pop( @_ );
  my $decision = pop( @_ );
  my $ShortDirectoryName = pop( @_ );
  my $newsgroup = pop( @_ );
  my $Subject = pop( @_ );

  my $address = $newsgroups_index{$newsgroup};

  my $message = "To: $newsgroups_index{$newsgroup}\n" .
		"Subject: $Subject\n" .
                "Organization: http://www.algebra.com/~ichudov/stump\n";

  $message .= "\n$decision\n";
  $message .= "comment $comment\n" if $comment;
  &email_message( $message, $address );

print STDERR "DECISION: $decision for $ShortDirectoryName sent to $address, for $newsgroup\n";

  &rmdir_rf( &article_file_name( $ShortDirectoryName ) );

}


###################################################################### checkAck
# checks the string matches one of the substrings. A name is matched
# against the substrings as regexps and substrings as literal substrings.
#
# Arguments: address, listname
sub name_is_in_list { # address, listname
  my $listName = pop( @_ );
  my $address = pop( @_ );

  my $item = "";
  my $Result = "";

  $address = "\L$address";

  open( LIST, &full_config_file_name( $listName ) ) || return "";

  while( $item = <LIST> ) {

    chop $item;

    next if $item =~ /^\s*$/;

    my $quoted_item = quotemeta( $item );

    if( eval { $address =~ /$item/i; } || $address =~ /$quoted_item/i ) {
      $Result = $item;
    }
  }

  close( LIST );

  return $Result;
}


######################################################################
# reviews incoming message and decides: approve, reject, keep
# in queue for human review
#
# Arguments: Newsgroup, From, Subject, Message, Dir
#
# RealSubject is the shorter subject from original posting
sub review_incoming_message { # Newsgroup, From, Subject, RealSubject, Message, Dir
  my $dir = pop( @_ );
  my $message = pop( @_ );
  my $real_subject = pop( @_ );
  my $subject = pop( @_ );
  my $from = pop( @_ );
  my $newsgroup = pop( @_ );

  if( &name_is_in_list( $from, "bad.posters.list" ) ) {
    &process_approval_decision( $subject, $newsgroup, $dir, "reject abuse", "" );
    return;
  }

  if( &name_is_in_list( $real_subject, "bad.subjects.list" ) ) {
    &process_approval_decision( $subject, $newsgroup, $dir, "reject thread", "" );
    return;
  }

  if( &name_is_in_list( $message, "bad.words.list" ) ) {
    &process_approval_decision( $subject, $newsgroup, $dir, "reject charter", 
    "Your message has been autorejected because it appears to be off topic
    based on our filtering criteria. Like everything, filters do not
    always work perfectly and you can always appeal this decision." );
    return;
  }

  my $warning_file = &article_file_name( $dir ) . "/stump-warning.txt";
  my $match;

  $ignore_demo_mode = 1;

  if( $match = &name_is_in_list( $from, "watch.posters.list" ) ) {
    &append_to_file( $warning_file, "Warning: poster '$from' matches '$match' from the list of suspicious posters\n" );
print STDERR "Filing Article for review because poster '$from' matches '$match'\n";
    return; # file message
  }

  if( $match = &name_is_in_list( $real_subject, "watch.subjects.list" ) ) {
    &append_to_file( $warning_file, "Warning: subject '$real_subject' matches '$match' from the list of suspicious subjects\n" );
print STDERR "Filing Article for review because subject '$subject' matches '$match'\n";
    return; # file message
  }

  if( $match = &name_is_in_list( $message, "watch.words.list" ) ) {
    &append_to_file( $warning_file, "Warning: article matches '$match' from the list of suspicious words\n" );
print STDERR "Filing Article for review because article matches '$match'\n";
    return; # file message
  }

  if( &name_is_in_list( $from, "good.posters.list" ) ) {
    &process_approval_decision( $subject, $newsgroup, $dir, "approve", "" );
    return;
  }

  if( &name_is_in_list( $real_subject, "good.subjects.list" ) ) {
    &process_approval_decision( $subject, $newsgroup, $dir, "approve", "" );
    return;
  }

  # if the message remains here, it is stored for human review.

}

1;