aboutsummaryrefslogtreecommitdiffstats
path: root/whine.pl
blob: d8cc39174d72fa7fe51f7df47eac18374e1f8f3b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
#!/usr/bin/perl -wT
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.

################################################################################
# Script Initialization
################################################################################

use 5.10.1;
use strict;
use lib qw(. lib);

use Bugzilla;
use Bugzilla::Constants;
use Bugzilla::Search;
use Bugzilla::User;
use Bugzilla::Mailer;
use Bugzilla::Util;
use Bugzilla::Group;

# create some handles that we'll need
my $template = Bugzilla->template;
my $dbh      = Bugzilla->dbh;
my $sth;

# @seen_schedules is a list of all of the schedules that have already been
# touched by reset_timer.  If reset_timer sees a schedule more than once, it
# sets it to NULL so it won't come up again until the next execution of
# whine.pl
my @seen_schedules = ();

# These statement handles should live outside of their functions in order to
# allow the database to keep their SQL compiled.
my $sth_run_queries =
    $dbh->prepare("SELECT " .
                  "query_name, title, onemailperbug " .
                  "FROM whine_queries " .
                  "WHERE eventid=? " .
                  "ORDER BY sortkey");
my $sth_get_query =
    $dbh->prepare("SELECT query FROM namedqueries " .
                  "WHERE userid = ? AND name = ?");

# get the event that's scheduled with the lowest run_next value
my $sth_next_scheduled_event = $dbh->prepare(
    "SELECT " .
    " whine_schedules.eventid, " .
    " whine_events.owner_userid, " .
    " whine_events.subject, " .
    " whine_events.body, " .
    " whine_events.mailifnobugs " .
    "FROM whine_schedules " .
    "LEFT JOIN whine_events " .
    " ON whine_events.id = whine_schedules.eventid " .
    "WHERE run_next <= NOW() " .
    "ORDER BY run_next " .
    $dbh->sql_limit(1)
);

# get all pending schedules matching an eventid
my $sth_schedules_by_event = $dbh->prepare(
    "SELECT id, mailto_type, mailto " .
    "FROM whine_schedules " .
    "WHERE eventid=? AND run_next <= NOW()"
);


################################################################################
# Main Body Execution
################################################################################

# This script needs to check through the database for schedules that have
# run_next set to NULL, which means that schedule is new or has been altered.
# It then sets it to run immediately if the schedule entry has it running at
# an interval like every hour, otherwise to the appropriate day and time.

# After that, it looks over each user to see if they have schedules that need
# running, then runs those and generates the email messages.

# Send whines from the address in the 'mailfrom' Parameter so that all
# Bugzilla-originated mail appears to come from a single address.
my $fromaddress = Bugzilla->params->{'mailfrom'};

# get the current date and time
my ($now_sec, $now_minute, $now_hour, $now_day, $now_month, $now_year, 
    $now_weekday) = localtime;
# Convert year to two digits
$now_year = sprintf("%02d", $now_year % 100);
# Convert the month to January being "1" instead of January being "0".
$now_month++;

my @daysinmonth = qw(0 31 28 31 30 31 30 31 31 30 31 30 31);
# Alter February in case of a leap year.  This simple way to do it only
# applies if you won't be looking at February of next year, which whining
# doesn't need to do.
if (($now_year % 4 == 0) &&
    (($now_year % 100 != 0) || ($now_year % 400 == 0))) {
    $daysinmonth[2] = 29;
}

# run_day can contain either a calendar day (1, 2, 3...), a day of the week
# (Mon, Tue, Wed...), a range of days (All, MF), or 'last' for the last day of
# the month.
#
# run_time can contain either an hour (0, 1, 2...) or an interval
# (60min, 30min, 15min).
#
# We go over each uninitialized schedule record and use its settings to
# determine what the next time it runs should be
my $sched_h = $dbh->prepare("SELECT id, run_day, run_time " .
                            "FROM whine_schedules " .
                            "WHERE run_next IS NULL" );
$sched_h->execute();
while (my ($schedule_id, $day, $time) = $sched_h->fetchrow_array) {
    # fill in some defaults in case they're blank
    $day  ||= '0';
    $time ||= '0';

    # If this schedule is supposed to run today, we see if it's supposed to be
    # run at a particular hour.  If so, we set it for that hour, and if not,
    # it runs at an interval over the course of a day, which means we should
    # set it to run immediately.
    if (&check_today($day)) {
        # Values that are not entirely numeric are intervals, like "30min"
        if ($time !~ /^\d+$/) {
            # set it to now
            $sth = $dbh->prepare( "UPDATE whine_schedules " .
                                  "SET run_next=NOW() " .
                                  "WHERE id=?");
            $sth->execute($schedule_id);
        }
        # A time greater than now means it still has to run today
        elsif ($time >= $now_hour) {
            # set it to today + number of hours
            $sth = $dbh->prepare(
                "UPDATE whine_schedules " .
                   "SET run_next = " .
                        $dbh->sql_date_math('CURRENT_DATE', '+', '?', 'HOUR') .
                " WHERE id = ?");
            $sth->execute($time, $schedule_id);
        }
        # the target time is less than the current time
        else { # set it for the next applicable day
            $day = &get_next_date($day);
            my $run_next = $dbh->sql_date_math('(' 
                . $dbh->sql_date_math('CURRENT_DATE', '+', '?', 'DAY')
                . ')', '+', '?', 'HOUR');
            $sth = $dbh->prepare("UPDATE whine_schedules " .
                                    "SET run_next = $run_next
                                   WHERE id = ?");
            $sth->execute($day, $time, $schedule_id);
        }

    }
    # If the schedule is not supposed to run today, we set it to run on the
    # appropriate date and time
    else {
        my $target_date = &get_next_date($day);
        # If configured for a particular time, set it to that, otherwise
        # midnight
        my $target_time = ($time =~ /^\d+$/) ? $time : 0;

       my $run_next = $dbh->sql_date_math('(' 
            . $dbh->sql_date_math('CURRENT_DATE', '+', '?', 'DAY') 
            . ')', '+', '?', 'HOUR');
        $sth = $dbh->prepare("UPDATE whine_schedules " .
                                "SET run_next = $run_next
                               WHERE id = ?");
        $sth->execute($target_date, $target_time, $schedule_id);
    }
}
$sched_h->finish();

# get_next_event
#
# This function will:
#   1. Lock whine_schedules
#   2. Grab the most overdue pending schedules on the same event that must run
#   3. Update those schedules' run_next value
#   4. Unlock the table
#   5. Return an event hashref
#
# The event hashref consists of:
#   eventid - ID of the event 
#   author  - user object for the event's creator
#   users   - array of user objects for recipients
#   subject - Subject line for the email
#   body    - the text inserted above the bug lists
#   mailifnobugs - send message even if there are no query or query results

sub get_next_event {
    my $event = {};

    # Loop until there's something to return
    until (scalar keys %{$event}) {

        $dbh->bz_start_transaction();

        # Get the event ID for the first pending schedule
        $sth_next_scheduled_event->execute;
        my $fetched = $sth_next_scheduled_event->fetch;
        $sth_next_scheduled_event->finish;
        return undef unless $fetched;
        my ($eventid, $owner_id, $subject, $body, $mailifnobugs) = @{$fetched};

        my $owner = Bugzilla::User->new($owner_id);

        my $whineatothers = $owner->in_group('bz_canusewhineatothers');

        my %user_objects;   # Used for keeping track of who has been added

        # Get all schedules that match that event ID and are pending
        $sth_schedules_by_event->execute($eventid);

        # Add the users from those schedules to the list
        while (my $row = $sth_schedules_by_event->fetch) {
            my ($sid, $mailto_type, $mailto) = @{$row};

            # Only bother doing any work if this user has whine permission
            if ($owner->in_group('bz_canusewhines')) {

                if ($mailto_type == MAILTO_USER) {
                    if (not defined $user_objects{$mailto}) {
                        if ($mailto == $owner_id) {
                            $user_objects{$mailto} = $owner;
                        }
                        elsif ($whineatothers) {
                            $user_objects{$mailto} = Bugzilla::User->new($mailto);
                        }
                    }
                }
                elsif ($mailto_type == MAILTO_GROUP) {
                    my $sth = $dbh->prepare("SELECT name FROM groups " .
                                            "WHERE id=?");
                    $sth->execute($mailto);
                    my $groupname = $sth->fetch->[0];
                    my $group_id = Bugzilla::Group::ValidateGroupName(
                        $groupname, $owner);
                    if ($group_id) {
                        my $glist = join(',',
                            @{Bugzilla::Group->flatten_group_membership(
                            $group_id)});
                        $sth = $dbh->prepare("SELECT user_id FROM " .
                                             "user_group_map " .
                                             "WHERE group_id IN ($glist)");
                        $sth->execute();
                        for my $row (@{$sth->fetchall_arrayref}) {
                            if (not defined $user_objects{$row->[0]}) {
                                $user_objects{$row->[0]} =
                                    Bugzilla::User->new($row->[0]);
                            }
                        }
                    }
                }

            }

            reset_timer($sid);
        }

        $dbh->bz_commit_transaction();

        # Only set $event if the user is allowed to do whining
        if ($owner->in_group('bz_canusewhines')) {
            my @users = values %user_objects;
            $event = {
                    'eventid' => $eventid,
                    'author'  => $owner,
                    'mailto'  => \@users,
                    'subject' => $subject,
                    'body'    => $body,
                    'mailifnobugs' => $mailifnobugs,
            };
        }
    }
    return $event;
}

# Run the queries for each event
#
# $event:
#   eventid (the database ID for this event)
#   author  (user object for who created the event)
#   mailto  (array of user objects for mail targets)
#   subject (subject line for message)
#   body    (text blurb at top of message)
#   mailifnobugs (send message even if there are no query or query results)
while (my $event = get_next_event) {

    my $eventid = $event->{'eventid'};

    # We loop for each target user because some of the queries will be using
    # subjective pronouns
    $dbh = Bugzilla->switch_to_shadow_db();
    for my $target (@{$event->{'mailto'}}) {
        my $args = {
            'subject'     => $event->{'subject'},
            'body'        => $event->{'body'},
            'eventid'     => $event->{'eventid'},
            'author'      => $event->{'author'},
            'recipient'   => $target,
            'from'        => $fromaddress,
        };

        # run the queries for this schedule
        my $queries = run_queries($args);

        # If mailifnobugs is false, make sure there is something to output
        if (!$event->{'mailifnobugs'}) {
            my $there_are_bugs = 0;
            for my $query (@{$queries}) {
                $there_are_bugs = 1 if scalar @{$query->{'bugs'}};
            }
            next unless $there_are_bugs;
        }

        $args->{'queries'} = $queries;

        mail($args);
    }
    $dbh = Bugzilla->switch_to_main_db();
}

################################################################################
# Functions
################################################################################

# The mail and run_queries functions use an anonymous hash ($args) for their
# arguments, which are then passed to the templates.
#
# When run_queries is run, $args contains the following fields:
#  - body           Message body defined in event
#  - from           Bugzilla system email address
#  - queries        array of hashes containing:
#          - bugs:  array of hashes mapping fieldnames to values for this bug
#          - title: text title given to this query in the whine event
#          - columnlist: array of fieldnames to display in the mail
#          - name:  text name of this query
#  - schedule_id    integer id of the schedule being run
#  - subject        Subject line for the message
#  - recipient      user object for the recipient
#  - author         user object of the person who created the whine event
#
# In addition, mail adds two more fields to $args:
#  - alternatives   array of hashes defining mime multipart types and contents
#  - boundary       a MIME boundary generated using the process id and time
#
sub mail {
    my $args = shift;
    my $addressee = $args->{recipient};
    # Don't send mail to someone whose bugmail notification is disabled.
    return if $addressee->email_disabled;

    my $template = Bugzilla->template_inner($addressee->setting('lang'));
    my $msg = ''; # it's a temporary variable to hold the template output
    $args->{'alternatives'} ||= [];

    # put together the different multipart mime segments

    $template->process("whine/mail.txt.tmpl", $args, \$msg)
        or die($template->error());
    push @{$args->{'alternatives'}},
        {
            'content' => $msg,
            'type'    => 'text/plain',
        };
    $msg = '';

    $template->process("whine/mail.html.tmpl", $args, \$msg)
        or die($template->error());
    push @{$args->{'alternatives'}},
        {
            'content' => $msg,
            'type'    => 'text/html',
        };
    $msg = '';

    # now produce a ready-to-mail mime-encoded message

    $args->{'boundary'} = "----------" . $$ . "--" . time() . "-----";

    $template->process("whine/multipart-mime.txt.tmpl", $args, \$msg)
        or die($template->error());

    MessageToMTA($msg);

    delete $args->{'boundary'};
    delete $args->{'alternatives'};

}

# run_queries runs all of the queries associated with a schedule ID, adding
# the results to $args or mailing off the template if a query wants individual
# messages for each bug
sub run_queries {
    my $args = shift;

    my $return_queries = [];

    $sth_run_queries->execute($args->{'eventid'});
    my @queries = ();
    for (@{$sth_run_queries->fetchall_arrayref}) {
        push(@queries,
            {
              'name'          => $_->[0],
              'title'         => $_->[1],
              'onemailperbug' => $_->[2],
              'columnlist'    => [],
              'bugs'          => [],
            }
        );
    }

    foreach my $thisquery (@queries) {
        next unless $thisquery->{'name'};   # named query is blank

        my $savedquery = get_query($thisquery->{'name'}, $args->{'author'});
        next unless $savedquery;    # silently ignore missing queries

        # Execute the saved query
        my @searchfields = ('bug_id', DEFAULT_COLUMN_LIST);

        # A new Bugzilla::CGI object needs to be created to allow
        # Bugzilla::Search to execute a saved query.  It's exceedingly weird,
        # but that's how it works.
        my $searchparams = new Bugzilla::CGI($savedquery);

        # Use the columnlist for the saved query, if it exists, and make
        # sure bug_id is always in the list.
        if (my $columnlist = $searchparams->param('columnlist')) {
            @searchfields = split(/[\s,]+/, $columnlist);
            unshift(@searchfields, 'bug_id') unless grep { $_ eq 'bug_id' } @searchfields;
        }
        push @{$thisquery->{'columnlist'}}, @searchfields;

        my @orderstrings = split(/,\s*/, $searchparams->param('order') || '');
        my $search = new Bugzilla::Search(
            'fields' => \@searchfields,
            'params' => scalar $searchparams->Vars,
            'user'   => $args->{'recipient'}, # the search runs as the recipient
            'order'  => \@orderstrings
        );
        # If a query fails for whatever reason, it shouldn't kill the script.
        my $data = eval { $search->data };
        if ($@) {
            print STDERR get_text('whine_query_failed', { query_name => $thisquery->{'name'},
                                                          author => $args->{'author'},
                                                          reason => $@ }) . "\n";
            next;
        }

        foreach my $row (@$data) {
            my $bug = {};
            for my $field (@searchfields) {
                my $fieldname = $field;
                $fieldname =~ s/^bugs\.//;  # No need for bugs.whatever
                $bug->{$fieldname} = shift @$row;
            }

            if ($thisquery->{'onemailperbug'}) {
                $args->{'queries'} = [
                    {
                        'name' => $thisquery->{'name'},
                        'title' => $thisquery->{'title'},
                        'columnlist' => $thisquery->{'columnlist'},
                        'bugs' => [ $bug ],
                    },
                ];
                mail($args);
                delete $args->{'queries'};
            }
            else {  # It belongs in one message with any other lists
                push @{$thisquery->{'bugs'}}, $bug;
            }
        }
        if (!$thisquery->{'onemailperbug'} && @{$thisquery->{'bugs'}}) {
            push @{$return_queries}, $thisquery;
        }
    }

    return $return_queries;
}

# get_query gets the namedquery.  It's similar to LookupNamedQuery (in
# buglist.cgi), but doesn't care if a query name really exists or not, since
# individual named queries might go away without the whine_queries that point
# to them being removed.
sub get_query {
    my ($name, $user) = @_;
    my $qname = $name;
    $sth_get_query->execute($user->id, $qname);
    my $fetched = $sth_get_query->fetch;
    $sth_get_query->finish;
    return $fetched ? $fetched->[0] : '';
}

# check_today gets a run day from the schedule and sees if it matches today
# a run day value can contain any of:
#   - a three-letter day of the week
#   - a number for a day of the month
#   - 'last' for the last day of the month
#   - 'All' for every day
#   - 'MF' for every weekday

sub check_today {
    my $run_day  = shift;

    if (($run_day eq 'MF')
     && ($now_weekday > 0)
     && ($now_weekday < 6)) {
        return 1;
    }
    elsif (
         length($run_day) == 3 &&
         index("SunMonTueWedThuFriSat", $run_day)/3 == $now_weekday) {
        return 1;
    }
    elsif  (($run_day eq 'All')
         || (($run_day eq 'last')  &&
             ($now_day == $daysinmonth[$now_month] ))
         || ($run_day eq $now_day)) {
        return 1;
    }
    return 0;
}

# reset_timer sets the next time a whine is supposed to run, assuming it just
# ran moments ago.  Its only parameter is a schedule ID.
#
# reset_timer does not lock the whine_schedules table.  Anything that calls it
# should do that itself.
sub reset_timer {
    my $schedule_id = shift;

    # Schedules may not be executed more than once for each invocation of
    # whine.pl -- there are legitimate circumstances that can cause this, like
    # a set of whines that take a very long time to execute, so it's done
    # quietly.
    if (grep($_ == $schedule_id, @seen_schedules)) {
        null_schedule($schedule_id);
        return;
    }
    push @seen_schedules, $schedule_id;

    $sth = $dbh->prepare( "SELECT run_day, run_time FROM whine_schedules " .
                          "WHERE id=?" );
    $sth->execute($schedule_id);
    my ($run_day, $run_time) = $sth->fetchrow_array;

    # It may happen that the run_time field is NULL or blank due to
    # a bug in editwhines.cgi when this field was initially 0.
    $run_time ||= 0;

    my $run_today = 0;
    my $minute_offset = 0;

    # If the schedule is to run today, and it runs many times per day,
    # it shall be set to run immediately.
    $run_today = &check_today($run_day);
    if (($run_today) && ($run_time !~ /^\d+$/)) {
        # The default of 60 catches any bad value
        my $minute_interval = 60;
        if ($run_time =~ /^(\d+)min$/i) {
            $minute_interval = $1;
        }

        # set the minute offset to the next interval point
        $minute_offset = $minute_interval - ($now_minute % $minute_interval);
    }
    elsif (($run_today) && ($run_time > $now_hour)) {
        # timed event for later today
        # (This should only happen if, for example, an 11pm scheduled event
        #  didn't happen until after midnight)
        $minute_offset = (60 * ($run_time - $now_hour)) - $now_minute;
    }
    else {
        # it's not something that runs later today.
        $minute_offset = 0;

        # Set the target time if it's a specific hour
        my $target_time = ($run_time =~ /^\d+$/) ? $run_time : 0;

        my $nextdate = &get_next_date($run_day);
        my $run_next = $dbh->sql_date_math('('
            . $dbh->sql_date_math('CURRENT_DATE', '+', '?', 'DAY')
            . ')', '+', '?', 'HOUR');
        $sth = $dbh->prepare("UPDATE whine_schedules " .
                                "SET run_next = $run_next
                               WHERE id = ?");
        $sth->execute($nextdate, $target_time, $schedule_id);
        return;
    }

    if ($minute_offset > 0) {
        # Scheduling is done in terms of whole minutes.
        
        my $next_run = $dbh->selectrow_array(
            'SELECT ' . $dbh->sql_date_math('NOW()', '+', '?', 'MINUTE'),
            undef, $minute_offset);
        $next_run = format_time($next_run, "%Y-%m-%d %R");

        $sth = $dbh->prepare("UPDATE whine_schedules " .
                             "SET run_next = ? WHERE id = ?");
        $sth->execute($next_run, $schedule_id);
    } else {
        # The minute offset is zero or less, which is not supposed to happen.
        # complain to STDERR
        null_schedule($schedule_id);
        print STDERR "Error: bad minute_offset for schedule ID $schedule_id\n";
    }
}

# null_schedule is used to safeguard against infinite loops.  Schedules with
# run_next set to NULL will not be available to get_next_event until they are
# rescheduled, which only happens when whine.pl starts.
sub null_schedule {
    my $schedule_id = shift;
    $sth = $dbh->prepare("UPDATE whine_schedules " .
                         "SET run_next = NULL " .
                         "WHERE id=?");
    $sth->execute($schedule_id);
}

# get_next_date determines the difference in days between now and the next
# time a schedule should run, excluding today
#
# It takes a run_day argument (see check_today, above, for an explanation),
# and returns an integer, representing a number of days.
sub get_next_date {
    my $day = shift;

    my $add_days = 0;

    if ($day eq 'All') {
        $add_days = 1;
    }
    elsif ($day eq 'last') {
        # next_date should contain the last day of this month, or next month
        # if it's today
        if ($daysinmonth[$now_month] == $now_day) {
            my $month = $now_month + 1;
            $month = 1 if $month > 12;
            $add_days = $daysinmonth[$month] + 1;
        }
        else {
            $add_days = $daysinmonth[$now_month] - $now_day;
        }
    }
    elsif ($day eq 'MF') { # any day Monday through Friday
        if ($now_weekday < 5) { # Sun-Thurs
            $add_days = 1;
        }
        elsif ($now_weekday == 5) { # Friday
            $add_days = 3;
        }
        else { # it's 6, Saturday
            $add_days = 2;
        }
    }
    elsif ($day !~ /^\d+$/) { # A specific day of the week
        # The default is used if there is a bad value in the database, in
        # which case we mark it to a less-popular day (Sunday)
        my $day_num = 0;

        if (length($day) == 3) {
            $day_num = (index("SunMonTueWedThuFriSat", $day)/3) or 0;
        }

        $add_days = $day_num - $now_weekday;
        if ($add_days <= 0) { # it's next week
            $add_days += 7;
        }
    }
    else { # it's a number, so we set it for that calendar day
        $add_days = $day - $now_day;
        # If it's already beyond that day this month, set it to the next one
        if ($add_days <= 0) {
            $add_days += $daysinmonth[$now_month];
        }
    }
    return $add_days;
}