2 // +----------------------------------------------------------------------+
3 // | Anuko Time Tracker
4 // +----------------------------------------------------------------------+
5 // | Copyright (c) Anuko International Ltd. (https://www.anuko.com)
6 // +----------------------------------------------------------------------+
7 // | LIBERAL FREEWARE LICENSE: This source code document may be used
8 // | by anyone for any purpose, and freely redistributed alone or in
9 // | combination with other software, provided that the license is obeyed.
11 // | There are only two ways to violate the license:
13 // | 1. To redistribute this code in source form, with the copyright
14 // | notice or license removed or altered. (Distributing in compiled
15 // | forms without embedded copyright notices is permitted).
17 // | 2. To redistribute modified versions of this code in *any* form
18 // | that bears insufficient indications that the modifications are
19 // | not the work of the original author(s).
21 // | This license applies to this document only, not any other software
22 // | that it may be combined with.
24 // +----------------------------------------------------------------------+
26 // | https://www.anuko.com/time_tracker/credits.htm
27 // +----------------------------------------------------------------------+
29 import('ttConfigHelper');
30 import('ttGroupHelper');
33 var $login = null; // User login.
34 var $name = null; // User name.
35 var $id = null; // User id.
36 var $org_id = null; // Organization id.
37 var $group_id = null; // Group id.
38 var $role_id = null; // Role id.
39 var $role_name = null; // Role name.
40 var $rank = null; // User role rank.
41 var $client_id = null; // Client id for client user role.
42 var $behalf_id = null; // User id, on behalf of whom we are working.
43 var $behalf_group_id = null; // Group id, on behalf of which we are working.
44 var $behalf_name = null; // User name, on behalf of whom we are working.
45 var $group_name = null; // Group name.
46 var $behalf_group_name = null;// Group name, on behalf of which we are working.
47 var $email = null; // User email.
48 var $lang = null; // Language.
49 var $decimal_mark = null; // Decimal separator.
50 var $date_format = null; // Date format.
51 var $time_format = null; // Time format.
52 var $week_start = 0; // Week start day.
53 var $show_holidays = 0; // Whether to show holidays in calendar.
54 var $tracking_mode = 0; // Tracking mode.
55 var $project_required = 0; // Whether project selection is required on time entires.
56 var $task_required = 0; // Whether task selection is required on time entires.
57 var $record_type = 0; // Record type (duration vs start and finish, or both).
58 var $punch_mode = 0; // Whether punch mode is enabled for user.
59 var $allow_overlap = 0; // Whether to allow overlapping time entries.
60 var $future_entries = 0; // Whether to allow creating future entries.
61 var $uncompleted_indicators = 0; // Uncompleted time entry indicators (show nowhere or on users page).
62 var $bcc_email = null; // Bcc email.
63 var $allow_ip = null; // Specification from where user is allowed access.
64 var $password_complexity = null; // Password complexity example.
65 var $currency = null; // Currency.
66 var $plugins = null; // Comma-separated list of enabled plugins.
67 var $config = null; // Comma-separated list of miscellaneous config options.
68 var $custom_logo = 0; // Whether to use a custom logo for group.
69 var $lock_spec = null; // Cron specification for record locking.
70 var $workday_minutes = 480; // Number of work minutes in a regular day.
71 var $rights = array(); // An array of user rights such as 'track_own_time', etc.
72 var $is_client = false; // Whether user is a client as determined by missing 'track_own_time' right.
73 var $minutes_in_unit = 15; // Number of minutes in unit for Work units plugin.
74 var $first_unit_threshold = 0;// Threshold for 1st unit for Work units plugin.
75 var $unit_totals_only = 0; // Totals only option for the Work units plugin.
78 function __construct($login, $id = null) {
79 if (!$login && !$id) {
80 // nothing to initialize
84 $mdb2 = getConnection();
86 $sql = "SELECT u.id, u.login, u.name, u.group_id, u.role_id, r.rank, r.name as role_name, r.rights, u.client_id, u.email,
87 g.org_id, g.name as group_name, g.currency, g.lang, g.decimal_mark, g.date_format, g.time_format, g.week_start,
88 g.tracking_mode, g.project_required, g.task_required, g.record_type,
89 g.bcc_email, g.allow_ip, g.password_complexity, g.plugins, g.config, g.lock_spec, g.workday_minutes, g.custom_logo
90 FROM tt_users u LEFT JOIN tt_groups g ON (u.group_id = g.id) LEFT JOIN tt_roles r on (r.id = u.role_id) WHERE ";
94 $sql .= "u.login = ".$mdb2->quote($login);
95 $sql .= " AND u.status = 1";
97 $res = $mdb2->query($sql);
98 if (is_a($res, 'PEAR_Error')) {
102 $val = $res->fetchRow();
103 if ($val['id'] > 0) {
104 $this->login = $val['login'];
105 $this->name = $val['name'];
106 $this->id = $val['id'];
107 $this->org_id = $val['org_id'];
108 $this->group_id = $val['group_id'];
109 $this->role_id = $val['role_id'];
110 $this->role_name = $val['role_name'];
111 $this->rights = explode(',', $val['rights']);
112 $this->is_client = !in_array('track_own_time', $this->rights);
113 $this->rank = $val['rank'];
114 $this->client_id = $val['client_id'];
115 $this->email = $val['email'];
116 $this->lang = $val['lang'];
117 $this->decimal_mark = $val['decimal_mark'];
118 $this->date_format = $val['date_format'];
119 $this->time_format = $val['time_format'];
120 $this->week_start = $val['week_start'];
121 $this->tracking_mode = $val['tracking_mode'];
122 $this->project_required = $val['project_required'];
123 $this->task_required = $val['task_required'];
124 $this->record_type = $val['record_type'];
125 $this->bcc_email = $val['bcc_email'];
126 $this->allow_ip = $val['allow_ip'];
127 $this->password_complexity = $val['password_complexity'];
128 $this->group_name = $val['group_name'];
129 $this->currency = $val['currency'];
130 $this->plugins = $val['plugins'];
131 $this->lock_spec = $val['lock_spec'];
132 $this->workday_minutes = $val['workday_minutes'];
133 $this->custom_logo = $val['custom_logo'];
135 $this->config = $val['config'];
136 $config = new ttConfigHelper($this->config);
137 // Set user config options.
138 $this->show_holidays = $config->getDefinedValue('show_holidays');
139 $this->punch_mode = $config->getDefinedValue('punch_mode');
140 $this->allow_overlap = $config->getDefinedValue('allow_overlap');
141 $this->future_entries = $config->getDefinedValue('future_entries');
142 $this->uncompleted_indicators = $config->getDefinedValue('uncompleted_indicators');
143 if ($this->isPluginEnabled('wu')) {
144 $minutes_in_unit = $config->getIntValue('minutes_in_unit');
145 if ($minutes_in_unit) $this->minutes_in_unit = $minutes_in_unit;
146 $first_unit_threshold = $config->getIntValue('1st_unit_threshold');
147 if ($first_unit_threshold) $this->first_unit_threshold = $first_unit_threshold;
148 $this->unit_totals_only = $config->getDefinedValue('unit_totals_only');
151 // Set "on behalf" id and name (user).
152 if (isset($_SESSION['behalf_id'])) {
153 $this->behalf_id = $_SESSION['behalf_id'];
154 $this->behalf_name = $_SESSION['behalf_name'];
156 // Set "on behalf" id and name (group).
157 if (isset($_SESSION['behalf_group_id'])) {
158 $this->behalf_group_id = $_SESSION['behalf_group_id'];
159 $this->behalf_group_name = $_SESSION['behalf_group_name'];
164 // The getActiveUser returns user id on behalf of whom the current user is operating.
165 function getActiveUser() {
166 return ($this->behalf_id ? $this->behalf_id : $this->id);
169 // The getActiveGroup returns group id on behalf of which the current user is operating.
170 function getActiveGroup() {
171 return ($this->behalf_group_id ? $this->behalf_group_id : $this->group_id);
174 // can - determines whether user has a right to do something.
175 function can($do_something) {
176 return in_array($do_something, $this->rights);
179 // isClient - determines whether current user is a client.
180 function isClient() {
181 return $this->is_client;
184 // isPluginEnabled checks whether a plugin is enabled for user.
185 function isPluginEnabled($plugin)
187 return in_array($plugin, explode(',', $this->plugins));
190 // getAssignedProjects - returns an array of assigned projects.
191 function getAssignedProjects()
194 $mdb2 = getConnection();
196 $group_id = $this->behalf_group_id ? $this->behalf_group_id : $this->group_id;
197 // Do a query with inner join to get assigned projects.
198 $sql = "select p.id, p.name, p.description, p.tasks, upb.rate from tt_projects p
199 inner join tt_user_project_binds upb on (upb.user_id = ".$this->getActiveUser()." and upb.project_id = p.id and upb.status = 1)
200 where p.group_id = $group_id and p.status = 1 order by p.name";
201 $res = $mdb2->query($sql);
202 if (!is_a($res, 'PEAR_Error')) {
203 while ($val = $res->fetchRow()) {
210 // getAssignedTasks - returns an array of assigned tasks.
211 function getAssignedTasks()
213 // Start with projects;
214 $projects = $this->getAssignedProjects();
215 if (!$projects) return false;
217 // Build an array of task ids.
219 foreach($projects as $project) {
220 $one_project_tasks = $project['tasks'] ? explode(',', $project['tasks']) : array();
221 $task_ids = array_unique(array_merge($task_ids, $one_project_tasks));
223 if (!$task_ids) return false;
225 // Get task descriptions.
227 $mdb2 = getConnection();
228 $tasks = implode(',', $task_ids); // This is a comma-separated list of task ids.
230 $sql = "select id, name, description from tt_tasks".
231 " where group_id = $this->group_id and status = 1 and id in ($tasks) order by name";
232 $res = $mdb2->query($sql);
233 if (!is_a($res, 'PEAR_Error')) {
234 while ($val = $res->fetchRow()) {
241 // getAssignedClients - returns an array of clients assigned to own projects.
242 function getAssignedClients()
244 // Start with projects;
245 $projects = $this->getAssignedProjects();
246 if (!$projects) return false;
247 $assigned_project_ids = array();
248 foreach($projects as $project) {
249 $assigned_project_ids[] = $project['id'];
252 $mdb2 = getConnection();
254 // Get active clients for group.
256 $sql = "select id, name, address, projects from tt_clients where group_id = $this->group_id and status = 1";
257 $res = $mdb2->query($sql);
258 if (!is_a($res, 'PEAR_Error')) {
259 while ($val = $res->fetchRow()) {
260 $client_project_ids = $val['projects'] ? explode(',', $val['projects']) : array();
261 if (array_intersect($assigned_project_ids, $client_project_ids))
262 $clients[] = $val; // Add client if one of user projects is a client project, too.
268 // isDateLocked checks whether a specifc date is locked for modifications.
269 function isDateLocked($date)
271 if (!$this->isPluginEnabled('lk'))
272 return false; // Locking feature is disabled.
274 if (!$this->lock_spec)
275 return false; // There is no lock specification.
277 if (!$this->behalf_id && $this->can('override_own_date_lock'))
278 return false; // User is working as self and can override own date lock.
280 if ($this->behalf_id && $this->can('override_date_lock'))
281 return false; // User is working on behalf of someone else and can override date lock.
283 require_once(LIBRARY_DIR.'/tdcron/class.tdcron.php');
284 require_once(LIBRARY_DIR.'/tdcron/class.tdcron.entry.php');
286 // Calculate the last occurrence of a lock.
287 $last = tdCron::getLastOccurrence($this->lock_spec, time());
288 $lockdate = new DateAndTime(DB_DATEFORMAT, strftime('%Y-%m-%d', $last));
289 if ($date->before($lockdate))
295 // canOverridePunchMode checks whether a user can override punch mode in a situation.
296 function canOverridePunchMode()
298 if (!$this->behalf_id && !$this->can('override_own_punch_mode'))
299 return false; // User is working as self and cannot override for self.
301 if ($this->behalf_id && !$this->can('override_punch_mode'))
302 return false; // User is working on behalf of someone else and cannot override.
307 // getUsers obtains users in a group, as specififed by options.
308 function getUsers($options) {
310 $mdb2 = getConnection();
312 $skipClients = !isset($options['include_clients']);
313 $includeSelf = isset($options['include_self']);
314 $group_id = isset($options['group_id']) ? $options['group_id'] : $this->group_id;
316 $select_part = 'select u.id, u.name';
317 if (isset($options['include_login'])) $select_part .= ', u.login';
318 if (!isset($options['include_clients'])) $select_part .= ', r.rights';
319 if (isset($options['include_role'])) $select_part .= ', r.name as role_name, r.rank';
321 $from_part = ' from tt_users u';
324 if (isset($options['max_rank']) || $skipClients || isset($options['include_role']))
325 $left_joins .= ' left join tt_roles r on (u.role_id = r.id)';
327 $where_part = " where u.org_id = $this->org_id and u.group_id = $group_id";
328 if (isset($options['status']))
329 $where_part .= ' and u.status = '.(int)$options['status'];
331 $where_part .= ' and u.status is not null';
333 $where_part .= " and (u.id = $this->id || r.rank <= ".(int)$options['max_rank'].')';
335 if (isset($options['max_rank'])) $where_part .= ' and r.rank <= '.(int)$options['max_rank'];
338 $order_part = " order by upper(u.name)";
340 $sql = $select_part.$from_part.$left_joins.$where_part.$order_part;
341 $res = $mdb2->query($sql);
342 $user_list = array();
343 if (is_a($res, 'PEAR_Error'))
346 while ($val = $res->fetchRow()) {
348 $isClient = in_array('track_own_time', explode(',', $val['rights'])) ? 0 : 1; // Clients do not have track_own_time right.
350 continue; // Skip adding clients.
355 if (isset($options['self_first'])) {
356 // Put own entry at the front.
357 $cnt = count($user_list);
358 for($i = 0; $i < $cnt; $i++) {
359 if ($user_list[$i]['id'] == $this->id) {
360 $self = $user_list[$i]; // Found self.
361 array_unshift($user_list, $self); // Put own entry at the front.
362 array_splice($user_list, $i+1, 1); // Remove duplicate.
369 // getGroups obtains an array consisting of:
370 // - A parent group (..) of a currently selected group, if available.
371 // - A currently selected group (.) represented by $behalf_group_id.
372 // - All subgroups (only immediate children) of a currently selected group.
373 function getGroups() {
374 $mdb2 = getConnection();
376 $selected_group_id = ($this->behalf_group_id ? $this->behalf_group_id : $this->group_id);
377 $selected_group_name = ($this->behalf_group_id ? $this->behalf_group_name : $this->group_name);
379 // Start with parent group.
380 if ($selected_group_id != $this->group_id) {
381 // We are in one of subgroups, and a parent exists.
382 // Get parent group info.
383 $sql = "select parent_id from tt_groups where org_id = $this->org_id and id = $selected_group_id and status = 1";
384 $res = $mdb2->query($sql);
385 if (!is_a($res, 'PEAR_Error')) {
386 $val = $res->fetchRow();
387 $parent_id = $val['parent_id'];
389 // Get parent group name.
390 $sql = "select name from tt_groups where org_id = $this->org_id and id = $parent_id and status = 1";
391 $res = $mdb2->query($sql);
392 if (!is_a($res, 'PEAR_Error')) {
393 $val = $res->fetchRow();
394 $groups[] = array('id'=>$parent_id,'name'=>$val['name']);
400 // Add current group.
401 $groups[] = array('id'=>$selected_group_id,'name'=>$selected_group_name);
404 $sql = "select id, name from tt_groups where org_id = $this->org_id and parent_id = $selected_group_id and status = 1";
406 $res = $mdb2->query($sql);
407 if (!is_a($res, 'PEAR_Error')) {
408 while ($val = $res->fetchRow()) {
415 // getSubgroups obtains a list of immediate subgroups.
416 function getSubgroups($group_id = null) {
417 $mdb2 = getConnection();
419 if (!$group_id) $group_id = $this->getActiveGroup();
421 $sql = "select id, name, description from tt_groups where org_id = $this->org_id".
422 " and parent_id = $group_id and status is not null";
423 $res = $mdb2->query($sql);
424 if (!is_a($res, 'PEAR_Error')) {
425 while ($val = $res->fetchRow()) {
432 // getUser function is used to manage users in group and returns user details.
433 // At the moment, the function is used for user edits and deletes.
434 function getUser($user_id) {
435 if (!$this->can('manage_users')) return false;
437 $mdb2 = getConnection();
439 $sql = "select u.id, u.name, u.login, u.role_id, u.client_id, u.status, u.rate, u.email from tt_users u".
440 " left join tt_roles r on (u.role_id = r.id)".
441 " where u.id = $user_id and u.group_id = $this->group_id and u.status is not null".
442 " and (r.rank < $this->rank or (r.rank = $this->rank and u.id = $this->id))"; // Users with lesser roles or self.
443 $res = $mdb2->query($sql);
444 if (!is_a($res, 'PEAR_Error')) {
445 $val = $res->fetchRow();
451 // checkBehalfId checks whether behalf_id is appropriate.
452 // On behalf user must be active and have lower rank if the user is from home group,
454 // - subgroup must ve valid;
455 // - user should be a member of it.
456 function checkBehalfId() {
457 if (!$this->behalf_group_id) {
458 // Checking user from home group.
459 $options = array('status'=>ACTIVE,'max_rank'=>$this->rank-1);
460 $users = $this->getUsers($options);
461 foreach($users as $one_user) {
462 if ($one_user['id'] == $this->behalf_id)
466 // Checking user from a subgroup.
467 $group_id = $this->behalf_group_id;
468 if (!$this->isSubgroupValid($group_id))
471 // So far, so good. Check user now.
472 $options = array('group_id'=>$group_id,'status'=>ACTIVE,'max_rank'=>MAX_RANK);
473 $users = $this->getUsers($options);
474 foreach($users as $one_user) {
475 if ($one_user['id'] == $this->behalf_id)
482 // adjustBehalfId attempts to adjust behalf_id and behalf_name to a first found
485 // Needed for situations when user does not have do_own_something right.
486 // Example: has view_charts but does not have view_own_charts.
487 // In this case we still allow access to charts, but set behalf_id to someone else.
488 // Another example: working in a subgroup on behalf of someone else.
489 function adjustBehalfId() {
490 $group_id = $this->behalf_group_id ? $this->behalf_group_id : $this->group_id;
491 $rank = $this->getMaxRankForGroup($group_id);
493 // Adjust to first found user in group.
494 $options = array('group_id'=>$group_id,'status'=>ACTIVE,'max_rank'=>$rank);
495 $users = $this->getUsers($options);
496 foreach($users as $one_user) {
497 // Fake loop to access first element.
498 $this->behalf_id = $one_user['id'];
499 $this->behalf_name = $one_user['name'];
500 $_SESSION['behalf_id'] = $this->behalf_id;
501 $_SESSION['behalf_name'] = $this->behalf_name;
507 // updateGroup updates group information with new data.
508 function updateGroup($fields) {
509 if (!($this->can('manage_basic_settings') ||
510 $this->can('manage_advanced_settings') ||
511 $this->can('manage_features'))) return false;
512 // TODO: update the above for subgroup updates.
514 $group_id = $fields['group_id'];
515 if ($group_id && !$this->isGroupValid($group_id)) return false;
517 $mdb2 = getConnection();
518 if (!$group_id) $group_id = $this->getActiveGroup();
520 if (isset($fields['name'])) $name_part = ', name = '.$mdb2->quote($fields['name']);
521 if (isset($fields['currency'])) $currency_part = ', currency = '.$mdb2->quote($fields['currency']);
522 if (isset($fields['lang'])) $lang_part = ', lang = '.$mdb2->quote($fields['lang']);
523 if (isset($fields['decimal_mark'])) $decimal_mark_part = ', decimal_mark = '.$mdb2->quote($fields['decimal_mark']);
524 if (isset($fields['date_format'])) $date_format_part = ', date_format = '.$mdb2->quote($fields['date_format']);
525 if (isset($fields['time_format'])) $time_format_part = ', time_format = '.$mdb2->quote($fields['time_format']);
526 if (isset($fields['week_start'])) $week_start_part = ', week_start = '.(int) $fields['week_start'];
527 if (isset($fields['tracking_mode'])) {
528 $tracking_mode_part = ', tracking_mode = '.(int) $fields['tracking_mode'];
529 $project_required_part = ' , project_required = '.(int) $fields['project_required'];
530 $task_required_part = ' , task_required = '.(int) $fields['task_required'];
532 if (isset($fields['record_type'])) $record_type_part = ', record_type = '.(int) $fields['record_type'];
533 if (isset($fields['bcc_email'])) $bcc_email_part = ', bcc_email = '.$mdb2->quote($fields['bcc_email']);
534 if (isset($fields['allow_ip'])) $allow_ip_part = ', allow_ip = '.$mdb2->quote($fields['allow_ip']);
535 if (isset($fields['plugins'])) $plugins_part = ', plugins = '.$mdb2->quote($fields['plugins']);
536 if (isset($fields['config'])) $config_part = ', config = '.$mdb2->quote($fields['config']);
537 if (isset($fields['lock_spec'])) $lock_spec_part = ', lock_spec = '.$mdb2->quote($fields['lock_spec']);
538 if (isset($fields['workday_minutes'])) $workday_minutes_part = ', workday_minutes = '.$mdb2->quote($fields['workday_minutes']);
539 $modified_part = ', modified = now(), modified_ip = '.$mdb2->quote($_SERVER['REMOTE_ADDR']).', modified_by = '.$mdb2->quote($this->id);
541 $parts = trim($name_part.$currency_part.$lang_part.$decimal_mark_part.$date_format_part.
542 $time_format_part.$week_start_part.$tracking_mode_part.$task_required_part.$project_required_part.$record_type_part.
543 $bcc_email_part.$allow_ip_part.$plugins_part.$config_part.$lock_spec_part.$workday_minutes_part.$modified_part, ',');
545 $sql = "update tt_groups set $parts where id = $group_id and org_id = $this->org_id";
546 $affected = $mdb2->exec($sql);
547 if (is_a($affected, 'PEAR_Error')) return false;
552 // markUserDeleted marks a user in group as deleted.
553 function markUserDeleted($user_id) {
554 if (!$this->can('manage_users') || $this->id == $user_id)
557 // Make sure we operate on a legit user.
558 $user_details = $this->getUser($user_id);
559 if (!$user_details) return false;
561 $mdb2 = getConnection();
563 // Mark user to project binds as deleted.
564 $sql = "update tt_user_project_binds set status = NULL where user_id = $user_id";
565 $affected = $mdb2->exec($sql);
566 if (is_a($affected, 'PEAR_Error'))
569 // Mark user favorite reports as deleted.
570 $sql = "update tt_fav_reports set status = NULL where user_id = $user_id";
571 $affected = $mdb2->exec($sql);
572 if (is_a($affected, 'PEAR_Error'))
575 // Mark user as deleted.
576 $sql = "update tt_users set status = NULL where id = $user_id and group_id = ".$this->group_id;
577 $affected = $mdb2->exec($sql);
578 if (is_a($affected, 'PEAR_Error'))
584 // enablePlugin either enables or disables a specific plugin for group.
585 function enablePlugin($plugin, $enable = true)
587 if (!$this->can('manage_advanced_settings'))
588 return false; // Note: enablePlugin is currently only used on week_view.php.
589 // So, it's not really a plugin we are enabling, but rather week view display options.
590 // Therefore, a check for manage_advanced_settings, not manage_features.
592 $plugin_array = explode(',', $this->plugins);
593 if ($enable && !in_array($plugin, $plugin_array))
594 $plugin_array[] = $plugin; // Add plugin to array.
596 if (!$enable && in_array($plugin, $plugin_array)) {
597 $key = array_search($plugin, $plugin_array);
599 unset($plugin_array[$key]); // Remove plugin from array.
602 $plugins = implode(',', $plugin_array);
603 if ($plugins != $this->plugins) {
604 if (!$this->updateGroup(array('plugins' => $plugins)))
606 $this->plugins = $plugins;
612 // isGroupValid determines if a group is valid for user.
613 function isGroupValid($group_id) {
614 if ($group_id == $this->group_id)
617 return $this->isSubgroupValid($group_id);
620 // isSubgroupValid determines if a subgroup is valid for user.
621 // A subgroup is valid if:
622 // - user can manage_subgroups;
623 // - subgroup is either a direct child of user group, or "on the path"
624 // to it (grand-child, etc.).
625 function isSubgroupValid($subgroup_id) {
626 if (!$this->can('manage_subgroups')) return false; // User cannot manage subgroups.
628 $current_group_id = $subgroup_id;
629 while ($parent_group_id = ttGroupHelper::getParentGroup($current_group_id)) {
630 if ($parent_group_id == $this->group_id) {
631 return true; // Found it.
633 $current_group_id = $parent_group_id;
638 // getMaxRankForGroup determines effective user rank for a user in a given group.
639 // For home group it is the existing user rank (as per role) minus 1.
640 // For subgroups, if user can "manage_subgroups", it is MAX_RANK.
641 function getMaxRankForGroup($group_id) {
643 $max_rank = 0; // Start safely.
644 if ($this->group_id == $group_id) {
645 $max_rank = $this->rank - 1;
649 if ($this->isSubgroupValid($group_id))
650 $max_rank = MAX_RANK;