From 0052eff67ab498236579b945f1e1a3c368f23e89 Mon Sep 17 00:00:00 2001
From: Lai Wei <lai.wei@enovation.ie>
Date: Tue, 27 Sep 2022 10:54:55 +0100
Subject: [PATCH] Update group mailNickname length check

---
 .../o365/classes/feature/coursesync/main.php  |  3 ++
 .../o365/classes/feature/coursesync/utils.php | 31 +++++++++----------
 local/o365/lang/en/local_o365.php             |  2 +-
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/local/o365/classes/feature/coursesync/main.php b/local/o365/classes/feature/coursesync/main.php
index eaee75889..ea294e3ca 100644
--- a/local/o365/classes/feature/coursesync/main.php
+++ b/local/o365/classes/feature/coursesync/main.php
@@ -951,6 +951,9 @@ public function process_course_reset(stdClass $course, stdClass $o365object, boo
                     $resetgroupnameprefix = 'disconnected-';
                 }
                 $updatedmailnickname = $resetgroupnameprefix . utils::get_group_mail_alias($course);
+                if (strlen($updatedmailnickname) > 59) {
+                    $updatedmailnickname = substr($updatedmailnickname, 0, 59);
+                }
                 $updatedexistinggroup = [
                     'id' => $existinggroup['id'],
                     'mailNickname' => $updatedmailnickname,
diff --git a/local/o365/classes/feature/coursesync/utils.php b/local/o365/classes/feature/coursesync/utils.php
index 78057eee8..7102e9c5a 100644
--- a/local/o365/classes/feature/coursesync/utils.php
+++ b/local/o365/classes/feature/coursesync/utils.php
@@ -332,11 +332,10 @@ public static function get_sample_team_group_names() : array {
      * Return the email alias of group for the given course according to configuration.
      *
      * @param stdClass $course
-     * @param stdClass|null $group
      *
      * @return string
      */
-    public static function get_group_mail_alias(stdClass $course, stdClass $group = null) : string {
+    public static function get_group_mail_alias(stdClass $course) : string {
         $groupmailaliasprefix = get_config('local_o365', 'group_mail_alias_prefix');
         if ($groupmailaliasprefix) {
             $groupmailaliasprefix = static::clean_up_group_mail_alias($groupmailaliasprefix);
@@ -365,35 +364,33 @@ public static function get_group_mail_alias(stdClass $course, stdClass $group =
                 $coursepart = $course->shortname;
         }
 
-        if ($group) {
-            $grouppart = $group->id . '_' . $group->name;
-            $grouppart = static::clean_up_group_mail_alias($grouppart);
-            if (strlen($grouppart) > 16) {
-                $grouppart = substr($grouppart, 0, 16);
-            }
-            $grouppart = '-' . $grouppart;
-        } else {
-            $grouppart = '';
-        }
-
         $coursepart = static::clean_up_group_mail_alias($coursepart);
 
-        $coursepartmaxlength = 64 - strlen($groupmailaliasprefix) - strlen($groupmailaliassuffix) - strlen($grouppart);
+        $coursepartmaxlength = 59 - strlen($groupmailaliasprefix) - strlen($groupmailaliassuffix);
         if (strlen($coursepart) > $coursepartmaxlength) {
             $coursepart = substr($coursepart, 0, $coursepartmaxlength);
         }
 
-        return $groupmailaliasprefix . $coursepart . $grouppart . $groupmailaliassuffix;
+        return $groupmailaliasprefix . $coursepart . $groupmailaliassuffix;
     }
 
     /**
      * Remove unsupported characters from the mail alias parts, and return the result.
      *
      * @param string $mailalias
-     * @return string|string[]|null
+     * @return string
      */
     public static function clean_up_group_mail_alias(string $mailalias) {
-        return preg_replace('/[^a-z0-9-_]+/iu', '', $mailalias);
+        $notallowedbasicchars = ['@', '(', ')', "\\", '[', ']', '"', ';', ':', '.', '<', '>', ' '];
+        $chars = preg_split( '//u', $mailalias, null, PREG_SPLIT_NO_EMPTY);
+        foreach($chars as $key => $char){
+            $charorder = ord($char);
+            if ($charorder < 0 || $charorder > 127 || in_array($char, $notallowedbasicchars)) {
+                unset($chars[$key]);
+            }
+        }
+
+        return implode($chars);
     }
 
     /**
diff --git a/local/o365/lang/en/local_o365.php b/local/o365/lang/en/local_o365.php
index 5a207041e..1c9eaeefd 100644
--- a/local/o365/lang/en/local_o365.php
+++ b/local/o365/lang/en/local_o365.php
@@ -219,7 +219,7 @@
 <li>All spaces will be removed from the group mail alias.</li>
 <li>Only upper and lower case letters, numbers, - and _ are allowed in the group mail alias.</li>
 <li>Group mail alias, including prefix and suffix cannot exceed 64 characters.</li>
-<li>Mail alias of the group needs to be unique, otherwise a random 4 digit number will be appended to ensure uniqueness.</li>
+<li>Mail alias of the group needs to be unique, otherwise a random 4-digit number will be appended to ensure uniqueness.</li>
 </ul>';
 $string['settings_team_name_prefix'] = 'Teams name prefix';
 $string['settings_team_name_prefix_desc'] = '';