diff --git a/public/main/announcements/announcements.php b/public/main/announcements/announcements.php
index 231513a546..2fa8355d61 100644
--- a/public/main/announcements/announcements.php
+++ b/public/main/announcements/announcements.php
@@ -4,6 +4,7 @@
 
 use Chamilo\CoreBundle\Framework\Container;
 use Chamilo\CourseBundle\Entity\CAnnouncement;
+use Chamilo\CourseBundle\Entity\CGroup;
 
 /**
  * @author Frederik Vermeire <frederik.vermeire@pandora.be>, UGent Internship
@@ -49,6 +50,7 @@ $tbl_item_property = Database::get_course_table(TABLE_ITEM_PROPERTY);
 
 $isTutor = false;
 if (!empty($group_id)) {
+    $groupEntity = api_get_group_entity($group_id);
     $groupProperties = GroupManager::get_group_properties($group_id);
     $interbreadcrumb[] = [
         'url' => api_get_path(WEB_CODE_PATH).'group/group.php?'.api_get_cidreq(),
@@ -61,7 +63,7 @@ if (!empty($group_id)) {
 
     if (false === $allowToEdit) {
         // Check if user is tutor group
-        $isTutor = GroupManager::is_tutor_of_group(api_get_user_id(), $groupProperties, $courseId);
+        $isTutor = $groupEntity->userIsTutor(api_get_user_entity());
         if ($isTutor) {
             $allowToEdit = true;
         }
diff --git a/public/main/calendar/agenda_js.php b/public/main/calendar/agenda_js.php
index be578b60b6..4e2b74d2fd 100644
--- a/public/main/calendar/agenda_js.php
+++ b/public/main/calendar/agenda_js.php
@@ -40,18 +40,12 @@ api_protect_course_group(GroupManager::GROUP_TOOL_CALENDAR);
 
 $agenda = new Agenda($type);
 
-$is_group_tutor = false;
 $session_id = api_get_session_id();
 $group_id = api_get_group_id();
 $courseId = api_get_course_int_id();
 
 if (!empty($group_id)) {
     $group_properties = GroupManager::get_group_properties($group_id);
-    $is_group_tutor = GroupManager::is_tutor_of_group(
-        api_get_user_id(),
-        $group_properties,
-        $courseId
-    );
     $interbreadcrumb[] = [
         "url" => api_get_path(WEB_CODE_PATH)."group/group.php?".api_get_cidreq(),
         "name" => get_lang('Groups'),
@@ -108,7 +102,7 @@ switch ($type) {
 $tpl->assign('js_format_date', 'll');
 $region_value = api_get_language_isocode();
 
-if ('en' == $region_value) {
+if ('en' === $region_value) {
     $region_value = 'en-GB';
 }
 $tpl->assign('region_value', $region_value);
diff --git a/public/main/cron/import_csv.php b/public/main/cron/import_csv.php
index 9a3e5fafd7..2a6dec365b 100644
--- a/public/main/cron/import_csv.php
+++ b/public/main/cron/import_csv.php
@@ -1805,7 +1805,7 @@ class ImportCsv
                         ) {
                             foreach ($groupBackup['tutor'][$teacherId][$courseInfo['code']] as $data) {
                                 $groupInfo = GroupManager::get_group_properties($data['group_id']);
-                                GroupManager::subscribe_tutors(
+                                GroupManager::subscribeTutors(
                                     [$teacherId],
                                     $groupInfo,
                                     $data['c_id']
@@ -1818,10 +1818,9 @@ class ImportCsv
                             !empty($groupBackup['user'][$teacherId][$courseInfo['code']])
                         ) {
                             foreach ($groupBackup['user'][$teacherId][$courseInfo['code']] as $data) {
-                                $groupInfo = GroupManager::get_group_properties($data['group_id']);
-                                GroupManager::subscribe_users(
+                                GroupManager::subscribeUsers(
                                     [$teacherId],
-                                    $groupInfo,
+                                    api_get_group_entity($data['group_id']),
                                     $data['c_id']
                                 );
                             }
diff --git a/public/main/forum/editpost.php b/public/main/forum/editpost.php
index 9ea009819c..08270a4fc4 100644
--- a/public/main/forum/editpost.php
+++ b/public/main/forum/editpost.php
@@ -90,9 +90,11 @@ if (api_is_in_gradebook()) {
         'name' => get_lang('Assessments'),
     ];
 }
+$group_id = api_get_group_id();
+$groupEntity = null;
+if ('group' === $origin && $group_id) {
+    $groupEntity = api_get_group_entity($group_id);
 
-$group_properties = GroupManager::get_group_properties(api_get_group_id());
-if ('group' === $origin) {
     $_clean['toolgroup'] = api_get_group_id();
     $interbreadcrumb[] = [
         'url' => api_get_path(WEB_CODE_PATH).'group/group.php?'.api_get_cidreq(),
@@ -100,7 +102,7 @@ if ('group' === $origin) {
     ];
     $interbreadcrumb[] = [
         'url' => api_get_path(WEB_CODE_PATH).'group/group_space.php?'.api_get_cidreq(),
-        'name' => get_lang('Group area').' '.$group_properties['name'],
+        'name' => get_lang('Group area').' '.$groupEntity->getName(),
     ];
     $interbreadcrumb[] = [
         'url' => api_get_path(WEB_CODE_PATH).'forum/viewforum.php?'.api_get_cidreq().'&forum='.$forumId,
@@ -181,7 +183,7 @@ $group_id = api_get_group_id();
 
 if (!api_is_allowed_to_edit(null, true) &&
     0 == $forum->getAllowEdit() &&
-    !GroupManager::is_tutor_of_group(api_get_user_id(), $group_properties)
+    !GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity)
 ) {
     api_not_allowed(true);
 }
diff --git a/public/main/forum/forumfunction.inc.php b/public/main/forum/forumfunction.inc.php
index cab1fd3bc1..b014481ae8 100644
--- a/public/main/forum/forumfunction.inc.php
+++ b/public/main/forum/forumfunction.inc.php
@@ -12,6 +12,7 @@ use Chamilo\CourseBundle\Entity\CForumNotification;
 use Chamilo\CourseBundle\Entity\CForumPost;
 use Chamilo\CourseBundle\Entity\CForumThread;
 use Chamilo\CoreBundle\Entity\Course;
+use Chamilo\CourseBundle\Entity\CGroup;
 use ChamiloSession as Session;
 use Doctrine\Common\Collections\Criteria;
 use Symfony\Component\HttpFoundation\File\UploadedFile;
@@ -1883,7 +1884,6 @@ function getPosts(
     ;
 
     $groupId = api_get_group_id();
-    $groupInfo = GroupManager::get_group_properties($groupId);
     $filterModerated = true;
 
     if (empty($groupId)) {
@@ -1891,7 +1891,8 @@ function getPosts(
             $filterModerated = false;
         }
     } else {
-        if (GroupManager::is_tutor_of_group(api_get_user_id(), $groupInfo) ||
+        $groupEntity = api_get_group_entity($groupId);
+        if (GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity) ||
             api_is_allowed_to_edit(false, true)
         ) {
             $filterModerated = false;
@@ -3831,13 +3832,11 @@ function displayUserLink(User $user)
 
 function displayUserImage(User $user)
 {
-    $url = Container::getIllustrationRepository()->getIllustrationUrl($user, null, ICON_SIZE_BIG);
+    $url = Container::getIllustrationRepository()->getIllustrationUrl($user, '', ICON_SIZE_BIG);
 
     return '<div class="thumbnail"><img src="'.$url.'?w=100"/></div>';
 }
 
-
-
 /**
  * The thread view counter gets increased every time someone looks at the thread.
  *
@@ -5059,16 +5058,11 @@ function delete_attachment($postId, $attachmentId)
  *
  * @todo this is basically the same code as the get_forums function. Consider merging the two.
  */
-function get_forums_of_group($groupInfo)
+function get_forums_of_group(CGroup $group)
 {
-    $groupId = (int) $groupInfo['id'];
-
-    $group = api_get_group_entity($groupId);
     $course = api_get_course_entity();
     $session = api_get_session_entity();
-
     $repo = Container::getForumRepository();
-
     $qb = $repo->getResourcesByCourse($course, $session, $group);
 
     return $qb->getQuery()->getResult();
diff --git a/public/main/forum/viewforum.php b/public/main/forum/viewforum.php
index 92f23f515c..b10a8fa890 100644
--- a/public/main/forum/viewforum.php
+++ b/public/main/forum/viewforum.php
@@ -22,8 +22,8 @@ $userId = api_get_user_id();
 $sessionId = api_get_session_id();
 $groupId = api_get_group_id();
 $courseId = api_get_course_int_id();
-$groupInfo = GroupManager::get_group_properties($groupId);
-$isTutor = GroupManager::is_tutor_of_group($userId, $groupInfo, $courseId);
+//$groupInfo = GroupManager::get_group_properties($groupId);
+//$isTutor = GroupManager::is_tutor_of_group($userId, $groupInfo, $courseId);
 $isAllowedToEdit = api_is_allowed_to_edit(false, true) && api_is_allowed_to_session_edit(false, true);
 $repo = Container::getForumRepository();
 
@@ -46,11 +46,10 @@ $category = $forumEntity->getForumCategory();
 $is_group_tutor = false;
 
 if (!empty($groupId)) {
-    //Group info & group category info
-    $group_properties = GroupManager::get_group_properties($groupId);
-    $is_group_tutor = GroupManager::is_tutor_of_group(
+    $groupEntity = api_get_group_entity($groupId);
+    $is_group_tutor = GroupManager::isTutorOfGroup(
         api_get_user_id(),
-        $group_properties
+        $groupEntity
     );
 
     // Course
@@ -102,7 +101,7 @@ if (!empty($groupId)) {
     ];
     $interbreadcrumb[] = [
         'url' => api_get_path(WEB_CODE_PATH).'group/group_space.php?'.api_get_cidreq(),
-        'name' => get_lang('Group area').' '.$group_properties['name'],
+        'name' => get_lang('Group area').' '.$groupEntity->getName(),
     ];
     $interbreadcrumb[] = [
         'url' => '#',
diff --git a/public/main/forum/viewthread.php b/public/main/forum/viewthread.php
index da03748dad..9502168afe 100644
--- a/public/main/forum/viewthread.php
+++ b/public/main/forum/viewthread.php
@@ -62,7 +62,11 @@ if (api_is_in_gradebook()) {
 }
 
 $groupId = api_get_group_id();
-$group_properties = GroupManager::get_group_properties($groupId);
+$groupEntity = null;
+if (!empty($groupId)) {
+    $groupEntity = api_get_group_entity($groupId);
+}
+
 $sessionId = api_get_session_id();
 
 $ajaxURL = api_get_path(WEB_AJAX_PATH).'forum.ajax.php?'.api_get_cidreq().'&a=change_post_status';
@@ -109,7 +113,7 @@ switch ($my_action) {
             isset($_GET['content']) &&
             isset($_GET['id']) &&
             (api_is_allowed_to_edit(false, true) ||
-                (isset($group_properties['iid']) && GroupManager::is_tutor_of_group(api_get_user_id(), $group_properties)))
+                ($groupEntity && GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity)))
         ) {
             /** @var CForumPost $postEntity */
             $postEntity = $repoPost->find($_GET['id']);
@@ -123,7 +127,7 @@ switch ($my_action) {
     case 'visible':
         if (isset($_GET['id']) &&
             (api_is_allowed_to_edit(false, true) ||
-                (isset($group_properties['iid']) && GroupManager::is_tutor_of_group(api_get_user_id(), $group_properties)))
+                ($groupEntity && GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity)))
         ) {
             /** @var CForumPost $postEntity */
             $postEntity = $repoPost->find($_GET['id']);
@@ -179,7 +183,7 @@ if (!empty($groupId)) {
     ];
     $interbreadcrumb[] = [
         'url' => api_get_path(WEB_CODE_PATH).'group/group_space.php?'.api_get_cidreq(),
-        'name' => get_lang('Group area').' '.$group_properties['name'],
+        'name' => get_lang('Group area').' '.$groupEntity->getName(),
     ];
     $interbreadcrumb[] = [
         'url' => api_get_path(WEB_CODE_PATH).'forum/viewforum.php?forum='.$forumId.'&'.api_get_cidreq().'&search='.Security::remove_XSS(urlencode($my_search)),
@@ -312,14 +316,18 @@ $group_id = api_get_group_id();
 $locked = api_resource_is_locked_by_gradebook($threadId, LINK_FORUM_THREAD);
 $sessionId = api_get_session_id();
 $userId = api_get_user_id();
-$groupInfo = GroupManager::get_group_properties($group_id);
 $postCount = 1;
 $allowUserImageForum = api_get_course_setting('allow_user_image_forum');
+$tutorGroup = false;
+$groupEntity = null;
+if (!empty($group_id)) {
+    $groupEntity = api_get_group_entity($group_id);
+    // The user who posted it can edit his thread only if the course admin allowed this in the properties
+    // of the forum
+    // The course admin him/herself can do this off course always
+    $tutorGroup = GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity);
+}
 
-// The user who posted it can edit his thread only if the course admin allowed this in the properties
-// of the forum
-// The course admin him/herself can do this off course always
-$tutorGroup = GroupManager::is_tutor_of_group(api_get_user_id(), $groupInfo);
 
 $postList = [];
 foreach ($posts as $post) {
@@ -393,7 +401,7 @@ foreach ($posts as $post) {
     $editButton = '';
     $askForRevision = '';
 
-    if ((isset($groupInfo['iid']) && $tutorGroup) ||
+    if (($groupEntity && $tutorGroup) ||
         (1 == $forumEntity->getAllowEdit() && $posterId == $userId) ||
         (api_is_allowed_to_edit(false, true) &&
         !(api_is_session_general_coach() && $forumEntity->getSessionId() != $sessionId))
@@ -414,7 +422,7 @@ foreach ($posts as $post) {
         }
     }
 
-    if ((isset($groupInfo['iid']) && $tutorGroup) ||
+    if (($groupEntity && $tutorGroup) ||
         api_is_allowed_to_edit(false, true) &&
         !(api_is_session_general_coach() && $forumEntity->getSessionId() != $sessionId)
     ) {
diff --git a/public/main/group/group.php b/public/main/group/group.php
index db3eb707df..3981a379f7 100644
--- a/public/main/group/group.php
+++ b/public/main/group/group.php
@@ -81,8 +81,8 @@ if (isset($_GET['action']) && $is_allowed_in_course) {
 
             break;
         case 'self_reg':
-            if (GroupManager::is_self_registration_allowed($userId, $groupInfo)) {
-                GroupManager::subscribe_users($userId, $groupInfo);
+            if (GroupManager::is_self_registration_allowed($userId, $groupEntity)) {
+                GroupManager::subscribeUsers($userId, $groupEntity);
                 Display::addFlash(Display::return_message(get_lang('You are now a member of this group.')));
                 header("Location: $currentUrl");
                 exit;
@@ -94,8 +94,8 @@ if (isset($_GET['action']) && $is_allowed_in_course) {
 
             break;
         case 'self_unreg':
-            if (GroupManager::is_self_unregistration_allowed($userId, $groupInfo)) {
-                GroupManager::unsubscribe_users($userId, $groupInfo);
+            if (GroupManager::is_self_unregistration_allowed($userId, $groupEntity)) {
+                GroupManager::subscribeUsers($userId, $groupEntity);
                 Display::addFlash(Display::return_message(get_lang('You\'re now unsubscribed.')));
                 header("Location: $currentUrl");
                 exit;
@@ -128,7 +128,7 @@ if (api_is_allowed_to_edit(false, true)) {
             case 'empty_selected':
                 if (is_array($_POST['group'])) {
                     foreach ($_POST['group'] as $myGroupId) {
-                        GroupManager::unsubscribe_all_users($myGroupId);
+                        GroupManager::unsubscribeAllUsers($myGroupId);
                     }
 
                     Display::addFlash(Display::return_message(get_lang('All selected groups are now empty')));
@@ -241,18 +241,24 @@ if ('true' === api_get_setting('allow_group_categories')) {
 
     foreach ($categories as $index => $category) {
         $categoryId = $category['iid'];
-        $group_list = GroupManager::get_group_list($categoryId);
-        $groupToShow = GroupManager::process_groups($group_list, $categoryId);
+        $groupList = GroupManager::get_group_list($categoryId, [],
+             null,
+            null,
+             false,
+            null,
+            true
+        );
+        $groupToShow = GroupManager::processGroups($groupList, $categoryId);
 
         if (empty($groupToShow)) {
             continue;
         }
 
-        if (empty($categoryId) && empty($group_list)) {
+        if (empty($categoryId) && empty($groupList)) {
             continue;
         }
 
-        $label = Display::label(count($group_list).' '.get_lang('Groups'), 'info');
+        $label = Display::label(count($groupList).' '.get_lang('Groups'), 'info');
         $actions = null;
         if (api_is_allowed_to_edit(false, true) && !empty($categoryId) && empty($sessionId)) {
             // Edit
@@ -292,7 +298,17 @@ if ('true' === api_get_setting('allow_group_categories')) {
         echo $groupToShow;
     }
 } else {
-    echo GroupManager::process_groups(GroupManager::get_group_list());
+    echo GroupManager::processGroups(
+        GroupManager::get_group_list(
+            null,
+            null,
+            null,
+            null,
+            false,
+            null,
+            true
+        )
+    );
 }
 
 if (!isset($_GET['origin']) || 'learnpath' !== $_GET['origin']) {
diff --git a/public/main/group/group_space.php b/public/main/group/group_space.php
index a4bbd5aec3..dce65440d2 100644
--- a/public/main/group/group_space.php
+++ b/public/main/group/group_space.php
@@ -21,9 +21,13 @@ require_once api_get_path(SYS_CODE_PATH).'forum/forumfunction.inc.php';
 
 $group_id = api_get_group_id();
 $user_id = api_get_user_id();
-$current_group = GroupManager::get_group_properties($group_id);
-$group_id = $current_group['iid'];
-if (empty($current_group)) {
+$groupEntity = null;
+if (!empty($group_id)) {
+    $groupEntity = api_get_group_entity($group_id);
+}
+
+$group_id = $groupEntity->getIid();
+if (empty($groupEntity)) {
     api_not_allowed(true);
 }
 
@@ -35,8 +39,8 @@ $interbreadcrumb[] = [
 ];
 
 /*	Ensure all private groups // Juan Carlos Raña Trabado */
-$forums = get_forums_of_group($current_group);
-if (!GroupManager::userHasAccessToBrowse($user_id, $current_group, api_get_session_id())) {
+$forums = get_forums_of_group($groupEntity);
+if (!GroupManager::userHasAccessToBrowse($user_id, $groupEntity, api_get_session_id())) {
     api_not_allowed(true);
 }
 
@@ -44,9 +48,9 @@ if (!GroupManager::userHasAccessToBrowse($user_id, $current_group, api_get_sessi
  * User wants to register in this group
  */
 if (!empty($_GET['selfReg']) &&
-    GroupManager::is_self_registration_allowed($user_id, $current_group)
+    GroupManager::is_self_registration_allowed($user_id, $groupEntity)
 ) {
-    GroupManager::subscribe_users($user_id, $current_group);
+    GroupManager::subscribeUsers($user_id, $groupEntity);
     Display::addFlash(Display::return_message(get_lang('You are now a member of this group.')));
 }
 
@@ -54,16 +58,16 @@ if (!empty($_GET['selfReg']) &&
  * User wants to unregister from this group
  */
 if (!empty($_GET['selfUnReg']) &&
-    GroupManager::is_self_unregistration_allowed($user_id, $current_group)
+    GroupManager::is_self_unregistration_allowed($user_id, $groupEntity)
 ) {
-    GroupManager::unsubscribe_users($user_id, $current_group);
+    GroupManager::unsubscribeUsers($user_id, $groupEntity);
     Display::addFlash(
         Display::return_message(get_lang('You\'re now unsubscribed.'), 'normal')
     );
 }
 
 Display::display_header(
-    $nameTools.' '.Security::remove_XSS($current_group['name']),
+    $nameTools.' '.Security::remove_XSS($groupEntity->getName()),
     'Group'
 );
 
@@ -84,10 +88,10 @@ $confirmationMessage = addslashes(api_htmlentities(get_lang('Please confirm your
 
 // Register to group.
 $subscribe_group = '';
-if (GroupManager::is_self_registration_allowed($user_id, $current_group)) {
+if (GroupManager::is_self_registration_allowed($user_id, $groupEntity)) {
     $subscribe_group = '<a
             class="btn btn-default"
-            href="'.api_get_self().'?selfReg=1&group_id='.$current_group['id'].'"
+            href="'.api_get_self().'?selfReg=1&group_id='.$group_id.'"
             onclick="javascript: if(!confirm('."'".$confirmationMessage."'".')) return false;">'.
         get_lang('Add me to this group').
     '</a>';
@@ -95,7 +99,7 @@ if (GroupManager::is_self_registration_allowed($user_id, $current_group)) {
 
 // Unregister from group.
 $unsubscribe_group = '';
-if (GroupManager :: is_self_unregistration_allowed($user_id, $current_group)) {
+if (GroupManager::is_self_unregistration_allowed($user_id, $groupEntity)) {
     $unsubscribe_group = '<a
         class="btn btn-default" href="'.api_get_self().'?selfUnReg=1"
         onclick="javascript: if(!confirm('."'".$confirmationMessage."'".')) return false;">'.
@@ -105,7 +109,7 @@ echo '&nbsp;</div>';
 
 $edit_url = '';
 if (api_is_allowed_to_edit(false, true) ||
-    GroupManager::is_tutor_of_group($user_id, $current_group)
+    GroupManager::isTutorOfGroup($user_id, $groupEntity)
 ) {
     $edit_url = '<a
         href="'.api_get_path(WEB_CODE_PATH).'group/settings.php?'.api_get_cidreq().'">'.
@@ -114,20 +118,19 @@ if (api_is_allowed_to_edit(false, true) ||
 }
 
 echo Display::page_header(
-    Security::remove_XSS($current_group['name']).' '.$edit_url.' '.$subscribe_group.' '.$unsubscribe_group
+    Security::remove_XSS($groupEntity->getName()).' '.$edit_url.' '.$subscribe_group.' '.$unsubscribe_group
 );
 
-if (!empty($current_group['description'])) {
-    echo '<p>'.Security::remove_XSS($current_group['description']).'</p>';
+if (!empty($groupEntity->getDescription())) {
+    echo '<p>'.Security::remove_XSS($groupEntity->getDescription()).'</p>';
 }
 
-//if (GroupManager::userHasAccessToBrowse($user_id, $this_group, $session_id)) {
 if (api_is_allowed_to_edit(false, true) ||
-    GroupManager::userHasAccessToBrowse($user_id, $current_group, api_get_session_id())
+    GroupManager::userHasAccessToBrowse($user_id, $groupEntity, api_get_session_id())
 ) {
     $actions_array = [];
     if (is_array($forums)) {
-        if (GroupManager::TOOL_NOT_AVAILABLE != $current_group['forum_state']) {
+        if (GroupManager::TOOL_NOT_AVAILABLE != $groupEntity->getForumState()) {
             foreach ($forums as $forum) {
                 if ('public' === $forum->getForumGroupPublicPrivate() ||
                     ('private' === $forum->getForumGroupPublicPrivate()) ||
@@ -149,7 +152,7 @@ if (api_is_allowed_to_edit(false, true) ||
         }
     }
 
-    if (GroupManager::TOOL_NOT_AVAILABLE != $current_group['doc_state']) {
+    if (GroupManager::TOOL_NOT_AVAILABLE != $groupEntity->getDocState()) {
         // Link to the documents area of this group
         $actions_array[] = [
             'url' => api_get_path(WEB_CODE_PATH).'document/document.php?'.api_get_cidreq(),
@@ -157,7 +160,7 @@ if (api_is_allowed_to_edit(false, true) ||
         ];
     }
 
-    if (GroupManager::TOOL_NOT_AVAILABLE != $current_group['calendar_state']) {
+    if (GroupManager::TOOL_NOT_AVAILABLE != $groupEntity->getCalendarState()) {
         $groupFilter = '';
         if (!empty($group_id)) {
             $groupFilter = "&type=course&user_id=GROUP:$group_id";
@@ -169,14 +172,14 @@ if (api_is_allowed_to_edit(false, true) ||
         ];
     }
 
-    if (GroupManager::TOOL_NOT_AVAILABLE != $current_group['work_state']) {
+    if (GroupManager::TOOL_NOT_AVAILABLE != $groupEntity->getWorkState()) {
         // Link to the works area of this group
         $actions_array[] = [
             'url' => api_get_path(WEB_CODE_PATH).'work/work.php?'.api_get_cidreq(),
             'content' => Display::return_icon('work.png', get_lang('Assignments'), [], 32),
         ];
     }
-    if (GroupManager::TOOL_NOT_AVAILABLE != $current_group['announcements_state']) {
+    if (GroupManager::TOOL_NOT_AVAILABLE != $groupEntity->getAnnouncementsState()) {
         // Link to a group-specific part of announcements
         $actions_array[] = [
             'url' => api_get_path(WEB_CODE_PATH).'announcements/announcements.php?'.api_get_cidreq(),
@@ -184,28 +187,28 @@ if (api_is_allowed_to_edit(false, true) ||
         ];
     }
 
-    if (GroupManager::TOOL_NOT_AVAILABLE != $current_group['wiki_state']) {
+    if (GroupManager::TOOL_NOT_AVAILABLE != $groupEntity->getWikiState()) {
         // Link to the wiki area of this group
         $actions_array[] = [
             'url' => api_get_path(WEB_CODE_PATH).
-                'wiki/index.php?'.api_get_cidreq().'&action=show&title=index&sid='.api_get_session_id().'&group_id='.$current_group['id'],
+                'wiki/index.php?'.api_get_cidreq().'&action=show&title=index&sid='.api_get_session_id().'&group_id='.$groupEntity->getIid(),
             'content' => Display::return_icon('wiki.png', get_lang('Wiki'), [], 32),
         ];
     }
 
-    if (GroupManager::TOOL_NOT_AVAILABLE != $current_group['chat_state']) {
+    if (GroupManager::TOOL_NOT_AVAILABLE != $groupEntity->getChatState()) {
         // Link to the chat area of this group
         if (api_get_course_setting('allow_open_chat_window')) {
             $actions_array[] = [
                 'url' => 'javascript: void(0);',
                 'content' => Display::return_icon('chat.png', get_lang('Chat'), [], 32),
                 'url_attributes' => [
-                    'onclick' => " window.open('../chat/chat.php?".api_get_cidreq().'&toolgroup='.$current_group['id']."','window_chat_group_".api_get_course_id().'_'.api_get_group_id()."','height=380, width=625, left=2, top=2, toolbar=no, menubar=no, scrollbars=yes, resizable=yes, location=no, directories=no, status=no')",
+                    'onclick' => " window.open('../chat/chat.php?".api_get_cidreq().'&toolgroup='.$groupEntity->getIid()."','window_chat_group_".api_get_course_id().'_'.api_get_group_id()."','height=380, width=625, left=2, top=2, toolbar=no, menubar=no, scrollbars=yes, resizable=yes, location=no, directories=no, status=no')",
                 ],
             ];
         } else {
             $actions_array[] = [
-                'url' => api_get_path(WEB_CODE_PATH).'chat/chat.php?'.api_get_cidreq().'&gid='.$current_group['id'],
+                'url' => api_get_path(WEB_CODE_PATH).'chat/chat.php?'.api_get_cidreq().'&gid='.$groupEntity->getIid(),
                 'content' => Display::return_icon('chat.png', get_lang('Chat'), [], 32),
             ];
         }
@@ -236,12 +239,13 @@ if (api_is_allowed_to_edit(false, true) ||
 } else {
     $actions_array = [];
     if (is_array($forums)) {
-        if (GroupManager::TOOL_PUBLIC == $current_group['forum_state']) {
+        if (GroupManager::TOOL_PUBLIC == $groupEntity->getForumState()) {
             foreach ($forums as $forum) {
                 if ('public' === $forum->getForumGroupPublicPrivate()) {
                     $actions_array[] = [
                         'url' => api_get_path(WEB_CODE_PATH).
-                            'forum/viewforum.php?cid='.api_get_course_int_id().'&forum='.$forum->getIid().'&gid='.$current_group['id'].'&origin=group',
+                            'forum/viewforum.php?cid='.api_get_course_int_id().
+                            '&forum='.$forum->getIid().'&gid='.$groupEntity->getIid().'&origin=group',
                         'content' => Display::return_icon(
                             'forum.png',
                             get_lang('Group Forum'),
@@ -254,7 +258,7 @@ if (api_is_allowed_to_edit(false, true) ||
         }
     }
 
-    if (GroupManager::TOOL_PUBLIC == $current_group['doc_state']) {
+    if (GroupManager::TOOL_PUBLIC == $groupEntity->getDocState()) {
         // Link to the documents area of this group
         $actions_array[] = [
             'url' => api_get_path(WEB_CODE_PATH).'document/document.php?'.api_get_cidreq(),
@@ -262,7 +266,7 @@ if (api_is_allowed_to_edit(false, true) ||
         ];
     }
 
-    if (GroupManager::TOOL_PUBLIC == $current_group['calendar_state']) {
+    if (GroupManager::TOOL_PUBLIC == $groupEntity->getCalendarState()) {
         $groupFilter = '';
         if (!empty($group_id)) {
             $groupFilter = "&type=course&user_id=GROUP:$group_id";
@@ -274,7 +278,7 @@ if (api_is_allowed_to_edit(false, true) ||
         ];
     }
 
-    if (GroupManager::TOOL_PUBLIC == $current_group['work_state']) {
+    if (GroupManager::TOOL_PUBLIC == $groupEntity->getWorkState()) {
         // Link to the works area of this group
         $actions_array[] = [
             'url' => api_get_path(WEB_CODE_PATH).'work/work.php?'.api_get_cidreq(),
@@ -282,7 +286,7 @@ if (api_is_allowed_to_edit(false, true) ||
         ];
     }
 
-    if (GroupManager::TOOL_PUBLIC == $current_group['announcements_state']) {
+    if (GroupManager::TOOL_PUBLIC == $groupEntity->getAnnouncementsState()) {
         // Link to a group-specific part of announcements
         $actions_array[] = [
             'url' => api_get_path(WEB_CODE_PATH).'announcements/announcements.php?'.api_get_cidreq(),
@@ -290,24 +294,25 @@ if (api_is_allowed_to_edit(false, true) ||
         ];
     }
 
-    if (GroupManager::TOOL_PUBLIC == $current_group['wiki_state']) {
+    if (GroupManager::TOOL_PUBLIC == $groupEntity->getWikiState()) {
         // Link to the wiki area of this group
         $actions_array[] = [
-            'url' => api_get_path(WEB_CODE_PATH).'wiki/index.php?'.api_get_cidreq().'&action=show&title=index&sid='.api_get_session_id().'&gid='.$current_group['id'],
+            'url' => api_get_path(WEB_CODE_PATH).'wiki/index.php?'.
+                api_get_cidreq().'&action=show&title=index&sid='.api_get_session_id().'&gid='.$group_id,
             'content' => Display::return_icon('wiki.png', get_lang('Wiki'), [], 32),
         ];
     }
 
-    if (GroupManager::TOOL_PUBLIC == $current_group['chat_state']) {
+    if (GroupManager::TOOL_PUBLIC == $groupEntity->getChatState()) {
         // Link to the chat area of this group
         if (api_get_course_setting('allow_open_chat_window')) {
             $actions_array[] = [
-                'url' => "javascript: void(0);\" onclick=\"window.open('../chat/chat.php?".api_get_cidreq().'&toolgroup='.$current_group['id']."','window_chat_group_".api_get_course_id().'_'.api_get_group_id()."','height=380, width=625, left=2, top=2, toolbar=no, menubar=no, scrollbars=yes, resizable=yes, location=no, directories=no, status=no') \"",
+                'url' => "javascript: void(0);\" onclick=\"window.open('../chat/chat.php?".api_get_cidreq().'&toolgroup='.$group_id."','window_chat_group_".api_get_course_id().'_'.api_get_group_id()."','height=380, width=625, left=2, top=2, toolbar=no, menubar=no, scrollbars=yes, resizable=yes, location=no, directories=no, status=no') \"",
                 'content' => Display::return_icon('chat.png', get_lang('Chat'), [], 32),
             ];
         } else {
             $actions_array[] = [
-                'url' => api_get_path(WEB_CODE_PATH).'chat/chat.php?'.api_get_cidreq().'&toolgroup='.$current_group['id'],
+                'url' => api_get_path(WEB_CODE_PATH).'chat/chat.php?'.api_get_cidreq().'&toolgroup='.$group_id,
                 'content' => Display::return_icon('chat.png', get_lang('Chat'), [], 32),
             ];
         }
@@ -321,16 +326,15 @@ if (api_is_allowed_to_edit(false, true) ||
 /*
  * List all the tutors of the current group
  */
-$tutors = GroupManager::get_subscribed_tutors($current_group);
+$tutors = $groupEntity->getTutors();
 $userRepo = Container::getUserRepository();
 $tutor_info = '';
 if (0 == count($tutors)) {
     $tutor_info = get_lang('(none)');
 } else {
     $tutor_info .= '<ul class="thumbnails">';
-    foreach ($tutors as $index => $tutor) {
-        /** @var User $user */
-        $user = $userRepo->find($tutor['user_id']);
+    foreach ($tutors as $tutor) {
+        $user = $tutor->getUser();
         $username = api_htmlentities(sprintf(get_lang('Login: %s'), $user->getUsername()), ENT_QUOTES);
         $completeName = UserManager::formatUserFullName($user);
         $avatar = Container::getIllustrationRepository()->getIllustrationUrl($user);
diff --git a/public/main/group/member_settings.php b/public/main/group/member_settings.php
index 170f5e9805..049a985087 100644
--- a/public/main/group/member_settings.php
+++ b/public/main/group/member_settings.php
@@ -2,15 +2,8 @@
 
 /* For licensing terms, see /license.txt */
 
-/**
- * This script displays an area where teachers can edit the group properties and member list.
- * Groups are also often called "teams" in the Dokeos code.
- *
- * @author various contributors
- * @author Roan Embrechts (VUB), partial code cleanup, initial virtual course support
- *
- * @todo course admin functionality to create groups based on who is in which course (or class).
- */
+use Chamilo\CoreBundle\Framework\Container;
+
 require_once __DIR__.'/../inc/global.inc.php';
 $this_section = SECTION_COURSES;
 $current_course_tool = TOOL_GROUP;
@@ -20,12 +13,13 @@ api_protect_course_script(true);
 
 $group_id = api_get_group_id();
 $current_group = GroupManager::get_group_properties($group_id);
+$groupEntity = api_get_group_entity($group_id);
 
 $nameTools = get_lang('Edit this group');
 $interbreadcrumb[] = ['url' => 'group.php', 'name' => get_lang('Groups')];
-$interbreadcrumb[] = ['url' => 'group_space.php?'.api_get_cidreq(), 'name' => $current_group['name']];
+$interbreadcrumb[] = ['url' => 'group_space.php?'.api_get_cidreq(), 'name' => $groupEntity->getName()];
 
-$is_group_member = GroupManager::is_tutor_of_group(api_get_user_id(), $current_group);
+$is_group_member = GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity);
 
 if (!api_is_allowed_to_edit(false, true) && !$is_group_member) {
     api_not_allowed(true);
@@ -112,7 +106,7 @@ $form = new FormValidator(
     api_get_self().'?'.api_get_cidreq()
 );
 $form->addElement('hidden', 'action');
-$form->addElement('hidden', 'max_student', $current_group['max_student']);
+$form->addElement('hidden', 'max_student', $groupEntity->getMaxStudent());
 
 $complete_user_list = CourseManager::get_user_list_from_course_code(
     api_get_course_id(),
@@ -182,11 +176,11 @@ if ($form->validate()) {
     $values = $form->exportValues();
 
     // Storing the users (we first remove all users and then add only those who were selected)
-    GroupManager::unsubscribe_all_users($current_group);
+    GroupManager::unsubscribeAllUsers($groupEntity->getIid());
     if (isset($_POST['group_members']) && count($_POST['group_members']) > 0) {
-        GroupManager::subscribe_users(
+        GroupManager::subscribeUsers(
             $values['group_members'],
-            $current_group
+            $groupEntity
         );
     }
 
@@ -215,7 +209,7 @@ $action = isset($_GET['action']) ? $_GET['action'] : null;
 switch ($action) {
     case 'empty':
         if (api_is_allowed_to_edit(false, true)) {
-            GroupManager:: unsubscribe_all_users($current_group);
+            GroupManager::unsubscribeAllUsers($group_id);
             echo Display::return_message(get_lang('The group is now empty'), 'confirm');
         }
 
diff --git a/public/main/group/settings.php b/public/main/group/settings.php
index 077bf24fa0..c9fb1e92b8 100644
--- a/public/main/group/settings.php
+++ b/public/main/group/settings.php
@@ -18,15 +18,18 @@ api_protect_course_script(true);
 
 $group_id = api_get_group_id();
 $current_group = GroupManager::get_group_properties($group_id);
+$groupRepo = \Chamilo\CoreBundle\Framework\Container::getGroupRepository();
+/** @var \Chamilo\CourseBundle\Entity\CGroup $groupEntity */
+$groupEntity = $groupRepo->find($group_id);
 
-if (empty($current_group)) {
+if (empty($groupEntity)) {
     api_not_allowed(true);
 }
 
 $nameTools = get_lang('Edit this group');
 $interbreadcrumb[] = ['url' => 'group.php?'.api_get_cidreq(), 'name' => get_lang('Groups')];
-$interbreadcrumb[] = ['url' => 'group_space.php?'.api_get_cidreq(), 'name' => $current_group['name']];
-$groupMember = GroupManager::is_tutor_of_group(api_get_user_id(), $current_group);
+$interbreadcrumb[] = ['url' => 'group_space.php?'.api_get_cidreq(), 'name' => $groupEntity->getName()];
+$groupMember = GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity);
 
 if (!$groupMember && !api_is_allowed_to_edit(false, true)) {
     api_not_allowed(true);
diff --git a/public/main/group/tutor_settings.php b/public/main/group/tutor_settings.php
index 9616d147cd..1296f60e43 100644
--- a/public/main/group/tutor_settings.php
+++ b/public/main/group/tutor_settings.php
@@ -2,15 +2,6 @@
 
 /* For licensing terms, see /license.txt */
 
-/**
- * This script displays an area where teachers can edit the group properties and member list.
- * Groups are also often called "teams" in the Dokeos code.
- *
- * @author various contributors
- * @author Roan Embrechts (VUB), partial code cleanup, initial virtual course support
- *
- * @todo course admin functionality to create groups based on who is in which course (or class).
- */
 require_once __DIR__.'/../inc/global.inc.php';
 $this_section = SECTION_COURSES;
 $current_course_tool = TOOL_GROUP;
@@ -19,13 +10,16 @@ $current_course_tool = TOOL_GROUP;
 api_protect_course_script(true);
 
 $group_id = api_get_group_id();
+$groupRepo = \Chamilo\CoreBundle\Framework\Container::getGroupRepository();
+/** @var \Chamilo\CourseBundle\Entity\CGroup $groupEntity */
+$groupEntity = $groupRepo->find($group_id);
 $current_group = GroupManager::get_group_properties($group_id);
 
 $nameTools = get_lang('Edit this group');
 $interbreadcrumb[] = ['url' => 'group.php?'.api_get_cidreq(), 'name' => get_lang('Groups')];
-$interbreadcrumb[] = ['url' => 'group_space.php?'.api_get_cidreq(), 'name' => $current_group['name']];
+$interbreadcrumb[] = ['url' => 'group_space.php?'.api_get_cidreq(), 'name' => $groupEntity->getName()];
 
-$is_group_member = GroupManager::is_tutor_of_group(api_get_user_id(), $current_group);
+$is_group_member = GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity);
 
 if (!api_is_allowed_to_edit(false, true) && !$is_group_member) {
     api_not_allowed(true);
@@ -92,11 +86,11 @@ $form = new FormValidator('group_edit', 'post', api_get_self().'?'.api_get_cidre
 $form->addElement('hidden', 'action');
 
 // Group tutors
-$group_tutor_list = GroupManager::get_subscribed_tutors($current_group);
+$group_tutor_list = $groupEntity->getTutors();
 
 $selected_tutors = [];
-foreach ($group_tutor_list as $index => $user) {
-    $selected_tutors[] = $user['user_id'];
+foreach ($group_tutor_list as $user) {
+    $selected_tutors[] = $user->getUser()->getId();
 }
 
 $complete_user_list = CourseManager::get_user_list_from_course_code(
@@ -164,9 +158,9 @@ if ($form->validate()) {
     $values = $form->exportValues();
 
     // Storing the tutors (we first remove all the tutors and then add only those who were selected)
-    GroupManager :: unsubscribe_all_tutors($current_group['iid']);
+    GroupManager::unsubscribe_all_tutors($current_group['iid']);
     if (isset($_POST['group_tutors']) && count($_POST['group_tutors']) > 0) {
-        GroupManager::subscribe_tutors($values['group_tutors'], $current_group);
+        GroupManager::subscribeTutors($values['group_tutors'], $groupEntity);
     }
 
     // Returning to the group area (note: this is inconsistent with the rest of chamilo)
diff --git a/public/main/inc/ajax/announcement.ajax.php b/public/main/inc/ajax/announcement.ajax.php
index b16967d7c1..ae9c28cdfa 100644
--- a/public/main/inc/ajax/announcement.ajax.php
+++ b/public/main/inc/ajax/announcement.ajax.php
@@ -1,4 +1,5 @@
 <?php
+
 /* For licensing terms, see /license.txt */
 
 use Chamilo\CoreBundle\Framework\Container;
@@ -16,7 +17,10 @@ $sessionId = api_get_session_id();
 $isTutor = false;
 if (!empty($groupId)) {
     $groupInfo = GroupManager::get_group_properties($groupId);
-    $isTutor = GroupManager::is_tutor_of_group(api_get_user_id(), $groupInfo);
+    $groupRepo = \Chamilo\CoreBundle\Framework\Container::getGroupRepository();
+    /** @var \Chamilo\CourseBundle\Entity\CGroup $groupEntity */
+    $groupEntity = $groupRepo->find($groupId);
+    $isTutor = GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity);
     if ($isTutor) {
         $isAllowedToEdit = true;
     }
@@ -35,15 +39,17 @@ switch ($action) {
         }
 
         if (false === $allowToEdit && !empty($groupId)) {
-            $groupProperties = GroupManager::get_group_properties($groupId);
+            $groupRepo = \Chamilo\CoreBundle\Framework\Container::getGroupRepository();
+            /** @var \Chamilo\CourseBundle\Entity\CGroup $groupEntity */
+            $groupEntity = $groupRepo->find($groupId);
             // Check if user is tutor group
-            $isTutor = GroupManager::is_tutor_of_group(api_get_user_id(), $groupProperties, $courseId);
+            $isTutor = GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity);
             if ($isTutor) {
                 $allowToEdit = true;
             }
 
             // Last chance ... students can send announcements.
-            if (GroupManager::TOOL_PRIVATE_BETWEEN_USERS == $groupProperties['announcements_state']) {
+            if (GroupManager::TOOL_PRIVATE_BETWEEN_USERS == $groupEntity->getAnnouncementsState()) {
                 $allowToEdit = true;
             }
         }
diff --git a/public/main/inc/ajax/document.ajax.php b/public/main/inc/ajax/document.ajax.php
index 8208c46dfc..e262527c0e 100644
--- a/public/main/inc/ajax/document.ajax.php
+++ b/public/main/inc/ajax/document.ajax.php
@@ -49,10 +49,10 @@ switch ($action) {
 
         // This needs cleaning!
         if (api_get_group_id()) {
-            $groupInfo = GroupManager::get_group_properties(api_get_group_id());
+            $group = api_get_group_entity(api_get_group_id());
             // Only course admin or group members allowed
-            if ($is_allowed_to_edit || GroupManager::is_user_in_group(api_get_user_id(), $groupInfo)) {
-                if (!GroupManager::allowUploadEditDocument(api_get_user_id(), api_get_course_int_id(), $groupInfo)) {
+            if ($is_allowed_to_edit || GroupManager::isUserInGroup(api_get_user_id(), $group)) {
+                if (!GroupManager::allowUploadEditDocument(api_get_user_id(), api_get_course_int_id(), $group)) {
                     exit;
                 }
             } else {
diff --git a/public/main/inc/ajax/forum.ajax.php b/public/main/inc/ajax/forum.ajax.php
index 74b2c927f6..a326f0b9f2 100644
--- a/public/main/inc/ajax/forum.ajax.php
+++ b/public/main/inc/ajax/forum.ajax.php
@@ -133,10 +133,10 @@ if (!empty($action)) {
                     break;
                 }
                 $group_id = api_get_group_id();
-                $groupInfo = GroupManager::get_group_properties($group_id);
+                $groupEntity = api_get_group_entity();
                 if (!api_is_allowed_to_edit(null, true) &&
                     0 == $current_forum['allow_edit'] &&
-                    ($group_id && !GroupManager::is_tutor_of_group(api_get_user_id(), $groupInfo))
+                    ($group_id && !GroupManager::isTutorOfGroup(api_get_user_id(), $groupEntity))
                 ) {
                     $json['errorMessage'] = '4. if editing of replies is not allowed';
                     break;
diff --git a/public/main/inc/lib/AnnouncementManager.php b/public/main/inc/lib/AnnouncementManager.php
index f9c7267b11..8a972fbf1f 100644
--- a/public/main/inc/lib/AnnouncementManager.php
+++ b/public/main/inc/lib/AnnouncementManager.php
@@ -1691,7 +1691,7 @@ class AnnouncementManager
             ICON_SIZE_SMALL
         );
 
-        $isTutor = false;
+        /*$isTutor = false;
         if (!empty($group_id)) {
             $groupInfo = GroupManager::get_group_properties(api_get_group_id());
             //User has access in the group?
@@ -1699,7 +1699,7 @@ class AnnouncementManager
                 api_get_user_id(),
                 $groupInfo
             );
-        }
+        }*/
 
         $results = [];
         /** @var CAnnouncement $announcement */
diff --git a/public/main/inc/lib/agenda.lib.php b/public/main/inc/lib/agenda.lib.php
index 4655420104..1c287d6f52 100644
--- a/public/main/inc/lib/agenda.lib.php
+++ b/public/main/inc/lib/agenda.lib.php
@@ -79,17 +79,16 @@ class Agenda
                     $isAllowToEdit = true;
                 }
 
-                $groupId = api_get_group_id();
-                if (!empty($groupId)) {
-                    $groupInfo = GroupManager::get_group_properties($groupId);
+                $group = api_get_group_entity();
+                if (!empty($group)) {
                     $userHasAccess = GroupManager::user_has_access(
                         api_get_user_id(),
-                        $groupInfo['iid'],
+                        $group->getIid(),
                         GroupManager::GROUP_TOOL_CALENDAR
                     );
-                    $isTutor = GroupManager::is_tutor_of_group(
+                    $isTutor = GroupManager::isTutorOfGroup(
                         api_get_user_id(),
-                        $groupInfo
+                        $group
                     );
 
                     $isGroupAccess = $userHasAccess || $isTutor;
@@ -2545,9 +2544,8 @@ class Agenda
      */
     public function displayActions($view, $filter = 0)
     {
-        $groupInfo = GroupManager::get_group_properties(api_get_group_id());
-        $groupIid = isset($groupInfo['iid']) ? $groupInfo['iid'] : 0;
-
+        $group = api_get_group_entity();
+        $groupIid = null === $group ? 0 : $group->getIid();
         $codePath = api_get_path(WEB_CODE_PATH);
 
         $currentUserId = api_get_user_id();
@@ -2569,7 +2567,7 @@ class Agenda
             api_is_allowed_to_session_edit(false, true)
             || (
                 GroupManager::user_has_access($currentUserId, $groupIid, GroupManager::GROUP_TOOL_CALENDAR)
-                && GroupManager::is_tutor_of_group($currentUserId, $groupInfo)
+                && GroupManager::isTutorOfGroup($currentUserId, $group)
             )
         ) {
             $actionsLeft .= Display::url(
@@ -2603,7 +2601,7 @@ class Agenda
             }
         }
 
-        if ('personal' == $this->type && !api_is_anonymous()) {
+        if ('personal' === $this->type && !api_is_anonymous()) {
             $actionsLeft .= Display::url(
                 Display::return_icon('1day.png', get_lang('Sessions plan calendar'), [], ICON_SIZE_MEDIUM),
                 $codePath."calendar/planification.php"
@@ -2624,7 +2622,7 @@ class Agenda
             api_is_session_admin() ||
             api_is_coach()
         ) {
-            if ('personal' == $this->type) {
+            if ('personal' === $this->type) {
                 $form = null;
                 if (!isset($_GET['action'])) {
                     $form = new FormValidator(
diff --git a/public/main/inc/lib/document.lib.php b/public/main/inc/lib/document.lib.php
index 2be3978c05..690f7e1e69 100644
--- a/public/main/inc/lib/document.lib.php
+++ b/public/main/inc/lib/document.lib.php
@@ -6347,7 +6347,7 @@ This folder contains all sessions that have been opened in the chat. Although th
         }
 
         $courseId = $courseInfo['real_id'];
-        $group_properties = GroupManager::get_group_properties($groupId);
+        $group = api_get_group_entity($groupId);
 
         $sortable_data = [];
         foreach ($documentAndFolders as $key => $document_data) {
@@ -6462,7 +6462,7 @@ This folder contains all sessions that have been opened in the chat. Although th
             $groupMemberWithEditRightsCheckDocument = GroupManager::allowUploadEditDocument(
                 $userId,
                 $courseId,
-                $group_properties,
+                $group,
                 $document_data
             );
 
diff --git a/public/main/inc/lib/groupmanager.lib.php b/public/main/inc/lib/groupmanager.lib.php
index 40e1ba1194..82e3ef9b7b 100644
--- a/public/main/inc/lib/groupmanager.lib.php
+++ b/public/main/inc/lib/groupmanager.lib.php
@@ -109,7 +109,8 @@ class GroupManager
         $status = null,
         $sessionId = 0,
         $getCount = false,
-        $filterByKeyword = ''
+        $filterByKeyword = '',
+        $returnEntityList = false
     ) {
         $course_info = empty($course_info) ? api_get_course_info() : $course_info;
 
@@ -147,6 +148,10 @@ class GroupManager
             return $qb->getQuery()->getSingleScalarResult();
         }
 
+        if ($returnEntityList) {
+            return $qb->getQuery()->getResult();
+        }
+
         return $qb->getQuery()->getArrayResult();
 
         $table_group = Database::get_course_table(TABLE_GROUP);
@@ -409,10 +414,9 @@ class GroupManager
         $members = [];
         foreach ($users as $index => $user_id) {
             $groupId = $group_ids[$index % $number_of_groups];
-            $groupInfo = self::get_group_properties($groupId);
-            self::subscribe_users(
+            self::subscribeUsers(
                 $user_id,
-                $groupInfo
+                api_get_group_entity($groupId)
             );
             $members[$group_ids[$groupId]]++;
         }
@@ -448,8 +452,7 @@ class GroupManager
             );
 
             if ($groupId) {
-                $groupInfo = self::get_group_properties($groupId);
-                self::subscribe_users($userList, $groupInfo);
+                self::subscribeUsers($userList, api_get_group_entity($groupId));
                 $group_ids[] = $groupId;
             }
         }
@@ -482,60 +485,20 @@ class GroupManager
         $groupIid = $group->getIid();
 
         // Unsubscribe all users
-        self::unsubscribe_all_users($groupIid);
+        self::unsubscribeAllUsers($groupIid);
         self::unsubscribe_all_tutors($groupIid);
 
-        if (!empty($groupInfo['secret_directory'])) {
-            /*
-            $directory = $groupInfo['secret_directory'];
-            // move group-documents to garbage
-            $source_directory = api_get_path(SYS_COURSE_PATH).$course_info['path']."/document".$directory;
-            // File to renamed
-            $destination_dir = api_get_path(SYS_COURSE_PATH).$course_info['path']."/document".$directory.'_DELETED_'.$groupInfo['id'];
-            //Deleting from document tool
-            DocumentManager::delete_document(
-                $course_info,
-                $directory,
-                $source_directory
-            );
-
-            if (file_exists($source_directory)) {
-                if ('true' === api_get_setting('permanently_remove_deleted_files')) {
-                    // Delete
-                    my_delete($source_directory);
-                } else {
-                    // Rename
-                    rename($source_directory, $destination_dir);
-                }
-            }*/
-        }
-
         $em
             ->createQuery(
                 'DELETE FROM ChamiloCourseBundle:CForumForum f WHERE f.forumOfGroup = :group'
             )
             ->execute(['group' => $groupIid]);
 
-        // Delete item properties of this group.
-        // to_group_id is related to c_group_info.iid
-        /*$em
-            ->createQuery(
-                'DELETE FROM ChamiloCourseBundle:CItemProperty ci WHERE ci.course = :course AND ci.group = :group'
-            )
-            ->execute(['course' => $course_id, 'group' => $groupId]);
-        */
         // delete the groups
         $repo = Container::getGroupRepository();
         $em->remove($group);
         $em->flush();
 
-        /*$em
-            ->createQuery(
-                'DELETE FROM ChamiloCourseBundle:CGroup g WHERE g.course = :course AND g.iid = :id'
-            )
-            ->execute(['course' => $course_id, 'id' => $groupIid]);*/
-
-
         return true;
     }
 
@@ -627,10 +590,11 @@ class GroupManager
             $result['count_users'] = count(
                 self::get_subscribed_users($result)
             );
-            $result['count_tutor'] = count(
+            /*$result['count_tutor'] = count(
                 self::get_subscribed_tutors($result)
-            );
-            $result['count_all'] = $result['count_users'] + $result['count_tutor'];
+            );*/
+            //$result['count_all'] = $result['count_users'] + $result['count_tutor'];
+            $result['count_all'] = null;
             $result['document_access'] = isset($db_object->document_access) ? $db_object->document_access : self::DOCUMENT_MODE_SHARE;
         }
 
@@ -1382,6 +1346,7 @@ class GroupManager
         $activeCondition = $filterOnlyActive ? 'AND u.active = 1' : '';
 
         $em = Database::getManager();
+
         return $em
             ->createQuery("
                 SELECT COUNT(u.id) FROM ChamiloCoreBundle:User u
@@ -1478,7 +1443,7 @@ class GroupManager
 
         $usersToAdd = [];
         foreach ($complete_user_list as $userInfo) {
-            $isSubscribed = self::is_subscribed($userInfo['user_id'], $groupInfo);
+            $isSubscribed = self::is_subscribed($userInfo['user_id'], $group);
             if ($isSubscribed) {
                 continue;
             }
@@ -1495,7 +1460,7 @@ class GroupManager
         }
 
         foreach ($usersToAdd as $userId) {
-            self::subscribe_users($userId, $groupInfo);
+            self::subscribeUsers($userId, $group);
         }
     }
 
@@ -1586,31 +1551,21 @@ class GroupManager
      * Is sef-registration allowed?
      *
      * @param int   $user_id
-     * @param array $groupInfo
      *
      * @return bool TRUE if self-registration is allowed in the given group
      */
-    public static function is_self_registration_allowed($user_id, $groupInfo)
+    public static function is_self_registration_allowed($user_id, CGroup $group)
     {
-        $course_id = api_get_course_int_id();
         if (empty($user_id)) {
             return false;
         }
 
-        $groupIid = $groupInfo['iid'];
-        $table = Database::get_course_table(TABLE_GROUP);
-        if (isset($groupIid)) {
-            $sql = "SELECT status, self_registration_allowed
-                    FROM $table
-                    WHERE iid = $groupIid";
-            $result = Database::query($sql);
-            $group = Database::fetch_object($result);
-
-            if (0 == $group->status || 1 != $group->self_registration_allowed) {
+        if ($group) {
+            if (0 == $group->getStatus() || 1 != $group->getSelfRegistrationAllowed()) {
                 return false;
             }
 
-            return self::canUserSubscribe($user_id, $groupInfo);
+            return self::canUserSubscribe($user_id, $group);
         }
 
         return false;
@@ -1620,49 +1575,37 @@ class GroupManager
      * Is sef-unregistration allowed?
      *
      * @param int   $user_id
-     * @param array $groupInfo
      *
      * @return bool TRUE if self-unregistration is allowed in the given group
      */
-    public static function is_self_unregistration_allowed($user_id, $groupInfo)
+    public static function is_self_unregistration_allowed($user_id, CGroup $group)
     {
-        if (empty($user_id) || empty($groupInfo)) {
+        if (empty($user_id) || empty($group)) {
             return false;
         }
-        $groupIid = $groupInfo['iid'];
-        $table = Database::get_course_table(TABLE_GROUP);
-        $course_id = api_get_course_int_id();
-
-        $sql = "SELECT status, self_unregistration_allowed
-                FROM $table
-                WHERE iid = $groupIid";
-        $result = Database::query($sql);
-        $group = Database::fetch_object($result);
-
-        if (0 == $group->status || 1 != $group->self_unregistration_allowed) {
+        if (0 == $group->getStatus() || 1 != $group->getSelfUnregistrationAllowed()) {
             return false;
         }
 
-        return self::is_subscribed($user_id, $groupInfo);
+        return self::is_subscribed($user_id, $group);
     }
 
     /**
      * Is user subscribed in group?
      *
-     * @param int   $user_id
-     * @param array $groupInfo
+     * @param int    $user_id
      *
      * @return bool TRUE if given user is subscribed in given group
      */
-    public static function is_subscribed($user_id, $groupInfo)
+    public static function is_subscribed($user_id, CGroup $group)
     {
         $course_id = api_get_course_int_id();
-        if (empty($user_id) || empty($groupInfo) || empty($course_id)) {
+        if (empty($user_id) || empty($group) || empty($course_id)) {
             return false;
         }
         $table = Database::get_course_table(TABLE_GROUP_USER);
-        $group_id = intval($groupInfo['iid']);
-        $user_id = intval($user_id);
+        $group_id = $group->getIid();
+        $user_id = (int) $user_id;
 
         $sql = "SELECT 1 FROM $table
                 WHERE
@@ -1678,19 +1621,18 @@ class GroupManager
      * Can a user subscribe to a specified group in a course.
      *
      * @param int   $user_id
-     * @param array $groupInfo
      * @param bool  $checkMaxNumberStudents
      *
-     * @return bool TRUE if given user  can be subscribed in given group
+     * @return bool true if success
      */
     public static function canUserSubscribe(
         $user_id,
-        $groupInfo,
+        CGroup $group,
         $checkMaxNumberStudents = true
     ) {
-        $groupIid = $groupInfo['iid'];
+        $groupIid =  $group->getIid();
         if ($checkMaxNumberStudents) {
-            $category = self::get_category_from_group($groupIid);
+            $category = self::get_category_from_group($group->getIid());
             if ($category) {
                 if (self::GROUP_PER_MEMBER_NO_LIMIT == $category['groups_per_user']) {
                     $category['groups_per_user'] = self::INFINITE;
@@ -1708,13 +1650,13 @@ class GroupManager
             }
         }
 
-        $result = self::is_tutor_of_group($user_id, $groupInfo);
+        $result = self::isTutorOfGroup($user_id, $group);
 
         if ($result) {
             return false;
         }
 
-        $result = self::is_subscribed($user_id, $groupInfo);
+        $result = self::is_subscribed($user_id, $group);
 
         if ($result) {
             return false;
@@ -1782,77 +1724,28 @@ class GroupManager
         return $users;
     }
 
-    /**
-     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
-     * Get all subscribed tutors of a group
-     *
-     * @param array $groupInfo
-     *
-     * @return array An array with information of all users from the given group.
-     *               (user_id, firstname, lastname, email)
-     */
-    public static function get_subscribed_tutors($groupInfo, $id_only = false)
-    {
-        if (empty($groupInfo)) {
-            return [];
-        }
-
-        $table_user = Database::get_main_table(TABLE_MAIN_USER);
-        $table_group_tutor = Database::get_course_table(TABLE_GROUP_TUTOR);
-        $order_clause = api_sort_by_first_name() ? ' ORDER BY u.firstname, u.lastname' : ' ORDER BY u.lastname, u.firstname';
-
-        $orderListByOfficialCode = api_get_setting('order_user_list_by_official_code');
-        if ('true' === $orderListByOfficialCode) {
-            $order_clause = ' ORDER BY u.official_code, u.firstname, u.lastname';
-        }
-
-        $group_id = (int) $groupInfo['iid'];
-        $course_id = api_get_course_int_id();
-
-        $sql = "SELECT u.id, u.lastname, u.firstname, u.email
-                FROM $table_user u
-                INNER JOIN $table_group_tutor tg
-                ON (tg.user_id = u.id)
-                WHERE
-                    tg.group_id = $group_id
-                    $order_clause
-                ";
-        $db_result = Database::query($sql);
-        $users = [];
-        while ($user = Database::fetch_object($db_result)) {
-            if (!$id_only) {
-                $member['user_id'] = $user->id;
-                $member['firstname'] = $user->firstname;
-                $member['lastname'] = $user->lastname;
-                $member['email'] = $user->email;
-                $users[] = $member;
-            } else {
-                $users[] = $user->id;
-            }
-        }
-
-        return $users;
-    }
-
     /**
      * Subscribe user(s) to a specified group in current course (as a student).
      *
-     * @param mixed $user_ids  Can be an array with user-id's or a single user-id
-     * @param array $groupInfo
+     * @param mixed $userList  Can be an array with user-id's or a single user-id
+     * @param CGroup $group
      * @param int   $course_id
      *
-     * @return bool TRUE if successful
+     * @return bool
      */
-    public static function subscribe_users($user_ids, $groupInfo, $course_id = null)
+    public static function subscribeUsers($userList, CGroup $group = null, $course_id = null)
     {
-        $user_ids = is_array($user_ids) ? $user_ids : [$user_ids];
+        if (empty($group)) {
+            return false;
+        }
+        $userList = is_array($userList) ? $userList : [$userList];
         $course_id = empty($course_id) ? api_get_course_int_id() : (int) $course_id;
-        $group_id = $groupInfo['iid'];
+        $group_id = $group->getIid();
 
-        if (!empty($user_ids)) {
+        if (!empty($userList)) {
             $table = Database::get_course_table(TABLE_GROUP_USER);
-            foreach ($user_ids as $user_id) {
-                if (self::canUserSubscribe($user_id, $groupInfo)) {
+            foreach ($userList as $user_id) {
+                if (self::canUserSubscribe($user_id, $group)) {
                     $user_id = (int) $user_id;
                     $sql = "INSERT INTO $table (c_id, user_id, group_id, status, role)
                             VALUES ('$course_id', '".$user_id."', '".$group_id."', 0, '')";
@@ -1867,27 +1760,24 @@ class GroupManager
     /**
      * Subscribe tutor(s) to a specified group in current course.
      *
-     * @param mixed $user_ids  Can be an array with user-id's or a single user-id
+     * @param mixed $userList  Can be an array with user-id's or a single user-id
      * @param array $groupInfo
      * @param int   $course_id
-     *
-     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
-     *
-     * @see subscribe_users. This function is almost an exact copy of that function.
-     *
-     * @return bool TRUE if successful
      */
-    public static function subscribe_tutors($user_ids, $groupInfo, $course_id = 0)
+    public static function subscribeTutors($userList, CGroup $group = null, $course_id = 0)
     {
-        $user_ids = is_array($user_ids) ? $user_ids : [$user_ids];
+        if (empty($group)) {
+            return false;
+        }
+        $userList = is_array($userList) ? $userList : [$userList];
         $result = true;
         $course_id = isset($course_id) && !empty($course_id) ? intval($course_id) : api_get_course_int_id();
         $table_group_tutor = Database::get_course_table(TABLE_GROUP_TUTOR);
-        $groupId = (int) $groupInfo['iid'];
+        $groupId = (int) $group->getIid();
 
-        foreach ($user_ids as $user_id) {
+        foreach ($userList as $user_id) {
             $user_id = intval($user_id);
-            if (self::canUserSubscribe($user_id, $groupInfo, false)) {
+            if (self::canUserSubscribe($user_id, $group, false)) {
                 $sql = 'INSERT INTO '.$table_group_tutor." (c_id, user_id, group_id)
                         VALUES ('$course_id', '".$user_id."', '".$groupId."')";
                 $result = Database::query($sql);
@@ -1900,21 +1790,23 @@ class GroupManager
     /**
      * Unsubscribe user(s) from a specified group in current course.
      *
-     * @param mixed $user_ids  Can be an array with user-id's or a single user-id
-     * @param array $groupInfo
+     * @param mixed $userList  Can be an array with user-id's or a single user-id
      *
-     * @return bool TRUE if successful
+     * @return bool
      */
-    public static function unsubscribe_users($user_ids, $groupInfo)
+    public static function unsubscribeUsers($userList, CGroup $group = null)
     {
-        $user_ids = is_array($user_ids) ? $user_ids : [$user_ids];
+        if (empty($group)) {
+            return false;
+        }
+        $userList = is_array($userList) ? $userList : [$userList];
         $table_group_user = Database::get_course_table(TABLE_GROUP_USER);
-        $group_id = intval($groupInfo['iid']);
+        $group_id = $group->getIid();
         $course_id = api_get_course_int_id();
         $sql = 'DELETE FROM '.$table_group_user.'
                 WHERE
                     group_id = '.$group_id.' AND
-                    user_id IN ('.implode(',', $user_ids).')
+                    user_id IN ('.implode(',', $userList).')
                 ';
         Database::query($sql);
     }
@@ -1924,9 +1816,9 @@ class GroupManager
      *
      * @param int $groupId
      *
-     * @return bool TRUE if successful
+     * @return bool
      */
-    public static function unsubscribe_all_users($groupId)
+    public static function unsubscribeAllUsers($groupId)
     {
         $groupId = (int) $groupId;
         if (empty($groupId)) {
@@ -1965,9 +1857,7 @@ class GroupManager
             $table_group_tutor = Database::get_course_table(TABLE_GROUP_TUTOR);
             $sql = "DELETE FROM $table_group_tutor
                     WHERE group_id = $groupId ";
-            $result = Database::query($sql);
-
-            return $result;
+            Database::query($sql);
         }
 
         return true;
@@ -1975,43 +1865,26 @@ class GroupManager
 
     /**
      * Is the user a tutor of this group?
-     *
-     * @param int   $user_id   the id of the user
-     * @param array $groupInfo
-     * @param int   $courseId
-     *
-     * @return bool true/false
-     *
-     * @todo use the function user_has_access that includes this function
-     *
-     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
+     * @todo replace this function with $group->isUserTutor
      */
-    public static function is_tutor_of_group($user_id, $groupInfo, $courseId = 0)
+    public static function isTutorOfGroup($userId, CGroup $group = null)
     {
-        if (empty($groupInfo)) {
-            return false;
-        }
-
-        $courseId = empty($courseId) ? api_get_course_int_id() : (int) $courseId;
-        if (empty($courseId)) {
+        if (empty($group)) {
             return false;
         }
 
-        $user_id = (int) $user_id;
-        $group_id = (int) $groupInfo['iid'];
+        $userId = (int) $userId;
+        $group_id = (int) $group->getIid();
 
         $table = Database::get_course_table(TABLE_GROUP_TUTOR);
 
         $sql = "SELECT * FROM $table
                 WHERE
-                    user_id = $user_id AND
+                    user_id = $userId AND
                     group_id = $group_id";
         $result = Database::query($sql);
-        if (Database::num_rows($result) > 0) {
-            return true;
-        }
 
-        return false;
+        return Database::num_rows($result) > 0;
     }
 
     /**
@@ -2021,22 +1894,15 @@ class GroupManager
      * before you had to check if the user was
      * 1. a member of the group OR
      * 2. a tutor of the group. This function combines both.
-     *
-     * @param int   $user_id   the id of the user
-     * @param array $groupInfo
-     *
-     * @return bool true/false
-     *
-     * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
      */
-    public static function is_user_in_group($user_id, $groupInfo)
+    public static function isUserInGroup($user_id, CGroup $group)
     {
-        $member = self::is_subscribed($user_id, $groupInfo);
+        $member = self::is_subscribed($user_id, $group);
         if ($member) {
             return true;
         }
 
-        $tutor = self::is_tutor_of_group($user_id, $groupInfo);
+        $tutor = self::isTutorOfGroup($user_id, $group);
         if ($tutor) {
             return true;
         }
@@ -2162,14 +2028,14 @@ class GroupManager
                 return true;
                 break;
             case self::TOOL_PRIVATE:
-                $userIsInGroup = self::is_user_in_group($user_id, $groupInfo);
+                $userIsInGroup = self::isUserInGroup($user_id, $groupInfo);
                 if ($userIsInGroup) {
                     return true;
                 }
                 break;
             case self::TOOL_PRIVATE_BETWEEN_USERS:
                 // Only works for announcements for now
-                $userIsInGroup = self::is_user_in_group($user_id, $groupInfo);
+                $userIsInGroup = self::isUserInGroup($user_id, $groupInfo);
                 if ($userIsInGroup && self::GROUP_TOOL_ANNOUNCEMENT == $tool) {
                     return true;
                 }
@@ -2180,15 +2046,15 @@ class GroupManager
     }
 
     /**
-     * @param int   $userId
-     * @param array $groupInfo
-     * @param int   $sessionId
+     * @param int    $userId
+     * @param CGroup $group
+     * @param int    $sessionId
      *
      * @return bool
      */
-    public static function userHasAccessToBrowse($userId, $groupInfo, $sessionId = 0)
+    public static function userHasAccessToBrowse($userId, CGroup $group, $sessionId = 0)
     {
-        if (empty($groupInfo)) {
+        if (empty($group)) {
             return false;
         }
 
@@ -2212,14 +2078,14 @@ class GroupManager
             }
         }
 
-        $groupId = $groupInfo['iid'];
-        if (self::is_tutor_of_group($userId, $groupInfo)) {
+        if (self::isTutorOfGroup($userId, $group)) {
             return true;
         }
 
-        if (0 == $groupInfo['status']) {
+        if (0 == $group->getStatus()) {
             return false;
         }
+        $groupId = $group->getIid();
 
         if (self::user_has_access($userId, $groupId, self::GROUP_TOOL_FORUM) ||
             self::user_has_access($userId, $groupId, self::GROUP_TOOL_DOCUMENTS) ||
@@ -2231,8 +2097,10 @@ class GroupManager
         ) {
             return true;
         }
+        //@todo check group session id
+        $groupSessionId = null;
 
-        if (api_is_session_general_coach() && $groupInfo['session_id'] == $sessionId) {
+        if (api_is_session_general_coach() && $groupSessionId == $sessionId) {
             return true;
         }
 
@@ -2308,12 +2176,12 @@ class GroupManager
     }
 
     /**
-     * @param array $group_list
+     * @param CGroup[] $groupList
      * @param int   $category_id
      *
      * @return string
      */
-    public static function process_groups($group_list, $category_id = 0)
+    public static function processGroups($groupList, $category_id = 0)
     {
         $charset = 'UTF-8';
         $category_id = (int) $category_id;
@@ -2327,75 +2195,78 @@ class GroupManager
         $surveyGroupExists = $extraField->get_handler_field_info_by_field_variable('group_id') ? true : false;
         $url = api_get_path(WEB_CODE_PATH).'group/';
 
-        foreach ($group_list as $this_group) {
-            $groupId = $this_group['iid'];
+        foreach ($groupList as $group) {
+            $groupId = $group->getIid();
+
             // Validation when belongs to a session
             $session_img = '';
-            //$session_img = api_get_session_image($this_group['session_id'], $user_info['status']);
+            //$session_img = api_get_session_image($group['session_id'], $user_info['status']);
 
             // All the tutors of this group
-            $tutors = self::get_subscribed_tutors($this_group, true);
-            $isMember = self::is_subscribed($user_id, $this_group);
+            $tutors = $group->getTutors();
+            $isMember = self::is_subscribed($user_id, $group);
 
             // Create a new table-row
             $row = [];
             // Checkbox
-            if (api_is_allowed_to_edit(false, true) && count($group_list) > 1) {
-                $row[] = $this_group['iid'];
+            if (api_is_allowed_to_edit(false, true) && count($groupList) > 1) {
+                $row[] = $groupId;
             }
 
-            if (self::userHasAccessToBrowse($user_id, $this_group, $session_id)) {
+            if (self::userHasAccessToBrowse($user_id, $group, $session_id)) {
                 // Group name
                 $groupNameClass = null;
-                if (0 == $this_group['status']) {
+                if (0 == $group->getStatus()) {
                     $groupNameClass = 'muted';
                 }
 
                 $group_name = '<a
                     class="'.$groupNameClass.'"
                     href="group_space.php?'.api_get_cidreq(true, false).'&gid='.$groupId.'">'.
-                    Security::remove_XSS($this_group['name']).'</a> ';
+                    Security::remove_XSS($group->getName()).'</a> ';
 
                 $group_name2 = '';
                 if (api_get_configuration_value('extra')) {
                     $group_name2 = '<a
                         href="group_space_tracking.php?cid='.api_get_course_int_id().'&gid='.$groupId.'">'.
-                        get_lang('suivi_de').''.stripslashes($this_group['name']).'</a>';
+                        get_lang('suivi_de').''.stripslashes($group->getName()).'</a>';
                 }
 
+                /*
                 if (!empty($user_id) && !empty($this_group['id_tutor']) && $user_id == $this_group['id_tutor']) {
                     $group_name .= Display::label(get_lang('my supervision'), 'success');
                 } elseif ($isMember) {
                     $group_name .= Display::label(get_lang('my group'), 'success');
-                }
+                }*/
 
-                if (api_is_allowed_to_edit() && !empty($this_group['session_name'])) {
+                /*if (api_is_allowed_to_edit() && !empty($this_group['session_name'])) {
                     $group_name .= ' ('.$this_group['session_name'].')';
                 }
-                $group_name .= $session_img;
-                $row[] = $group_name.$group_name2.'<br />'.stripslashes(trim($this_group['description']));
+                $group_name .= $session_img;*/
+
+                $row[] = $group_name.$group_name2.'<br />'.stripslashes(trim($group->getDescription()));
             } else {
                 if ('true' === $hideGroup) {
                     continue;
                 }
-                $row[] = $this_group['name'].'<br />'.stripslashes(trim($this_group['description']));
+                $row[] = $group->getName().'<br />'.stripslashes(trim($group->getDescription()));
             }
 
             // Tutor name
             $tutor_info = '';
             if (count($tutors) > 0) {
-                foreach ($tutors as $tutor_id) {
-                    $tutor = api_get_user_info($tutor_id);
+                foreach ($tutors as $tutorGroup) {
+                    $tutor = $tutorGroup->getUser();
                     $username = api_htmlentities(
-                        sprintf(get_lang('Login: %s'), $tutor['username']),
+                        sprintf(get_lang('Login: %s'), $tutor->getUsername()),
                         ENT_QUOTES
                     );
                     if ('true' === api_get_setting('show_email_addresses')) {
                         $tutor_info .= Display::tag(
                             'span',
                             Display::encrypted_mailto_link(
-                                $tutor['mail'],
-                                $tutor['complete_name']
+                                $tutor->getEmail(),
+                                UserManager::formatUserFullName($tutor)
                             ),
                             ['title' => $username]
                         ).', ';
@@ -2404,15 +2275,15 @@ class GroupManager
                             $tutor_info .= Display::tag(
                             'span',
                                 Display::encrypted_mailto_link(
-                                    $tutor['mail'],
-                                    $tutor['complete_name_with_username']
+                                    $tutor->getEmail(),
+                                    UserManager::formatUserFullName($tutor)
                                 ),
                                 ['title' => $username]
                             ).', ';
                         } else {
                             $tutor_info .= Display::tag(
                                 'span',
-                                $tutor['complete_name'],
+                                    UserManager::formatUserFullName($tutor),
                                 ['title' => $username]
                             ).', ';
                         }
@@ -2428,19 +2299,21 @@ class GroupManager
             $row[] = $tutor_info;
 
             // Max number of members in group
-            $max_members = self::MEMBER_PER_GROUP_NO_LIMIT == $this_group['maxStudent'] ? ' ' : ' / '.$this_group['maxStudent'];
+            $max_members = self::MEMBER_PER_GROUP_NO_LIMIT == $group->getMaxStudent() ? ' ' : ' / '.$group->getMaxStudent();
             $registeredUsers = self::getStudentsCount($groupId);
             // Number of members in group
             $row[] = $registeredUsers.$max_members;
-            $confirmMessage = addslashes(api_htmlentities(get_lang('Please confirm your choice'), ENT_QUOTES, $charset));
+            $confirmMessage = addslashes(
+                api_htmlentities(get_lang('Please confirm your choice'), ENT_QUOTES, $charset)
+            );
             // Self-registration / unregistration
             if (!api_is_allowed_to_edit(false, true)) {
-                if (self::is_self_registration_allowed($user_id, $this_group)) {
+                if (self::is_self_registration_allowed($user_id, $group)) {
                     $row[] = '<a
                         class = "btn btn-default"
                         href="group.php?'.api_get_cidreq().'&category='.$category_id.'&action=self_reg&group_id='.$groupId.'"
                         onclick="javascript:if(!confirm('."'".$confirmMessage."'".')) return false;">'.get_lang('register').'</a>';
-                } elseif (self::is_self_unregistration_allowed($user_id, $this_group)) {
+                } elseif (self::is_self_unregistration_allowed($user_id, $group)) {
                     $row[] = '<a
                         class = "btn btn-default"
                         href="group.php?'.api_get_cidreq().'&category='.$category_id.'&action=self_unreg&group_id='.$groupId.'"
@@ -2450,9 +2323,12 @@ class GroupManager
                 }
             }
 
+            // @todo fix group session access.
+            $groupSessionId = null;
+
             // Edit-links
             if (api_is_allowed_to_edit(false, true) &&
-                !(api_is_session_general_coach() && intval($this_group['session_id']) != $session_id)
+                !(api_is_session_general_coach() && $groupSessionId != $session_id)
             ) {
                 $edit_actions = '<a
                     href="'.$url.'settings.php?'.api_get_cidreq(true, false).'&gid='.$groupId.'"
@@ -2460,7 +2336,7 @@ class GroupManager
                     Display::return_icon('edit.png', get_lang('Edit this group'), '', ICON_SIZE_SMALL).
                     '</a>&nbsp;';
 
-                if (1 == $this_group['status']) {
+                if (1 == $group->getStatus()) {
                     $edit_actions .= '<a
                         href="'.api_get_self().'?'.api_get_cidreq(true, false).'&category='.$category_id.'&action=set_invisible&group_id='.$groupId.'"
                         title="'.get_lang('Hide').'">'.
@@ -2500,9 +2376,10 @@ class GroupManager
 
                 $row[] = $edit_actions;
             }
-            if (!empty($this_group['nbMember'])) {
+
+            /*if (!empty($this_group['nbMember'])) {
                 $totalRegistered = $totalRegistered + $this_group['nbMember'];
-            }
+            }*/
             $group_data[] = $row;
         }
 
@@ -2521,7 +2398,7 @@ class GroupManager
         );
         $table->set_additional_parameters(['category' => $category_id]);
         $column = 0;
-        if (api_is_allowed_to_edit(false, true) and count($group_list) > 1) {
+        if (api_is_allowed_to_edit(false, true) && count($groupList) > 1) {
             $table->set_header($column++, '', false);
         }
         $table->set_header($column++, get_lang('Groups'));
@@ -2540,7 +2417,7 @@ class GroupManager
             $form_actions['fill_selected'] = get_lang('Fill the group randomly with course students');
             $form_actions['empty_selected'] = get_lang('unsubscribe all users');
             $form_actions['delete_selected'] = get_lang('Delete');
-            if (count($group_list) > 1) {
+            if (count($groupList) > 1) {
                 $table->set_form_actions($form_actions, 'group');
             }
         }
@@ -2725,7 +2602,7 @@ class GroupManager
 
                         $studentUserIdList[] = $userInfo['user_id'];
                     }
-                    self::subscribe_users($studentUserIdList, $groupInfo);
+                    self::subscribeUsers($studentUserIdList, api_get_group_entity($groupInfo['iid']));
                 }
 
                 $tutors = isset($data['tutors']) ? explode(',', $data['tutors']) : [];
@@ -2757,7 +2634,7 @@ class GroupManager
 
                         $tutorIdList[] = $userInfo['user_id'];
                     }
-                    self::subscribe_tutors($tutorIdList, $groupInfo);
+                    self::subscribeTutors($tutorIdList, api_get_group_entity($groupInfo['iid']));
                 }
 
                 $elementsFound['groups'][] = $groupId;
@@ -3002,6 +2879,7 @@ class GroupManager
 
         return $content;
     }
+
     /**
      * @param array  $courseInfo
      * @param string $keyword
@@ -3090,7 +2968,7 @@ class GroupManager
     /**
      * @param int   $userId
      * @param int   $courseId
-     * @param array $groupInfo
+     * @param CGroup  $group
      * @param array $documentInfoToBeCheck
      * @param bool  $blockPage
      *
@@ -3099,7 +2977,7 @@ class GroupManager
     public static function allowUploadEditDocument(
         $userId,
         $courseId,
-        $groupInfo,
+        CGroup $group,
         $documentInfoToBeCheck = null,
         $blockPage = false
     ) {
@@ -3108,7 +2986,7 @@ class GroupManager
             return true;
         }
 
-        if (empty($groupInfo) || !isset($groupInfo['iid'])) {
+        if (empty($group)) {
             if ($blockPage) {
                 api_not_allowed(true);
             }
@@ -3117,14 +2995,14 @@ class GroupManager
         }
 
         // Tutor can also make any change
-        $isTutor = self::is_tutor_of_group($userId, $groupInfo, $courseId);
+        $isTutor = self::isTutorOfGroup($userId, $group);
 
         if ($isTutor) {
             return true;
         }
 
         // Just in case also check if document in group is available
-        if (0 == $groupInfo['doc_state']) {
+        if (0 == $group->getDocState()) {
             if ($blockPage) {
                 api_not_allowed(true);
             }
@@ -3147,9 +3025,7 @@ class GroupManager
         // Check group document access
         $allow = api_get_configuration_value('group_document_access');
         if ($allow) {
-            if (isset($groupInfo['document_access'])) {
-                $documentAccess = (int) $groupInfo['document_access'];
-            }
+            $documentAccess = (int) $group->getDocumentAccess();
         }
 
         // Check access for students
@@ -3158,7 +3034,7 @@ class GroupManager
             case self::DOCUMENT_MODE_SHARE:
                 // Default chamilo behaviour
                 // Student can upload his own content, cannot modify another content.
-                $isMember = self::is_subscribed($userId, $groupInfo);
+                $isMember = self::is_subscribed($userId, $group);
                 if ($isMember) {
                     // No document to check, allow access to document feature.
                     if (empty($documentInfoToBeCheck)) {
@@ -3202,7 +3078,7 @@ class GroupManager
                 break;
             case self::DOCUMENT_MODE_COLLABORATION:
                 // Student can upload content, can modify another content.
-                $isMember = self::is_subscribed($userId, $groupInfo);
+                $isMember = self::is_subscribed($userId, $group);
                 if ($isMember) {
                     $result = true;
                 }
diff --git a/public/main/inc/lib/pdf.lib.php b/public/main/inc/lib/pdf.lib.php
index c27d9c9e5e..c171c577d5 100644
--- a/public/main/inc/lib/pdf.lib.php
+++ b/public/main/inc/lib/pdf.lib.php
@@ -1,4 +1,5 @@
 <?php
+
 /* See license terms in /license.txt */
 
 use Chamilo\CoreBundle\Component\Utils\ChamiloApi;
@@ -273,7 +274,6 @@ class PDF
             }
 
             if (!file_exists($file)) {
-                // the file doesn't exist, skip
                 continue;
             }
 
@@ -326,7 +326,6 @@ class PDF
                 $title = api_get_title_html($documentHtml, 'UTF-8', 'UTF-8');
                 // $_GET[] too, as it is done with file name.
                 // At the moment the title is retrieved from the html document itself.
-                //echo $documentHtml;exit;
                 if (empty($title)) {
                     $title = $filename; // Here file name is expected to contain ASCII symbols only.
                 }
@@ -644,6 +643,20 @@ class PDF
         $this->pdf->SetHTMLFooter($footerHTML, 'O'); //Odd pages
     }
 
+    public function setCertificateFooter()
+    {
+        $this->pdf->defaultfooterfontsize = 12; // in pts
+        $this->pdf->defaultfooterfontstyle = 'B'; // blank, B, I, or BI
+        $this->pdf->defaultfooterline = 1; // 1 to include line below header/above footer
+
+        $view = new Template('', false, false, false, true, false, false);
+        $template = $view->get_template('export/pdf_certificate_footer.tpl');
+        $footerHTML = $view->fetch($template);
+
+        $this->pdf->SetHTMLFooter($footerHTML, 'E'); //Even pages
+        $this->pdf->SetHTMLFooter($footerHTML, 'O'); //Odd pages
+    }
+
     /**
      * Sets the PDF header.
      *
@@ -678,7 +691,6 @@ class PDF
                 $visualTheme = api_get_visual_theme();
                 $img = api_get_path(SYS_CSS_PATH).'themes/'.$visualTheme.'/images/pdf_logo_header.png';
                 if (file_exists($img)) {
-                    //$img = api_get_path(WEB_CSS_PATH).'themes/'.$visualTheme.'/images/pdf_logo_header.png';
                     $organization = "<img src='$img'>";
                 }
             }
diff --git a/public/main/inc/lib/sessionmanager.lib.php b/public/main/inc/lib/sessionmanager.lib.php
index 6585e71d33..ce00daa259 100644
--- a/public/main/inc/lib/sessionmanager.lib.php
+++ b/public/main/inc/lib/sessionmanager.lib.php
@@ -5689,10 +5689,9 @@ class SessionManager
                                         !empty($groupBackup['user'][$teacherToAdd][$course_code])
                                     ) {
                                         foreach ($groupBackup['user'][$teacherToAdd][$course_code] as $data) {
-                                            $groupInfo = GroupManager::get_group_properties($data['group_id']);
-                                            GroupManager::subscribe_users(
+                                            GroupManager::subscribeUsers(
                                                 $teacherToAdd,
-                                                $groupInfo,
+                                                api_get_group_entity($data['group_id']),
                                                 $data['c_id']
                                             );
                                         }
@@ -5703,10 +5702,9 @@ class SessionManager
                                         !empty($groupBackup['tutor'][$teacherToAdd][$course_code])
                                     ) {
                                         foreach ($groupBackup['tutor'][$teacherToAdd][$course_code] as $data) {
-                                            $groupInfo = GroupManager::get_group_properties($data['group_id']);
-                                            GroupManager::subscribe_tutors(
+                                            GroupManager::subscribeTutors(
                                                 $teacherToAdd,
-                                                $groupInfo,
+                                                api_get_group_entity($data['group_id']),
                                                 $data['c_id']
                                             );
                                         }
@@ -5812,10 +5810,9 @@ class SessionManager
                                             !empty($groupBackup['user'][$teacherId][$course_code])
                                         ) {
                                             foreach ($groupBackup['user'][$teacherId][$course_code] as $data) {
-                                                $groupInfo = GroupManager::get_group_properties($data['group_id']);
-                                                GroupManager::subscribe_users(
+                                                GroupManager::subscribeUsers(
                                                     $teacherId,
-                                                    $groupInfo,
+                                                    api_get_group_entity($data['group_id']),
                                                     $data['c_id']
                                                 );
                                             }
@@ -5826,10 +5823,9 @@ class SessionManager
                                             !empty($groupBackup['tutor'][$teacherId][$course_code])
                                         ) {
                                             foreach ($groupBackup['tutor'][$teacherId][$course_code] as $data) {
-                                                $groupInfo = GroupManager::get_group_properties($data['group_id']);
-                                                GroupManager::subscribe_tutors(
+                                                GroupManager::subscribeTutors(
                                                     $teacherId,
-                                                    $groupInfo,
+                                                    api_get_group_entity($data['group_id']),
                                                     $data['c_id']
                                                 );
                                             }
diff --git a/public/main/wiki/wiki.inc.php b/public/main/wiki/wiki.inc.php
index 21d8961d2e..0b796f55eb 100644
--- a/public/main/wiki/wiki.inc.php
+++ b/public/main/wiki/wiki.inc.php
@@ -1074,7 +1074,7 @@ class Wiki
         if ($row && '' == $row['content'] && '' == $row['title'] && 'index' === $page) {
             if (api_is_allowed_to_edit(false, true) ||
                 api_is_platform_admin() ||
-                GroupManager::is_user_in_group(api_get_user_id(), $groupInfo) ||
+                GroupManager::isUserInGroup(api_get_user_id(), api_get_group_entity()) ||
                 api_is_allowed_in_course()
             ) {
                 //Table structure for better export to pdf
@@ -1157,9 +1157,9 @@ class Wiki
                 $actionsLeft .= $editLink;
             } else {
                 if ((api_is_allowed_in_course() ||
-                    GroupManager::is_user_in_group(
+                    GroupManager::isUserInGroup(
                         api_get_user_id(),
-                        $groupInfo
+                        api_get_group_entity()
                     ))
                 ) {
                     $actionsLeft .= $editLink;
@@ -1255,9 +1255,9 @@ class Wiki
             if ($row['id']) {
                 if (api_is_allowed_to_session_edit(false, true) &&
                     api_is_allowed_to_edit() ||
-                    GroupManager::is_user_in_group(
+                    GroupManager::isUserInGroup(
                         api_get_user_id(),
-                        $groupInfo
+                        api_get_group_entity()
                     )
                 ) {
                     // menu discuss page
@@ -2553,6 +2553,8 @@ class Wiki
         $session_id = $this->session_id;
         $groupId = api_get_group_id();
         $groupInfo = GroupManager::get_group_properties($groupId);
+        $group = api_get_group_entity($groupId);
+
         if (0 == $groupId) {
             //extract course members
             if (!empty($session_id)) {
@@ -2569,9 +2571,11 @@ class Wiki
         } else {
             //extract group members
             $subscribed_users = GroupManager::get_subscribed_users($groupInfo);
-            $subscribed_tutors = GroupManager::get_subscribed_tutors(
-                $groupInfo
-            );
+            $tutors = $group->getTutors();
+            $subscribed_tutors = [];
+            foreach ($tutors as $tutor) {
+                $subscribed_tutors[] =$tutor->getUser()->getId();
+            }
             $a_users_to_add_with_duplicates = array_merge(
                 $subscribed_users,
                 $subscribed_tutors
@@ -2637,15 +2641,15 @@ class Wiki
                     )." . ".$username;
                 $photo = '<img src="'.$userPicture.'" alt="'.$name.'"  width="40" height="50" align="bottom" title="'.$name.'"  />';
 
-                $is_tutor_of_group = GroupManager::is_tutor_of_group(
+                $is_tutor_of_group = GroupManager::isTutorOfGroup(
                     $assig_user_id,
-                    $groupInfo
+                    $group
                 ); //student is tutor
-                $is_tutor_and_member = GroupManager::is_tutor_of_group(
+                $is_tutor_and_member = GroupManager::isTutorOfGroup(
                         $assig_user_id,
-                        $groupInfo
+                        $group
                     ) &&
-                    GroupManager::is_subscribed($assig_user_id, $groupInfo);
+                    GroupManager::is_subscribed($assig_user_id, $group);
                 // student is tutor and member
                 if ($is_tutor_and_member) {
                     $status_in_group = get_lang('Coach and group member');
@@ -5358,7 +5362,7 @@ class Wiki
                 //Only teacher, platform admin and group members can edit a wiki group
                 if (api_is_allowed_to_edit(false, true) ||
                     api_is_platform_admin() ||
-                    GroupManager::is_user_in_group($userId, $groupInfo) ||
+                    GroupManager::isUserInGroup($userId, api_get_group_entity($this->group_id)) ||
                     api_is_allowed_in_course()
                 ) {
                     $PassEdit = true;
@@ -6248,7 +6252,7 @@ class Wiki
                 //Only teacher, platform admin and group members can edit a wiki group
                 if (api_is_allowed_to_edit(false, true) ||
                     api_is_platform_admin() ||
-                    GroupManager::is_user_in_group($userId, $groupInfo)
+                    GroupManager::isUserInGroup($userId, api_get_group_entity($groupId))
                 ) {
                     $PassEdit = true;
                 } else {
@@ -7084,9 +7088,9 @@ class Wiki
                 if (self::checktitle('index')) {
                     if (api_is_allowed_to_edit(false, true) ||
                         api_is_platform_admin() ||
-                        GroupManager::is_user_in_group(
+                        GroupManager::isUserInGroup(
                             api_get_user_id(),
-                            $groupInfo
+                            api_get_group_entity()
                         ) ||
                         api_is_allowed_in_course()
                     ) {
@@ -7124,9 +7128,9 @@ class Wiki
                     );
                     if (api_is_allowed_to_edit(false, true) ||
                         api_is_platform_admin() ||
-                        GroupManager::is_user_in_group(
+                        GroupManager::isUserInGroup(
                             api_get_user_id(),
-                            $groupInfo
+                            api_get_group_entity
                         ) ||
                         0 == $_GET['group_id']
                     ) {
diff --git a/public/main/work/work.php b/public/main/work/work.php
index 06fadad82d..c4dcbb0f7e 100644
--- a/public/main/work/work.php
+++ b/public/main/work/work.php
@@ -123,10 +123,9 @@ Event::registerLog($logInfo);
 $groupId = api_get_group_id();
 $isTutor = false;
 if (!empty($groupId)) {
-    $groupInfo = GroupManager::get_group_properties($groupId);
-    $isTutor = GroupManager::is_tutor_of_group(
+    $isTutor = GroupManager::isTutorOfGroup(
         api_get_user_id(),
-        $groupInfo
+        api_get_group_entity()
     );
 }
 
diff --git a/public/plugin/bbb/listing.php b/public/plugin/bbb/listing.php
index 76ea64f03a..1ae846e3a2 100644
--- a/public/plugin/bbb/listing.php
+++ b/public/plugin/bbb/listing.php
@@ -379,9 +379,9 @@ if (false === $bbb->isGlobalConference() &&
         $groups = GroupManager::get_groups();
     } else {
         if (!empty($groupId)) {
-            $groupInfo = GroupManager::get_group_properties($groupId);
-            if ($groupInfo) {
-                $isSubscribed = GroupManager::is_user_in_group(api_get_user_id(), $groupInfo);
+            $group = api_get_group_entity($groupId);
+            if ($group) {
+                $isSubscribed = GroupManager::isUserInGroup(api_get_user_id(), $group);
                 if (false === $isSubscribed) {
                     api_not_allowed(true);
                 }
diff --git a/public/plugin/zoom/lib/ZoomPlugin.php b/public/plugin/zoom/lib/ZoomPlugin.php
index 5b893a4d95..32237133c8 100644
--- a/public/plugin/zoom/lib/ZoomPlugin.php
+++ b/public/plugin/zoom/lib/ZoomPlugin.php
@@ -968,8 +968,7 @@ class ZoomPlugin extends Plugin
 
                     if ($isSubscribed) {
                         if ($meeting->isCourseGroupMeeting()) {
-                            $groupInfo = GroupManager::get_group_properties($meeting->getGroup()->getIid(), true);
-                            $isInGroup = GroupManager::is_user_in_group($userId, $groupInfo);
+                            $isInGroup = GroupManager::isUserInGroup($userId, $meeting->getGroup());
                             if (false === $isInGroup) {
                                 throw new Exception($this->get_lang('YouAreNotRegisteredToThisMeeting'));
                             }
diff --git a/src/CoreBundle/Security/Authorization/Voter/GroupVoter.php b/src/CoreBundle/Security/Authorization/Voter/GroupVoter.php
index 19dbb77c2f..bee37f3f5a 100644
--- a/src/CoreBundle/Security/Authorization/Voter/GroupVoter.php
+++ b/src/CoreBundle/Security/Authorization/Voter/GroupVoter.php
@@ -79,14 +79,9 @@ class GroupVoter extends Voter
         }
         /** @var CGroup $group */
         $group = $subject;
-        $groupInfo = [
-            'iid' => $group->getIid(),
-            'session_id' => 0,
-            'status' => $group->getStatus(),
-        ];
 
         // Legacy
-        return \GroupManager::userHasAccessToBrowse($user->getId(), $groupInfo);
+        return \GroupManager::userHasAccessToBrowse($user->getId(), $group);
 
         switch ($attribute) {
             case self::VIEW: