From f057a2aef9b4af9f1cb46f0a077958e0748d7afa Mon Sep 17 00:00:00 2001
From: Mihail Geshoski <mihail@moodle.com>
Date: Wed, 29 Mar 2023 10:59:13 +0800
Subject: [PATCH] MDL-76445 grade: Helper that returns all gradable users in a
 course

---
 grade/lib.php            | 31 ++++++++++++++++++++
 grade/tests/lib_test.php | 63 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)

diff --git a/grade/lib.php b/grade/lib.php
index 1d68991383a..f069d54da72 100644
--- a/grade/lib.php
+++ b/grade/lib.php
@@ -781,6 +781,37 @@ function grade_get_plugin_info($courseid, $active_type, $active_plugin) {
     return $plugin_info;
 }
 
+/**
+ * Load a valid list of gradable users in a course.
+ *
+ * @param int $courseid The course ID.
+ * @param int|null $groupid The group ID (optional).
+ * @return array $users A list of enrolled gradable users.
+ */
+function get_gradable_users(int $courseid, ?int $groupid = null): array {
+    global $CFG;
+
+    $context = context_course::instance($courseid);
+    // Create a graded_users_iterator because it will properly check the groups etc.
+    $defaultgradeshowactiveenrol = !empty($CFG->grade_report_showonlyactiveenrol);
+    $onlyactiveenrol = get_user_preferences('grade_report_showonlyactiveenrol', $defaultgradeshowactiveenrol) ||
+        !has_capability('moodle/course:viewsuspendedusers', $context);
+
+    $course = get_course($courseid);
+    $gui = new graded_users_iterator($course, null, $groupid);
+    $gui->require_active_enrolment($onlyactiveenrol);
+    $gui->init();
+
+    // Flatten the users.
+    $users = [];
+    while ($user = $gui->next_user()) {
+        $users[$user->user->id] = $user->user;
+    }
+    $gui->close();
+
+    return $users;
+}
+
 /**
  * A simple class containing info about grade plugins.
  * Can be subclassed for special rules
diff --git a/grade/tests/lib_test.php b/grade/tests/lib_test.php
index a8173ef80b1..eedff6ddc07 100644
--- a/grade/tests/lib_test.php
+++ b/grade/tests/lib_test.php
@@ -711,4 +711,67 @@ class lib_test extends \advanced_testcase {
         $this->assertArrayHasKey('assign', $gradeitems2);
         $this->assertArrayHasKey('manual', $gradeitems2);
     }
+
+    /**
+     * Test get_gradable_users() function.
+     *
+     * @covers ::get_gradable_users
+     */
+    public function test_get_gradable_users() {
+        global $DB;
+
+        $this->setAdminUser();
+        $this->resetAfterTest(true);
+
+        $roleteacher = $DB->get_record('role', ['shortname' => 'teacher'], '*', MUST_EXIST);
+
+        // Create a course.
+        $course = $this->getDataGenerator()->create_course();
+        $coursecontext = \context_course::instance($course->id);
+        // Create groups.
+        $group1 = $this->getDataGenerator()->create_group(['courseid' => $course->id]);
+        $group2 = $this->getDataGenerator()->create_group(['courseid' => $course->id]);
+        // Create and enrol a teacher and some students into the course.
+        $teacher = $this->getDataGenerator()->create_and_enrol($course, 'teacher');
+        $student1 = $this->getDataGenerator()->create_and_enrol($course, 'student');
+        $student2 = $this->getDataGenerator()->create_and_enrol($course, 'student');
+        $student3 = $this->getDataGenerator()->create_and_enrol($course, 'student');
+        // Add student1 and student2 to group1.
+        $this->getDataGenerator()->create_group_member(['groupid' => $group1->id, 'userid' => $student1->id]);
+        $this->getDataGenerator()->create_group_member(['groupid' => $group1->id, 'userid' => $student2->id]);
+        // Add student3 to group2.
+        $this->getDataGenerator()->create_group_member(['groupid' => $group2->id, 'userid' => $student3->id]);
+
+        // Perform a regrade before creating the report.
+        grade_regrade_final_grades($course->id);
+        // Should return all gradable users (only students).
+        $gradableusers = get_gradable_users($course->id);
+        $this->assertEqualsCanonicalizing([$student1->id, $student2->id, $student3->id], array_keys($gradableusers));
+
+        // Now, let's suspend the enrolment of student2.
+        $this->getDataGenerator()->enrol_user($student2->id, $course->id, 'student', 'manual', 0, 0, ENROL_USER_SUSPENDED);
+        // Should return only the active gradable users (student1 and student3).
+        $gradableusers = get_gradable_users($course->id);
+        $this->assertEqualsCanonicalizing([$student1->id, $student3->id], array_keys($gradableusers));
+
+        // Give teacher 'viewsuspendedusers' capability and set a preference to display suspended users.
+        assign_capability('moodle/course:viewsuspendedusers', CAP_ALLOW, $roleteacher->id, $coursecontext, true);
+        set_user_preference('grade_report_showonlyactiveenrol', false, $teacher);
+        accesslib_clear_all_caches_for_unit_testing();
+
+        $this->setUser($teacher);
+        // Should return all gradable users (including suspended enrolments).
+        $gradableusers = get_gradable_users($course->id);
+        $this->assertEqualsCanonicalizing([$student1->id, $student2->id, $student3->id], array_keys($gradableusers));
+
+        // Reactivate the course enrolment of student2.
+        $this->getDataGenerator()->enrol_user($student2->id, $course->id, 'student', 'manual', 0, 0, ENROL_USER_ACTIVE);
+        $this->setAdminUser();
+        // Should return all gradable users from group1 (student1 and student2).
+        $gradableusers = get_gradable_users($course->id, $group1->id);
+        $this->assertEqualsCanonicalizing([$student1->id, $student2->id], array_keys($gradableusers));
+        // Should return all gradable users from group2 (student3).
+        $gradableusers = get_gradable_users($course->id, $group2->id);
+        $this->assertEqualsCanonicalizing([$student3->id], array_keys($gradableusers));
+    }
 }