From e66b915c40518bd1d9885c907fd2bb4ae0fd8135 Mon Sep 17 00:00:00 2001
From: Mark Nelson <markn@moodle.com>
Date: Thu, 18 Oct 2018 21:17:12 +0800
Subject: [PATCH] MDL-63691 core_message: added
 api::can_create_group_conversation

---
 message/classes/api.php    | 19 +++++++++++++++++++
 message/tests/api_test.php | 29 +++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/message/classes/api.php b/message/classes/api.php
index b3e78288352..317d40d2b6e 100644
--- a/message/classes/api.php
+++ b/message/classes/api.php
@@ -1385,6 +1385,25 @@ class api {
         return $conversation->id;
     }
 
+    /**
+     * Checks if a user can create a group conversation.
+     *
+     * @param int $userid The id of the user attempting to create the conversation
+     * @param \context $context The context they are creating the conversation from, most likely course context
+     * @return bool
+     */
+    public static function can_create_group_conversation(int $userid, \context $context) : bool {
+        global $CFG;
+
+        // If we can't message at all, then we can't create a conversation.
+        if (empty($CFG->messaging)) {
+            return false;
+        }
+
+        // We need to check they have the capability to create the conversation.
+        return has_capability('moodle/course:creategroupconversations', $context, $userid);
+    }
+
     /**
      * Checks if a user can create a contact request.
      *
diff --git a/message/tests/api_test.php b/message/tests/api_test.php
index 8be0f3f6070..d67f36363a6 100644
--- a/message/tests/api_test.php
+++ b/message/tests/api_test.php
@@ -2416,6 +2416,35 @@ class core_message_api_testcase extends core_message_messagelib_testcase {
         $this->assertFalse(\core_message\api::is_user_in_conversation($user3->id, $conversationid));
     }
 
+    /**
+     * Test can create a group conversation.
+     */
+    public function test_can_create_group_conversation() {
+        global $CFG;
+
+        $student = self::getDataGenerator()->create_user();
+        $teacher = self::getDataGenerator()->create_user();
+        $course = self::getDataGenerator()->create_course();
+
+        $coursecontext = context_course::instance($course->id);
+
+        $this->getDataGenerator()->enrol_user($student->id, $course->id);
+        $this->getDataGenerator()->enrol_user($teacher->id, $course->id, 'editingteacher');
+
+        // Disable messaging.
+        $CFG->messaging = 0;
+        $this->assertFalse(\core_message\api::can_create_group_conversation($student->id, $coursecontext));
+
+        // Re-enable messaging.
+        $CFG->messaging = 1;
+
+        // Student shouldn't be able to.
+        $this->assertFalse(\core_message\api::can_create_group_conversation($student->id, $coursecontext));
+
+        // Teacher should.
+        $this->assertTrue(\core_message\api::can_create_group_conversation($teacher->id, $coursecontext));
+    }
+
     /**
      * Comparison function for sorting contacts.
      *