MDL-22077 forum: Update post.php to respect private replies

mod/forum/classes/local/managers/capability.php

@@ -346,7 +346,7 @@ public function can_view_post(stdClass $user, discussion_entity $discussion, pos
      *
      */
     public function can_view_post_shell(stdClass $user, post_entity $post) : bool {
-        if (empty($post->get_private_reply_recipient_id())) {
+        if (!$post->is_private_reply()) {
             return true;
         }
 

mod/forum/classes/local/vaults/forum.php

@@ -155,4 +155,41 @@ public function get_from_course_module_ids(array $ids) : array {
 
         return $this->transform_db_records_to_entities($records);
     }
+
+    /**
+     * Get the forum entity for the given post id.
+     *
+     * @param int $id The course module id
+     * @return forum_entity|null
+     */
+    public function get_from_post_id(int $id) : ?forum_entity {
+        $db = $this->get_db();
+        $alias = $this->get_table_alias();
+        $tablefields = $db->get_preload_columns(self::TABLE, $alias);
+        $coursemodulefields = $db->get_preload_columns('course_modules', 'cm_');
+        $coursefields = $db->get_preload_columns('course', 'c_');
+
+        $fields = implode(', ', [
+            $db->get_preload_columns_sql($tablefields, $alias),
+            context_helper::get_preload_record_columns_sql('ctx'),
+            $db->get_preload_columns_sql($coursemodulefields, 'cm'),
+            $db->get_preload_columns_sql($coursefields, 'c'),
+        ]);
+
+        $tables = "{forum_posts} p";
+        $tables .= " JOIN {forum_discussions} d ON d.id = p.discussion";
+        $tables .= ' JOIN {' . self::TABLE . "} {$alias} ON {$alias}.id = d.forum";
+        $tables .= " JOIN {modules} m ON m.name = 'forum'";
+        $tables .= " JOIN {course_modules} cm ON cm.module = m.id AND cm.instance = {$alias}.id";
+        $tables .= ' JOIN {context} ctx ON ctx.contextlevel = ' . CONTEXT_MODULE .  ' AND ctx.instanceid = cm.id';
+        $tables .= " JOIN {course} c ON c.id = {$alias}.course";
+
+        $sql = "SELECT {$fields} FROM {$tables} WHERE p.id = :postid";
+        $records = $this->get_db()->get_records_sql($sql, [
+            'postid' => $id,
+        ]);
+
+        $records = $this->transform_db_records_to_entities($records);
+        return count($records) ? array_shift($records) : null;
+    }
 }

mod/forum/classes/local/vaults/post.php

@@ -265,6 +265,59 @@ public function get_reply_count_for_discussion_ids(stdClass $user, array $discus
         return $this->get_db()->get_records_sql_menu($sql, array_merge($params, $privateparams));
     }
 
+    /**
+     * Get a mapping of replies to the specified discussions.
+     *
+     * @param   stdClass    $user The user to check the unread count for
+     * @param   int         $postid The post to collect replies to
+     * @param   int         $discussionid The list of discussions to fetch counts for
+     * @param   bool        $canseeprivatereplies Whether this user can see all private replies or not
+     * @return  int         The number of replies for each discussion returned in an associative array
+     */
+    public function get_reply_count_for_post_id_in_discussion_id(
+            stdClass $user, int $postid, int $discussionid, bool $canseeprivatereplies) : int {
+        [
+            'where' => $privatewhere,
+            'params' => $privateparams,
+        ] = $this->get_private_reply_sql($user, $canseeprivatereplies);
+
+        $alias = $this->get_table_alias();
+        $table = self::TABLE;
+
+        $sql = "SELECT {$alias}.id, {$alias}.parent
+                  FROM {{$table}} {$alias}
+                 WHERE p.discussion = :discussionid {$privatewhere}";
+
+        $postparents = $this->get_db()->get_records_sql_menu($sql, array_merge([
+                'discussionid' => $discussionid,
+            ], $privateparams));
+
+        return $this->count_children_from_parent_recursively($postparents, $postid);
+    }
+
+    /**
+     * Count the children whose parent matches the current record recursively.
+     *
+     * @param   array   $postparents The full mapping of posts.
+     * @param   int     $postid The ID to check for
+     * @return  int     $count
+     */
+    private function count_children_from_parent_recursively(array $postparents, int $postid) : int {
+        if (!isset($postparents[$postid])) {
+            // Post not found at all.
+            return 0;
+        }
+
+        $count = 0;
+        foreach ($postparents as $pid => $parentid) {
+            if ($postid == $parentid) {
+                $count += $this->count_children_from_parent_recursively($postparents, $pid) + 1;
+            }
+        }
+
+        return $count;
+    }
+
     /**
      * Get a mapping of unread post counts for the specified discussions.
      *
@@ -308,7 +361,8 @@ public function get_unread_count_for_discussion_ids(stdClass $user, array $discu
      * @param   bool        $canseeprivatereplies Whether this user can see all private replies or not
      * @return  int[]       The post id of the most recent post for each discussions returned in an associative array
      */
-    public function get_latest_post_id_for_discussion_ids(stdClass $user, array $discussionids, bool $canseeprivatereplies) : array {
+    public function get_latest_post_id_for_discussion_ids(
+            stdClass $user, array $discussionids, bool $canseeprivatereplies) : array {
         global $CFG;
 
         if (empty($discussionids)) {

mod/forum/deprecatedlib.php

@@ -1620,3 +1620,33 @@ function forum_print_latest_discussions($course, $forum, $maxdiscussions = -1, $
         echo $OUTPUT->paging_bar($numdiscussions, $page, $perpage, "view.php?f=$forum->id");
     }
 }
+
+/**
+ * Count the number of replies to the specified post.
+ *
+ * @param object $post
+ * @param bool $children
+ * @return int
+ * @deprecated since Moodle 3.7
+ */
+function forum_count_replies($post, $children = true) {
+    global $USER;
+    debugging('forum_count_replies has been deprecated. Please use the Post vault instead.', DEBUG_DEVELOPER);
+
+    if (!$children) {
+        return $DB->count_records('forum_posts', array('parent' => $post->id));
+    }
+
+    $entityfactory = mod_forum\local\container::get_entity_factory();
+    $postentity = $entityfactory->get_post_from_stdclass($post);
+
+    $vaultfactory = mod_forum\local\container::get_vault_factory();
+    $postvault = $vaultfactory->get_post_vault();
+
+    return $postvault->get_reply_count_for_post_id_in_discussion_id(
+            $USER,
+            $postentity->get_id(),
+            $postentity->get_discussion_id(),
+            true
+        );
+}

mod/forum/lang/en/forum.php

@@ -60,6 +60,7 @@
 $string['cannotcreatediscussion'] = 'Could not create new discussion';
 $string['cannotcreateinstanceforteacher'] = 'Could not create new course module instance for the teacher forum';
 $string['cannotdeletepost'] = 'You can\'t delete this post!';
+$string['cannotdeletediscussioninsinglediscussion'] = 'You cannot delete the first post in a single discussion';
 $string['cannoteditposts'] = 'You can\'t edit other people\'s posts!';
 $string['cannotfinddiscussion'] = 'Could not find the discussion in this forum';
 $string['cannotfindfirstpost'] = 'Could not find the first post in this forum';

mod/forum/lib.php

@@ -3478,30 +3478,6 @@ function forum_trigger_content_uploaded_event($post, $cm, $name) {
     return true;
 }
 
-/**
- * @global object
- * @param object $post
- * @param bool $children
- * @return int
- */
-function forum_count_replies($post, $children=true) {
-    global $DB;
-    $count = 0;
-
-    if ($children) {
-        if ($childposts = $DB->get_records('forum_posts', array('parent' => $post->id))) {
-           foreach ($childposts as $childpost) {
-               $count ++;                   // For this child
-               $count += forum_count_replies($childpost, true);
-           }
-        }
-    } else {
-        $count += $DB->count_records('forum_posts', array('parent' => $post->id));
-    }
-
-    return $count;
-}
-
 /**
  * Given a new post, subscribes or unsubscribes as appropriate.
  * Returns some text which describes what happened.