Implement a command to rebuild the conversation stats

files/lib/command/conversation/RebuildConversation.class.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace wcf\command\conversation;
+
+use wcf\data\conversation\Conversation;
+use wcf\data\conversation\ConversationEditor;
+use wcf\system\WCF;
+
+/**
+ * Rebuilds the conversation data.
+ *
+ * @author Olaf Braun
+ * @copyright 2001-2025 WoltLab GmbH
+ * @license GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @since 6.3
+ */
+final class RebuildConversation
+{
+    public function __construct(
+        private readonly Conversation $conversation
+    ) {}
+
+    public function __invoke(): void
+    {
+        ['messages' => $messages, 'attachments' => $attachments] = $this->getConversationStats($this->conversation->conversationID);
+
+        $editor = new ConversationEditor($this->conversation);
+        if ($messages === 0) {
+            $editor->delete();
+
+            return;
+        }
+
+        $editor->update([
+            'attachments' => $attachments,
+            'replies' => $messages - 1,
+        ]);
+
+        $editor->updateFirstMessage();
+        $editor->updateLastMessage();
+    }
+
+    /**
+     * @return array{attachments: int, messages: int}
+     */
+    private function getConversationStats(int $conversationID): array
+    {
+        $sql = "SELECT      COUNT(messageID) AS messages,
+                            COALESCE(SUM(attachments), 0) AS attachments
+                FROM        wcf1_conversation_message
+                WHERE       conversationID = ?";
+        $statement = WCF::getDB()->prepare($sql);
+        $statement->execute([$conversationID]);
+        $row = $statement->fetchArray();
+
+        return [
+            'messages' => $row['messages'],
+            'attachments' => $row['attachments'],
+        ];
+    }
+}

files/lib/data/conversation/ConversationAction.class.php

@@ -3,6 +3,7 @@
 namespace wcf\data\conversation;
 
 use wcf\command\conversation\MarkAllConversationsAsRead;
+use wcf\command\conversation\RebuildConversation;
 use wcf\data\AbstractDatabaseObjectAction;
 use wcf\data\conversation\message\ConversationMessageAction;
 use wcf\data\conversation\message\ConversationMessageList;
@@ -563,46 +564,17 @@ public function getConversations(): array
      * Rebuilds the conversation data of the relevant conversations.
      *
      * @return void
+     *
+     * @deprecated 6.3 Use the `RebuildConversation` command instead.
      */
     public function rebuild()
     {
         if (empty($this->objects)) {
             $this->readObjects();
         }
 
-        // collect number of messages for each conversation
-        $conditionBuilder = new PreparedStatementConditionBuilder();
-        $conditionBuilder->add('conversation_message.conversationID IN (?)', [$this->objectIDs]);
-        $sql = "SELECT      conversationID, COUNT(messageID) AS messages, SUM(attachments) AS attachments
-                FROM        wcf1_conversation_message conversation_message
-                " . $conditionBuilder . "
-                GROUP BY    conversationID";
-        $statement = WCF::getDB()->prepare($sql);
-        $statement->execute($conditionBuilder->getParameters());
-
-        $objectIDs = [];
-        while ($row = $statement->fetchArray()) {
-            if (!$row['messages']) {
-                continue;
-            }
-            $objectIDs[] = $row['conversationID'];
-
-            $conversationEditor = new ConversationEditor(new Conversation(null, [
-                'conversationID' => $row['conversationID'],
-            ]));
-            $conversationEditor->update([
-                'attachments' => $row['attachments'],
-                'replies' => $row['messages'] - 1,
-            ]);
-            $conversationEditor->updateFirstMessage();
-            $conversationEditor->updateLastMessage();
-        }
-
-        // delete conversations without messages
-        $deleteConversationIDs = \array_diff($this->objectIDs, $objectIDs);
-        if (!empty($deleteConversationIDs)) {
-            $conversationAction = new self($deleteConversationIDs, 'delete');
-            $conversationAction->executeAction();
+        foreach ($this->objects as $editor) {
+            (new RebuildConversation($editor->getDecoratedObject()))();
         }
     }
 }

files/lib/data/conversation/message/ConversationMessageAction.class.php

@@ -2,6 +2,7 @@
 
 namespace wcf\data\conversation\message;
 
+use wcf\command\conversation\RebuildConversation;
 use wcf\data\AbstractDatabaseObjectAction;
 use wcf\data\conversation\Conversation;
 use wcf\data\conversation\ConversationAction;
@@ -242,21 +243,19 @@ public function delete()
     {
         $count = parent::delete();
 
-        $attachmentMessageIDs = $conversationIDs = [];
+        $attachmentMessageIDs = $conversations = [];
         foreach ($this->getObjects() as $message) {
-            if (!\in_array($message->conversationID, $conversationIDs)) {
-                $conversationIDs[] = $message->conversationID;
+            if (!\array_key_exists($message->conversationID, $conversations)) {
+                $conversations[$message->conversationID] = $message->getConversation();
             }
 
             if ($message->attachments) {
                 $attachmentMessageIDs[] = $message->messageID;
             }
         }
 
-        // rebuild conversations
-        if (!empty($conversationIDs)) {
-            $conversationAction = new ConversationAction($conversationIDs, 'rebuild');
-            $conversationAction->executeAction();
+        foreach ($conversations as $conversation) {
+            (new RebuildConversation($conversation))();
         }
 
         if (!empty($this->objectIDs)) {