From 6e76cbb0e41a9fc8c79989fe919071e2f9aac450 Mon Sep 17 00:00:00 2001
From: Sho Kusano <rosylilly@aduca.org>
Date: Sun, 18 Feb 2024 20:49:29 +0900
Subject: [PATCH] Reject spammer

---
 app/lib/activitypub/activity/create.rb | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index 58d094023..0ddd798a5 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -84,8 +84,16 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     ApplicationRecord.transaction do
       @status = Status.create!(@params)
       attach_tags(@status)
+
+      # Delete status on zero follower user and nearly created account with include some replies
+      if like_a_spam?
+        @status = nil
+        raise ActiveRecord::Rollback
+      end
     end
 
+    return if @status.nil?
+
     resolve_thread(@status)
     fetch_replies(@status)
     distribute
@@ -445,4 +453,12 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   rescue
     nil
   end
+  def like_a_spam?
+    (
+      !@status.account.local? &&
+      @status.account.followers_count.zero? &&
+      @status.account.created_at > 1.day.ago &&
+      @mentions.count >= 2
+    )
+  end
 end