1 files changed, 65 insertions, 0 deletions
diff --git a/app/lib/activitypub/forwarder.rb b/app/lib/activitypub/forwarder.rb
new file mode 100644
index 000000000..4206b9d82
--- /dev/null
+++ b/app/lib/activitypub/forwarder.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+class ActivityPub::Forwarder
+  def initialize(account, original_json, status)
+    @json    = original_json
+    @account = account
+    @status  = status
+  end
+
+  def forwardable?
+    @json['signature'].present? && @status.distributable?
+  end
+
+  def forward!
+    ActivityPub::LowPriorityDeliveryWorker.push_bulk(inboxes) do |inbox_url|
+      [payload, signature_account_id, inbox_url]
+    end
+  end
+
+  private
+
+  def payload
+    @payload ||= Oj.dump(@json)
+  end
+
+  def reblogged_by_account_ids
+    @reblogged_by_account_ids ||= @status.reblogs.includes(:account).references(:account).merge(Account.local).pluck(:account_id)
+  end
+
+  def signature_account_id
+    @signature_account_id ||= begin
+      if in_reply_to_local?
+        in_reply_to.account_id
+      else
+        reblogged_by_account_ids.first
+      end
+    end
+  end
+
+  def inboxes
+    @inboxes ||= begin
+      arr  = inboxes_for_followers_of_reblogged_by_accounts
+      arr += inboxes_for_followers_of_replied_to_account if in_reply_to_local?
+      arr -= [@account.preferred_inbox_url]
+      arr.uniq!
+      arr
+    end
+  end
+
+  def inboxes_for_followers_of_reblogged_by_accounts
+    Account.where(id: ::Follow.where(target_account_id: reblogged_by_account_ids).select(:account_id)).inboxes
+  end
+
+  def inboxes_for_followers_of_replied_to_account
+    in_reply_to.account.followers.inboxes
+  end
+
+  def in_reply_to
+    @status.thread
+  end
+
+  def in_reply_to_local?
+    @status.thread&.account&.local?
+  end
+end