mastodon/app/services/authorize_follow_service.rb

# frozen_string_literal: true

class AuthorizeFollowService < BaseService
  def call(source_account, target_account, **options)
    if options[:skip_follow_request]
      follow_request = FollowRequest.new(account: source_account, target_account: target_account)
    else
      follow_request = FollowRequest.find_by!(account: source_account, target_account: target_account)
      follow_request.authorize!
    end

    create_notification(follow_request) unless source_account.local?
    follow_request
  end

  private

  def create_notification(follow_request)
    if follow_request.account.ostatus?
      NotificationWorker.perform_async(build_xml(follow_request), follow_request.target_account_id, follow_request.account_id)
    elsif follow_request.account.activitypub?
      ActivityPub::DeliveryWorker.perform_async(build_json(follow_request), follow_request.target_account_id, follow_request.account.inbox_url)
    end
  end

  def build_json(follow_request)
    Oj.dump(ActivityPub::LinkedDataSignature.new(ActiveModelSerializers::SerializableResource.new(
      follow_request,
      serializer: ActivityPub::AcceptFollowSerializer,
      adapter: ActivityPub::Adapter
    ).as_json).sign!(follow_request.target_account))
  end

  def build_xml(follow_request)
    OStatus::AtomSerializer.render(OStatus::AtomSerializer.new.authorize_follow_request_salmon(follow_request))
  end
end