class ElasticAPM::Subscriber

def finish(_name, id, _payload)
  # debug "AS::Notification#finish:#{name}:#{id}"
  return unless (transaction = @agent.current_transaction)
  while (notification = transaction.notifications.pop)
    next unless notification.id == id
    if (span = notification.span)
      @agent.end_span if span == @agent.current_span
    end
    return
  end
end

def initialize(agent)
  @agent = agent
  @normalizers = Normalizers.build(agent.config)
end

def notifications_regex
  @notifications_regex ||= /(#{@normalizers.keys.join('|')})/
end

def register!
  unregister! if @subscription
  @subscription =
    ActiveSupport::Notifications.subscribe(notifications_regex, self)
end

def start(name, id, payload)
  # debug "AS::Notification#start:#{name}:#{id}"
  return unless (transaction = @agent.current_transaction)
  normalized = @normalizers.normalize(transaction, name, payload)
  span =
    if normalized == :skip
      nil
    else
      name, type, context = normalized
      @agent.start_span(name, type, context: context)
    end
  transaction.notifications << Notification.new(id, span)
end

def unregister!
  ActiveSupport::Notifications.unsubscribe @subscription
  @subscription = nil
end