class MQTT::Packet::Connect

def parse_body(buffer)
  super(buffer)
  @protocol_name = shift_string(buffer)
  @protocol_level = shift_byte(buffer).to_i
  if @protocol_name == 'MQIsdp' && @protocol_level == 3
    @version = '3.1.0'
  elsif @protocol_name == 'MQTT' && @protocol_level == 4
    @version = '3.1.1'
  else
    raise ProtocolException, "Unsupported protocol: #{@protocol_name}/#{@protocol_level}"
  end
  @connect_flags = shift_byte(buffer)
  @clean_session = ((@connect_flags & 0x02) >> 1) == 0x01
  @keep_alive = shift_short(buffer)
  @client_id = shift_string(buffer)
  if ((@connect_flags & 0x04) >> 2) == 0x01
    # Last Will and Testament
    @will_qos = ((@connect_flags & 0x18) >> 3)
    @will_retain = ((@connect_flags & 0x20) >> 5) == 0x01
    @will_topic = shift_string(buffer)
    # The MQTT v3.1 specification says that the payload is a UTF-8 string
    @will_payload = shift_string(buffer)
  end
  if ((@connect_flags & 0x80) >> 7) == 0x01 && buffer.bytesize > 0
    @username = shift_string(buffer)
  end
  if ((@connect_flags & 0x40) >> 6) == 0x01 && buffer.bytesize > 0 # rubocop: disable Style/GuardClause
    @password = shift_string(buffer)
  end
end