#define NUNCHUK_BUFFER_SIZE 6

class Nunchuk {
public:
  void initialize();
  bool update();
  
  int joystick_x() const { return _buffer[0]; }
  int joystick_y() const { return _buffer[1]; }
  
  bool left()  const { return _buffer[0] < 50; }
  bool right() const { return _buffer[0] > 200; }
  bool up()    const { return _buffer[1] > 200; }
  bool down()  const { return _buffer[1] < 60; }
  
  int x_acceleration() const {
    return ((int)(_buffer[2]) << 2) | ((_buffer[5] >> 2) & 0x03);
  }
  int y_acceleration() const {
    return ((int)(_buffer[3]) << 2) | ((_buffer[5] >> 4) & 0x03);
  }
  int z_acceleration() const {
    return ((int)(_buffer[4]) << 2) | ((_buffer[5] >> 6) & 0x03);
  }
  
  bool z_button() const { return !(_buffer[5] & 0x01); }
  bool c_button() const { return !(_buffer[5] & 0x02); }

private:
  void request_data();
  char decode_byte(const char);
  
  unsigned char _buffer[NUNCHUK_BUFFER_SIZE];
};