public class EngineController {
	private Posix.termios newtio;
	private Posix.termios restoretio;
	private int fd=-1;
	private int byterate;

	private void setup(string device, int rate, int bits, int stopbits) {
		Posix.speed_t baudrate = Posix.B9600;

		fd = Posix.open(device, Posix.O_RDWR /*| Posix.O_NONBLOCK*/);

		if(fd < 0) {
			fd = -1;
			stderr.printf("Could not open device!\n");
			return;
		}

		Posix.tcflush(fd, Posix.TCIOFLUSH);

		Posix.tcgetattr(fd, out restoretio);

		/* apply settings */
		switch(rate) {
			case 300:
				baudrate = Posix.B300;
				break;
			case 600:
				baudrate = Posix.B600;
				break;
			case 1200:
				baudrate = Posix.B1200;
				break;
			case 2400:
				baudrate = Posix.B2400;
				break;
			case 4800:
				baudrate = Posix.B4800;
				break;
			case 9600:
				baudrate = Posix.B9600;
				break;
			case 19200:
				baudrate = Posix.B19200;
				break;
			case 38400:
				baudrate = Posix.B38400;
				break;
			case 57600:
				baudrate = Posix.B57600;
				break;
			case 115200:
				baudrate = Posix.B115200;
				break;
			case 230400:
				baudrate = Posix.B230400;
				break;
			default:
				/* not supported */
				rate = 9600;
				break;
		}

		Posix.cfsetospeed(ref newtio, baudrate);
		Posix.cfsetispeed(ref newtio, baudrate);

		switch(bits) {
			case 5:
				newtio.c_cflag = (newtio.c_cflag & ~Posix.CSIZE) | Posix.CS5;
				break;
			case 6:
				newtio.c_cflag = (newtio.c_cflag & ~Posix.CSIZE) | Posix.CS6;
				break;
			case 7:
				newtio.c_cflag = (newtio.c_cflag & ~Posix.CSIZE) | Posix.CS7;
				break;
			case 8:
			default:
				newtio.c_cflag = (newtio.c_cflag & ~Posix.CSIZE) | Posix.CS8;
				break;
		}

		newtio.c_cflag |= Posix.CLOCAL | Posix.CREAD;

		newtio.c_cflag &= ~(Posix.PARENB | Posix.PARODD);

		/* TODO: parity */

		newtio.c_cflag &= ~Linux.Termios.CRTSCTS;

		if(stopbits == 2)
			newtio.c_cflag |= Posix.CSTOPB;
		else
			newtio.c_cflag &= ~Posix.CSTOPB;

		newtio.c_iflag = Posix.IGNBRK;

		newtio.c_lflag = 0;
		newtio.c_oflag = 0;

		newtio.c_cc[Posix.VTIME]=1;
		newtio.c_cc[Posix.VMIN]=1;

		newtio.c_lflag &= ~(Posix.ECHONL|Posix.NOFLSH);

		int mcs=0;
		Posix.ioctl(fd, Linux.Termios.TIOCMGET, out mcs);
		mcs |= Linux.Termios.TIOCM_RTS;
		Posix.ioctl(fd, Linux.Termios.TIOCMSET, out mcs);

		Posix.tcsetattr(fd, Posix.TCSANOW, newtio);

		this.byterate = rate/bits;
	}

	public EngineController(string device) {
		setup(device, 9600, 8, 1);
	}

	private ssize_t read(void *buf, size_t count) {
		if(fd >= 0)
			return Posix.read(fd, buf, count);
		else
			stderr.printf("not connected!\n");
		return 0;
	}

	private ssize_t write(void *buf, size_t count) {
		if(fd >= 0) {
			ssize_t size = Posix.write(fd, buf, count);
			return size;
		} else {
			stderr.printf("not connected!\n");
			return 0;
		}
	}

	public bool disable() {
		uint8[4] buf = new uint8[4];
		buf[0] = 0xDE;
		buf[1] = 0xAD;
		buf[2] = 0xBA;
		buf[3] = 0xBE;

		if(fd < 0) {
			stderr.printf("not connected!\n");
			return false;
		}

		write(buf, 4);
		read(buf, 1);

		if(buf[0] == '.')
			return true;
		else
			return false;
	}

	public bool enable() {
		uint8[4] buf = new uint8[4];
		buf[0] = 0xCA;
		buf[1] = 0xFE;
		buf[2] = 0xBA;
		buf[3] = 0xBE;

		if(fd < 0) {
			stderr.printf("not connected!\n");
			return false;
		}

		write(buf, 4);
		read(buf, 1);

		if(buf[0] == '.')
			return true;
		else
			return false;
	}

	public bool no_operation() {
		uint8[1] buf = new uint8[1];
		buf[0] = 0x00;

		if(fd < 0) {
			stderr.printf("not connected!\n");
			return false;
		}

		write(buf, 1);
		read(buf, 1);

		if(buf[0] == '.')
			return true;
		else
			return false;
	}

	public bool set_speed(uint8 engine, uint8 speed) {
		uint8[2] buf = new uint8[2];
		buf[0] = engine+1;
		buf[1] = speed;

		if(fd < 0) {
			stderr.printf("not connected!\n");
			return false;
		}

		if(engine > 5)
			return false;

		write(buf, 2);
		read(buf, 2);

		if(buf[0] == '.')
			return true;
		else
			return false;
	}

	public bool set_speed_all(uint8 speed) {
		uint8[2] buf = new uint8[2];
		buf[0] = 0xFF;
		buf[1] = speed;

		if(fd < 0) {
			stderr.printf("not connected!\n");
			return false;
		}

		write(buf, 2);
		read(buf, 2);

		if(buf[0] == '.')
			return true;
		else
			return false;
	}
}