/* This file implements system calls that are not compatible with UNIX */
/* Moved to libntp/termios.c */

#include <config.h>
#include <io.h>
#include <stdio.h>

#include "ntp.h"
#include "ntp_tty.h"
#include "lib_strbuf.h"
#include "ntp_assert.h"
#include "win32_io.h"

#define MAX_SERIAL 255	/* COM1: - COM255: */

typedef struct comhandles_tag {
	HANDLE		h;
	size_t		opens;
	HANDLE *	dupes;
} comhandles;

comhandles *	hnds;	/* handle/dupes array */
size_t		c_hnds;	/* current array size */

/*
 * common_serial_open ensures duplicate opens of the same port
 * work by duplicating the handle for the 2nd open, allowing
 * refclock_atom to share a GPS refclock's comm port.
 */
HANDLE
common_serial_open(
	const char *	dev,
	char **		pwindev
	)
{
	char *		windev;
	HANDLE		handle;
	size_t		unit;
	size_t		prev_c_hnds;
	size_t		opens;
	const char *	pch;

	/*
	 * This is odd, but we'll take any unix device path
	 * by looking for the initial '/' and strip off everything
	 * before the final digits, then translate that to COM__:
	 * maintaining backward compatibility with NTP practice of
	 * mapping unit 0 to the nonfunctional COM0:
	 *
	 * To ease the job of taking the windows COMx: device names
	 * out of reference clocks, we'll also work with those
	 * equanimously.
	 */

	TRACE(1, ("common_serial_open given %s\n", dev));

	pch = NULL;
	if ('/' == dev[0]) {
		pch = dev + strlen(dev) - 1;

		if (isdigit(pch[0])) {
			while (isdigit(pch[0])) {
				pch--;
			}
			pch++;
		}
		TRACE(1, ("common_serial_open skipped to ending digits leaving %s\n", pch));
	} else if ('c' == tolower(dev[0])
		   && 'o' == tolower(dev[1])
		   && 'm' == tolower(dev[2])) {
		pch = dev + 3;
		TRACE(1, ("common_serial_open skipped COM leaving %s\n", pch));
	}

	if (!pch || !isdigit(pch[0])) {
		TRACE(1, ("not a digit: %s\n", pch ? pch : "[NULL]"));
		return INVALID_HANDLE_VALUE;
	}

	if (1 != sscanf(pch, "%d", &unit) 
	    || unit > MAX_SERIAL
	    || unit < 0) {
		TRACE(1, ("sscanf failure of %s\n", pch));
		return INVALID_HANDLE_VALUE;
	}


	if (c_hnds < unit + 1) {
		prev_c_hnds = c_hnds;
		c_hnds = unit + 1;
		/* round up to closest multiple of 4 to avoid churn */
		c_hnds = (c_hnds + 3) & ~3;
		hnds = erealloc_zero(hnds, c_hnds * sizeof(hnds[0]),
				     prev_c_hnds * sizeof(hnds[0]));
	}

	if (NULL == hnds[unit].h) {
		INSIST(0 == hnds[unit].opens);
		LIB_GETBUF(windev);
		snprintf(windev, LIB_BUFLENGTH, "\\\\.\\COM%d", unit);
		TRACE(1, ("windows device %s\n", windev));
		*pwindev = windev;
		hnds[unit].h =
		    CreateFile(
			windev,
			GENERIC_READ | GENERIC_WRITE,
			0, /* sharing prohibited */
			NULL, /* default security */
			OPEN_EXISTING,
			FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
			NULL);
		if (INVALID_HANDLE_VALUE == hnds[unit].h)
			hnds[unit].h = NULL;
	}

	if (NULL != hnds[unit].h) {
		/* think handle = dup(hnds[unit].h); */
		DuplicateHandle(
			GetCurrentProcess(),
			hnds[unit].h,
			GetCurrentProcess(),
			&handle,
			0,
			FALSE,
			DUPLICATE_SAME_ACCESS
			);
		hnds[unit].opens++;
		opens = hnds[unit].opens;
		hnds[unit].dupes = erealloc(hnds[unit].dupes, opens *
					    sizeof(hnds[unit].dupes[0]));
		hnds[unit].dupes[opens - 1] = handle;
		return handle;
	}

	return INVALID_HANDLE_VALUE;
}


/*
 * closeserial() is used in place of close by ntpd refclock I/O for ttys
 */
int
closeserial(int fd)
{
	HANDLE	h;
	BOOL	found;
	size_t	u;
	size_t	d;

	h = (HANDLE)_get_osfhandle(fd);
	if (INVALID_HANDLE_VALUE == h) {
		errno = EBADF;
		return -1;
	}

	d = 0;		/* silence potent. uninit. warning */
	found = FALSE;
	for (u = 0; u < c_hnds; u++) {
		for (d = 0; d < hnds[u].opens; d++) {
			if (hnds[u].dupes[d] == h) {
				found = TRUE;
				break;
			}
		}
		if (found)
			break;
	}
	if (found) {
		hnds[u].opens--;
		if (d < hnds[u].opens)
			memmove(&hnds[u].dupes[d],
				&hnds[u].dupes[d + 1],
				hnds[u].opens - d *
				    sizeof(hnds[u].dupes[d]));
		if (0 == hnds[u].opens) {
			CloseHandle(hnds[u].h);
			hnds[u].h = NULL;
		}
	}

	return close(fd);
}

/*
 * isserialhandle() -- check if a handle is a COM port handle
 */
int isserialhandle(
	HANDLE h
	)
{
	size_t	u;
	size_t	d;


	for (u = 0; u < c_hnds; u++)
		for (d = 0; d < hnds[u].opens; d++)
			if (hnds[u].dupes[d] == h)
				return TRUE;
	return FALSE;
}


/*
 * tty_open - open serial port for refclock special uses
 *
 * This routine opens a serial port for and returns the 
 * file descriptor if success and -1 if failure.
 */
int tty_open(
	const char *dev,	/* device name pointer */
	int access,		/* O_RDWR */
	int mode		/* unused */
	)
{
	HANDLE	Handle;
	char *	windev;

	/*
	 * open communication port handle
	 */
	windev = NULL;
	Handle = common_serial_open(dev, &windev);
	windev = (windev)
		     ? windev
		     : dev;

	if (Handle == INVALID_HANDLE_VALUE) {  
		msyslog(LOG_ERR, "tty_open: device %s CreateFile error: %m", windev);
		errno = EMFILE; /* lie, lacking conversion from GetLastError() */
		return -1;
	}

	return (int)_open_osfhandle((intptr_t)Handle, _O_TEXT);
}


/*
 * refclock_open - open serial port for reference clock
 *
 * This routine opens a serial port for I/O and sets default options. It
 * returns the file descriptor or -1 indicating failure.
 */
int
refclock_open(
	const char *	dev,	/* device name pointer */
	u_int		speed,	/* serial port speed (code) */
	u_int		flags	/* line discipline flags */
	)
{
	char *		windev;
	HANDLE		h;
	COMMTIMEOUTS	timeouts;
	DCB		dcb;
	DWORD		dwEvtMask;
	int		fd;
	int		translate;

	/*
	 * open communication port handle
	 */
	windev = NULL;
	h = common_serial_open(dev, &windev);
	windev = (windev) ? windev : dev;

	if (INVALID_HANDLE_VALUE == h) {
		SAVE_ERRNO(
			msyslog(LOG_ERR, "CreateFile(%s) error: %m",
				windev);
		)
		return -1;
	}

	/* Change the input/output buffers to be large. */
	if (!SetupComm(h, 1024, 1024)) {
		SAVE_ERRNO(
			msyslog(LOG_ERR, "SetupComm(%s) error: %m",
				windev);
		)
		return -1;
	}

	dcb.DCBlength = sizeof(dcb);

	if (!GetCommState(h, &dcb)) {
		SAVE_ERRNO(
			msyslog(LOG_ERR,
				"GetCommState(%s) error: %m",
				windev);
		)
		return -1;
	}

	switch (speed) {

	case B300:
		dcb.BaudRate = 300;
		break;

	case B1200:  
		dcb.BaudRate = 1200;
		break;

	case B2400:
		dcb.BaudRate = 2400;
		break;

	case B4800:
		dcb.BaudRate = 4800;
		break;

	case B9600:
		dcb.BaudRate = 9600;
		break;

	case B19200:
		dcb.BaudRate = 19200;
		break;

	case B38400:
		dcb.BaudRate = 38400;
		break;

	case B57600:
		dcb.BaudRate = 57600;
		break;

	case B115200:
		dcb.BaudRate = 115200;
		break;

	default:
		msyslog(LOG_ERR, "%s unsupported bps code %u", windev,
			speed);
		SetLastError(ERROR_INVALID_PARAMETER);
		return -1;
	}

	dcb.fBinary = TRUE;
	dcb.fParity = TRUE;
	dcb.fOutxCtsFlow = 0;
	dcb.fOutxDsrFlow = 0;
	dcb.fDtrControl = DTR_CONTROL_ENABLE;
	dcb.fDsrSensitivity = 0;
	dcb.fTXContinueOnXoff = TRUE;
	dcb.fOutX = 0; 
	dcb.fInX = 0;
	dcb.fErrorChar = 0;
	dcb.fNull = 0;
	dcb.fRtsControl = RTS_CONTROL_DISABLE;
	dcb.fAbortOnError = 0;
	dcb.ByteSize = 8;
	dcb.StopBits = ONESTOPBIT;
	dcb.Parity = NOPARITY;
	dcb.ErrorChar = 0;
	dcb.EofChar = 0;
	if (LDISC_RAW & flags)
		dcb.EvtChar = 0;
	else
		dcb.EvtChar = '\r';

	if (!SetCommState(h, &dcb)) {
		SAVE_ERRNO(
			msyslog(LOG_ERR, "SetCommState(%s) error: %m",
				windev);
		)
		return -1;
	}

	/* watch out for CR (dcb.EvtChar) as well as the CD line */
	dwEvtMask = EV_RLSD;
	if (LDISC_RAW & flags)
		dwEvtMask |= EV_RXCHAR;
	else
		dwEvtMask |= EV_RXFLAG;
	if (!SetCommMask(h, dwEvtMask)) {
		SAVE_ERRNO(
			msyslog(LOG_ERR, "SetCommMask(%s) error: %m",
				windev);
		)
		return -1;
	}

	/* configure the handle to never block */
	timeouts.ReadIntervalTimeout = MAXDWORD;
	timeouts.ReadTotalTimeoutMultiplier = 0;
	timeouts.ReadTotalTimeoutConstant = 0;
	timeouts.WriteTotalTimeoutMultiplier = 0;
	timeouts.WriteTotalTimeoutConstant = 0;

	if (!SetCommTimeouts(h, &timeouts)) {
		SAVE_ERRNO(
			msyslog(LOG_ERR,
				"Device %s SetCommTimeouts error: %m",
				windev);
		)
		return -1;
	}

	translate = (LDISC_RAW & flags)
			? 0
			: _O_TEXT;
	fd = _open_osfhandle((intptr_t)h, translate);
	/* refclock_open() long returned 0 on failure, avoid it. */
	if (0 == fd) {
		fd = _dup(0);
		_close(0);
	}

	return fd;
}


int
ioctl_tiocmget(
	HANDLE h,
	int *pi
	)
{
	DWORD	dw;

	if (!GetCommModemStatus(h, &dw)) {
		errno = ENOTTY;
		return -1;
	}

	*pi = ((dw & MS_CTS_ON)  ? TIOCM_CTS : 0)
	    | ((dw & MS_DSR_ON)  ? TIOCM_DSR : 0)
	    | ((dw & MS_RLSD_ON) ? TIOCM_CAR : 0)
	    | ((dw & MS_RING_ON) ? TIOCM_RI  : 0);

	return 0;
}


int
ioctl_tiocmset(
	HANDLE h,
	int *pi
	)
{
	BOOL	failed;
	int	result;
	
	failed = !EscapeCommFunction(
			h, 
			(*pi & TIOCM_RTS) 
			    ? SETRTS
			    : CLRRTS
			);

	if (!failed)
		failed = !EscapeCommFunction(
				h, 
				(*pi & TIOCM_DTR) 
				    ? SETDTR
				    : CLRDTR
				);

	if (failed) {
		errno = ENOTTY;
		result = -1;
	} else
		result = 0;

	return result;
}


int 
ioctl(
	int fd,
	int op,
	void *pv
	)
{
	HANDLE	h;
	int	result;
	int	modctl;
	int *pi = (int *) pv;
	
	h = (HANDLE)_get_osfhandle(fd);

	if (INVALID_HANDLE_VALUE == h) {
		/* errno already set */
		return -1;
	}

	switch (op) {

	case TIOCMGET:
		result = ioctl_tiocmget(h, pi);
		break;

	case TIOCMSET:
		result = ioctl_tiocmset(h, pi);
		break;

	case TIOCMBIC:
		result = ioctl_tiocmget(h, &modctl);
		if (result < 0)
			return result;
		modctl &= ~(*pi);
		result = ioctl_tiocmset(h, &modctl);
		break;

	case TIOCMBIS:
		result = ioctl_tiocmget(h, &modctl);
		if (result < 0)
			return result;
		modctl |= *pi;
		result = ioctl_tiocmset(h, &modctl);
		break;

	default:
		errno = EINVAL;
		result = -1;
	}

	return result;
}


int	
tcsetattr(
	int			fd, 
	int			optional_actions, 
	const struct termios *	tios
	)
{
	DCB dcb;
	HANDLE h;

	UNUSED_ARG(optional_actions);

	h = (HANDLE)_get_osfhandle(fd);

	if (INVALID_HANDLE_VALUE == h) {
		/* errno already set */
		return -1;
	}

	dcb.DCBlength = sizeof(dcb);
	if (!GetCommState(h, &dcb)) {
		errno = ENOTTY;
		return -1;
	}

	switch (max(tios->c_ospeed, tios->c_ispeed)) {

	case B300:
		dcb.BaudRate = 300;
		break;

	case B1200:
		dcb.BaudRate = 1200;
		break;

	case B2400:
		dcb.BaudRate = 2400;
		break;

	case B4800:
		dcb.BaudRate = 4800;
		break;

	case B9600:
		dcb.BaudRate = 9600;
		break;

	case B19200:
		dcb.BaudRate = 19200;
		break;

	case B38400:
		dcb.BaudRate = 38400;
		break;

	case B57600:
		dcb.BaudRate = 57600;
		break;

	case B115200:
		dcb.BaudRate = 115200;
		break;

	default:
		msyslog(LOG_ERR, "unsupported serial baud rate");
		errno = EINVAL;
		return -1;
	}

	switch (tios->c_cflag & CSIZE) {

	case CS5:
		dcb.ByteSize = 5;
		break;

	case CS6:
		dcb.ByteSize = 6;
		break;

	case CS7:
		dcb.ByteSize = 7;
		break;

	case CS8:
		dcb.ByteSize = 8;
		break;

	default:
		msyslog(LOG_ERR, "unsupported serial word size");
		errno = EINVAL;
		return FALSE;
	}

	if (PARENB & tios->c_cflag) {
		dcb.fParity = TRUE;
		dcb.Parity = (tios->c_cflag & PARODD)
				? ODDPARITY
				: EVENPARITY;
	} else {
		dcb.fParity = FALSE;
		dcb.Parity = NOPARITY;
	}

	dcb.StopBits = (CSTOPB & tios->c_cflag)
			? TWOSTOPBITS
			: ONESTOPBIT;

	if (!SetCommState(h, &dcb)) {
		errno = ENOTTY;
		return -1;
	}

	return 0;
}


int
tcgetattr(
	int		fd,
	struct termios *tios
	)
{
	DCB	dcb;
	HANDLE	h;

	h = (HANDLE)_get_osfhandle(fd);

	if (INVALID_HANDLE_VALUE == h) {
		/* errno already set */
		return -1;
	}

	dcb.DCBlength = sizeof(dcb);

	if (!GetCommState(h, &dcb)) {
		errno = ENOTTY;
		return -1;
	}

	/*  Set c_ispeed & c_ospeed */

	switch (dcb.BaudRate) {

	case 300:
		tios->c_ispeed = tios->c_ospeed = B300;
		break;

	case 1200: 
		tios->c_ispeed = tios->c_ospeed = B1200;
		break;

	case 2400:
		tios->c_ispeed = tios->c_ospeed = B2400;
		break;

	case 4800: 
		tios->c_ispeed = tios->c_ospeed = B4800;
		break;

	case 9600:
		tios->c_ispeed = tios->c_ospeed = B9600;
		break;

	case 19200:
		tios->c_ispeed = tios->c_ospeed = B19200;
		break;

	case 38400:
		tios->c_ispeed = tios->c_ospeed = B38400;
		break;

	case 57600:
		tios->c_ispeed = tios->c_ospeed = B57600;
		break;

	case 115200:
		tios->c_ispeed = tios->c_ospeed = B115200;
		break;

	default:
		tios->c_ispeed = tios->c_ospeed = B9600;
	}
	

	switch (dcb.ByteSize) {
		case 5:
			tios->c_cflag = CS5;
			break;

		case 6:
			tios->c_cflag = CS6;
			break;

		case 7: 
			tios->c_cflag = CS7; 
			break;

		case 8:
		default:
			tios->c_cflag = CS8;
	}

	if (dcb.fParity) {
		tios->c_cflag |= PARENB;

		if (ODDPARITY == dcb.Parity)
			tios->c_cflag |= PARODD;
	}

	if (TWOSTOPBITS == dcb.StopBits)
		tios->c_cflag |= CSTOPB;

	tios->c_iflag = 0;
	tios->c_lflag = 0;
	tios->c_line = 0;
	tios->c_oflag = 0;

	return 0;
}


int
tcflush(
	int fd,
	int mode
	)
{
	HANDLE	h;
	BOOL	success;
	DWORD	flags;
	int	result;

	h = (HANDLE)_get_osfhandle(fd);

	if (INVALID_HANDLE_VALUE == h) {
		/* errno already set */
		return -1;
	}

	switch (mode) {

	case TCIFLUSH:
		flags = PURGE_RXCLEAR;
		break;

	case TCOFLUSH:
		flags = PURGE_TXABORT;
		break;

	case TCIOFLUSH:
		flags = PURGE_RXCLEAR | PURGE_TXABORT;
		break;

	default:
		errno = EINVAL;
		return -1;
	}

	success = PurgeComm(h, flags);

	if (success)
		result = 0;
	else {
		errno = ENOTTY;
		result = -1;
	}

	return result;
}