#include <stdio.h>
#define INCL_DOS
#include <os2.h>
#include <time.h>

#include "ttyio.h"

extern int Debug;

int _modem;			/* a readwrite attachment to the modem */
DCBINFO _modcontrol;		/* the way the modem looks */
DCBINFO _modsavedctl;		/* .. and looked, before we got to it */

/*
 * ttyopen() attaches ourself to a modem port
 */
int
ttyopen(dev, flow)
char *dev;
int flow;
{
    short info;
    char device[20];
    static char control[3] = { 8, 0, 0 };
    
    sprintf(device, "/dev/%s", dev);
    if (DosOpen(device, &_modem, &info, 0L, 0, 0x01, 0x2042, 0L) == 0) {
	/* opened the file - so now get the existing modem config
	 * and replace it with our own
	 */
	DosDevIOCtl(&_modsavedctl, (int*)0, 0x73, 1, _modem);
	_modcontrol = _modsavedctl;
	_modcontrol.usWriteTimeout = 0;		/* no write timeout */
	_modcontrol.usReadTimeout  = 0;		/* no read timeout */
	_modcontrol.fbCtlHndShake  = (flow==TTYF_RTSCTS) ? 0x08 : 0;
	_modcontrol.fbFlowReplace  = (flow==TTYF_RTSCTS) ? 0xc0 : 0;
	_modcontrol.fbTimeout      = 0x04;	/* normal timeout processing */
	DosDevIOCtl((int*)0, &_modcontrol, 0x53, 1, _modem);

	/* set the modem up for 8 characters, no parity, 1 stop bit
	 */
	DosDevIOCtl((int*)0, control, 0x42, 1, _modem);
	
	enable();
	return 1;
    }
    _modem = -1;
    return 0;
} /* ttyopen() */


/*
 * ttyclose() detaches ourself from a modem port and restores it to
 * the state it was in before we started hacking on it
 */
void
ttyclose()
{
    disable();
    DosDevIOCtl((int*)0, &_modsavedctl, 0x53, 1, _modem);
    DosClose(_modem);
} /* ttyclose() */


/*
 * ttystat() tells us if there are characters waiting on input
 */
int
ttystat()
{
    int control[2];

    DosDevIOCtl(control, (int*)0, 0x68, 1, _modem);
    return (control[0] > 0);
} /* ttystat */


/*
 * dobreak() set or clear a break condition
 */
void
dobreak(setit)
int setit;
{
    int status;

    DosDevIOCtl(&status, (int*)0, setit ? 0x4b : 0x45, 1, _modem);
}


/*
 * ttyspeed() set tty speed
 */
int
ttyspeed(speed)
long speed;
{
    int intspeed;

    if (speed < 0 || speed > 19200)
	return 0;
    intspeed = (int)speed;
    return (DosDevIOCtl((int*)0, &intspeed, 0x41, 1, _modem) == 0);
}


/*
 * carrier() - detects carrier
 *
 * note: we don't want to spend too much time doing ioctls, so we'll only
 * check for carrier on 1-second intervals; if we've checked within the
 * last second, we'll return the value we found then.
 */
int
carrier()
{
    static char _cd_carrier = 0;	/* latest carrier-detection flag */
    static char _cd_active  = 0;	/* have we checked at all? */
    static clock_t _cd_stale= 0;	/* time when _cd_carrier goes stale */

    unsigned char flags;
    clock_t now;

    now = clock();
    if (_cd_active == 0 || now > _cd_stale) {
	DosDevIOCtl(&flags, (int*)0, 0x67, 1, _modem);
	_cd_stale = now+1000L;	/* only check cd at 1 sec intervals */
	_cd_active = 1;
	_cd_carrier = flags & (0x80);
    }
    return _cd_carrier;
} /* carrier */


/*
 * disable the modem
 */
void
disable()
{
    char control[2];
    int status;

    control[0] = 0x00;
    control[1] = 0xfe;

    DosDevIOCtl(&status, control, 0x46, 1, _modem);
} /* disable */


/*
 * enable the modem
 */
void
enable()
{
    char control[2];
    int status;

    control[0] = 0x01;
    control[1] = 0xff;

    DosDevIOCtl(&status, control, 0x46, 1, _modem);
} /* enable */


/*
 * flush() the modem input buffer
 */
void
flush()
{
    while (receive(0) >= 0)
	;
} /* flush */


/*
 * receive() a character from the modem, timing out after a while
 */
int
receive(timeout)
int timeout;
{
    ttytimeout(timeout);
    return ttyin();
} /* receive */


/*
 * ttyin() gets a character from the modem
 */
int
ttyin()
{
    unsigned char c;

    return (read(_modem, &c, 1) == 1) ? (0xff & c) : (-1);
} /* receive */


/*
 * ttytimeout() changes the tty read timeout
 */
ttytimeout(timeout)
int timeout;
{
    static int _prev_timeout = -1;

    if (timeout == _prev_timeout)
	return 0;

    _prev_timeout = timeout;
    /* do an ioctl to set up the new improved read timeout
     */
    _modcontrol.usReadTimeout = timeout * 100;
    if (timeout == 0)
	_modcontrol.fbTimeout |= 0x06;
    else
	_modcontrol.fbTimeout = (_modcontrol.fbTimeout & ~ 0x06) | 0x04;

    DosDevIOCtl((int*)0, &_modcontrol, 0x53, 1, _modem);
} /* ttytimeout */


/*
 * slowputs() writes a string to modem s*l*o*w*l*y
 */
void
slowputs(s)
register char *s;
{
    register long delay;

    while (*s) {
	if (*s & 0200) {	/* anything > 127 causes delay */
	    delay = (0xff & *++s);
	    nap(delay * 100L);
	    if (Debug > 1)
		fprintf(stderr, "{%ld}", delay);
	}
	else {
	    if (Debug > 1)
		putc((*s == '\r') ? '\n' : (*s), stderr);
	    nap(80L);
	    ttyout(*s);
	}
	++s;
    }
} /* receive */


/*
 * ttyout() writes a single character to the modem
 */
void
ttyout(c)
char c;
{
    int sz;

    DosWrite(_modem, &c, 1, &sz);
} /* ttyout */


/*
 * ttywrite() writes a string to the modem as fast as possible
 */
void
ttywrite(bfr, size)
register char *bfr;
register size;
{
    int sz;

    DosWrite(_modem, bfr, size, &sz);
} /* ttywrite */