/* tty.c: modified for Herriot-Watt tty driver 2/2/82 - PLS
 *        (compile with -DH_WDRIVER for EUUG driver
 *            "     "   -DQMCDRIVER for QMC driver
 *            "     "   -DUMVDRIVER for UMIST Vax driver with paging
 *         default .................... BELL or Berkeley driver)
 */
#include "ded.h"
#include "char.h"
#include "tty.h"
#include "signal.h"
#include "ter.h"

/************************************************************************
 *                                                                      *
 *                      copyright Richard Bornat 1981                   *
 *                                                                      *
 ************************************************************************/

#include "SITE.def"

/* mode-remembering stuff */
#ifdef V7
  struct sgttyb tmode, sv_tmode;
  struct tchars tchars, sv_tchars;
#  if vax
  struct ltchars ltchars, sv_ltchars;
#  endif
#else
  struct TTYMODE
   {  char ispeed, ospeed, terase, kill;
      int flags;
      char nldelay, crdelay, tbdelay, vtdelay;
      char width, length;
      int brktab[8];
   } tmode, sv_tmode;

#endif

ttyinterrupt()
 {  signal(SIGINT, ttyinterrupt);
    ttyzonk();
    intr_typed = true;
 }

ttyzonk()
 {  ttyinbuf.n_in = 0;
    ttyinbuf.nxch = ttyinbuf.tbuf;
    complain();
 }

/* find user's attitude without disturbing .dlog file */
char qread()
 {  char c;
    ttyflush();
    while (read(std_in,&c,1)!=1) ;
    return(c);
 }

int query(str)
char *str;
 { register char c;

   do
    {  x_cdiag(&str);
       c=qread();
    } while (c!='y' && c!='n');

   return(c=='y');
 }

ttyquit()
 {  signal(SIGQUIT, SIG_IGN);
    ttyzonk();
    if (query("do you really want a core dump?"))
     { ttyreset(); abort(); }
    else
     { diag("I'll let you off this time, then");
       signal(SIGQUIT, ttyquit);
       fixpos();
       /* ttyflush(); */
     }
    quit_typed = true;
 }

/* variables to help in setting up interrupts */
int (*savquit)() = ttyquit, (*savintr)() = ttyinterrupt;

/* start up funny tty mode */
ttysetup()
 {  ttybuf.n_in = 0;
    ttybuf.nxch = ttybuf.tbuf;

    dlogbuf.n_in = 0;
    dlogbuf.nxch = dlogbuf.tbuf;

    ttyinbuf.n_in = 0;
    ttyinbuf.nxch = ttyinbuf.tbuf;

    ttysetmode();
 }

ttysetmode()
 {  int tncols, tnrows;
    extern char *getenv();      /* to keep the vax cc happy! -pls */

    if (!setup_done)
    /* discover tty modes */
#ifdef V7
     {
#  if H_WDRIVER | UMVDRIVER
	ioctl(STD_TER, TIOCGETA, &tmode);
#  else
	ioctl(STD_TER, TIOCGETP, &tmode);       /* old-style gtty */
#  endif
	sv_tmode = tmode;
	tmode.sg_flags &= ~(RAW | CRMOD | ECHO | XTABS);
#  ifdef T_STARTC
	tmode.sg_flags |= (CBREAK | TANDEM);
#  else
	tmode.sg_flags |= CBREAK;
#  endif
#  if QMCDRIVER | H_WDRIVER | UMVDRIVER
	tncols = tmode.sg_width; tnrows = tmode.sg_length;
	tmode.sg_width = tmode.sg_length = 0;
#  endif
#  if H_WDRIVER
	tmode.sg_nldly = tmode.sg_crdly = tmode.sg_htdly = tmode.sg_vtdly = 0;
#  endif

	ioctl(STD_TER, TIOCGETC, &tchars);      /* new-style get characters */
	sv_tchars = tchars;
	tchars.t_intrc = 03;    /* control-C */
	tchars.t_quitc = 034;   /* control-shift-L */
	/* start and stop are terminal_dependent - there really exist
	 * terminals which use handshaking
	 */
#  ifdef T_STARTC
	tchars.t_startc = T_STARTC;
	tchars.t_stopc = T_STOPC;
	tchars.t_eofc = tchars.t_brkc = -1;
#  else
	tchars.t_startc = tchars.t_stopc = tchars.t_eofc = tchars.t_brkc = -1;
#  endif

#  if vax
	ioctl(STD_TER, TIOCGLTC, &ltchars);     /* more characters on vax */
	sv_ltchars = ltchars;
	ltchars.t_suspc = ltchars.t_dsuspc = ltchars.t_rprntc =
	ltchars.t_flushc = ltchars.t_werasc = ltchars.t_lnextc = -1;
#  endif
     }
#else
     /* under version 6 we always use the QMC driver - or at
      * least we have RARE mode
      */
     {  gterm(STD_TER, &tmode);
	sv_tmode = tmode;
	tmode.flags =& ~ (T_BITS | T_INDCTL | T_ECHO | T_TABS | T_CRLF);
	tmode.flags =| (T_RAW | T_RARE);
	tncols = tmode.width;
	tnrows = tmode.length;
	tmode.width = tmode.length = 0;
     }
#endif

    if (rowmap==0) /* first time in */
     {  /* set up teletype characteristics */

#if QMCDRIVER | H_WDRIVER | UMVDRIVER
	if (Pswitch)
	 { tnrows = Prows; tncols = Pcols; }
#endif

#ifdef V7
#  ifdef QMC
	{   char *t = getenv("TERM");

	    if (streq(t, N_QMC)) ter_setup(&qmc_ter);
	    else
	    if (streq(t, N_ITT)) ter_setup(&itt_ter);
	    else
/* no text terminal at present ...
	    if (streq(t, N_TXT)) ter_setup(&txt_ter);
	    else
 */
	      editerror("unknown terminal type %s - reset with stty", t);
	}
#  else (not QMC)
#  if UMIST | UMISTc | UMISTv | UMISTh | UMISTt
	{   char *t = getenv("TERM");

#    if UMIST | UMISTc
	    if (streq(t,"cifer")) ter_setup(&cif_ter);
	    else
#    endif
#    if UMIST | UMISTv
	    if (streq(t,"vt100")) ter_setup(&vt1_ter);
	    else
#    endif
#    if UMIST | UMISTh
	    if (streq(t,"hazeltine")) ter_setup(&haz_ter);
	    else
#    endif
#    if UMIST | UMISTt
	    if (streq(t,"tek4023")) ter_setup(&tek_ter);
	    else
#    endif
#    if vax
	    if (streq(t,"sjs")) ter_setup(&sjs_ter);
	    else
#    endif
	      editerror("unknown terminal type %s - change $TERM in env.", t);
	}
#  else (not UMIST)
#  ifdef COMPU
	{   char *t = getenv("TERM");

	    if (streq(t,"VT100")) ter_setup(&vt1_ter);
	    else
	    if (streq(t,"vt100")) ter_setup(&vt1_ter);
	    else
	    if (streq(t,"VT52")) ter_setup(&vt5_ter);
	    else
	    if (streq(t,"vt52")) ter_setup(&vt5_ter);
	    else
	      editerror("unknown terminal type %s - have you set $TERM ?", t);
	}
#  else (not COMPU)
#  ifdef BRISTOL
	{   char *t = getenv("TERM");

	    if (streq(t,"vt100")) ter_setup(&vt1_ter);
	    else
	    if (streq(t,"dt22")) ter_setup(&dt2_ter);
	    else
	      editerror("unknown terminal type %s - have you set $TERM ?", t);
	}
#  else (not BRISTOL)
	ter_setup(&TER_TAB);
#  endif BRISTOL
#  endif COMPU
#  endif UMIST
#  endif QMC
#else (V6)
	/* under version 6 we always use the QMC driver, of course */
#  ifdef QMC
	{   int tertype = sv_tmode.flags & T_BITS;

	    if (tertype==T_TXT) ter_setup(&txt_ter);
	    else
	    if (tertype==T_ITT) ter_setup(&itt_ter);
	    else
	    if (tertype==T_QMC) ter_setup(&qmc_ter);
	    else
	      editerror("invalid terminal mode - reset with ter");
	}
#  else (not QMC)
	ter_setup(&TER_TAB);
#  endif (QMC or not)
#endif (V7 or not)

#if QMCDRIVER | H_WDRIVER | UMVDRIVER
	if (tnrows<2 || tncols<MARGIN+1)
	  editerror("reset screen size with stty/ter (min 2 rows, %d cols)",
			MARGIN+1);
	else
	if (nrows<tnrows || ncols<tncols)
	  editerror("reset screen size with stty/ter (max %d rows, %d cols)",
			nrows, ncols);

	nrows = tnrows; ncols = tncols;
#else
	if (Pswitch)
	 { nrows = Prows; ncols = Pcols; }
	else
	    nrows = TER_ROWS; ncols = TER_COLS;
#endif

	if (ncols+1>ENOUGH)
	  editerror("screen size too wide (max %d cols) [ttysetup]",
			ENOUGH-1);
	else
	  rowmap = newscreen(); /* don't set up auxscreen yet */
     }

    /* do the things that are necessary to frig ded for this terminal
     * - moved from ter_setup (ter.c) so that it is called every time
     *   ded is re-entered, in case any terminal setup sequences have
     *   to be sent out.  Done before tty modes are set, however, so
     *   that modes can be changed on an individual terminal basis in
     *   *ter.setup if necessary - PLS UMIST 20/12/83
     */
    (*ter.setup)();

    if (!Pswitch)
#ifdef V7
     {
#  if H_WDRIVER | UMVDRIVER
	ioctl(STD_TER, TIOCSETA, &tmode);
#  else
	ioctl(STD_TER, TIOCSETN, &tmode);       /* old-style stty */
#  endif
	ioctl(STD_TER, TIOCSETC, &tchars);      /* new-style set characters */
#  if vax
	ioctl(STD_TER, TIOCSLTC, &ltchars);      /* more for the vax */
#  endif
     }
#else
      sterm(STD_TER,&tmode);
#endif
    setup_done=true;

    NINROWS = (nrows-1);
    LASTINROW = (nrows-2);
    EDITROW = (nrows-1);
    FOOTROW = (nrows-1);
    SCROLL = (nrows/3);
    RIGHTCOL = (ncols-1);

    signal(SIGQUIT, savquit);
    signal(SIGINT, savintr);
 }

ttyreset()
 {  ttyflush(); dlogflush();

    /* turn off interrupts */
    savquit = signal(SIGQUIT, SIG_IGN);
    savintr = signal(SIGINT, SIG_IGN);

    if (setup_done)
     {
#ifdef V7
	if (!Pswitch)
	 {
#  if H_WDRIVER | UMVDRIVER
	    ioctl(STD_TER, TIOCSETA, &sv_tmode);   /* set mode */
#  else
	    ioctl(STD_TER, TIOCSETN, &sv_tmode);   /* set mode */
#  endif
	    ioctl(STD_TER, TIOCSETC, &sv_tchars);  /* set characters */
#  if vax
	    ioctl(STD_TER, TIOCSLTC, &sv_ltchars);  /* more for the vax */
#  endif
	 }
#else
	if (!Pswitch) sterm(STD_TER,&sv_tmode);
#endif
     }

    if (ter.restore) (*ter.restore)();                          /* UMIST */
    ttyflush();
    setup_done=false;
 }

/* stuff characters in buffer, to save too many system calls */
ttyout(c)
register int c;
 {  if (ttybuf.n_in >= TTYBUFSIZE) ttyflush();

    if (c&0200 && sendseq(ter.vidseq.bright))
		/* top bit set - display bright if possible */
     {  ttyout(c&0177);
	sendseq(ter.vidseq.normal); /* must be one of these! */
     }
    else
     { *(ttybuf.nxch++) = (c&0177); ttybuf.n_in++; }
 }

/* empty buffer */
ttyflush()
 { bufflush(&ttybuf, std_out); }

dlogflush()
 { if (bufflush(&dlogbuf, dlogger) < 0)
     {  dlogbuf.n_in = 0;
	editerror("[dlogflush] dlogwrite failed - not enough space?");
     }
 }

bufflush(abuf, chan)
register struct TTYBUF *abuf;
register int chan;
 {  register int count;

    if ((count = abuf->n_in) != 0)
     { if (write(chan, abuf->tbuf, count) != count) return(-1);
	abuf->nxch = abuf->tbuf;
	abuf->n_in=0;
     }
    return(1);
 }

/* a procedure to read in from the teletype and record
 * each character in the .dlog file
 */
ttyin()
 {  register int count, input;
    register char c;

    input = tty_input;

    while (--ttyinbuf.n_in < 0)
     {  count = (input==dlogger ? TTYBUFSIZE : mode==EDMODE ? 1 : 3);
	ttyflush(); /* don't do it unless waiting for input */

	if ((count=read(input,ttyinbuf.tbuf,count))<=0 && input==dlogger)
	     {  input=tty_input=std_in;    /* end of dlog input */
		diag("** end of %s **", dlogname);
		fixpos(); return(0); /* if anyone wants it */
	     }

	ttyinbuf.n_in = count; ttyinbuf.nxch = ttyinbuf.tbuf;
     }

    c = *(ttyinbuf.nxch++);

    if (input!=dlogger) dlogout(c);

    return(c);
 }

/* put a character in the dlog file */
dlogout(c)
register char c;
 { if (dlogbuf.n_in >= TTYBUFSIZE) dlogflush();
   *(dlogbuf.nxch++) = c;
   dlogbuf.n_in++;
   if ((c<040 || c==0177) && dlogbuf.n_in>10) dlogflush();
 }