/* ENIC CP/M-68K 8.4.1997.
 * The functions in this file
 * negotiate with the operating system
 * for characters, and write characters in
 * a barely buffered fashion on the display.
 * All operating systems.
 */
#include	<stdio.h>
#include	"ed.h"

#if	VMS
#include	<stsdef.h>
#include	<ssdef.h>
#include	<descrip.h>
#include	<iodef.h>
#include	<ttdef.h>

#define	NIBUF	128			/* Input  buffer size		*/
#define	NOBUF	1024			/* MM says bug buffers win!	*/
#define	EFN	0			/* Event flag			*/

char	obuf[NOBUF];			/* Output buffer		*/
int	nobuf;				/* # of bytes in above		*/
char	ibuf[NIBUF];			/* Input buffer			*/
int	nibuf;				/* # of bytes in above		*/
int	ibufi;				/* Read index			*/
int	oldmode[2];			/* Old TTY mode bits		*/
int	newmode[2];			/* New TTY mode bits		*/
short	iochan;				/* TTY I/O channel		*/
#endif

#if	CPM
#include	<bios.h>
#endif

#if	MSDOS
#include	<dos.h>
#endif

#if V7
#include	<sgtty.h>		/* for stty/gtty functions */
struct	sgttyb	ostate;			/* saved tty state */
struct	sgttyb	nstate;			/* values for editor mode */
#endif

/*
 * This function is called once
 * to set up the terminal device streams.
 * On VMS, it translates SYS$INPUT until it
 * finds the terminal, then assigns a channel to it
 * and sets it raw. On CPM it is a no-op.
 */
ttopen()
{
#if	VMS
	struct	dsc$descriptor	idsc;
	struct	dsc$descriptor	odsc;
	char	oname[40];
	int	iosb[2];
	int	status;

	odsc.dsc$a_pointer = "SYS$INPUT";
	odsc.dsc$w_length  = strlen(odsc.dsc$a_pointer);
	odsc.dsc$b_dtype   = DSC$K_DTYPE_T;
	odsc.dsc$b_class   = DSC$K_CLASS_S;
	idsc.dsc$b_dtype   = DSC$K_DTYPE_T;
	idsc.dsc$b_class   = DSC$K_CLASS_S;
	do {
		idsc.dsc$a_pointer = odsc.dsc$a_pointer;
		idsc.dsc$w_length  = odsc.dsc$w_length;
		odsc.dsc$a_pointer = &oname[0];
		odsc.dsc$w_length  = sizeof(oname);
		status = LIB$SYS_TRNLOG(&idsc, &odsc.dsc$w_length, &odsc);
		if (status!=SS$_NORMAL && status!=SS$_NOTRAN)
			exit(status);
		if (oname[0] == 0x1B) {
			odsc.dsc$a_pointer += 4;
			odsc.dsc$w_length  -= 4;
		}
	} while (status == SS$_NORMAL);
	status = SYS$ASSIGN(&odsc, &iochan, 0, 0);
	if (status != SS$_NORMAL)
		exit(status);
	status = SYS$QIOW(EFN, iochan, IO$_SENSEMODE, iosb, 0, 0,
			  oldmode, sizeof(oldmode), 0, 0, 0, 0);
	if (status!=SS$_NORMAL || (iosb[0]&0xFFFF)!=SS$_NORMAL)
		exit(status);
	newmode[0] = oldmode[0];
	newmode[1] = oldmode[1] | TT$M_PASSALL | TT$M_NOECHO;
	status = SYS$QIOW(EFN, iochan, IO$_SETMODE, iosb, 0, 0,
			  newmode, sizeof(newmode), 0, 0, 0, 0);
	if (status!=SS$_NORMAL || (iosb[0]&0xFFFF)!=SS$_NORMAL)
		exit(status);
#endif
#if	CPM
#endif
#if	MSDOS
#endif
#if	V7
	gtty(1, &ostate);			/* save old state */
	gtty(1, &nstate);			/* get base of new state */
	nstate.sg_flags |= RAW;
	nstate.sg_flags &= ~(ECHO|CRMOD);	/* no echo for now... */
	stty(1, &nstate);			/* set mode */
#endif
}

/*
 * This function gets called just
 * before we go back home to the command interpreter.
 * On VMS it puts the terminal back in a reasonable state.
 * Another no-operation on CPM.
 */
ttclose()
{
#if	VMS
	int	status;
	int	iosb[1];

	ttflush();
	status = SYS$QIOW(EFN, iochan, IO$_SETMODE, iosb, 0, 0,
	         oldmode, sizeof(oldmode), 0, 0, 0, 0);
	if (status!=SS$_NORMAL || (iosb[0]&0xFFFF)!=SS$_NORMAL)
		exit(status);
	status = SYS$DASSGN(iochan);
	if (status != SS$_NORMAL)
		exit(status);
#endif
#if	CPM
#endif
#if	MSDOS
#endif
#if	V7
	stty(1, &ostate);
#endif
}

/*
 * Write a character to the display.
 * On VMS, terminal output is buffered, and
 * we just put the characters in the big array,
 * after cheching for overflow. On CPM terminal I/O
 * unbuffered, so we just write the byte out.
 * Ditto on MS-DOS (use the very very raw console
 * output routine).
 */
ttputc(c)
{
#if	VMS
	if (nobuf >= NOBUF)
		ttflush();
	obuf[nobuf++] = c;
#endif
#if	CPM
	bios(CONOUT, c, 0);
#endif
#if	MSDOS
	dosb(CONDIO, c, 0);
#endif
#if	V7
	fputc(c, stdout);
#endif
}

/*
 * Flush terminal buffer. Does real work
 * where the terminal output is buffered up. A
 * no-operation on systems where byte at a time
 * terminal I/O is done.
 */
ttflush()
{
#if	VMS
	int	status;
	int	iosb[2];

	status = SS$_NORMAL;
	if (nobuf != 0) {
		status = SYS$QIOW(EFN, iochan, IO$_WRITELBLK|IO$M_NOFORMAT,
			 iosb, 0, 0, obuf, nobuf, 0, 0, 0, 0);
		if (status == SS$_NORMAL)
			status = iosb[0] & 0xFFFF;
		nobuf = 0;
	}
	return (status);
#endif
#if	CPM
#endif
#if	MSDOS
#endif
#if	V7
	fflush(stdout);
#endif
}

/*
 * Read a character from the terminal,
 * performing no editing and doing no echo at all.
 * More complex in VMS that almost anyplace else, which
 * figures. Very simple on CPM, because the system can
 * do exactly what you want.
 */
ttgetc()
{
#if	VMS
	int	status;
	int	iosb[2];
	int	term[2];

	while (ibufi >= nibuf) {
		ibufi = 0;
		term[0] = 0;
		term[1] = 0;
		status = SYS$QIOW(EFN, iochan, IO$_READLBLK|IO$M_TIMED,
			 iosb, 0, 0, ibuf, NIBUF, 0, term, 0, 0);
		if (status != SS$_NORMAL)
			exit(status);
		status = iosb[0] & 0xFFFF;
		if (status!=SS$_NORMAL && status!=SS$_TIMEOUT)
			exit(status);
		nibuf = (iosb[0]>>16) + (iosb[1]>>16);
		if (nibuf == 0) {
			status = sys$qiow(EFN, iochan, IO$_READLBLK,
				 iosb, 0, 0, ibuf, 1, 0, term, 0, 0);
			if (status != SS$_NORMAL
			|| (status = (iosb[0]&0xFFFF)) != SS$_NORMAL)
				exit(status);
			nibuf = (iosb[0]>>16) + (iosb[1]>>16);
		}
	}
	return (ibuf[ibufi++] & 0xFF);		/* Allow multinational	*/
#endif
#if	CPM
	return (bios(CONIN, 0));
#endif
#if	MSDOS
	return (dosb(CONRAW, 0, 0));
#endif
#if	V7
	return(fgetc(stdin));
#endif
}