/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
static char *sccsid = "@(#)tty.c	5.2 (Berkeley) 6/21/85";
#endif not lint

/*
 * Mail -- a mail program
 *
 * Generally useful tty stuff.
 */

#include "rcv.h"

static	int	c_erase;		/* Current erase char */
static	int	c_kill;			/* Current kill char */
static	int	hadcont;		/* Saw continue signal */
static	jmp_buf	rewrite;		/* Place to go when continued */
#ifndef TIOCSTI
static	int	ttyset;			/* We must now do erase/kill */
#endif

/*
 * Read all relevant header fields.
 */

grabh(hp, gflags)
	struct header *hp;
{
	struct sgttyb ttybuf;
	int ttycont(), signull();
#ifndef TIOCSTI
	int (*savesigs[2])();
#endif
	int (*savecont)();
	register int s;
	int errs;

# ifdef VMUNIX
	savecont = sigset(SIGCONT, signull);
# endif VMUNIX
	errs = 0;
#ifndef TIOCSTI
	ttyset = 0;
#endif
	if (gtty(fileno(stdin), &ttybuf) < 0) {
		perror("gtty");
		return(-1);
	}
	c_erase = ttybuf.sg_erase;
	c_kill = ttybuf.sg_kill;
#ifndef TIOCSTI
	ttybuf.sg_erase = 0;
	ttybuf.sg_kill = 0;
	for (s = SIGINT; s <= SIGQUIT; s++)
		if ((savesigs[s-SIGINT] = sigset(s, SIG_IGN)) == SIG_DFL)
			sigset(s, SIG_DFL);
#endif
	if (gflags & GTO) {
#ifndef TIOCSTI
		if (!ttyset && hp->h_to != NOSTR)
			ttyset++, stty(fileno(stdin), &ttybuf);
#endif
		hp->h_to = readtty("To: ", hp->h_to);
		if (hp->h_to != NOSTR)
			hp->h_seq++;
	}
	if (gflags & GSUBJECT) {
#ifndef TIOCSTI
		if (!ttyset && hp->h_subject != NOSTR)
			ttyset++, stty(fileno(stdin), &ttybuf);
#endif
		hp->h_subject = readtty("Subject: ", hp->h_subject);
		if (hp->h_subject != NOSTR)
			hp->h_seq++;
	}
	if (gflags & GCC) {
#ifndef TIOCSTI
		if (!ttyset && hp->h_cc != NOSTR)
			ttyset++, stty(fileno(stdin), &ttybuf);
#endif
		hp->h_cc = readtty("Cc: ", hp->h_cc);
		if (hp->h_cc != NOSTR)
			hp->h_seq++;
	}
	if (gflags & GBCC) {
#ifndef TIOCSTI
		if (!ttyset && hp->h_bcc != NOSTR)
			ttyset++, stty(fileno(stdin), &ttybuf);
#endif
		hp->h_bcc = readtty("Bcc: ", hp->h_bcc);
		if (hp->h_bcc != NOSTR)
			hp->h_seq++;
	}
# ifdef VMUNIX
	sigset(SIGCONT, savecont);
# endif VMUNIX
#ifndef TIOCSTI
	ttybuf.sg_erase = c_erase;
	ttybuf.sg_kill = c_kill;
	if (ttyset)
		stty(fileno(stdin), &ttybuf);
	for (s = SIGINT; s <= SIGQUIT; s++)
		sigset(s, savesigs[s-SIGINT]);
#endif
	return(errs);
}

/*
 * Read up a header from standard input.
 * The source string has the preliminary contents to
 * be read.
 *
 */

char *
readtty(pr, src)
	char pr[], src[];
{
	char ch, canonb[BUFSIZ];
	int c, signull();
	register char *cp, *cp2;

	fputs(pr, stdout);
	fflush(stdout);
	if (src != NOSTR && strlen(src) > BUFSIZ - 2) {
		printf("too long to edit\n");
		return(src);
	}
#ifndef TIOCSTI
	if (src != NOSTR)
		cp = copy(src, canonb);
	else
		cp = copy("", canonb);
	fputs(canonb, stdout);
	fflush(stdout);
#else
	cp = src == NOSTR ? "" : src;
	while (c = *cp++) {
		if (c == c_erase || c == c_kill) {
			ch = '\\';
			ioctl(0, TIOCSTI, &ch);
		}
		ch = c;
		ioctl(0, TIOCSTI, &ch);
	}
	cp = canonb;
	*cp = 0;
#endif
	cp2 = cp;
	while (cp2 < canonb + BUFSIZ)
		*cp2++ = 0;
	cp2 = cp;
	if (setjmp(rewrite))
		goto redo;
# ifdef VMUNIX
	sigset(SIGCONT, ttycont);
# endif VMUNIX
	clearerr(stdin);
	while (cp2 < canonb + BUFSIZ) {
		c = getc(stdin);
		if (c == EOF || c == '\n')
			break;
		*cp2++ = c;
	}
	*cp2 = 0;
# ifdef VMUNIX
	sigset(SIGCONT, signull);
# endif VMUNIX
	if (c == EOF && ferror(stdin) && hadcont) {
redo:
		hadcont = 0;
		cp = strlen(canonb) > 0 ? canonb : NOSTR;
		clearerr(stdin);
		return(readtty(pr, cp));
	}
#ifndef TIOCSTI
	if (cp == NOSTR || *cp == '\0')
		return(src);
	cp2 = cp;
	if (!ttyset)
		return(strlen(canonb) > 0 ? savestr(canonb) : NOSTR);
	while (*cp != '\0') {
		c = *cp++;
		if (c == c_erase) {
			if (cp2 == canonb)
				continue;
			if (cp2[-1] == '\\') {
				cp2[-1] = c;
				continue;
			}
			cp2--;
			continue;
		}
		if (c == c_kill) {
			if (cp2 == canonb)
				continue;
			if (cp2[-1] == '\\') {
				cp2[-1] = c;
				continue;
			}
			cp2 = canonb;
			continue;
		}
		*cp2++ = c;
	}
	*cp2 = '\0';
#endif
	if (equal("", canonb))
		return(NOSTR);
	return(savestr(canonb));
}

# ifdef VMUNIX
/*
 * Receipt continuation.
 */
ttycont(s)
{

	hadcont++;
	longjmp(rewrite, 1);
}
# endif VMUNIX

/*
 * Null routine to satisfy
 * silly system bug that denies us holding SIGCONT
 */
signull(s)
{}