/*-
 * Copyright (c) 1992, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *	Keith Bostic.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Brian Hirt.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/queue.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <bitstring.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#ifdef HAVE_LIBUTIL_H
#include <libutil.h>
#elif defined HAVE_PTY_H
#include <pty.h>
#else
#include <util.h>
#endif

#include "../common/common.h"
#include "../vi/vi.h"
#include "script.h"
#include "pathnames.h"

static void	sscr_check(SCR *);
static int	sscr_getprompt(SCR *);
static int	sscr_init(SCR *);
static int	sscr_insert(SCR *);
static int	sscr_matchprompt(SCR *, char *, size_t, size_t *);
static int	sscr_setprompt(SCR *, char *, size_t);

/*
 * ex_script -- : sc[ript][!] [file]
 *	Switch to script mode.
 *
 * PUBLIC: int ex_script(SCR *, EXCMD *);
 */
int
ex_script(SCR *sp, EXCMD *cmdp)
{
	/* Vi only command. */
	if (!F_ISSET(sp, SC_VI)) {
		msgq(sp, M_ERR,
		    "150|The script command is only available in vi mode");
		return (1);
	}

	/* Switch to the new file. */
	if (cmdp->argc != 0 && ex_edit(sp, cmdp))
		return (1);

	/* Create the shell, figure out the prompt. */
	if (sscr_init(sp))
		return (1);

	return (0);
}

/*
 * sscr_init --
 *	Create a pty setup for a shell.
 */
static int
sscr_init(SCR *sp)
{
	SCRIPT *sc;
	char *sh, *sh_path;

	/* We're going to need a shell. */
	if (opts_empty(sp, O_SHELL, 0))
		return (1);

	MALLOC_RET(sp, sc, sizeof(SCRIPT));
	sp->script = sc;
	sc->sh_prompt = NULL;
	sc->sh_prompt_len = 0;

	/*
	 * There are two different processes running through this code.
	 * They are the shell and the parent.
	 */
	sc->sh_master = sc->sh_slave = -1;

	if (tcgetattr(STDIN_FILENO, &sc->sh_term) == -1) {
		msgq(sp, M_SYSERR, "tcgetattr");
		goto err;
	}

	/*
	 * Turn off output postprocessing and echo.
	 */
	sc->sh_term.c_oflag &= ~OPOST;
	sc->sh_term.c_cflag &= ~(ECHO|ECHOE|ECHONL|ECHOK);

	if (ioctl(STDIN_FILENO, TIOCGWINSZ, &sc->sh_win) == -1) {
		msgq(sp, M_SYSERR, "tcgetattr");
		goto err;
	}

	if (openpty(&sc->sh_master,
	    &sc->sh_slave, sc->sh_name, &sc->sh_term, &sc->sh_win) == -1) {
		msgq(sp, M_SYSERR, "openpty");
		goto err;
	}

	/*
	 * __TK__ huh?
	 * Don't use vfork() here, because the signal semantics differ from
	 * implementation to implementation.
	 */
	switch (sc->sh_pid = fork()) {
	case -1:			/* Error. */
		msgq(sp, M_SYSERR, "fork");
err:		if (sc->sh_master != -1)
			(void)close(sc->sh_master);
		if (sc->sh_slave != -1)
			(void)close(sc->sh_slave);
		return (1);
	case 0:				/* Utility. */
		/*
		 * XXX
		 * So that shells that do command line editing turn it off.
		 */
		(void)setenv("TERM", "emacs", 1);
		(void)setenv("TERMCAP", "emacs:", 1);
		(void)setenv("EMACS", "t", 1);

		(void)setsid();
#ifdef TIOCSCTTY
		/*
		 * 4.4BSD allocates a controlling terminal using the TIOCSCTTY
		 * ioctl, not by opening a terminal device file.  POSIX 1003.1
		 * doesn't define a portable way to do this.  If TIOCSCTTY is
		 * not available, hope that the open does it.
		 */
		(void)ioctl(sc->sh_slave, TIOCSCTTY, 0);
#endif
		(void)close(sc->sh_master);
		(void)dup2(sc->sh_slave, STDIN_FILENO);
		(void)dup2(sc->sh_slave, STDOUT_FILENO);
		(void)dup2(sc->sh_slave, STDERR_FILENO);
		(void)close(sc->sh_slave);

		/* Assumes that all shells have -i. */
		sh_path = O_STR(sp, O_SHELL);
		if ((sh = strrchr(sh_path, '/')) == NULL)
			sh = sh_path;
		else
			++sh;
		execl(sh_path, sh, "-i", NULL);
		msgq_str(sp, M_SYSERR, sh_path, "execl: %s");
		_exit(127);
	default:			/* Parent. */
		break;
	}

	if (sscr_getprompt(sp))
		return (1);

	F_SET(sp, SC_SCRIPT);
	F_SET(sp->gp, G_SCRWIN);
	return (0);
}

/*
 * sscr_getprompt --
 *	Eat lines printed by the shell until a line with no trailing
 *	carriage return comes; set the prompt from that line.
 */
static int
sscr_getprompt(SCR *sp)
{
	EX_PRIVATE *exp;
	struct timeval tv;
	char *endp, *p, *t, buf[1024];
	SCRIPT *sc;
	fd_set fdset;
	recno_t lline;
	size_t llen, len;
	int nr;
	CHAR_T *wp;
	size_t wlen;

	exp = EXP(sp);

	FD_ZERO(&fdset);
	endp = buf;
	len = sizeof(buf);

	/* Wait up to a second for characters to read. */
	tv.tv_sec = 5;
	tv.tv_usec = 0;
	sc = sp->script;
	FD_SET(sc->sh_master, &fdset);
	switch (select(sc->sh_master + 1, &fdset, NULL, NULL, &tv)) {
	case -1:		/* Error or interrupt. */
		msgq(sp, M_SYSERR, "select");
		goto prompterr;
	case  0:		/* Timeout */
		msgq(sp, M_ERR, "Error: timed out");
		goto prompterr;
	case  1:		/* Characters to read. */
		break;
	}

	/* Read the characters. */
more:	len = sizeof(buf) - (endp - buf);
	switch (nr = read(sc->sh_master, endp, len)) {
	case  0:			/* EOF. */
		msgq(sp, M_ERR, "Error: shell: EOF");
		goto prompterr;
	case -1:			/* Error or interrupt. */
		msgq(sp, M_SYSERR, "shell");
		goto prompterr;
	default:
		endp += nr;
		break;
	}

	/* If any complete lines, push them into the file. */
	for (p = t = buf; p < endp; ++p) {
		if (*p == '\r' || *p == '\n') {
			if (CHAR2INT5(sp, exp->ibcw, t, p - t, wp, wlen))
				goto conv_err;
			if (db_last(sp, &lline) ||
			    db_append(sp, 0, lline, wp, wlen))
				goto prompterr;
			t = p + 1;
		}
	}
	if (p > buf) {
		memmove(buf, t, endp - t);
		endp = buf + (endp - t);
	}
	if (endp == buf)
		goto more;

	/* Wait up 1/10 of a second to make sure that we got it all. */
	tv.tv_sec = 0;
	tv.tv_usec = 100000;
	switch (select(sc->sh_master + 1, &fdset, NULL, NULL, &tv)) {
	case -1:		/* Error or interrupt. */
		msgq(sp, M_SYSERR, "select");
		goto prompterr;
	case  0:		/* Timeout */
		break;
	case  1:		/* Characters to read. */
		goto more;
	}

	/* Timed out, so theoretically we have a prompt. */
	llen = endp - buf;
	endp = buf;

	/* Append the line into the file. */
	if (CHAR2INT5(sp, exp->ibcw, buf, llen, wp, wlen))
		goto conv_err;
	if (db_last(sp, &lline) || db_append(sp, 0, lline, wp, wlen)) {
		if (0)
conv_err:		msgq(sp, M_ERR, "323|Invalid input. Truncated.");
prompterr:	sscr_end(sp);
		return (1);
	}

	return (sscr_setprompt(sp, buf, llen));
}

/*
 * sscr_exec --
 *	Take a line and hand it off to the shell.
 *
 * PUBLIC: int sscr_exec(SCR *, recno_t);
 */
int
sscr_exec(SCR *sp, recno_t lno)
{
	SCRIPT *sc;
	recno_t last_lno;
	size_t blen, len, last_len, tlen;
	int isempty, matchprompt, nw, rval;
	char *bp = NULL, *p;
	CHAR_T *wp;
	size_t wlen;

	/* If there's a prompt on the last line, append the command. */
	if (db_last(sp, &last_lno))
		return (1);
	if (db_get(sp, last_lno, DBG_FATAL, &wp, &wlen))
		return (1);
	INT2CHAR(sp, wp, wlen, p, last_len);
	if (sscr_matchprompt(sp, p, last_len, &tlen) && tlen == 0) {
		matchprompt = 1;
		GET_SPACE_RETC(sp, bp, blen, last_len + 128);
		memmove(bp, p, last_len);
	} else
		matchprompt = 0;

	/* Get something to execute. */
	if (db_eget(sp, lno, &wp, &wlen, &isempty)) {
		if (isempty)
			goto empty;
		goto err1;
	}

	/* Empty lines aren't interesting. */
	if (wlen == 0)
		goto empty;
	INT2CHAR(sp, wp, wlen, p, len);

	/* Delete any prompt. */
	if (sscr_matchprompt(sp, p, len, &tlen)) {
		if (tlen == len) {
empty:			msgq(sp, M_BERR, "151|No command to execute");
			goto err1;
		}
		p += (len - tlen);
		len = tlen;
	}

	/* Push the line to the shell. */
	sc = sp->script;
	if ((nw = write(sc->sh_master, p, len)) != len)
		goto err2;
	rval = 0;
	if (write(sc->sh_master, "\n", 1) != 1) {
err2:		if (nw == 0)
			errno = EIO;
		msgq(sp, M_SYSERR, "shell");
		goto err1;
	}

	if (matchprompt) {
		ADD_SPACE_RETC(sp, bp, blen, last_len + len);
		memmove(bp + last_len, p, len);
		CHAR2INT(sp, bp, last_len + len, wp, wlen);
		if (db_set(sp, last_lno, wp, wlen))
err1:			rval = 1;
	}
	if (matchprompt)
		FREE_SPACE(sp, bp, blen);
	return (rval);
}

/*
 * sscr_input --
 *	Read any waiting shell input.
 *
 * PUBLIC: int sscr_input(SCR *);
 */
int
sscr_input(SCR *sp)
{
	GS *gp;
	struct timeval poll;
	fd_set rdfd;
	int maxfd;

	gp = sp->gp;

loop:	maxfd = 0;
	FD_ZERO(&rdfd);
	poll.tv_sec = 0;
	poll.tv_usec = 0;

	/* Set up the input mask. */
	TAILQ_FOREACH(sp, gp->dq, q)
		if (F_ISSET(sp, SC_SCRIPT)) {
			FD_SET(sp->script->sh_master, &rdfd);
			if (sp->script->sh_master > maxfd)
				maxfd = sp->script->sh_master;
		}

	/* Check for input. */
	switch (select(maxfd + 1, &rdfd, NULL, NULL, &poll)) {
	case -1:
		msgq(sp, M_SYSERR, "select");
		return (1);
	case 0:
		return (0);
	default:
		break;
	}

	/* Read the input. */
	TAILQ_FOREACH(sp, gp->dq, q)
		if (F_ISSET(sp, SC_SCRIPT) &&
		    FD_ISSET(sp->script->sh_master, &rdfd) &&
		    sscr_insert(sp))
			return (1);
	goto loop;
}

/*
 * sscr_insert --
 *	Take a line from the shell and insert it into the file.
 */
static int
sscr_insert(SCR *sp)
{
	EX_PRIVATE *exp;
	struct timeval tv;
	char *endp, *p, *t;
	SCRIPT *sc;
	fd_set rdfd;
	recno_t lno;
	size_t blen, len, tlen;
	int nr, rval;
	char *bp;
	CHAR_T *wp;
	size_t wlen = 0;

	exp = EXP(sp);


	/* Find out where the end of the file is. */
	if (db_last(sp, &lno))
		return (1);

#define	MINREAD	1024
	GET_SPACE_RETC(sp, bp, blen, MINREAD);
	endp = bp;

	/* Read the characters. */
	rval = 1;
	sc = sp->script;
more:	switch (nr = read(sc->sh_master, endp, MINREAD)) {
	case  0:			/* EOF; shell just exited. */
		sscr_end(sp);
		rval = 0;
		goto ret;
	case -1:			/* Error or interrupt. */
		msgq(sp, M_SYSERR, "shell");
		goto ret;
	default:
		endp += nr;
		break;
	}

	/* Append the lines into the file. */
	for (p = t = bp; p < endp; ++p) {
		if (*p == '\r' || *p == '\n') {
			len = p - t;
			if (CHAR2INT5(sp, exp->ibcw, t, len, wp, wlen))
				goto conv_err;
			if (db_append(sp, 1, lno++, wp, wlen))
				goto ret;
			t = p + 1;
		}
	}
	if (p > t) {
		len = p - t;
		/*
		 * If the last thing from the shell isn't another prompt, wait
		 * up to 1/10 of a second for more stuff to show up, so that
		 * we don't break the output into two separate lines.  Don't
		 * want to hang indefinitely because some program is hanging,
		 * confused the shell, or whatever.
		 */
		if (!sscr_matchprompt(sp, t, len, &tlen) || tlen != 0) {
			tv.tv_sec = 0;
			tv.tv_usec = 100000;
			FD_ZERO(&rdfd);
			FD_SET(sc->sh_master, &rdfd);
			if (select(sc->sh_master + 1,
			    &rdfd, NULL, NULL, &tv) == 1) {
				memmove(bp, t, len);
				endp = bp + len;
				goto more;
			}
		}
		if (sscr_setprompt(sp, t, len))
			return (1);
		if (CHAR2INT5(sp, exp->ibcw, t, len, wp, wlen))
			goto conv_err;
		if (db_append(sp, 1, lno++, wp, wlen))
			goto ret;
	}

	/* The cursor moves to EOF. */
	sp->lno = lno;
	sp->cno = wlen ? wlen - 1 : 0;
	rval = vs_refresh(sp, 1);

	if (0)
conv_err:	msgq(sp, M_ERR, "323|Invalid input. Truncated.");

ret:	FREE_SPACE(sp, bp, blen);
	return (rval);
}

/*
 * sscr_setprompt --
 *
 * Set the prompt to the last line we got from the shell.
 *
 */
static int
sscr_setprompt(SCR *sp, char *buf, size_t len)
{
	SCRIPT *sc;

	sc = sp->script;
	free(sc->sh_prompt);
	MALLOC(sp, sc->sh_prompt, len + 1);
	if (sc->sh_prompt == NULL) {
		sscr_end(sp);
		return (1);
	}
	memmove(sc->sh_prompt, buf, len);
	sc->sh_prompt_len = len;
	sc->sh_prompt[len] = '\0';
	return (0);
}

/*
 * sscr_matchprompt --
 *	Check to see if a line matches the prompt.  Nul's indicate
 *	parts that can change, in both content and size.
 */
static int
sscr_matchprompt(SCR *sp, char *lp, size_t line_len, size_t *lenp)
{
	SCRIPT *sc;
	size_t prompt_len;
	char *pp;

	sc = sp->script;
	if (line_len < (prompt_len = sc->sh_prompt_len))
		return (0);

	for (pp = sc->sh_prompt;
	    prompt_len && line_len; --prompt_len, --line_len) {
		if (*pp == '\0') {
			for (; prompt_len && *pp == '\0'; --prompt_len, ++pp);
			if (!prompt_len)
				return (0);
			for (; line_len && *lp != *pp; --line_len, ++lp);
			if (!line_len)
				return (0);
		}
		if (*pp++ != *lp++)
			break;
	}

	if (prompt_len)
		return (0);
	if (lenp != NULL)
		*lenp = line_len;
	return (1);
}

/*
 * sscr_end --
 *	End the pipe to a shell.
 *
 * PUBLIC: int sscr_end(SCR *);
 */
int
sscr_end(SCR *sp)
{
	SCRIPT *sc;

	if ((sc = sp->script) == NULL)
		return (0);

	/* Turn off the script flags. */
	F_CLR(sp, SC_SCRIPT);
	sscr_check(sp);

	/* Close down the parent's file descriptors. */
	if (sc->sh_master != -1)
	    (void)close(sc->sh_master);
	if (sc->sh_slave != -1)
	    (void)close(sc->sh_slave);

	/* This should have killed the child. */
	(void)proc_wait(sp, (long)sc->sh_pid, "script-shell", 0, 0);

	/* Free memory. */
	free(sc->sh_prompt);
	free(sc);
	sp->script = NULL;

	return (0);
}

/*
 * sscr_check --
 *	Set/clear the global scripting bit.
 */
static void
sscr_check(SCR *sp)
{
	GS *gp;

	gp = sp->gp;
	TAILQ_FOREACH(sp, gp->dq, q)
		if (F_ISSET(sp, SC_SCRIPT)) {
			F_SET(gp, G_SCRWIN);
			return;
		}
	F_CLR(gp, G_SCRWIN);
}