/*	$OpenBSD: cl_main.c,v 1.36 2021/10/24 21:24:17 deraadt Exp $	*/

/*-
 * Copyright (c) 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1993, 1994, 1995, 1996
 *	Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/queue.h>

#include <bitstring.h>
#include <curses.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <term.h>
#include <termios.h>
#include <unistd.h>

#include "../common/common.h"
#include "cl.h"

GS *__global_list;				/* GLOBAL: List of screens. */

volatile sig_atomic_t cl_sigint;
volatile sig_atomic_t cl_sigterm;
volatile sig_atomic_t cl_sigwinch;

static void	   cl_func_std(GS *);
static CL_PRIVATE *cl_init(GS *);
static GS	  *gs_init(void);
static int	   setsig(int, struct sigaction *, void (*)(int));
static void	   sig_end(GS *);
static void	   term_init(char *);

/*
 * main --
 *	This is the main loop for the standalone curses editor.
 */
int
main(int argc, char *argv[])
{
	CL_PRIVATE *clp;
	GS *gp;
	size_t rows, cols;
	int rval;
	char *ttype;

	/* Create and initialize the global structure. */
	__global_list = gp = gs_init();

	/* Create and initialize the CL_PRIVATE structure. */
	clp = cl_init(gp);

	/*
	 * Initialize the terminal information.
	 *
	 * We have to know what terminal it is from the start, since we may
	 * have to use termcap/terminfo to find out how big the screen is.
	 */
	if ((ttype = getenv("TERM")) == NULL)
		ttype = "unknown";
	term_init(ttype);

	/* Add the terminal type to the global structure. */
	if ((OG_D_STR(gp, GO_TERM) =
	    OG_STR(gp, GO_TERM) = strdup(ttype)) == NULL)
		err(1, NULL);

	/* Figure out how big the screen is. */
	if (cl_ssize(NULL, 0, &rows, &cols, NULL))
		exit (1);

	/* Add the rows and columns to the global structure. */
	OG_VAL(gp, GO_LINES) = OG_D_VAL(gp, GO_LINES) = rows;
	OG_VAL(gp, GO_COLUMNS) = OG_D_VAL(gp, GO_COLUMNS) = cols;

	/* Ex wants stdout to be buffered. */
	(void)setvbuf(stdout, NULL, _IOFBF, 0);

	/* Start catching signals. */
	if (sig_init(gp, NULL))
		exit (1);

	/* Run ex/vi. */
	rval = editor(gp, argc, argv);

	/* Clean up signals. */
	sig_end(gp);

	/* Clean up the terminal. */
	(void)cl_quit(gp);

	/*
	 * XXX
	 * Reset the O_MESG option.
	 */
	if (clp->tgw != TGW_UNKNOWN)
		(void)cl_omesg(NULL, clp, clp->tgw == TGW_SET);

	/*
	 * XXX
	 * Reset the X11 xterm icon/window name.
	 */
	if (F_ISSET(clp, CL_RENAME)) {
		(void)printf(XTERM_RENAME, ttype);
		(void)fflush(stdout);
	}

	/* If a killer signal arrived, pretend we just got it. */
	if (cl_sigterm) {
		(void)signal(cl_sigterm, SIG_DFL);
		(void)kill(getpid(), cl_sigterm);
		/* NOTREACHED */
	}

	/* Free the global and CL private areas. */
#if defined(DEBUG) || defined(PURIFY)
	free(clp);
	free(gp);
#endif

	exit (rval);
}

/*
 * gs_init --
 *	Create and partially initialize the GS structure.
 */
static GS *
gs_init(void)
{
	GS *gp;

	/* Allocate the global structure. */
	if ((gp = calloc(1, sizeof(GS))) == NULL)
		err(1, NULL);

	return (gp);
}

/*
 * cl_init --
 *	Create and partially initialize the CL structure.
 */
static CL_PRIVATE *
cl_init(GS *gp)
{
	CL_PRIVATE *clp;
	int fd;

	/* Allocate the CL private structure. */
	if ((clp = calloc(1, sizeof(CL_PRIVATE))) == NULL)
		err(1, NULL);
	gp->cl_private = clp;

	/*
	 * Set the CL_STDIN_TTY flag.  It's purpose is to avoid setting
	 * and resetting the tty if the input isn't from there.  We also
	 * use the same test to determine if we're running a script or
	 * not.
	 */
	if (isatty(STDIN_FILENO))
		F_SET(clp, CL_STDIN_TTY);
	else
		F_SET(gp, G_SCRIPTED);

	/*
	 * We expect that if we've lost our controlling terminal that the
	 * open() (but not the tcgetattr()) will fail.
	 */
	if (F_ISSET(clp, CL_STDIN_TTY)) {
		if (tcgetattr(STDIN_FILENO, &clp->orig) == -1)
			goto tcfail;
	} else if ((fd = open(_PATH_TTY, O_RDONLY)) != -1) {
		if (tcgetattr(fd, &clp->orig) == -1)
tcfail:			err(1, "tcgetattr");
		(void)close(fd);
	}

	/* Initialize the list of curses functions. */
	cl_func_std(gp);

	return (clp);
}

/*
 * term_init --
 *	Initialize terminal information.
 */
static void
term_init(char *ttype)
{
	int err;

	/* Set up the terminal database information. */
	setupterm(ttype, STDOUT_FILENO, &err);
	switch (err) {
	case -1:
		errx(1, "No terminal database found");
	case 0:
		errx(1, "%s: unknown terminal type", ttype);
	}
}

static void
h_int(int signo)
{
	cl_sigint = 1;
}

static void
h_term(int signo)
{
	cl_sigterm = signo;
}

static void
h_winch(int signo)
{
	cl_sigwinch = 1;
}

/*
 * sig_init --
 *	Initialize signals.
 *
 * PUBLIC: int sig_init(GS *, SCR *);
 */
int
sig_init(GS *gp, SCR *sp)
{
	CL_PRIVATE *clp;

	clp = GCLP(gp);

	cl_sigint = 0;
	cl_sigterm = 0;
	cl_sigwinch = 0;

	if (sp == NULL) {
		if (setsig(SIGHUP, &clp->oact[INDX_HUP], h_term) ||
		    setsig(SIGINT, &clp->oact[INDX_INT], h_int) ||
		    setsig(SIGTERM, &clp->oact[INDX_TERM], h_term) ||
		    setsig(SIGWINCH, &clp->oact[INDX_WINCH], h_winch)
		    )
			err(1, NULL);
	} else
		if (setsig(SIGHUP, NULL, h_term) ||
		    setsig(SIGINT, NULL, h_int) ||
		    setsig(SIGTERM, NULL, h_term) ||
		    setsig(SIGWINCH, NULL, h_winch)
		    ) {
			msgq(sp, M_SYSERR, "signal-reset");
		}
	return (0);
}

/*
 * setsig --
 *	Set a signal handler.
 */
static int
setsig(int signo, struct sigaction *oactp, void (*handler)(int))
{
	struct sigaction act;

	/*
	 * Use sigaction(2), not signal(3), since we don't always want to
	 * restart system calls.  The example is when waiting for a command
	 * mode keystroke and SIGWINCH arrives.  Besides, you can't portably
	 * restart system calls (thanks, POSIX!).
	 */
	act.sa_handler = handler;
	sigemptyset(&act.sa_mask);

	act.sa_flags = 0;
	return (sigaction(signo, &act, oactp));
}

/*
 * sig_end --
 *	End signal setup.
 */
static void
sig_end(GS *gp)
{
	CL_PRIVATE *clp;

	clp = GCLP(gp);
	(void)sigaction(SIGHUP, NULL, &clp->oact[INDX_HUP]);
	(void)sigaction(SIGINT, NULL, &clp->oact[INDX_INT]);
	(void)sigaction(SIGTERM, NULL, &clp->oact[INDX_TERM]);
	(void)sigaction(SIGWINCH, NULL, &clp->oact[INDX_WINCH]);
}

/*
 * cl_func_std --
 *	Initialize the standard curses functions.
 */
static void
cl_func_std(GS *gp)
{
	gp->scr_addstr = cl_addstr;
	gp->scr_attr = cl_attr;
	gp->scr_baud = cl_baud;
	gp->scr_bell = cl_bell;
	gp->scr_busy = NULL;
	gp->scr_clrtoeol = cl_clrtoeol;
	gp->scr_cursor = cl_cursor;
	gp->scr_deleteln = cl_deleteln;
	gp->scr_event = cl_event;
	gp->scr_ex_adjust = cl_ex_adjust;
	gp->scr_fmap = cl_fmap;
	gp->scr_insertln = cl_insertln;
	gp->scr_keyval = cl_keyval;
	gp->scr_move = cl_move;
	gp->scr_msg = NULL;
	gp->scr_optchange = cl_optchange;
	gp->scr_refresh = cl_refresh;
	gp->scr_rename = cl_rename;
	gp->scr_screen = cl_screen;
	gp->scr_suspend = cl_suspend;
	gp->scr_usage = cl_usage;
}