/*
 *	main.c

 *	uEmacs/PK 4.0
 *
 *	Based on:
 *
 *	MicroEMACS 3.9
 *	Written by Dave G. Conroy.
 *	Substantially modified by Daniel M. Lawrence
 *	Modified by Petri Kutvonen
 *
 *	MicroEMACS 3.9 (c) Copyright 1987 by Daniel M. Lawrence
 *
 *	Original statement of copying policy:
 *
 *	MicroEMACS 3.9 can be copied and distributed freely for any
 *	non-commercial purposes. MicroEMACS 3.9 can only be incorporated
 *	into commercial software with the permission of the current author.
 *
 *	No copyright claimed for modifications made by Petri Kutvonen.
 *
 *	This file contains the main driving routine, and some keyboard
 *	processing code.
 *
 * REVISION HISTORY:
 *
 * 1.0  Steve Wilhite, 30-Nov-85
 *
 * 2.0  George Jones, 12-Dec-85
 *
 * 3.0  Daniel Lawrence, 29-Dec-85
 *
 * 3.2-3.6 Daniel Lawrence, Feb...Apr-86
 *
 * 3.7	Daniel Lawrence, 14-May-86
 *
 * 3.8	Daniel Lawrence, 18-Jan-87
 *
 * 3.9	Daniel Lawrence, 16-Jul-87
 *
 * 3.9e	Daniel Lawrence, 16-Nov-87
 *
 * After that versions 3.X and Daniel Lawrence went their own ways.
 * A modified 3.9e/PK was heavily used at the University of Helsinki
 * for several years on different UNIX, VMS, and MSDOS platforms.
 *
 * This modified version is now called eEmacs/PK.
 *
 * 4.0	Petri Kutvonen, 1-Sep-91
 *
 */

#include <stdio.h>

/* Make global definitions not external. */
#define	maindef

#include "estruct.h" /* Global structures and defines. */
#include "edef.h"    /* Global definitions. */
#include "efunc.h"   /* Function declarations and name table. */
#include "ebind.h"   /* Default key bindings. */
#include "version.h"

/* For MSDOS, increase the default stack space. */
#if MSDOS & TURBO
#if PKCODE
extern unsigned _stklen = 20000;
#else
extern unsigned _stklen = 32766;
#endif
#endif

#if VMS
#include <ssdef.h>
#define GOOD    (SS$_NORMAL)
#endif

#ifndef GOOD
#define GOOD    0
#endif

#if UNIX
#include <signal.h>
static void emergencyexit(int);
#ifdef SIGWINCH
extern void sizesignal(int);
#endif
#endif

void usage(int status)
{
  printf("Usage: %s filename\n", PROGRAM_NAME);
  printf("   or: %s [options]\n\n", PROGRAM_NAME);
  fputs("      +          start at the end of file\n", stdout);
  fputs("      +<n>       start at line <n>\n", stdout);
  fputs("      -g[G]<n>   go to line <n>\n", stdout);
  fputs("      --help     display this help and exit\n", stdout);
  fputs("      --version  output version information and exit\n", stdout);

  exit(status);
}

int main(int argc, char **argv)
{
	int c = -1;	/* command character */
	int f;		/* default flag */
	int n;		/* numeric repeat count */
	int mflag;	/* negative flag on repeat */
	struct buffer *bp;	/* temp buffer pointer */
	int firstfile;	/* first file flag */
	int carg;	/* current arg to scan */
	int startflag;	/* startup executed flag */
	struct buffer *firstbp = NULL;	/* ptr to first buffer in cmd line */
	int basec;		/* c stripped of meta character */
	int viewflag;		/* are we starting in view mode? */
	int gotoflag;		/* do we need to goto a line at start? */
	int gline = 0;		/* if so, what line? */
	int searchflag;		/* Do we need to search at start? */
	int saveflag;		/* temp store for lastflag */
	int errflag;		/* C error processing? */
	char bname[NBUFN];	/* buffer name of file to read */
#if	CRYPT
	int cryptflag;		/* encrypting on the way in? */
	char ekey[NPAT];	/* startup encryption key */
#endif
	int newc;

#if	PKCODE & VMS
	(void) umask(-1); /* Use old protection (this is at wrong place). */
#endif

#if	PKCODE & BSD
	sleep(1); /* Time for window manager. */
#endif

#if	UNIX
#ifdef SIGWINCH
	signal(SIGWINCH, sizesignal);
#endif
#endif
	if (argc == 2) {
		if (strcmp(argv[1], "--help") == 0) {
			usage(EXIT_FAILURE);
		}
		if (strcmp(argv[1], "--version") == 0) {
			version();
			exit(EXIT_SUCCESS);
		}
	}

	/* Initialize the editor. */
	vtinit();		/* Display */
	edinit("main");		/* Buffers, windows */
	varinit();		/* user variables */

	viewflag = FALSE;	/* view mode defaults off in command line */
	gotoflag = FALSE;	/* set to off to begin with */
	searchflag = FALSE;	/* set to off to begin with */
	firstfile = TRUE;	/* no file to edit yet */
	startflag = FALSE;	/* startup file not executed yet */
	errflag = FALSE;	/* not doing C error parsing */
#if	CRYPT
	cryptflag = FALSE;	/* no encryption by default */
#endif

	/* Parse the command line */
	for (carg = 1; carg < argc; ++carg) {
		/* Process Switches */
#if	PKCODE
		if (argv[carg][0] == '+') {
			gotoflag = TRUE;
			gline = atoi(&argv[carg][1]);
		} else
#endif
		if (argv[carg][0] == '-') {
			switch (argv[carg][1]) {
				/* Process Startup macroes */
			case 'a':	/* process error file */
			case 'A':
				errflag = TRUE;
				break;
			case 'e':	/* -e for Edit file */
			case 'E':
				viewflag = FALSE;
				break;
			case 'g':	/* -g for initial goto */
			case 'G':
				gotoflag = TRUE;
				gline = atoi(&argv[carg][2]);
				break;
#if	CRYPT
			case 'k':	/* -k<key> for code key */
			case 'K':
				cryptflag = TRUE;
				strcpy(ekey, &argv[carg][2]);
				break;
#endif
#if	PKCODE
			case 'n':	/* -n accept null chars */
			case 'N':
				nullflag = TRUE;
				break;
#endif
			case 'r':	/* -r restrictive use */
			case 'R':
				restflag = TRUE;
				break;
			case 's':	/* -s for initial search string */
			case 'S':
				searchflag = TRUE;
				strncpy(pat, &argv[carg][2], NPAT);
				break;
			case 'v':	/* -v for View File */
			case 'V':
				viewflag = TRUE;
				break;
			default:	/* unknown switch */
				/* ignore this for now */
				break;
			}

		} else if (argv[carg][0] == '@') {

			/* Process Startup macroes */
			if (startup(&argv[carg][1]) == TRUE)
				/* don't execute emacs.rc */
				startflag = TRUE;

		} else {

			/* Process an input file */

			/* set up a buffer for this file */
			makename(bname, argv[carg]);
			unqname(bname);

			/* set this to inactive */
			bp = bfind(bname, TRUE, 0);
			strcpy(bp->b_fname, argv[carg]);
			bp->b_active = FALSE;
			if (firstfile) {
				firstbp = bp;
				firstfile = FALSE;
			}

			/* set the modes appropriatly */
			if (viewflag)
				bp->b_mode |= MDVIEW;
#if	CRYPT
			if (cryptflag) {
				bp->b_mode |= MDCRYPT;
				myencrypt((char *) NULL, 0);
				myencrypt(ekey, strlen(ekey));
				strncpy(bp->b_key, ekey, NPAT);
			}
#endif
		}
	}

#if	UNIX
	signal(SIGHUP, emergencyexit);
	signal(SIGTERM, emergencyexit);
#endif

	/* if we are C error parsing... run it! */
	if (errflag) {
		if (startup("error.cmd") == TRUE)
			startflag = TRUE;
	}

	/* if invoked with no other startup files,
	   run the system startup file here */
	if (startflag == FALSE) {
		startup("");
		startflag = TRUE;
	}
	discmd = TRUE;		/* P.K. */

	/* if there are any files to read, read the first one! */
	bp = bfind("main", FALSE, 0);
	if (firstfile == FALSE && (gflags & GFREAD)) {
		swbuffer(firstbp);
		zotbuf(bp);
	} else
		bp->b_mode |= gmode;

	/* Deal with startup gotos and searches */
	if (gotoflag && searchflag) {
		update(FALSE);
		mlwrite("(Can not search and goto at the same time!)");
	} else if (gotoflag) {
		if (gotoline(TRUE, gline) == FALSE) {
			update(FALSE);
			mlwrite("(Bogus goto argument)");
		}
	} else if (searchflag) {
		if (forwhunt(FALSE, 0) == FALSE)
			update(FALSE);
	}

	/* Setup to process commands. */
	lastflag = 0;  /* Fake last flags. */

      loop:
	/* Execute the "command" macro...normally null. */
	saveflag = lastflag;  /* Preserve lastflag through this. */
	execute(META | SPEC | 'C', FALSE, 1);
	lastflag = saveflag;

#if TYPEAH && PKCODE
	if (typahead()) {
		newc = getcmd();
		update(FALSE);
		do {
			fn_t execfunc;

			if (c == newc && (execfunc = getbind(c)) != NULL
			    && execfunc != insert_newline
			    && execfunc != insert_tab)
				newc = getcmd();
			else
				break;
		} while (typahead());
		c = newc;
	} else {
		update(FALSE);
		c = getcmd();
	}
#else
	/* Fix up the screen    */
	update(FALSE);

	/* get the next command from the keyboard */
	c = getcmd();
#endif
	/* if there is something on the command line, clear it */
	if (mpresf != FALSE) {
		mlerase();
		update(FALSE);
#if	CLRMSG
		if (c == ' ')	/* ITS EMACS does this  */
			goto loop;
#endif
	}
	f = FALSE;
	n = 1;

	/* do META-# processing if needed */

	basec = c & ~META;	/* strip meta char off if there */
	if ((c & META) && ((basec >= '0' && basec <= '9') || basec == '-')) {
		f = TRUE;	/* there is a # arg */
		n = 0;		/* start with a zero default */
		mflag = 1;	/* current minus flag */
		c = basec;	/* strip the META */
		while ((c >= '0' && c <= '9') || (c == '-')) {
			if (c == '-') {
				/* already hit a minus or digit? */
				if ((mflag == -1) || (n != 0))
					break;
				mflag = -1;
			} else {
				n = n * 10 + (c - '0');
			}
			if ((n == 0) && (mflag == -1))	/* lonely - */
				mlwrite("Arg:");
			else
				mlwrite("Arg: %d", n * mflag);

			c = getcmd();	/* get the next key */
		}
		n = n * mflag;	/* figure in the sign */
	}

	/* do ^U repeat argument processing */

	if (c == reptc) {	/* ^U, start argument   */
		f = TRUE;
		n = 4;		/* with argument of 4 */
		mflag = 0;	/* that can be discarded. */
		mlwrite("Arg: 4");
		while (((c = getcmd()) >= '0' && c <= '9') || c == reptc
		       || c == '-') {
			if (c == reptc)
				if ((n > 0) == ((n * 4) > 0))
					n = n * 4;
				else
					n = 1;
			/*
			 * If dash, and start of argument string, set arg.
			 * to -1.  Otherwise, insert it.
			 */
			else if (c == '-') {
				if (mflag)
					break;
				n = 0;
				mflag = -1;
			}
			/*
			 * If first digit entered, replace previous argument
			 * with digit and set sign.  Otherwise, append to arg.
			 */
			else {
				if (!mflag) {
					n = 0;
					mflag = 1;
				}
				n = 10 * n + c - '0';
			}
			mlwrite("Arg: %d",
				(mflag >= 0) ? n : (n ? -n : -1));
		}
		/*
		 * Make arguments preceded by a minus sign negative and change
		 * the special argument "^U -" to an effective "^U -1".
		 */
		if (mflag == -1) {
			if (n == 0)
				n++;
			n = -n;
		}
	}

	/* and execute the command */
	execute(c, f, n);
	goto loop;
}

/*
 * Initialize all of the buffers and windows. The buffer name is passed down
 * as an argument, because the main routine may have been told to read in a
 * file by default, and we want the buffer name to be right.
 */
void edinit(char *bname)
{
	struct buffer *bp;
	struct window *wp;

	bp = bfind(bname, TRUE, 0);	/* First buffer         */
	blistp = bfind("*List*", TRUE, BFINVS);	/* Buffer list buffer   */
	wp = (struct window *)malloc(sizeof(struct window));	/* First window         */
	if (bp == NULL || wp == NULL || blistp == NULL)
		exit(1);
	curbp = bp;		/* Make this current    */
	wheadp = wp;
	curwp = wp;
	wp->w_wndp = NULL;	/* Initialize window    */
	wp->w_bufp = bp;
	bp->b_nwnd = 1;		/* Displayed.           */
	wp->w_linep = bp->b_linep;
	wp->w_dotp = bp->b_linep;
	wp->w_doto = 0;
	wp->w_markp = NULL;
	wp->w_marko = 0;
	wp->w_toprow = 0;
#if	COLOR
	/* initalize colors to global defaults */
	wp->w_fcolor = gfcolor;
	wp->w_bcolor = gbcolor;
#endif
	wp->w_ntrows = term.t_nrow - 1;	/* "-1" for mode line.  */
	wp->w_force = 0;
	wp->w_flag = WFMODE | WFHARD;	/* Full.                */
}

/*
 * This is the general command execution routine. It handles the fake binding
 * of all the keys to "self-insert". It also clears out the "thisflag" word,
 * and arranges to move it to the "lastflag", so that the next command can
 * look at it. Return the status of command.
 */
int execute(int c, int f, int n)
{
	int status;
	fn_t execfunc;

	/* if the keystroke is a bound function...do it */
	execfunc = getbind(c);
	if (execfunc != NULL) {
		thisflag = 0;
		status = (*execfunc) (f, n);
		lastflag = thisflag;
		return status;
	}

	/*
	 * If a space was typed, fill column is defined, the argument is non-
	 * negative, wrap mode is enabled, and we are now past fill column,
	 * and we are not read-only, perform word wrap.
	 */
	if (c == ' ' && (curwp->w_bufp->b_mode & MDWRAP) && fillcol > 0 &&
	    n >= 0 && getccol(FALSE) > fillcol &&
	    (curwp->w_bufp->b_mode & MDVIEW) == FALSE)
		execute(META | SPEC | 'W', FALSE, 1);

#if	PKCODE
	if ((c >= 0x20 && c <= 0x7E)	/* Self inserting.      */
#if	IBMPC
	    || (c >= 0x80 && c <= 0xFE)) {
#else
#if	VMS || BSD || USG	/* 8BIT P.K. */
	    || (c >= 0xA0 && c <= 0x10FFFF)) {
#else
	    ) {
#endif
#endif
#else
	if ((c >= 0x20 && c <= 0xFF)) {	/* Self inserting.      */
#endif
		if (n <= 0) {	/* Fenceposts.          */
			lastflag = 0;
			return n < 0 ? FALSE : TRUE;
		}
		thisflag = 0;	/* For the future.      */

		/* if we are in overwrite mode, not at eol,
		   and next char is not a tab or we are at a tab stop,
		   delete a char forword                        */
		if (curwp->w_bufp->b_mode & MDOVER &&
		    curwp->w_doto < curwp->w_dotp->l_used &&
		    (lgetc(curwp->w_dotp, curwp->w_doto) != '\t' ||
		     (curwp->w_doto) % 8 == 7))
			ldelchar(1, FALSE);

		/* do the appropriate insertion */
		if (c == '}' && (curbp->b_mode & MDCMOD) != 0)
			status = insbrace(n, c);
		else if (c == '#' && (curbp->b_mode & MDCMOD) != 0)
			status = inspound();
		else
			status = linsert(n, c);

#if	CFENCE
		/* check for CMODE fence matching */
		if ((c == '}' || c == ')' || c == ']') &&
		    (curbp->b_mode & MDCMOD) != 0)
			fmatch(c);
#endif

		/* check auto-save mode */
		if (curbp->b_mode & MDASAVE)
			if (--gacount == 0) {
				/* and save the file if needed */
				upscreen(FALSE, 0);
				filesave(FALSE, 0);
				gacount = gasave;
			}

		lastflag = thisflag;
		return status;
	}
	TTbeep();
	mlwrite("(Key not bound)");	/* complain             */
	lastflag = 0;		/* Fake last flags.     */
	return FALSE;
}

/*
 * Fancy quit command, as implemented by Norm. If the any buffer has
 * changed do a write on that buffer and exit emacs, otherwise simply exit.
 */
int quickexit(int f, int n)
{
	struct buffer *bp;	/* scanning pointer to buffers */
	struct buffer *oldcb;	/* original current buffer */
	int status;

	oldcb = curbp;		/* save in case we fail */

	bp = bheadp;
	while (bp != NULL) {
		if ((bp->b_flag & BFCHG) != 0	/* Changed.             */
		    && (bp->b_flag & BFTRUNC) == 0	/* Not truncated P.K.   */
		    && (bp->b_flag & BFINVS) == 0) {	/* Real.                */
			curbp = bp;	/* make that buffer cur */
			mlwrite("(Saving %s)", bp->b_fname);
#if	PKCODE
#else
			mlwrite("\n");
#endif
			if ((status = filesave(f, n)) != TRUE) {
				curbp = oldcb;	/* restore curbp */
				return status;
			}
		}
		bp = bp->b_bufp;	/* on to the next buffer */
	}
	quit(f, n);		/* conditionally quit   */
	return TRUE;
}

static void emergencyexit(int signr)
{
	quickexit(FALSE, 0);
	quit(TRUE, 0);
}

/*
 * Quit command. If an argument, always quit. Otherwise confirm if a buffer
 * has been changed and not written out. Normally bound to "C-X C-C".
 */
int quit(int f, int n)
{
	int s;

	if (f != FALSE		/* Argument forces it.  */
	    || anycb() == FALSE	/* All buffers clean.   */
	    /* User says it's OK.   */
	    || (s =
		mlyesno("Modified buffers exist. Leave anyway")) == TRUE) {
#if	(FILOCK && BSD) || SVR4
		if (lockrel() != TRUE) {
			TTputc('\n');
			TTputc('\r');
			TTclose();
			TTkclose();
			exit(1);
		}
#endif
		vttidy();
		if (f)
			exit(n);
		else
			exit(GOOD);
	}
	mlwrite("");
	return s;
}

/*
 * Begin a keyboard macro.
 * Error if not at the top level in keyboard processing. Set up variables and
 * return.
 */
int ctlxlp(int f, int n)
{
	if (kbdmode != STOP) {
		mlwrite("%%Macro already active");
		return FALSE;
	}
	mlwrite("(Start macro)");
	kbdptr = &kbdm[0];
	kbdend = kbdptr;
	kbdmode = RECORD;
	return TRUE;
}

/*
 * End keyboard macro. Check for the same limit conditions as the above
 * routine. Set up the variables and return to the caller.
 */
int ctlxrp(int f, int n)
{
	if (kbdmode == STOP) {
		mlwrite("%%Macro not active");
		return FALSE;
	}
	if (kbdmode == RECORD) {
		mlwrite("(End macro)");
		kbdmode = STOP;
	}
	return TRUE;
}

/*
 * Execute a macro.
 * The command argument is the number of times to loop. Quit as soon as a
 * command gets an error. Return TRUE if all ok, else FALSE.
 */
int ctlxe(int f, int n)
{
	if (kbdmode != STOP) {
		mlwrite("%%Macro already active");
		return FALSE;
	}
	if (n <= 0)
		return TRUE;
	kbdrep = n;		/* remember how many times to execute */
	kbdmode = PLAY;		/* start us in play mode */
	kbdptr = &kbdm[0];	/*    at the beginning */
	return TRUE;
}

/*
 * Abort.
 * Beep the beeper. Kill off any keyboard macro, etc., that is in progress.
 * Sometimes called as a routine, to do general aborting of stuff.
 */
int ctrlg(int f, int n)
{
	TTbeep();
	kbdmode = STOP;
	mlwrite("(Aborted)");
	return ABORT;
}

/*
 * tell the user that this command is illegal while we are in
 * VIEW (read-only) mode
 */
int rdonly(void)
{
	TTbeep();
	mlwrite("(Key illegal in VIEW mode)");
	return FALSE;
}

int resterr(void)
{
	TTbeep();
	mlwrite("(That command is RESTRICTED)");
	return FALSE;
}

/* user function that does NOTHING */
int nullproc(int f, int n)
{
	return TRUE;
}

/* dummy function for binding to meta prefix */
int metafn(int f, int n)
{
	return TRUE;
}

/* dummy function for binding to control-x prefix */
int cex(int f, int n)
{
	return TRUE;
}

/* dummy function for binding to universal-argument */
int unarg(int f, int n)
{
	return TRUE;
}

/*****		Compiler specific Library functions	****/

#if	RAMSIZE
/*	These routines will allow me to track memory usage by placing
	a layer on top of the standard system malloc() and free() calls.
	with this code defined, the environment variable, $RAM, will
	report on the number of bytes allocated via malloc.

	with SHOWRAM defined, the number is also posted on the
	end of the bottom mode line and is updated whenever it is changed.
*/

#undef	malloc
#undef	free

char *allocate(nbytes)
			    /* allocate nbytes and track */
unsigned nbytes;		/* # of bytes to allocate */

{
	char *mp;		/* ptr returned from malloc */
	char *malloc();

	mp = malloc(nbytes);
	if (mp) {
		envram += nbytes;
#if	RAMSHOW
		dspram();
#endif
	}

	return mp;
}

release(mp)
    /* release malloced memory and track */
char *mp;			/* chunk of RAM to release */

{
	unsigned *lp;		/* ptr to the long containing the block size */

	if (mp) {
		/* update amount of ram currently malloced */
		lp = ((unsigned *) mp) - 1;
		envram -= (long) *lp - 2;
		free(mp);
#if	RAMSHOW
		dspram();
#endif
	}
}

#if	RAMSHOW
dspram()
{				/* display the amount of RAM currently malloced */
	char mbuf[20];
	char *sp;

	TTmove(term.t_nrow - 1, 70);
#if	COLOR
	TTforg(7);
	TTbacg(0);
#endif
	sprintf(mbuf, "[%lu]", envram);
	sp = &mbuf[0];
	while (*sp)
		TTputc(*sp++);
	TTmove(term.t_nrow, 0);
	movecursor(term.t_nrow, 0);
}
#endif
#endif

/*	On some primitave operation systems, and when emacs is used as
	a subprogram to a larger project, emacs needs to de-alloc its
	own used memory
*/

#if	CLEAN

/*
 * cexit()
 *
 * int status;		return status of emacs
 */
int cexit(int status)
{
	struct buffer *bp;	/* buffer list pointer */
	struct window *wp;	/* window list pointer */
	struct window *tp;	/* temporary window pointer */

	/* first clean up the windows */
	wp = wheadp;
	while (wp) {
		tp = wp->w_wndp;
		free(wp);
		wp = tp;
	}
	wheadp = NULL;

	/* then the buffers */
	bp = bheadp;
	while (bp) {
		bp->b_nwnd = 0;
		bp->b_flag = 0;	/* don't say anything about a changed buffer! */
		zotbuf(bp);
		bp = bheadp;
	}

	/* and the kill buffer */
	kdelete();

	/* and the video buffers */
	vtfree();

#undef	exit
	exit(status);
}
#endif