/*
 * The routines in this file
 * handle the reading and writing of
 * disk files. All of details about the
 * reading and writing of the disk are
 * in "fileio.c".
 */
#include	<stdio.h>
#include	"ed.h"

/*
 * Read a file into the current
 * buffer. This is really easy; all you do it
 * find the name of the file, and call the standard
 * "read a file into the current buffer" code.
 * Bound to "C-X C-R".
 */
fileread(f, n)
{
	register int	s;
	char		fname[NFILEN];

	if ((s=mlreply("Read file: ", fname, NFILEN)) != TRUE)
		return (s);
	return (readin(fname));
}

/*
 * Select a file for editing.
 * Look around to see if you can find the
 * fine in another buffer; if you can find it
 * just switch to the buffer. If you cannot find
 * the file, create a new buffer, read in the
 * text, and switch to the new buffer.
 * Bound to C-X C-V.
 */
filevisit(f, n)
{
	register BUFFER	*bp;
	register WINDOW	*wp;
	register LINE	*lp;
	register int	i;
	register int	s;
	char		bname[NBUFN];
	char		fname[NFILEN];

	if ((s=mlreply("Visit file: ", fname, NFILEN)) != TRUE)
		return (s);
	for (bp=bheadp; bp!=NULL; bp=bp->b_bufp) {
		if ((bp->b_flag&BFTEMP)==0 && strcmp(bp->b_fname, fname)==0) {
			if (--curbp->b_nwnd == 0) {
				curbp->b_dotp  = curwp->w_dotp;
				curbp->b_doto  = curwp->w_doto;
				curbp->b_markp = curwp->w_markp;
				curbp->b_marko = curwp->w_marko;
			}
			curbp = bp;
			curwp->w_bufp  = bp;
			if (bp->b_nwnd++ == 0) {
				curwp->w_dotp  = bp->b_dotp;
				curwp->w_doto  = bp->b_doto;
				curwp->w_markp = bp->b_markp;
				curwp->w_marko = bp->b_marko;
			} else {
				wp = wheadp;
				while (wp != NULL) {
					if (wp!=curwp && wp->w_bufp==bp) {
						curwp->w_dotp  = wp->w_dotp;
						curwp->w_doto  = wp->w_doto;
						curwp->w_markp = wp->w_markp;
						curwp->w_marko = wp->w_marko;
						break;
					}
					wp = wp->w_wndp;
				}
			}
			lp = curwp->w_dotp;
			i = curwp->w_ntrows/2;
			while (i-- && lback(lp)!=curbp->b_linep)
				lp = lback(lp);
			curwp->w_linep = lp;
			curwp->w_flag |= WFMODE|WFHARD;
			mlwrite("[Old buffer]");
			return (TRUE);
		}
	}
	makename(bname, fname);			/* New buffer name.	*/
	while ((bp=bfind(bname, FALSE, 0)) != NULL) {
		s = mlreply("Buffer name: ", bname, NBUFN);
		if (s == ABORT)			/* ^G to just quit	*/
			return (s);
		if (s == FALSE) {		/* CR to clobber it	*/
			makename(bname, fname);
			break;
		}
	}
	if (bp==NULL && (bp=bfind(bname, TRUE, 0))==NULL) {
		mlwrite("Cannot create buffer");
		return (FALSE);
	}
	if (--curbp->b_nwnd == 0) {		/* Undisplay.		*/
		curbp->b_dotp = curwp->w_dotp;
		curbp->b_doto = curwp->w_doto;
		curbp->b_markp = curwp->w_markp;
		curbp->b_marko = curwp->w_marko;
	}
	curbp = bp;				/* Switch to it.	*/
	curwp->w_bufp = bp;
	curbp->b_nwnd++;
	return (readin(fname));			/* Read it in.		*/
}

/*
 * Read file "fname" into the current
 * buffer, blowing away any text found there. Called
 * by both the read and visit commands. Return the final
 * status of the read. Also called by the mainline,
 * to read in a file specified on the command line as
 * an argument.
 */
readin(fname)
char	fname[];
{
	register LINE	*lp1;
	register LINE	*lp2;
	register int	i;
	register WINDOW	*wp;
	register BUFFER	*bp;
	register int	s;
	register int	nbytes;
	register int	nline;
	char		line[NLINE];

	bp = curbp;				/* Cheap.		*/
	if ((s=bclear(bp)) != TRUE)		/* Might be old.	*/
		return (s);
	bp->b_flag &= ~(BFTEMP|BFCHG);
	strcpy(bp->b_fname, fname);
	if ((s=ffropen(fname)) == FIOERR) 	/* Hard file open.	*/
		goto out;
	if (s == FIOFNF) {			/* File not found.	*/
		mlwrite("[New file]");
		goto out;
	}
	mlwrite("[Reading file]");
	nline = 0;
	while ((s=ffgetline(line, NLINE)) == FIOSUC) {
		nbytes = strlen(line);
		if ((lp1=lalloc(nbytes)) == NULL) {
			s = FIOERR;		/* Keep message on the	*/
			break;			/* display.		*/
		}
		lp2 = lback(curbp->b_linep);
		lp2->l_fp = lp1;
		lp1->l_fp = curbp->b_linep;
		lp1->l_bp = lp2;
		curbp->b_linep->l_bp = lp1;
		for (i=0; i<nbytes; ++i)
			lputc(lp1, i, line[i]);
		++nline;
	}
	ffclose();				/* Ignore errors.	*/
	if (s == FIOEOF) {			/* Don't zap message!	*/
		if (nline == 1)
			mlwrite("[Read 1 line]");
		else
			mlwrite("[Read %d lines]", nline);
	}
out:
	for (wp=wheadp; wp!=NULL; wp=wp->w_wndp) {
		if (wp->w_bufp == curbp) {
			wp->w_linep = lforw(curbp->b_linep);
			wp->w_dotp  = lforw(curbp->b_linep);
			wp->w_doto  = 0;
			wp->w_markp = NULL;
			wp->w_marko = 0;
			wp->w_flag |= WFMODE|WFHARD;
		}
	}
	if (s == FIOERR)			/* False if error.	*/
		return (FALSE);
	return (TRUE);
}

/*
 * Take a file name, and from it
 * fabricate a buffer name. This routine knows
 * about the syntax of file names on the target system.
 * I suppose that this information could be put in
 * a better place than a line of code.
 */
makename(bname, fname)
char	bname[];
char	fname[];
{
	register char	*cp1;
	register char	*cp2;

	cp1 = &fname[0];
	while (*cp1 != 0)
		++cp1;
#if	VMS
	while (cp1!=&fname[0] && cp1[-1]!=':' && cp1[-1]!=']')
		--cp1;
#endif
#if	CPM
	while (cp1!=&fname[0] && cp1[-1]!=':')
		--cp1;
#endif
#if	MSDOS
	while (cp1!=&fname[0] && cp1[-1]!=':' && cp1[-1]!='\\')
		--cp1;
#endif
#if	V7
	while (cp1!=&fname[0] && cp1[-1]!='/')
		--cp1;
#endif
	cp2 = &bname[0];
	while (cp2!=&bname[NBUFN-1] && *cp1!=0 && *cp1!=';')
		*cp2++ = *cp1++;
	*cp2 = 0;
}

/*
 * Ask for a file name, and write the
 * contents of the current buffer to that file.
 * Update the remembered file name and clear the
 * buffer changed flag. This handling of file names
 * is different from the earlier versions, and
 * is more compatable with Gosling EMACS than
 * with ITS EMACS. Bound to "C-X C-W".
 */
filewrite(f, n)
{
	register WINDOW	*wp;
	register int	s;
	char		fname[NFILEN];

	if ((s=mlreply("Write file: ", fname, NFILEN)) != TRUE)
		return (s);
	if ((s=writeout(fname)) == TRUE) {
		strcpy(curbp->b_fname, fname);
		curbp->b_flag &= ~BFCHG;
		wp = wheadp;			/* Update mode lines.	*/
		while (wp != NULL) {
			if (wp->w_bufp == curbp)
				wp->w_flag |= WFMODE;
			wp = wp->w_wndp;
		}
	}
	return (s);
}

/*
 * Save the contents of the current
 * buffer in its associatd file. No nothing
 * if nothing has changed (this may be a bug, not a
 * feature). Error if there is no remembered file
 * name for the buffer. Bound to "C-X C-S". May
 * get called by "C-Z".
 */
filesave(f, n)
{
	register WINDOW	*wp;
	register int	s;

	if ((curbp->b_flag&BFCHG) == 0)		/* Return, no changes.	*/
		return (TRUE);
	if (curbp->b_fname[0] == 0) {		/* Must have a name.	*/
		mlwrite("No file name");
		return (FALSE);
	}
	if ((s=writeout(curbp->b_fname)) == TRUE) {
		curbp->b_flag &= ~BFCHG;
		wp = wheadp;			/* Update mode lines.	*/
		while (wp != NULL) {
			if (wp->w_bufp == curbp)
				wp->w_flag |= WFMODE;
			wp = wp->w_wndp;
		}
	}
	return (s);
}

/*
 * This function performs the details of file
 * writing. Uses the file management routines in the
 * "fileio.c" package. The number of lines written is
 * displayed. Sadly, it looks inside a LINE; provide
 * a macro for this. Most of the grief is error
 * checking of some sort.
 */
writeout(fn)
char	*fn;
{
	register int	s;
	register LINE	*lp;
	register int	nline;

	if ((s=ffwopen(fn)) != FIOSUC)		/* Open writes message.	*/
		return (FALSE);
	lp = lforw(curbp->b_linep);		/* First line.		*/
	nline = 0;				/* Number of lines.	*/
	while (lp != curbp->b_linep) {
		if ((s=ffputline(&lp->l_text[0], llength(lp))) != FIOSUC)
			break;
		++nline;
		lp = lforw(lp);
	}
	if (s == FIOSUC) {			/* No write error.	*/
		s = ffclose();
		if (s == FIOSUC) {		/* No close error.	*/
			if (nline == 1)
				mlwrite("[Wrote 1 line]");
			else
				mlwrite("[Wrote %d lines]", nline);
		}
	} else					/* Ignore close error	*/
		ffclose();			/* if a write error.	*/
	if (s != FIOSUC)			/* Some sort of error.	*/
		return (FALSE);
	return (TRUE);
}

/*
 * The command allows the user
 * to modify the file name associated with
 * the current buffer. It is like the "f" command
 * in UNIX "ed". The operation is simple; just zap
 * the name in the BUFFER structure, and mark the windows
 * as needing an update. You can type a blank line at the
 * prompt if you wish.
 */
filename(f, n)
{
	register WINDOW	*wp;
	register int	s;
	char	 	fname[NFILEN];

	if ((s=mlreply("Name: ", fname, NFILEN)) == ABORT)
		return (s);
	if (s == FALSE)
		strcpy(curbp->b_fname, "");
	else
		strcpy(curbp->b_fname, fname);
	wp = wheadp;				/* Update mode lines.	*/
	while (wp != NULL) {
		if (wp->w_bufp == curbp)
			wp->w_flag |= WFMODE;
		wp = wp->w_wndp;
	}
	return (TRUE);
}