/*	file.c
 *
 *	The routines in this file handle the reading, writing
 *	and lookup of disk files.  All of details about the
 *	reading and writing of the disk are in "fileio.c".
 *
 *	modified by Petri Kutvonen
 */

#include <stdio.h>
#include <unistd.h>

#include "estruct.h"
#include "edef.h"
#include "efunc.h"
#include "line.h"
#include "util.h"

#if defined(PKCODE)
/* Max number of lines from one file. */
#define	MAXNLINE 10000000
#endif

/*
 * 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".
 */
int fileread(int f, int n)
{
	int s;
	char fname[NFILEN];

	if (restflag)		/* don't allow this command if restricted */
		return resterr();
	if ((s = mlreply("Read file: ", fname, NFILEN)) != TRUE)
		return s;
	return readin(fname, TRUE);
}

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

	if (restflag)		/* don't allow this command if restricted */
		return resterr();
	if (curbp->b_mode & MDVIEW)	/* don't allow this command if      */
		return rdonly();	/* we are in read only mode     */
	if ((s = mlreply("Insert file: ", fname, NFILEN)) != TRUE)
		return s;
	if ((s = ifile(fname)) != TRUE)
		return s;
	return reposition(TRUE, -1);
}

/*
 * 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-F.
 */
int filefind(int f, int n)
{
	char fname[NFILEN];	/* file user wishes to find */
	int s;		/* status return */

	if (restflag)		/* don't allow this command if restricted */
		return resterr();
	if ((s = mlreply("Find file: ", fname, NFILEN)) != TRUE)
		return s;
	return getfile(fname, TRUE);
}

int viewfile(int f, int n)
{				/* visit a file in VIEW mode */
	char fname[NFILEN];	/* file user wishes to find */
	int s;		/* status return */
	struct window *wp;	/* scan for windows that need updating */

	if (restflag)		/* don't allow this command if restricted */
		return resterr();
	if ((s = mlreply("View file: ", fname, NFILEN)) != TRUE)
		return s;
	s = getfile(fname, FALSE);
	if (s) {		/* if we succeed, put it in view mode */
		curwp->w_bufp->b_mode |= MDVIEW;

		/* scan through and update mode lines of all windows */
		wp = wheadp;
		while (wp != NULL) {
			wp->w_flag |= WFMODE;
			wp = wp->w_wndp;
		}
	}
	return s;
}

#if	CRYPT
static int resetkey(void)
{				/* reset the encryption key if needed */
	int s;		/* return status */

	/* turn off the encryption flag */
	cryptflag = FALSE;

	/* if we are in crypt mode */
	if (curbp->b_mode & MDCRYPT) {
		if (curbp->b_key[0] == 0) {
			s = set_encryption_key(FALSE, 0);
			if (s != TRUE)
				return s;
		}

		/* let others know... */
		cryptflag = TRUE;

		/* and set up the key to be used! */
		/* de-encrypt it */
		myencrypt((char *) NULL, 0);
		myencrypt(curbp->b_key, strlen(curbp->b_key));

		/* re-encrypt it...seeding it to start */
		myencrypt((char *) NULL, 0);
		myencrypt(curbp->b_key, strlen(curbp->b_key));
	}

	return TRUE;
}
#endif

/*
 * getfile()
 *
 * char fname[];	file name to find
 * int lockfl;		check the file for locks?
 */
int getfile(char *fname, int lockfl)
{
	struct buffer *bp;
	struct line *lp;
	int i;
	int s;
	char bname[NBUFN];	/* buffer name to put file */

#if	MSDOS
	mklower(fname);		/* msdos isn't case sensitive */
#endif
	for (bp = bheadp; bp != NULL; bp = bp->b_bufp) {
		if ((bp->b_flag & BFINVS) == 0
		    && strcmp(bp->b_fname, fname) == 0) {
			swbuffer(bp);
			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;
			cknewwindow();
			mlwrite("(Old buffer)");
			return TRUE;
		}
	}
	makename(bname, fname);	/* New buffer name.     */
	while ((bp = bfind(bname, FALSE, 0)) != NULL) {
		/* old buffer name conflict code */
		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++;
	s = readin(fname, lockfl);	/* Read it in.          */
	cknewwindow();
	return s;
}

/*
 * Read file "fname" into the current buffer, blowing away any text
 * found there.  Called by both the read and find 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.
 * The command bound to M-FNR is called after the buffer is set up
 * and before it is read.
 *
 * char fname[];	name of file to read
 * int lockfl;		check for file locks?
 */
int readin(char *fname, int lockfl)
{
	struct line *lp1;
	struct line *lp2;
	int i;
	struct window *wp;
	struct buffer *bp;
	int s;
	int nbytes;
	int nline;
	char mesg[NSTRING];

#if	(FILOCK && BSD) || SVR4
	if (lockfl && lockchk(fname) == ABORT)
#if PKCODE
	{
		s = FIOFNF;
		bp = curbp;
		strcpy(bp->b_fname, "");
		goto out;
	}
#else
		return ABORT;
#endif
#endif
#if	CRYPT
	s = resetkey();
	if (s != TRUE)
		return s;
#endif
	bp = curbp;		/* Cheap.               */
	if ((s = bclear(bp)) != TRUE)	/* Might be old.        */
		return s;
	bp->b_flag &= ~(BFINVS | BFCHG);
	mystrscpy(bp->b_fname, fname, NFILEN);

	/* let a user macro get hold of things...if he wants */
	execute(META | SPEC | 'R', FALSE, 1);

	if ((s = ffropen(fname)) == FIOERR)	/* Hard file open.      */
		goto out;

	if (s == FIOFNF) {	/* File not found.      */
		mlwrite("(New file)");
		goto out;
	}

	/* read the file in */
	mlwrite("(Reading file)");
	nline = 0;
	while ((s = ffgetline()) == FIOSUC) {
		nbytes = strlen(fline);
		if ((lp1 = lalloc(nbytes)) == NULL) {
			s = FIOMEM;	/* Keep message on the  */
			break;	/* display.             */
		}
#if	PKCODE
		if (nline > MAXNLINE) {
			s = FIOMEM;
			break;
		}
#endif
		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, fline[i]);
		++nline;
	}
	ffclose();		/* Ignore errors.       */
	strcpy(mesg, "(");
	if (s == FIOERR) {
		strcat(mesg, "I/O ERROR, ");
		curbp->b_flag |= BFTRUNC;
	}
	if (s == FIOMEM) {
		strcat(mesg, "OUT OF MEMORY, ");
		curbp->b_flag |= BFTRUNC;
	}
	sprintf(&mesg[strlen(mesg)], "Read %d line", nline);
	if (nline != 1)
		strcat(mesg, "s");
	strcat(mesg, ")");
	mlwrite(mesg);

      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 || s == FIOFNF)	/* 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.
 */
void makename(char *bname, char *fname)
{
	char *cp1;
	char *cp2;

	cp1 = &fname[0];
	while (*cp1 != 0)
		++cp1;

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

/*
 * make sure a buffer name is unique
 *
 * char *name;		name to check on
 */
void unqname(char *name)
{
	char *sp;

	/* check to see if it is in the buffer list */
	while (bfind(name, 0, FALSE) != NULL) {

		/* go to the end of the name */
		sp = name;
		while (*sp)
			++sp;
		if (sp == name || (*(sp - 1) < '0' || *(sp - 1) > '8')) {
			*sp++ = '0';
			*sp = 0;
		} else
			*(--sp) += 1;
	}
}

/*
 * 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".
 */
int filewrite(int f, int n)
{
	struct window *wp;
	int s;
	char fname[NFILEN];

	if (restflag)		/* don't allow this command if restricted */
		return resterr();
	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".
 */
int filesave(int f, int n)
{
	struct window *wp;
	int s;

	if (curbp->b_mode & MDVIEW)	/* don't allow this command if      */
		return rdonly();	/* we are in read only mode     */
	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;
	}

	/* complain about truncated files */
	if ((curbp->b_flag & BFTRUNC) != 0) {
		if (mlyesno("Truncated file ... write it out") == FALSE) {
			mlwrite("(Aborted)");
			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 struct line; provide
 * a macro for this. Most of the grief is error
 * checking of some sort.
 */
int writeout(char *fn)
{
	int s;
	struct line *lp;
	int nline;

#if	CRYPT
	s = resetkey();
	if (s != TRUE)
		return s;
#endif

	if ((s = ffwopen(fn)) != FIOSUC) {	/* Open writes message. */
		return FALSE;
	}
	mlwrite("(Writing...)");	/* tell us were writing */
	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.
 */
int filename(int f, int n)
{
	struct window *wp;
	int s;
	char fname[NFILEN];

	if (restflag)		/* don't allow this command if restricted */
		return resterr();
	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;
	}
	curbp->b_mode &= ~MDVIEW;	/* no longer read only mode */
	return TRUE;
}

/*
 * Insert file "fname" into the current
 * buffer, Called by insert file command. Return the final
 * status of the read.
 */
int ifile(char *fname)
{
	struct line *lp0;
	struct line *lp1;
	struct line *lp2;
	int i;
	struct buffer *bp;
	int s;
	int nbytes;
	int nline;
	char mesg[NSTRING];

	bp = curbp;		/* Cheap.               */
	bp->b_flag |= BFCHG;	/* we have changed      */
	bp->b_flag &= ~BFINVS;	/* and are not temporary */
	if ((s = ffropen(fname)) == FIOERR)	/* Hard file open.      */
		goto out;
	if (s == FIOFNF) {	/* File not found.      */
		mlwrite("(No such file)");
		return FALSE;
	}
	mlwrite("(Inserting file)");

#if	CRYPT
	s = resetkey();
	if (s != TRUE)
		return s;
#endif
	/* back up a line and save the mark here */
	curwp->w_dotp = lback(curwp->w_dotp);
	curwp->w_doto = 0;
	curwp->w_markp = curwp->w_dotp;
	curwp->w_marko = 0;

	nline = 0;
	while ((s = ffgetline()) == FIOSUC) {
		nbytes = strlen(fline);
		if ((lp1 = lalloc(nbytes)) == NULL) {
			s = FIOMEM;	/* Keep message on the  */
			break;	/* display.             */
		}
		lp0 = curwp->w_dotp;	/* line previous to insert */
		lp2 = lp0->l_fp;	/* line after insert */

		/* re-link new line between lp0 and lp2 */
		lp2->l_bp = lp1;
		lp0->l_fp = lp1;
		lp1->l_bp = lp0;
		lp1->l_fp = lp2;

		/* and advance and write out the current line */
		curwp->w_dotp = lp1;
		for (i = 0; i < nbytes; ++i)
			lputc(lp1, i, fline[i]);
		++nline;
	}
	ffclose();		/* Ignore errors.       */
	curwp->w_markp = lforw(curwp->w_markp);
	strcpy(mesg, "(");
	if (s == FIOERR) {
		strcat(mesg, "I/O ERROR, ");
		curbp->b_flag |= BFTRUNC;
	}
	if (s == FIOMEM) {
		strcat(mesg, "OUT OF MEMORY, ");
		curbp->b_flag |= BFTRUNC;
	}
	sprintf(&mesg[strlen(mesg)], "Inserted %d line", nline);
	if (nline > 1)
		strcat(mesg, "s");
	strcat(mesg, ")");
	mlwrite(mesg);

      out:
	/* advance to the next line and mark the window for changes */
	curwp->w_dotp = lforw(curwp->w_dotp);
	curwp->w_flag |= WFHARD | WFMODE;

	/* copy window parameters back to the buffer structure */
	curbp->b_dotp = curwp->w_dotp;
	curbp->b_doto = curwp->w_doto;
	curbp->b_markp = curwp->w_markp;
	curbp->b_marko = curwp->w_marko;

	if (s == FIOERR)	/* False if error.      */
		return FALSE;
	return TRUE;
}