/*	FILEIO.C
 *
 * The routines in this file read and write ASCII files from the disk. All of
 * the knowledge about files are here.
 *
 *	modified by Petri Kutvonen
 */

#include        <stdio.h>
#include	"estruct.h"
#include        "edef.h"
#include	"efunc.h"

static FILE *ffp;			/* File pointer, all functions. */
static int eofflag;			/* end-of-file flag */

/*
 * Open a file for reading.
 */
int ffropen(char *fn)
{
	if ((ffp = fopen(fn, "r")) == NULL)
		return (FIOFNF);
	eofflag = FALSE;
	return (FIOSUC);
}

/*
 * Open a file for writing. Return TRUE if all is well, and FALSE on error
 * (cannot create).
 */
int ffwopen(char *fn)
{
#if     VMS
	register int fd;

	if ((fd = creat(fn, 0666, "rfm=var", "rat=cr")) < 0
	    || (ffp = fdopen(fd, "w")) == NULL) {
#else
	if ((ffp = fopen(fn, "w")) == NULL) {
#endif
		mlwrite("Cannot open file for writing");
		return (FIOERR);
	}
	return (FIOSUC);
}

/*
 * Close a file. Should look at the status in all systems.
 */
int ffclose(void)
{
	/* free this since we do not need it anymore */
	if (fline) {
		free(fline);
		fline = NULL;
	}
	eofflag = FALSE;

#if	MSDOS & CTRLZ
	fputc(26, ffp);		/* add a ^Z at the end of the file */
#endif

#if     V7 | USG | BSD | (MSDOS & (MSC | TURBO))
	if (fclose(ffp) != FALSE) {
		mlwrite("Error closing file");
		return (FIOERR);
	}
	return (FIOSUC);
#else
	fclose(ffp);
	return (FIOSUC);
#endif
}

/*
 * Write a line to the already opened file. The "buf" points to the buffer,
 * and the "nbuf" is its length, less the free newline. Return the status.
 * Check only at the newline.
 */
int ffputline(char *buf, int nbuf)
{
	register int i;
#if	CRYPT
	char c;			/* character to translate */

	if (cryptflag) {
		for (i = 0; i < nbuf; ++i) {
			c = buf[i] & 0xff;
			myencrypt(&c, 1);
			fputc(c, ffp);
		}
	} else
		for (i = 0; i < nbuf; ++i)
			fputc(buf[i] & 0xFF, ffp);
#else
	for (i = 0; i < nbuf; ++i)
		fputc(buf[i] & 0xFF, ffp);
#endif

	fputc('\n', ffp);

	if (ferror(ffp)) {
		mlwrite("Write I/O error");
		return (FIOERR);
	}

	return (FIOSUC);
}

/*
 * Read a line from a file, and store the bytes in the supplied buffer. The
 * "nbuf" is the length of the buffer. Complain about long lines and lines
 * at the end of the file that don't have a newline present. Check for I/O
 * errors too. Return status.
 */
int ffgetline(void)
{
	register int c;		/* current character read */
	register int i;		/* current index into fline */
	register char *tmpline;	/* temp storage for expanding line */

	/* if we are at the end...return it */
	if (eofflag)
		return (FIOEOF);

	/* dump fline if it ended up too big */
	if (flen > NSTRING) {
		free(fline);
		fline = NULL;
	}

	/* if we don't have an fline, allocate one */
	if (fline == NULL)
		if ((fline = malloc(flen = NSTRING)) == NULL)
			return (FIOMEM);

	/* read the line in */
#if	PKCODE
	if (!nullflag) {
		if (fgets(fline, NSTRING, ffp) == (char *) NULL) {	/* EOF ? */
			i = 0;
			c = EOF;
		} else {
			i = strlen(fline);
			c = 0;
			if (i > 0) {
				c = fline[i - 1];
				i--;
			}
		}
	} else {
		i = 0;
		c = fgetc(ffp);
	}
	while (c != EOF && c != '\n') {
#else
	i = 0;
	while ((c = fgetc(ffp)) != EOF && c != '\n') {
#endif
#if	PKCODE
		if (c) {
#endif
			fline[i++] = c;
			/* if it's longer, get more room */
			if (i >= flen) {
				if ((tmpline =
				     malloc(flen + NSTRING)) == NULL)
					return (FIOMEM);
				strncpy(tmpline, fline, flen);
				flen += NSTRING;
				free(fline);
				fline = tmpline;
			}
#if	PKCODE
		}
		c = fgetc(ffp);
#endif
	}

	/* test for any errors that may have occured */
	if (c == EOF) {
		if (ferror(ffp)) {
			mlwrite("File read error");
			return (FIOERR);
		}

		if (i != 0)
			eofflag = TRUE;
		else
			return (FIOEOF);
	}

	/* terminate and decrypt the string */
	fline[i] = 0;
#if	CRYPT
	if (cryptflag)
		myencrypt(fline, strlen(fline));
#endif
	return (FIOSUC);
}

/*
 * does <fname> exist on disk?
 *
 * char *fname;		file to check for existance
 */
int fexist(char *fname)
{
	FILE *fp;

	/* try to open the file for reading */
	fp = fopen(fname, "r");

	/* if it fails, just return false! */
	if (fp == NULL)
		return (FALSE);

	/* otherwise, close it and report true */
	fclose(fp);
	return (TRUE);
}