/*
 * util.c - part of LHx for UNIX
 */

#include <stdio.h>
#include <errno.h>

#ifdef __STDC__
#include <stdlib.h>
#endif
#include "lharc.h"

#define BUFFERSIZE 2048

extern unsigned short mcrc;
extern int quiet;

long copyfile(f1, f2, size, crc_flg)    /* return: size of source file */
FILE *f1;
FILE *f2;
long size;
int crc_flg;    /* 0: no crc, 1: crc check, 2: extract, 3: append */
{
    unsigned short xsize;
    char *buf;
    long rsize = 0;

    if ((buf = (char *)malloc(BUFFERSIZE)) == NULL)
        fatal_error("virtual memory exhausted.\n");
    mcrc = 0;
    if ((crc_flg == 2 || crc_flg) && text_mode)
        init_code_cache();
    while (size > 0) {
        /* read */
        if (crc_flg == 3 && text_mode) {
            xsize = fread_txt(buf, BUFFERSIZE, f1);
            if (xsize == 0)
                break;
            if (ferror(f1)) {
                fatal_error("file read error\n");
            }
        }
        else {
            xsize = (size > BUFFERSIZE) ? BUFFERSIZE : size;
            if (fread(buf, 1, xsize, f1) != xsize) {
                fatal_error("file read error\n");
            }
        }
        /* write */
        if (f2) {
            if (crc_flg == 2 && text_mode) {
                if (fwrite_txt(buf, xsize, f2)) {
                    fatal_error("file write error\n");
                }
            }
            else {
                if (fwrite(buf, 1, xsize, f2) != xsize) {
                    fatal_error("file write error\n");
                }
            }
        }
        /* calculate crc */
        if (crc_flg) {
            calccrc(buf, xsize);
        }
        rsize += xsize;
        if (crc_flg != 3 || !text_mode)
            size -= xsize;
    }
    free(buf);
    return rsize;
}

int
encode_stored_crc (ifp, ofp, size, original_size_var, write_size_var)
FILE *ifp, *ofp;
long size;
long *original_size_var;
long *write_size_var;
{
    int save_quiet;

    save_quiet = quiet;
    quiet = 1;
    size = copyfile (ifp,ofp,size,3);
    *original_size_var = *write_size_var = size;
    quiet = save_quiet;
    return mcrc;
}

/***************************************
    convert path delimiter
****************************************
    returns *filename
***************************************/
unsigned char *
convdelim(path, delim)
unsigned char *path;
unsigned char delim;
{
    unsigned char c;
    unsigned char *p;
#ifdef MULTIBYTE_CHAR
    int kflg;

    kflg = 0;
#endif
    for (p = path; (c = *p) != 0; p++) {
#ifdef MULTIBYTE_CHAR
        if (kflg) {
            kflg = 0;
        } 
        else if (iskanji(c)) {
            kflg = 1;
        } 
        else
#endif
            if (c == '\\' || c == DELIM || c == DELIM2)
            {
                *p = delim;
                path = p + 1;
            }
    }
    return path;
}

/* If TRUE, archive file name is msdos SFX file name. */
boolean
archive_is_msdos_sfx1 (name)
char *name;
{
    int len = strlen (name);

    return ((len >= 4) &&
        (strucmp (".COM",name + len - 4) == 0 ||
        strucmp (".EXE",name + len - 4) == 0)) ||
        ((len >= 2) &&
        (strucmp (".x",name + len - 2) == 0));
}

/* skip SFX header */
boolean
skip_msdos_sfx1_code (fp)
FILE *fp;
{
    unsigned char buffer[4096];
    unsigned char *p, *q;
    int n;

    n = fread (buffer, sizeof (char), 4096, fp);

    for (p = buffer + 2, q = buffer + n - 5; p < q; p ++)
    {
        /* found "-l??-" keyword (as METHOD type string) */
        if (p[0] == '-' && p[1] == 'l' && p[4] == '-')
        {
            /* size and checksum validate check */
            if (p[-2] > 20 && p[-1] == calc_sum (p, p[-2]))
            {
                fseek (fp, ((p - 2) - buffer) - n, SEEK_CUR);
                return TRUE;
            }
        }
    }

    fseek (fp, -n, SEEK_CUR);
    return FALSE;
}