/*
** This file was written by Daniel Stenberg. 
** Parts of it were stolen from the BSD uudecode command.
*/

/*
** Copyright (c) 1983 Regents of the University of California.
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. All advertising materials mentioning features or use of this software
**    must display the following acknowledgement:
**      This product includes software developed by the University of
**      California, Berkeley and its contributors.
** 4. Neither the name of the University nor the names of its contributors
**    may be used to endorse or promote products derived from this software
**    without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
*/

#include <sys/param.h>
#include "main.h"

#define DEC(c) (((c) - ' ') & 077)  /* single character decode */
#define IS_DEC(c) ( (((c) - ' ') >= 0) &&  (((c) - ' ') <= 077 + 1) )

/*
** uudecode returns non-zero on error 
*/

int uudecode(FILE *input,  /* get file data from (if needed) */
             char *iptr,   /* input string from where we are right now */
             char *output, /* write result to, needs to fit at least 80 bytes */
             int *length,  /* output size */
             char init)    /* set to non-zero when initing */
{
    register int n;
    register char    ch, *p;
    int mode;
    char buf[MAXPATHLEN];
    int outlen=0;

    if (length)
        *length=0; /* in case we abort early */

    if (init) {
        /* search for header line */
        while (2 != sscanf(iptr, "begin %o %s", &mode, buf)) {
            if (!fgets(buf, MAXPATHLEN, input)) {
                return 2;
            }
            iptr = buf;
        }
#if 0
    fprintf(stderr, "FIRST %s",    iptr);
#endif
        /* ignore file mode    */
        /* ignore file name too for now */
    }
    else {
        /* for each input line */
        p = iptr;

        /* first, just make sure this isn't the end line: */

        if (!strcmp(buf, "end") || !strcmp(buf, "end\n") || 
            !strcmp(buf, "end\r\n")) {
            /* muu->state = UU_HASENDED; */
            if (length)
            *length = 0;
            return 0;
        }

        n = DEC(*p);
        for (++p; n > 0; p += 4, n -= 3) {
            if (n >= 3) {

                if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) &&
                    IS_DEC(*(p + 2)) && IS_DEC(*(p + 3))))
                    return 33;

                ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
                output[outlen++]=ch;
                ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
                output[outlen++]=ch;
                ch = DEC(p[2]) << 6 | DEC(p[3]);
                output[outlen++]=ch;

            }
            else {
                if (n >= 1) {
                    if (!(IS_DEC(*p) && IS_DEC(*(p + 1))))
                        return 34;
                    ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
                    output[outlen++]=ch;
                }
                if (n >= 2) {
                    if (!(IS_DEC(*(p + 1)) && IS_DEC(*(p + 2))))
                        return 35;
                    ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
                    output[outlen++]=ch;
                }
                if (n >= 3) {
                    if (!(IS_DEC(*(p + 2)) && IS_DEC(*(p + 3))))
                        return 36;
                    ch = DEC(p[2]) << 6 | DEC(p[3]);
                    output[outlen++]=ch;
                }
            }
        }
    }
    if (output)
        output[outlen]=0; /* zero terminate    */

    if (length)
        *length = outlen; /* send back size    */

    return 0;
}