/*
**  OSSP lmtp2nntp - Mail to News Gateway
**  Copyright (c) 2002-2003 Ralf S. Engelschall <rse@engelschall.com>
**  Copyright (c) 2002-2003 The OSSP Project <http://www.ossp.org/>
**  Copyright (c) 2002-2003 Cable & Wireless Germany <http://www.cw.com/de/>
**
**  This file is part of OSSP lmtp2nntp, an LMTP speaking local
**  mailer which forwards mails as Usenet news articles via NNTP.
**  It can be found at http://www.ossp.org/pkg/tool/lmtp2nntp/.
**
**  This program is free software; you can redistribute it and/or
**  modify it under the terms of the GNU General Public  License
**  as published by the Free Software Foundation; either version
**  2.0 of the License, or (at your option) any later version.
**
**  This program is distributed in the hope that it will be useful,
**  but WITHOUT ANY WARRANTY; without even the implied warranty of
**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**  General Public License for more details.
**
**  You should have received a copy of the GNU General Public License
**  along with this file; if not, write to the Free Software
**  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
**  USA, or contact the OSSP project <ossp@ossp.org>.
**
**  argz.h: Zero-Terminated Argument Vector library
*/

/* Routines for dealing with '\0' separated arg vectors.
   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "lmtp2nntp_argz.h"

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#if defined(HAVE_DMALLOC_H) && defined(DMALLOC)
#include "dmalloc.h"
#endif

/* Find the length of STRING, but scan at most MAXLEN characters.
   If no '\0' terminator is found in that many characters, return MAXLEN.  */
static size_t my_strnlen(const char *string, size_t maxlen)
{
    const char *end = memchr(string, '\0', maxlen);
    return end ? (size_t) (end - string) : maxlen;
}

static char *my_strndup(const char *s, size_t n)
{
    size_t len = my_strnlen(s, n);
    char *new = malloc(len + 1);

    if (new == NULL)
        return NULL;
    new[len] = '\0';
    return (char *)memcpy(new, s, len);
}

/* Copy SRC to DEST, returning the address of the terminating '\0' in DEST. */
static char *my_stpcpy(char *dest, const char *src)
{
    register char *d = dest;
    register const char *s = src;

    do {
      *d++ = *s;
    } while (*s++ != '\0');
    return d - 1;
}

int argz_add_sep(char **argz, size_t * argz_len, const char *string, int delim)
{
	size_t nlen = strlen(string) + 1;

	if (nlen > 1) {
		const char *rp;
		char *wp;

		*argz = (char *)realloc(*argz, *argz_len + nlen);
		if (*argz == NULL)
			return ENOMEM;

		wp = *argz + *argz_len;
		rp = string;
		do {
			if (*rp == delim) {
				if (wp > *argz && wp[-1] != '\0')
					*wp++ = '\0';
				else
					--nlen;
			}
			else
				*wp++ = *rp;
		} while (*rp++ != '\0');

		*argz_len += nlen;
	}

	return 0;
}

/* Add BUF, of length BUF_LEN to the argz vector in ARGZ & ARGZ_LEN.  */
int argz_append(char **argz, size_t * argz_len, const char *buf, size_t buf_len)
{
	size_t new_argz_len = *argz_len + buf_len;
	char *new_argz = realloc(*argz, new_argz_len);
	if (new_argz) {
		memcpy(new_argz + *argz_len, buf, buf_len);
		*argz = new_argz;
		*argz_len = new_argz_len;
		return 0;
	}
	else
		return ENOMEM;
}

/* Add STR to the argz vector in ARGZ & ARGZ_LEN.  This should be moved into
 * argz.c in libshouldbelibc.  */
int argz_add(char **argz, size_t * argz_len, const char *str)
{
	return argz_append(argz, argz_len, str, strlen(str) + 1);
}

/* Returns the number of strings in ARGZ.  */
size_t argz_count(const char *argz, size_t len)
{
	size_t count = 0;
	while (len > 0) {
		size_t part_len = strlen(argz);
		argz += part_len + 1;
		len -= part_len + 1;
		count++;
	}
	return count;
}

/* Make a '\0' separated arg vector from a unix argv vector, returning it in
 * ARGZ, and the total length in LEN.  If a memory allocation error occurs,
 * ENOMEM is returned, otherwise 0.  */
int argz_create(char *const argv[], char **argz, size_t * len)
{
	int argc;
	size_t tlen = 0;
	char *const *ap;
	char *p;

	for (argc = 0; argv[argc] != NULL; ++argc)
		tlen += strlen(argv[argc]) + 1;

	if (tlen == 0)
		*argz = NULL;
	else {
		*argz = malloc(tlen);
		if (*argz == NULL)
			return ENOMEM;

		for (p = *argz, ap = argv; *ap; ++ap, ++p)
			p = my_stpcpy(p, *ap);
	}
	*len = tlen;

	return 0;
}

int argz_create_sep(const char *string, int delim, char **argz, size_t * len)
{
	size_t nlen = strlen(string) + 1;

	if (nlen > 1) {
		const char *rp;
		char *wp;

		*argz = (char *)malloc(nlen);
		if (*argz == NULL)
			return ENOMEM;

		rp = string;
		wp = *argz;
		do
			if (*rp == delim) {
				if (wp > *argz && wp[-1] != '\0')
					*wp++ = '\0';
				else
					--nlen;
			}
			else
				*wp++ = *rp;
		while (*rp++ != '\0');

		if (nlen == 0) {
			free(*argz);
			*argz = NULL;
			*len = 0;
		}

		*len = nlen;
	}
	else {
		*argz = NULL;
		*len = 0;
	}

	return 0;
}

/* Delete ENTRY from ARGZ & ARGZ_LEN, if any.  */
void argz_delete(char **argz, size_t * argz_len, char *entry)
{
	if (entry)
		/* Get rid of the old value for NAME.  */
	{
		size_t entry_len = strlen(entry) + 1;
		*argz_len -= entry_len;
		memmove(entry, entry + entry_len, *argz_len - (entry - *argz));
		if (*argz_len == 0) {
			free(*argz);
			*argz = 0;
		}
	}
}

/* Puts pointers to each string in ARGZ, plus a terminating 0 element, into
 * ARGV, which must be large enough to hold them all.  */
void argz_extract(const char *argz, size_t len, char **argv)
{
	while (len > 0) {
		size_t part_len = strlen(argz);
		*argv++ = (char *)argz;
		argz += part_len + 1;
		len -= part_len + 1;
	}
	*argv = 0;
}

/* Insert ENTRY into ARGZ & ARGZ_LEN before BEFORE, which should be an
 * existing entry in ARGZ; if BEFORE is NULL, ENTRY is appended to the end.
 * Since ARGZ's first entry is the same as ARGZ, argz_insert (ARGZ, ARGZ_LEN,
 * ARGZ, ENTRY) will insert ENTRY at the beginning of ARGZ.  If BEFORE is not
 * in ARGZ, EINVAL is returned, else if memory can't be allocated for the new
 * ARGZ, ENOMEM is returned, else 0.  */
int argz_insert(char **argz, size_t * argz_len, char *before, const char *entry)
{
	if (!before)
		return argz_add(argz, argz_len, entry);

	if (before < *argz || before >= *argz + *argz_len)
		return EINVAL;

	if (before > *argz)
		/* Make sure before is actually the beginning of an entry.  */
		while (before[-1])
			before--;

	{
		size_t after_before = *argz_len - (before - *argz);
		size_t entry_len = strlen(entry) + 1;
		size_t new_argz_len = *argz_len + entry_len;
		char *new_argz = realloc(*argz, new_argz_len);

		if (new_argz) {
			before = new_argz + (before - *argz);
			memmove(before + entry_len, before, after_before);
			memmove(before, entry, entry_len);
			*argz = new_argz;
			*argz_len = new_argz_len;
			return 0;
		}
		else
			return ENOMEM;
	}
}

char *argz_next(const char *argz, size_t argz_len, const char *entry)
{
	if (entry) {
		if (entry < argz + argz_len)
			entry = strchr(entry, '\0') + 1;

		return entry >= argz + argz_len ? NULL : (char *)entry;
	}
	else if (argz_len > 0)
		return (char *)argz;
	else
		return NULL;
}

/* Append BUF, of length BUF_LEN to *TO, of length *TO_LEN, reallocating and
 * updating *TO & *TO_LEN appropriately.  If an allocation error occurs,
 * *TO's old value is freed, and *TO is set to 0.  */
static void
str_append(char **to, size_t * to_len, const char *buf, const size_t buf_len)
{
	size_t new_len = *to_len + buf_len;
	char *new_to = realloc(*to, new_len + 1);

	if (new_to) {
		/* *((char *)__mempcpy(new_to + *to_len, buf, buf_len)) = '\0'; */
		memcpy(new_to + *to_len, buf, buf_len);
        *(new_to + *to_len + buf_len) = '\0';
		*to = new_to;
		*to_len = new_len;
	}
	else {
		free(*to);
		*to = 0;
	}
}

/* Replace any occurrences of the string STR in ARGZ with WITH, reallocating
 * ARGZ as necessary.  If REPLACE_COUNT is non-zero, *REPLACE_COUNT will be
 * incremented by number of replacements performed.  */
int argz_replace(char **argz, size_t * argz_len, const char *str,
			   const char *with, unsigned *replace_count)
{
	int err = 0;

	if (str && *str) {
		char *arg = 0;
		char *src = *argz;
		size_t src_len = *argz_len;
		char *dst = 0;
		size_t dst_len = 0;
		int delayed_copy = 1;		   /* True while we've avoided copying
									    * anything.  */
		size_t str_len = strlen(str), with_len = strlen(with);

		while (!err && (arg = argz_next(src, src_len, arg))) {
			char *match = strstr(arg, str);
			if (match) {
				char *from = match + str_len;
				size_t to_len = match - arg;
				char *to = my_strndup(arg, to_len);

				while (to && from) {
					str_append(&to, &to_len, with, with_len);
					if (to) {
						match = strstr(from, str);
						if (match) {
							str_append(&to, &to_len, from, match - from);
							from = match + str_len;
						}
						else {
							str_append(&to, &to_len, from, strlen(from));
							from = 0;
						}
					}
				}

				if (to) {
					if (delayed_copy)
						/* We avoided copying SRC to DST until we found a
						 * match; now that we've done so, copy everything
						 * from the start of SRC.  */
					{
						if (arg > src)
							err =
								argz_append(&dst, &dst_len, src,
											  (arg - src));
						delayed_copy = 0;
					}
					if (!err)
						err = argz_add(&dst, &dst_len, to);
					free(to);
				}
				else
					err = ENOMEM;

				if (replace_count)
					(*replace_count)++;
			}
			else if (!delayed_copy)
				err = argz_add(&dst, &dst_len, arg);
		}

		if (!err) {
			if (!delayed_copy)
				/* We never found any instances of str.  */
			{
				if (src)
					free(src);
				*argz = dst;
				*argz_len = dst_len;
			}
		}
		else if (dst_len > 0)
			free(dst);
	}

	return err;
}

/* Make '\0' separated arg vector ARGZ printable by converting all the '\0's
 * except the last into the character SEP.  */
void argz_stringify(char *argz, size_t len, int sep)
{
	if (len > 0) {
		while (1) {
			size_t part_len = my_strnlen(argz, len);
			argz += part_len;
			len -= part_len;
			if (len-- <= 1)			   /* includes final '\0' we want to stop 
									    * at */
				break;
			*argz++ = sep;
		}
    }
    return;
}