/*
 * Copyright (c) 1995-2000 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * 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. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
RCSID("$Id: snprintf.c,v 1.3 2003/07/15 23:17:01 shadow Exp $");
#endif
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#ifndef min
#define min(a, b)               ((a) > (b) ? (b) : (a))
#endif
#ifndef max
#define max(a, b)               ((a) < (b) ? (b) : (a))
#endif

enum format_flags {
    minus_flag = 1,
    plus_flag = 2,
    space_flag = 4,
    alternate_flag = 8,
    zero_flag = 16
};

/*
 * Common state
 */

struct state {
    unsigned char *str;
    unsigned char *s;
    unsigned char *theend;
    size_t sz;
    size_t max_sz;
    int (*append_char) (struct state *, unsigned char);
    int (*reserve) (struct state *, size_t);
    /* XXX - methods */
};

#ifndef HAVE_VSNPRINTF
static int
sn_reserve(struct state *state, size_t n)
{
    return state->s + n > state->theend;
}

static int
sn_append_char(struct state *state, unsigned char c)
{
    if (sn_reserve(state, 1)) {
	return 1;
    } else {
	*state->s++ = c;
	return 0;
    }
}
#endif

static int
as_reserve(struct state *state, size_t n)
{
    if (state->s + n > state->theend) {
	int off = state->s - state->str;
	unsigned char *tmp;

	if (state->max_sz && state->sz >= state->max_sz)
	    return 1;

	state->sz = max(state->sz * 2, state->sz + n);
	if (state->max_sz)
	    state->sz = min(state->sz, state->max_sz);
	tmp = realloc(state->str, state->sz);
	if (tmp == NULL)
	    return 1;
	state->str = tmp;
	state->s = state->str + off;
	state->theend = state->str + state->sz - 1;
    }
    return 0;
}

static int
as_append_char(struct state *state, unsigned char c)
{
    if (as_reserve(state, 1))
	return 1;
    else {
	*state->s++ = c;
	return 0;
    }
}

static int
append_number(struct state *state, unsigned long num, unsigned base,
	      char *rep, int width, int prec, int flags, int minusp)
{
    int len = 0;
    int i;

    /* given precision, ignore zero flag */
    if (prec != -1)
	flags &= ~zero_flag;
    else
	prec = 1;
    /* zero value with zero precision -> "" */
    if (prec == 0 && num == 0)
	return 0;
    do {
	if ((*state->append_char) (state, rep[num % base]))
	    return 1;
	len++;
	num /= base;
    } while (num);
    prec -= len;
    /* pad with prec zeros */
    while (prec-- > 0) {
	if ((*state->append_char) (state, '0'))
	    return 1;
	len++;
    }
    /* add length of alternate prefix (added later) to len */
    if (flags & alternate_flag && (base == 16 || base == 8))
	len += base / 8;
    /* pad with zeros */
    if (flags & zero_flag) {
	width -= len;
	if (minusp || (flags & space_flag) || (flags & plus_flag))
	    width--;
	while (width-- > 0) {
	    if ((*state->append_char) (state, '0'))
		return 1;
	    len++;
	}
    }
    /* add alternate prefix */
    if (flags & alternate_flag && (base == 16 || base == 8)) {
	if (base == 16)
	    if ((*state->append_char) (state, rep[10] + 23))	/* XXX */
		return 1;
	if ((*state->append_char) (state, '0'))
	    return 1;
    }
    /* add sign */
    if (minusp) {
	if ((*state->append_char) (state, '-'))
	    return 1;
	len++;
    } else if (flags & plus_flag) {
	if ((*state->append_char) (state, '+'))
	    return 1;
	len++;
    } else if (flags & space_flag) {
	if ((*state->append_char) (state, ' '))
	    return 1;
	len++;
    }
    if (flags & minus_flag)
	/* swap before padding with spaces */
	for (i = 0; i < len / 2; i++) {
	    char c = state->s[-i - 1];
	    state->s[-i - 1] = state->s[-len + i];
	    state->s[-len + i] = c;
	}
    width -= len;
    while (width-- > 0) {
	if ((*state->append_char) (state, ' '))
	    return 1;
	len++;
    }
    if (!(flags & minus_flag))
	/* swap after padding with spaces */
	for (i = 0; i < len / 2; i++) {
	    char c = state->s[-i - 1];
	    state->s[-i - 1] = state->s[-len + i];
	    state->s[-len + i] = c;
	}

    return 0;
}

static int
append_string(struct state *state, unsigned char *arg, int width, int prec,
	      int flags)
{
    if (arg == NULL)
	arg = (unsigned char *)"(null)";

    if (prec != -1)
	width -= prec;
    else
	width -= strlen((char *)arg);
    if (!(flags & minus_flag))
	while (width-- > 0)
	    if ((*state->append_char) (state, ' '))
		return 1;
    if (prec != -1) {
	while (*arg && prec--)
	    if ((*state->append_char) (state, *arg++))
		return 1;
    } else {
	while (*arg)
	    if ((*state->append_char) (state, *arg++))
		return 1;
    }
    if (flags & minus_flag)
	while (width-- > 0)
	    if ((*state->append_char) (state, ' '))
		return 1;
    return 0;
}

static int
append_char(struct state *state, unsigned char arg, int width, int flags)
{
    while (!(flags & minus_flag) && --width > 0)
	if ((*state->append_char) (state, ' '))
	    return 1;

    if ((*state->append_char) (state, arg))
	return 1;
    while ((flags & minus_flag) && --width > 0)
	if ((*state->append_char) (state, ' '))
	    return 1;

    return 0;
}

/*
 * This can't be made into a function...
 */

#define PARSE_INT_FORMAT(res, arg, unsig) \
if (long_flag) \
     res = (unsig long)va_arg(arg, unsig long); \
else if (short_flag) \
     res = (unsig short)va_arg(arg, unsig int); \
else \
     res = (unsig int)va_arg(arg, unsig int)

/*
 * zyxprintf - return 0 or -1
 */

static int
xyzprintf(struct state *state, const char *char_format, va_list ap)
{
    const unsigned char *format = (const unsigned char *)char_format;
    unsigned char c;

    while ((c = *format++)) {
	if (c == '%') {
	    int flags = 0;
	    int width = 0;
	    int prec = -1;
	    int long_flag = 0;
	    int short_flag = 0;

	    /* flags */
	    while ((c = *format++)) {
		if (c == '-')
		    flags |= minus_flag;
		else if (c == '+')
		    flags |= plus_flag;
		else if (c == ' ')
		    flags |= space_flag;
		else if (c == '#')
		    flags |= alternate_flag;
		else if (c == '0')
		    flags |= zero_flag;
		else
		    break;
	    }

	    if ((flags & space_flag) && (flags & plus_flag))
		flags ^= space_flag;

	    if ((flags & minus_flag) && (flags & zero_flag))
		flags ^= zero_flag;

	    /* width */
	    if (isdigit(c))
		do {
		    width = width * 10 + c - '0';
		    c = *format++;
		} while (isdigit(c));
	    else if (c == '*') {
		width = va_arg(ap, int);
		c = *format++;
	    }

	    /* precision */
	    if (c == '.') {
		prec = 0;
		c = *format++;
		if (isdigit(c))
		    do {
			prec = prec * 10 + c - '0';
			c = *format++;
		    } while (isdigit(c));
		else if (c == '*') {
		    prec = va_arg(ap, int);
		    c = *format++;
		}
	    }

	    /* size */

	    if (c == 'h') {
		short_flag = 1;
		c = *format++;
	    } else if (c == 'l') {
		long_flag = 1;
		c = *format++;
	    }

	    switch (c) {
	    case 'c':
		if (append_char(state, va_arg(ap, int), width, flags))
		      return -1;
		break;
	    case 's':
		if (append_string
		    (state, va_arg(ap, unsigned char *), width, prec, flags))
		      return -1;
		break;
	    case 'd':
	    case 'i':{
		    long arg;
		    unsigned long num;
		    int minusp = 0;

		    PARSE_INT_FORMAT(arg, ap, signed);

		    if (arg < 0) {
			minusp = 1;
			num = -arg;
		    } else
			num = arg;

		    if (append_number
			(state, num, 10, "0123456789", width, prec, flags,
			 minusp))
			return -1;
		    break;
		}
	    case 'u':{
		    unsigned long arg;

		    PARSE_INT_FORMAT(arg, ap, unsigned);

		    if (append_number
			(state, arg, 10, "0123456789", width, prec, flags, 0))
			return -1;
		    break;
		}
	    case 'o':{
		    unsigned long arg;

		    PARSE_INT_FORMAT(arg, ap, unsigned);

		    if (append_number
			(state, arg, 010, "01234567", width, prec, flags, 0))
			return -1;
		    break;
		}
	    case 'x':{
		    unsigned long arg;

		    PARSE_INT_FORMAT(arg, ap, unsigned);

		    if (append_number
			(state, arg, 0x10, "0123456789abcdef", width, prec,
			 flags, 0))
			return -1;
		    break;
		}
	    case 'X':{
		    unsigned long arg;

		    PARSE_INT_FORMAT(arg, ap, unsigned);

		    if (append_number
			(state, arg, 0x10, "0123456789ABCDEF", width, prec,
			 flags, 0))
			return -1;
		    break;
		}
	    case 'p':{
		    unsigned long arg = (unsigned long)va_arg(ap, void *);

		    if (append_number
			(state, arg, 0x10, "0123456789ABCDEF", width, prec,
			 flags, 0))
			return -1;
		    break;
		}
	    case 'n':{
		    int *arg = va_arg(ap, int *);
		    *arg = state->s - state->str;
		    break;
		}
	    case '\0':
		--format;
		/* FALLTHROUGH */
	    case '%':
		if ((*state->append_char) (state, c))
		    return -1;
		break;
	    default:
		if ((*state->append_char) (state, '%')
		    || (*state->append_char) (state, c))
		    return -1;
		break;
	    }
	} else if ((*state->append_char) (state, c))
	    return -1;
    }
    return 0;
}

#ifndef HAVE_SNPRINTF
int
snprintf(char *str, size_t sz, const char *format, ...)
{
    va_list args;
    int ret;

    va_start(args, format);
    ret = vsnprintf(str, sz, format, args);

#ifdef PARANOIA
    {
	int ret2;
	char *tmp;

	tmp = malloc(sz);
	if (tmp == NULL)
	    abort();

	ret2 = vsprintf(tmp, format, args);
	if (ret != ret2 || strcmp(str, tmp))
	    abort();
	free(tmp);
    }
#endif

    va_end(args);
    return ret;
}
#endif

#ifndef HAVE_ASPRINTF
int
asprintf(char **ret, const char *format, ...)
{
    va_list args;
    int val;

    va_start(args, format);
    val = vasprintf(ret, format, args);

#ifdef PARANOIA
    {
	int ret2;
	char *tmp;
	tmp = malloc(val + 1);
	if (tmp == NULL)
	    abort();

	ret2 = vsprintf(tmp, format, args);
	if (val != ret2 || strcmp(*ret, tmp))
	    abort();
	free(tmp);
    }
#endif

    va_end(args);
    return val;
}
#endif

#ifndef HAVE_ASNPRINTF
int
asnprintf(char **ret, size_t max_sz, const char *format, ...)
{
    va_list args;
    int val;

    va_start(args, format);
    val = vasnprintf(ret, max_sz, format, args);

#ifdef PARANOIA
    {
	int ret2;
	char *tmp;
	tmp = malloc(val + 1);
	if (tmp == NULL)
	    abort();

	ret2 = vsprintf(tmp, format, args);
	if (val != ret2 || strcmp(*ret, tmp))
	    abort();
	free(tmp);
    }
#endif

    va_end(args);
    return val;
}
#endif

#ifndef HAVE_VASPRINTF
int
vasprintf(char **ret, const char *format, va_list args)
{
    return vasnprintf(ret, 0, format, args);
}
#endif


#ifndef HAVE_VASNPRINTF
int
vasnprintf(char **ret, size_t max_sz, const char *format, va_list args)
{
    int st;
    size_t len;
    struct state state;

    state.max_sz = max_sz;
    state.sz = 1;
    state.str = malloc(state.sz);
    if (state.str == NULL) {
	*ret = NULL;
	return -1;
    }
    state.s = state.str;
    state.theend = state.s + state.sz - 1;
    state.append_char = as_append_char;
    state.reserve = as_reserve;

    st = xyzprintf(&state, format, args);
    if (st) {
	free(state.str);
	*ret = NULL;
	return -1;
    } else {
	char *tmp;

	*state.s = '\0';
	len = state.s - state.str;
	tmp = realloc(state.str, len + 1);
	if (tmp == NULL) {
	    free(state.str);
	    *ret = NULL;
	    return -1;
	}
	*ret = tmp;
	return len;
    }
}
#endif

#ifndef HAVE_VSNPRINTF
int
vsnprintf(char *str, size_t sz, const char *format, va_list args)
{
    struct state state;
    int ret;
    unsigned char *ustr = (unsigned char *)str;

    state.max_sz = 0;
    state.sz = sz;
    state.str = ustr;
    state.s = ustr;
    state.theend = ustr + sz - 1;
    state.append_char = sn_append_char;
    state.reserve = sn_reserve;

    ret = xyzprintf(&state, format, args);
    *state.s = '\0';
    if (ret)
	return sz;
    else
	return state.s - state.str;
}
#endif