/* -*- c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t -*- */
/* vim:set sts=4 ts=8: */

/*
 * Copyright (c) 2001-2011 XORP, Inc and Others
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License, Version
 * 2.1, June 1999 as published by the Free Software Foundation.
 * Redistribution and/or modification of this program under the terms of
 * any other version of the GNU Lesser General Public License is not
 * permitted.
 * 
 * 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. For more details,
 * see the GNU Lesser General Public License, Version 2.1, a copy of
 * which can be found in the XORP LICENSE.lgpl file.
 * 
 * XORP, Inc, 2953 Bunker Hill Lane, Suite 204, Santa Clara, CA 95054, USA;
 * http://xorp.net
 */




/*
 * strptime(3) implementation: a parser for data and time string
 */

/*
 * XXX: the particular implementation is taken from NetBSD-current
 * (as of 2006/02/06).
 * The rest is a front-end for it.
 * Note that the local implementation is used only if the system
 * doesn't have its own strptime(3) implementation.
 *
 * The changes are:
 *	- Included <time.h> and <strings.h>
 *	- The global function named strptime() is redefined as static
 *	  and is renamed to local_strptime().
 *	- The inclusion of some header files is removed.
 *	- Sone unused structure definitions are removed.
 *	- Conditional usage of __weak_alias() is removed.
 *	- TM_YEAR_BASE is defined conditionally.
 *	- A local implementation of UNUSED() is added.
 *	- All usage of isspace() is replaced with xorp_isspace().
 *	- New function xorp_strptime() is added as a front-end for
 *	  the local implementation.
 *	- Replaced "u_char" with "unsigned char" and "uint"
 *	  with "unsigned int".
 */

#include "xorp_config.h"

/*
 * XXX: Linux's glibc2 and NetBSD need to define _XOPEN_SOURCE for strptime(3).
 *
 * On the other hand, OpenBSD-3.9 cannot process <net/if.h> (included by
 * "libxorp/xorp.h") if _XOPEN_SOURCE is defined.
 * Hence, as an exception we include some stuff before "libxorp/xorp.h",
 * but then we undefine _XOPEN_SOURCE
 */
#define _XOPEN_SOURCE	500
#include <time.h>
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#undef _XOPEN_SOURCE

#include <string.h>

/*
 * XXX: don't include "libxorp/xorp.h", because it cannot be compiled
 * on Solaris 10 if _XOPEN_SOURCE is defined: _XOPEN_SOURCE itself
 * controls the definition of some other symbols.
 * Instead, include "xorp_config.h" and all other header files that may
 * be needed.
 */
/* #include "libxorp/xorp.h" */

#include "libxorp/utility.h"

#ifndef TM_YEAR_BASE
#define TM_YEAR_BASE 1900
#endif

static inline void *
UNCONST(const void *a)
{
	return ((const char *)a - (const char *)0) + (char *)0;
}


/*
 * Copyright (c) 1994 Winning Strategies, Inc.
 * 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 Winning Strategies, Inc.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

typedef struct {
	const char *abday[7];
	const char *day[7];
	const char *abmon[12];
	const char *mon[12];
	const char *am_pm[2];
	const char *d_t_fmt;
	const char *d_fmt;
	const char *t_fmt;
	const char *t_fmt_ampm;
} _TimeLocale;


/*	$NetBSD: _def_time.c,v 1.8 2005/06/12 05:21:27 lukem Exp $	*/

/*
 * Written by J.T. Conklin <jtc@NetBSD.org>.
 * Public domain.
 */

#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: _def_time.c,v 1.8 2005/06/12 05:21:27 lukem Exp $");
#endif /* LIBC_SCCS and not lint */

const _TimeLocale _DefaultTimeLocale = 
{
	{
		"Sun","Mon","Tue","Wed","Thu","Fri","Sat",
	},
	{
		"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday",
		"Friday", "Saturday"
	},
	{
		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
	},
	{
		"January", "February", "March", "April", "May", "June", "July",
		"August", "September", "October", "November", "December"
	},
	{
		"AM", "PM"
	},
	"%a %b %e %H:%M:%S %Y",
	"%m/%d/%y",
	"%H:%M:%S",
	"%I:%M:%S %p"
};

const _TimeLocale *_CurrentTimeLocale = &_DefaultTimeLocale;


/*	$NetBSD: strptime.c,v 1.25 2005/11/29 03:12:00 christos Exp $	*/

/*-
 * Copyright (c) 1997, 1998, 2005 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code was contributed to The NetBSD Foundation by Klaus Klein.
 * Heavily optimised by David Laight
 *
 * 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 NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: strptime.c,v 1.25 2005/11/29 03:12:00 christos Exp $");
#endif

#define	_ctloc(x)		(_CurrentTimeLocale->x)

/*
 * We do not implement alternate representations. However, we always
 * check whether a given modifier is allowed for a certain conversion.
 */
#define ALT_E			0x01
#define ALT_O			0x02
#define	LEGAL_ALT(x)		{ if (alt_format & ~(x)) return NULL; }


#ifndef HAVE_STRPTIME

static const unsigned char *conv_num(const unsigned char *, int *,
	unsigned int, unsigned int);
static const unsigned char *find_string(const unsigned char *, int *,
	const char * const *,
	const char * const *, int);


static char *
local_strptime(const char *buf, const char *fmt, struct tm *tm)
{
	unsigned char c;
	const unsigned char *bp;
	int alt_format, i, split_year = 0;
	const char *new_fmt;

	bp = (const unsigned char *)buf;

	while (bp != NULL && (c = *fmt++) != '\0') {
		/* Clear `alternate' modifier prior to new conversion. */
		alt_format = 0;
		i = 0;

		/* Eat up white-space. */
		if (xorp_isspace(c)) {
			while (xorp_isspace(*bp))
				bp++;
			continue;
		}

		if (c != '%')
			goto literal;


again:		switch (c = *fmt++) {
		case '%':	/* "%%" is converted to "%". */
literal:
			if (c != *bp++)
				return NULL;
			LEGAL_ALT(0);
			continue;

		/*
		 * "Alternative" modifiers. Just set the appropriate flag
		 * and start over again.
		 */
		case 'E':	/* "%E?" alternative conversion modifier. */
			LEGAL_ALT(0);
			alt_format |= ALT_E;
			goto again;

		case 'O':	/* "%O?" alternative conversion modifier. */
			LEGAL_ALT(0);
			alt_format |= ALT_O;
			goto again;

		/*
		 * "Complex" conversion rules, implemented through recursion.
		 */
		case 'c':	/* Date and time, using the locale's format. */
			new_fmt = _ctloc(d_t_fmt);
			goto recurse;

		case 'D':	/* The date as "%m/%d/%y". */
			new_fmt = "%m/%d/%y";
			LEGAL_ALT(0);
			goto recurse;

		case 'R':	/* The time as "%H:%M". */
			new_fmt = "%H:%M";
			LEGAL_ALT(0);
			goto recurse;

		case 'r':	/* The time in 12-hour clock representation. */
			new_fmt =_ctloc(t_fmt_ampm);
			LEGAL_ALT(0);
			goto recurse;

		case 'T':	/* The time as "%H:%M:%S". */
			new_fmt = "%H:%M:%S";
			LEGAL_ALT(0);
			goto recurse;

		case 'X':	/* The time, using the locale's format. */
			new_fmt =_ctloc(t_fmt);
			goto recurse;

		case 'x':	/* The date, using the locale's format. */
			new_fmt =_ctloc(d_fmt);
		    recurse:
			bp = (const unsigned char *)local_strptime((const char *)bp,
							    new_fmt, tm);
			LEGAL_ALT(ALT_E);
			continue;

		/*
		 * "Elementary" conversion rules.
		 */
		case 'A':	/* The day of week, using the locale's form. */
		case 'a':
			bp = find_string(bp, &tm->tm_wday, _ctloc(day),
					_ctloc(abday), 7);
			LEGAL_ALT(0);
			continue;

		case 'B':	/* The month, using the locale's form. */
		case 'b':
		case 'h':
			bp = find_string(bp, &tm->tm_mon, _ctloc(mon),
					_ctloc(abmon), 12);
			LEGAL_ALT(0);
			continue;

		case 'C':	/* The century number. */
			i = 20;
			bp = conv_num(bp, &i, 0, 99);

			i = i * 100 - TM_YEAR_BASE;
			if (split_year)
				i += tm->tm_year % 100;
			split_year = 1;
			tm->tm_year = i;
			LEGAL_ALT(ALT_E);
			continue;

		case 'd':	/* The day of month. */
		case 'e':
			bp = conv_num(bp, &tm->tm_mday, 1, 31);
			LEGAL_ALT(ALT_O);
			continue;

		case 'k':	/* The hour (24-hour clock representation). */
			LEGAL_ALT(0);
			/* FALLTHROUGH */
		case 'H':
			bp = conv_num(bp, &tm->tm_hour, 0, 23);
			LEGAL_ALT(ALT_O);
			continue;

		case 'l':	/* The hour (12-hour clock representation). */
			LEGAL_ALT(0);
			/* FALLTHROUGH */
		case 'I':
			bp = conv_num(bp, &tm->tm_hour, 1, 12);
			if (tm->tm_hour == 12)
				tm->tm_hour = 0;
			LEGAL_ALT(ALT_O);
			continue;

		case 'j':	/* The day of year. */
			i = 1;
			bp = conv_num(bp, &i, 1, 366);
			tm->tm_yday = i - 1;
			LEGAL_ALT(0);
			continue;

		case 'M':	/* The minute. */
			bp = conv_num(bp, &tm->tm_min, 0, 59);
			LEGAL_ALT(ALT_O);
			continue;

		case 'm':	/* The month. */
			i = 1;
			bp = conv_num(bp, &i, 1, 12);
			tm->tm_mon = i - 1;
			LEGAL_ALT(ALT_O);
			continue;

		case 'p':	/* The locale's equivalent of AM/PM. */
			bp = find_string(bp, &i, _ctloc(am_pm), NULL, 2);
			if (tm->tm_hour > 11)
				return NULL;
			tm->tm_hour += i * 12;
			LEGAL_ALT(0);
			continue;

		case 'S':	/* The seconds. */
			bp = conv_num(bp, &tm->tm_sec, 0, 61);
			LEGAL_ALT(ALT_O);
			continue;

		case 'U':	/* The week of year, beginning on sunday. */
		case 'W':	/* The week of year, beginning on monday. */
			/*
			 * XXX This is bogus, as we can not assume any valid
			 * information present in the tm structure at this
			 * point to calculate a real value, so just check the
			 * range for now.
			 */
			 bp = conv_num(bp, &i, 0, 53);
			 LEGAL_ALT(ALT_O);
			 continue;

		case 'w':	/* The day of week, beginning on sunday. */
			bp = conv_num(bp, &tm->tm_wday, 0, 6);
			LEGAL_ALT(ALT_O);
			continue;

		case 'Y':	/* The year. */
			i = TM_YEAR_BASE;	/* just for data sanity... */
			bp = conv_num(bp, &i, 0, 9999);
			tm->tm_year = i - TM_YEAR_BASE;
			LEGAL_ALT(ALT_E);
			continue;

		case 'y':	/* The year within 100 years of the epoch. */
			/* LEGAL_ALT(ALT_E | ALT_O); */
			bp = conv_num(bp, &i, 0, 99);

			if (split_year)
				/* preserve century */
				i += (tm->tm_year / 100) * 100;
			else {
				split_year = 1;
				if (i <= 68)
					i = i + 2000 - TM_YEAR_BASE;
				else
					i = i + 1900 - TM_YEAR_BASE;
			}
			tm->tm_year = i;
			continue;

		/*
		 * Miscellaneous conversions.
		 */
		case 'n':	/* Any kind of white-space. */
		case 't':
			while (xorp_isspace(*bp))
				bp++;
			LEGAL_ALT(0);
			continue;


		default:	/* Unknown/unsupported conversion. */
			return NULL;
		}
	}

	return (char *)UNCONST(bp);
}


static const unsigned char *
conv_num(const unsigned char *buf, int *dest, unsigned int llim,
	unsigned int ulim)
{
	unsigned int result = 0;
	unsigned char ch;

	/* The limit also determines the number of valid digits. */
	unsigned int rulim = ulim;

	ch = *buf;
	if (ch < '0' || ch > '9')
		return NULL;

	do {
		result *= 10;
		result += ch - '0';
		rulim /= 10;
		ch = *++buf;
	} while ((result * 10 <= ulim) && rulim && ch >= '0' && ch <= '9');

	if (result < llim || result > ulim)
		return NULL;

	*dest = result;
	return buf;
}

/*
 * XXX: The Windows' equivalent of strncasecmp(3) is called _strnicmp()
 * hence we need to do some renaming here.
 */
#ifdef HOST_OS_WINDOWS
#define STRNCASECMP(s1, s2, len) _strnicmp(s1, s2, len)
#else
#define STRNCASECMP(s1, s2, len) strncasecmp(s1, s2, len)
#endif

static const unsigned char *
find_string(const unsigned char *bp, int *tgt, const char * const *n1,
		const char * const *n2, int c)
{
	int i;
	unsigned int len;

	/* check full name - then abbreviated ones */
	for (; n1 != NULL; n1 = n2, n2 = NULL) {
		for (i = 0; i < c; i++, n1++) {
			len = strlen(*n1);
			if (STRNCASECMP(*n1, (const char *)bp, len) == 0) {
				*tgt = i;
				return bp + len;
			}
		}
	}

	/* Nothing matched */
	return NULL;
}

#endif /* HAVE_STRPTIME */


char *
xorp_strptime(const char *buf, const char *fmt, struct tm *tm)
{
#ifdef HAVE_STRPTIME
    return strptime(buf, fmt, tm);
#else
    return local_strptime(buf, fmt, tm);
#endif
}
