/*	$NetBSD: strptime.c,v 1.62 2017/08/24 01:01:09 ginsbach Exp $	*/

/*-
 * Copyright (c) 1997, 1998, 2005, 2008 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.
 *
 * 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.
 */

/*
	https://opensource.apple.com/source/lukemftp/lukemftp-3/lukemftp/libukem/strptime.c

	This file is used to implement the strptime API call that is missing on Windows
*/

#ifdef WIN32

#include "ndpi_main.h"

#ifndef TM_YEAR_BASE
#define TM_YEAR_BASE	1900
#endif /* !defined TM_YEAR_BASE */


 /*	$Id$	*/
 /*	$NetBSD: strptime.c,v 1.18 1999/04/29 02:58:30 tv Exp $	*/

 /*-
  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
  * All rights reserved.
  *
  * This code was contributed to The NetBSD Foundation by Klaus Klein.
  *
  * 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.
  */

#include "ndpi_main.h"

  /*
   * 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 (0); }


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

static const char* day[7] = {
	"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday",
	"Friday", "Saturday"
};
static const char* abday[7] = {
	"Sun","Mon","Tue","Wed","Thu","Fri","Sat"
};
static const char* mon[12] = {
	"January", "February", "March", "April", "May", "June", "July",
	"August", "September", "October", "November", "December"
};
static const char* abmon[12] = {
	"Jan", "Feb", "Mar", "Apr", "May", "Jun",
	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
static const char* am_pm[2] = {
	"AM", "PM"
};


char*
strptime(const char* buf, const char* fmt, struct tm* tm)
{
	char c;
	const char* bp;
	size_t len = 0;
	int alt_format, i, split_year = 0;

	bp = buf;

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

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

			fmt++;
			continue;
		}

		if ((c = *fmt++) != '%')
			goto literal;


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

		/*
		 * "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. */
		LEGAL_ALT(ALT_E);
		if (!(bp = strptime(bp, "%x %X", tm)))
			return (0);
		break;

	case 'D':	/* The date as "%m/%d/%y". */
		LEGAL_ALT(0);
		if (!(bp = strptime(bp, "%m/%d/%y", tm)))
			return (0);
		break;

	case 'R':	/* The time as "%H:%M". */
		LEGAL_ALT(0);
		if (!(bp = strptime(bp, "%H:%M", tm)))
			return (0);
		break;

	case 'r':	/* The time in 12-hour clock representation. */
		LEGAL_ALT(0);
		if (!(bp = strptime(bp, "%I:%M:%S %p", tm)))
			return (0);
		break;

	case 'T':	/* The time as "%H:%M:%S". */
		LEGAL_ALT(0);
		if (!(bp = strptime(bp, "%H:%M:%S", tm)))
			return (0);
		break;

	case 'X':	/* The time, using the locale's format. */
		LEGAL_ALT(ALT_E);
		if (!(bp = strptime(bp, "%H:%M:%S", tm)))
			return (0);
		break;

	case 'x':	/* The date, using the locale's format. */
		LEGAL_ALT(ALT_E);
		if (!(bp = strptime(bp, "%m/%d/%y", tm)))
			return (0);
		break;

		/*
		 * "Elementary" conversion rules.
		 */
	case 'A':	/* The day of week, using the locale's form. */
	case 'a':
		LEGAL_ALT(0);
		for (i = 0; i < 7; i++) {
			/* Full name. */
			len = strlen(day[i]);
			if (strncasecmp(day[i], bp, len) == 0)
				break;

			/* Abbreviated name. */
			len = strlen(abday[i]);
			if (strncasecmp(abday[i], bp, len) == 0)
				break;
		}

		/* Nothing matched. */
		if (i == 7)
			return (0);

		tm->tm_wday = i;
		bp += len;
		break;

	case 'B':	/* The month, using the locale's form. */
	case 'b':
	case 'h':
		LEGAL_ALT(0);
		for (i = 0; i < 12; i++) {
			/* Full name. */
			len = strlen(mon[i]);
			if (strncasecmp(mon[i], bp, len) == 0)
				break;

			/* Abbreviated name. */
			len = strlen(abmon[i]);
			if (strncasecmp(abmon[i], bp, len) == 0)
				break;
		}

		/* Nothing matched. */
		if (i == 12)
			return (0);

		tm->tm_mon = i;
		bp += len;
		break;

	case 'C':	/* The century number. */
		LEGAL_ALT(ALT_E);
		if (!(conv_num(&bp, &i, 0, 99)))
			return (0);

		if (split_year) {
			tm->tm_year = (tm->tm_year % 100) + (i * 100);
		}
		else {
			tm->tm_year = i * 100;
			split_year = 1;
		}
		break;

	case 'd':	/* The day of month. */
	case 'e':
		LEGAL_ALT(ALT_O);
		if (!(conv_num(&bp, &tm->tm_mday, 1, 31)))
			return (0);
		break;

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

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

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

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

	case 'm':	/* The month. */
		LEGAL_ALT(ALT_O);
		if (!(conv_num(&bp, &i, 1, 12)))
			return (0);
		tm->tm_mon = i - 1;
		break;

	case 'p':	/* The locale's equivalent of AM/PM. */
		LEGAL_ALT(0);
		/* AM? */
		if (strcasecmp(am_pm[0], bp) == 0) {
			if (tm->tm_hour > 11)
				return (0);

			bp += strlen(am_pm[0]);
			break;
		}
		/* PM? */
		else if (strcasecmp(am_pm[1], bp) == 0) {
			if (tm->tm_hour > 11)
				return (0);

			tm->tm_hour += 12;
			bp += strlen(am_pm[1]);
			break;
		}

		/* Nothing matched. */
		return (0);

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

	case 'U':	/* The week of year, beginning on sunday. */
	case 'W':	/* The week of year, beginning on monday. */
		LEGAL_ALT(ALT_O);
		/*
		 * 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.
		 */
		if (!(conv_num(&bp, &i, 0, 53)))
			return (0);
		break;

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

	case 'Y':	/* The year. */
		LEGAL_ALT(ALT_E);
		if (!(conv_num(&bp, &i, 0, 9999)))
			return (0);

		tm->tm_year = i - TM_YEAR_BASE;
		break;

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

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

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


	default:	/* Unknown/unsupported conversion. */
		return (0);
	}


	}

	/* LINTED functional specification */
	return ((char*)bp);
}

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

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

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

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

	if (result < llim || result > ulim)
		return (0);

	*dest = result;
	return (1);
}

#endif