/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2004, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id: strtoofft.c,v 1.7 2004/10/10 03:28:51 bagder Exp $
 ***************************************************************************/

#include "setup.h"
#include "strtoofft.h"

#ifdef NEED_CURL_STRTOLL
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>

static int get_char( char c, int base );

/**
 * Emulated version of the strtoll function.  This extracts a long long
 * value from the given input string and returns it.
 */
curl_off_t
curlx_strtoll( const char *nptr, char **endptr, int base ) {
	char *end;
	int is_negative = 0;
	int overflow;
	int i;
	curl_off_t value = 0;
	curl_off_t newval;

	/* Skip leading whitespace. */
	end = (char *)nptr;
	while ( isspace( (int)end[0] ) ) {
		end++;
	}

	/* Handle the sign, if any. */
	if ( end[0] == '-' ) {
		is_negative = 1;
		end++;
	} else if ( end[0] == '+' )      {
		end++;
	} else if ( end[0] == '\0' )       {
		/* We had nothing but perhaps some whitespace -- there was no number. */
		if ( endptr ) {
			*endptr = end;
		}
		return 0;
	}

	/* Handle special beginnings, if present and allowed. */
	if ( end[0] == '0' && end[1] == 'x' ) {
		if ( base == 16 || base == 0 ) {
			end += 2;
			base = 16;
		}
	} else if ( end[0] == '0' )      {
		if ( base == 8 || base == 0 ) {
			end++;
			base = 8;
		}
	}

	/* Matching strtol, if the base is 0 and it doesn't look like
	 * the number is octal or hex, we assume it's base 10.
	 */
	if ( base == 0 ) {
		base = 10;
	}

	/* Loop handling digits. */
	value = 0;
	overflow = 0;
	for ( i = get_char( end[0], base );
		  i != -1;
		  end++, i = get_char( end[0], base ) ) {
		newval = base * value + i;
		if ( newval < value ) {
			/* We've overflowed. */
			overflow = 1;
			break;
		} else {
			value = newval;
		}
	}

	if ( !overflow ) {
		if ( is_negative ) {
			/* Fix the sign. */
			value *= -1;
		}
	} else {
		if ( is_negative ) {
			value = CURL_LLONG_MIN;
		} else {
			value = CURL_LLONG_MAX;
		}

		errno = ERANGE;
	}

	if ( endptr ) {
		*endptr = end;
	}

	return value;
}

/**
 * Returns the value of c in the given base, or -1 if c cannot
 * be interpreted properly in that base (i.e., is out of range,
 * is a null, etc.).
 *
 * @param c     the character to interpret according to base
 * @param base  the base in which to interpret c
 *
 * @return  the value of c in base, or -1 if c isn't in range
 */
static int get_char( char c, int base ) {
	int value = -1;
	if ( c <= '9' && c >= '0' ) {
		value = c - '0';
	} else if ( c <= 'Z' && c >= 'A' )       {
		value = c - 'A' + 10;
	} else if ( c <= 'z' && c >= 'a' )       {
		value = c - 'a' + 10;
	}

	if ( value >= base ) {
		value = -1;
	}

	return value;
}
#endif  /* Only present if we need strtoll, but don't have it. */