/*
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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 of the License, or
 * (at your option) any later version
 *
 * Kamailio 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 program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef TRIM_H
#define TRIM_H

#include "str.h"


/*!
 * This switch-case statement is used in
 * trim_leading and trim_trailing. You can
 * define characters that should be skipped
 * here.
 */
#define TRIM_SWITCH(c) \
	switch(c) {        \
		case ' ':      \
		case '\t':     \
		case '\r':     \
		case '\n':     \
			break;     \
                       \
		default:       \
			return;    \
	}


/*
 * Remove any leading whitechars, like spaces,
 * horizontal tabs, carriage returns and line
 * feeds
 *
 * WARNING: String descriptor structure will be
 *          modified ! Make a copy otherwise you
 *          might be unable to free _s->s for
 *          example !
 *
 */
static inline void trim_leading(str *_s)
{
	for(; _s->len > 0; _s->len--, _s->s++) {
		TRIM_SWITCH(*(_s->s));
	}
}


/*
 * Remove any trailing white char, like spaces,
 * horizontal tabs, carriage returns and line feeds
 *
 * WARNING: String descriptor structure will be
 *          modified ! Make a copy otherwise you
 *          might be unable to free _s->s for
 *          example !
 */
static inline void trim_trailing(str *_s)
{
	for(; _s->len > 0; _s->len--) {
		TRIM_SWITCH(_s->s[_s->len - 1]);
	}
}


/*
 * Do trim_leading and trim_trailing
 *
 * WARNING: String structure will be modified !
 *          Make a copy otherwise you might be
 *          unable to free _s->s for example !
 */
static inline void trim(str *_s)
{
	trim_leading(_s);
	trim_trailing(_s);
}


/*
 * right and left space trimming
 *
 * WARNING: String structure will be modified !
 *          Make a copy otherwise you might be
 *          unable to free _s_->s for example !
 */
#define trim_spaces_lr(_s_)                                            \
	do {                                                               \
		for(; (_s_).s[(_s_).len - 1] == ' '; (_s_).s[--(_s_).len] = 0) \
			;                                                          \
		for(; (_s_).s[0] == ' '; (_s_).s = (_s_).s + 1, (_s_).len--)   \
			;                                                          \
                                                                       \
	} while(0);

/*
 * right and left zero trimming
 *
 * WARNING: String structure will be modified !
 *          Make a copy otherwise you might be
 *          unable to free _s_->s for example !
 */
#define trim_zeros_lr(_s_)                                                  \
	do {                                                                    \
		for(; (_s_)->s[(_s_)->len - 1] == '\0'; (_s_)->s[--(_s_)->len] = 0) \
			;                                                               \
		for(; (_s_)->s[0] == '\0'; (_s_)->s = (_s_)->s + 1, (_s_)->len--)   \
			;                                                               \
                                                                            \
	} while(0);

#endif /* TRIM_H */
