/***************************************************************************
 *                                  _   _ ____  _
 *  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: escape.c,v 1.36 2004/07/01 08:10:21 bagder Exp $
 ***************************************************************************/

/* Escape and unescape URL encoding in strings. The functions return a new
 * allocated string or NULL if an error occurred.  */

#include "setup.h"
#include <ctype.h>
#include <curl/curl.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "memory.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

/* The last #include file should be: */
#include "memdebug.h"

char *curl_escape( const char *string, int inlength ) {
	size_t alloc = ( inlength ? (size_t)inlength : strlen( string ) ) + 1;
	char *ns;
	char *testing_ptr = NULL;
	unsigned char in;
	size_t newlen = alloc;
	int strindex = 0;
	size_t length;

	ns = malloc( alloc );
	if ( !ns ) {
		return NULL;
	}

	length = alloc - 1;
	while ( length-- ) {
		in = *string;
		if ( !( in >= 'a' && in <= 'z' ) &&
			 !( in >= 'A' && in <= 'Z' ) &&
			 !( in >= '0' && in <= '9' ) ) {
			/* encode it */
			newlen += 2; /* the size grows with two, since this'll become a %XX */
			if ( newlen > alloc ) {
				alloc *= 2;
				testing_ptr = realloc( ns, alloc );
				if ( !testing_ptr ) {
					free( ns );
					return NULL;
				} else {
					ns = testing_ptr;
				}
			}
			snprintf( &ns[strindex], 4, "%%%02X", in );

			strindex += 3;
		} else {
			/* just copy this */
			ns[strindex++] = in;
		}
		string++;
	}
	ns[strindex] = 0; /* terminate it */
	return ns;
}

#define ishex( in ) ( ( in >= 'a' && in <= 'f' ) ||	\
					  ( in >= 'A' && in <= 'F' ) ||	\
					  ( in >= '0' && in <= '9' ) )

char *curl_unescape( const char *string, int length ) {
	int alloc = ( length ? length : (int)strlen( string ) ) + 1;
	char *ns = malloc( alloc );
	unsigned char in;
	int strindex = 0;
	long hex;

	if ( !ns ) {
		return NULL;
	}

	while ( --alloc > 0 ) {
		in = *string;
		if ( ( '%' == in ) && ishex( string[1] ) && ishex( string[2] ) ) {
			/* this is two hexadecimal digits following a '%' */
			char hexstr[3];
			char *ptr;
			hexstr[0] = string[1];
			hexstr[1] = string[2];
			hexstr[2] = 0;

			hex = strtol( hexstr, &ptr, 16 );

			in = (unsigned char)hex; /* this long is never bigger than 255 anyway */
			string += 2;
			alloc -= 2;
		}

		ns[strindex++] = in;
		string++;
	}
	ns[strindex] = 0; /* terminate it */
	return ns;
}

/* For operating systems/environments that use different malloc/free
   ssystems for the app and for this library, we provide a free that uses
   the library's memory system */
void curl_free( void *p ) {
	if ( p ) {
		free( p );
	}
}