/* strgutil.c -  miscellaneous utilities
 *	Copyright (C) 1998 Free Software Foundation, Inc.
 *
 * This file is part of GNUPG.
 *
 * GNUPG 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.
 *
 * GNUPG 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include <config.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "types.h"
#include "util.h"
#include "memory.h"


void
free_strlist( STRLIST sl )
{
    STRLIST sl2;

    for(; sl; sl = sl2 ) {
	sl2 = sl->next;
	m_free(sl);
    }
}


STRLIST
add_to_strlist( STRLIST *list, const char *string )
{
    STRLIST sl;

    sl = m_alloc( sizeof *sl + strlen(string));
    strcpy(sl->d, string);
    sl->next = *list;
    *list = sl;
    return sl;
}

STRLIST
append_to_strlist( STRLIST *list, const char *string )
{
    STRLIST r, sl;

    sl = m_alloc( sizeof *sl + strlen(string));
    strcpy(sl->d, string);
    sl->next = NULL;
    if( !*list )
	*list = sl;
    else {
	for( r = *list; r->next; r = r->next )
	    ;
	r->next = sl;
    }
    return sl;
}



STRLIST
strlist_prev( STRLIST head, STRLIST node )
{
    STRLIST n;

    for(n=NULL; head && head != node; head = head->next )
	n = head;
    return n;
}

STRLIST
strlist_last( STRLIST node )
{
    if( node )
	for( ; node->next ; node = node->next )
	    ;
    return node;
}



/****************
 * look for the substring SUB in buffer and return a pointer to that
 * substring in BUF or NULL if not found.
 * Comparison is case-insensitive.
 */
const char *
memistr( const char *buf, size_t buflen, const char *sub )
{
    const byte *t, *s ;
    size_t n;

    for( t=buf, n=buflen, s=sub ; n ; t++, n-- )
	if( toupper(*t) == toupper(*s) ) {
	    for( buf=t++, buflen = n--, s++;
		 n && toupper(*t) == toupper(*s); t++, s++, n-- )
		;
	    if( !*s )
		return buf;
	    t = buf; n = buflen; s = sub ;
	}

    return NULL ;
}

/****************
 * Wie strncpy(), aber es werden maximal n-1 zeichen kopiert und ein
 * '\0' angehängt. Ist n = 0, so geschieht nichts, ist Destination
 * gleich NULL, so wird via m_alloc Speicher besorgt, ist dann nicht
 * genügend Speicher vorhanden, so bricht die funktion ab.
 */
char *
mem2str( char *dest , const void *src , size_t n )
{
    char *d;
    const char *s;

    if( n ) {
	if( !dest )
	    dest = m_alloc( n ) ;
	d = dest;
	s = src ;
	for(n--; n && *s; n-- )
	    *d++ = *s++;
	*d = '\0' ;
    }

    return dest ;
}


/****************
 * remove leading and trailing white spaces
 */
char *
trim_spaces( char *str )
{
    char *string, *p, *mark;

    string = str;
    /* find first non space character */
    for( p=string; *p && isspace( *(byte*)p ) ; p++ )
	;
    /* move characters */
    for( (mark = NULL); (*string = *p); string++, p++ )
	if( isspace( *(byte*)p ) ) {
	    if( !mark )
		mark = string ;
	}
	else
	    mark = NULL ;
    if( mark )
	*mark = '\0' ;  /* remove trailing spaces */

    return str ;
}


int
string_count_chr( const char *string, int c )
{
    int count;
    for(count=0; *string; string++ )
	if( *string == c )
	    count++;
    return count;
}


/****************
 * Convert string, which is in native encoding to UTF8 and return the
 * new allocated UTF8 string.
 * This code assumes that native is iso-8859-1.
 */
char *
native_to_utf8( const char *string )
{
    const byte *s;
    char *buffer;
    byte *p;
    size_t length=0;

    for(s=string; *s; s++ ) {
	length++;
	if( *s & 0x80 )
	    length++;
    }
    buffer = m_alloc( length + 1 );
    for(p=buffer, s=string; *s; s++ ) {
	if( *s & 0x80 ) {
	    *p++ = 0xc0 | ((*s >> 6) & 3);
	    *p++ = 0x80 | ( *s & 0x3f );
	}
	else
	    *p++ = *s;
    }
    *p = 0;
    return buffer;
}


/****************
 * Convert string, which is in UTF8 to native encoding.  Replace
 * illegal encodings by some "\xnn".
 * This code assumes that native is iso-8859-1.
 */
char *
utf8_to_native( const char *string )
{
    /* FIXME: Not yet done */
    return m_strdup(string);
}


/*********************************************
 ********** missing string functions *********
 *********************************************/

#ifndef HAVE_STPCPY
char *
stpcpy(char *a,const char *b)
{
    while( *b )
	*a++ = *b++;
    *a = 0;

    return (char*)a;
}
#endif

#ifndef HAVE_STRLWR
char *
strlwr(char *s)
{
    char *p;
    for(p=s; *p; p++ )
	*p = tolower(*p);
    return s;
}
#endif

/****************
 * mingw32/cpd has a memicmp()
 */
#ifndef HAVE_MEMICMP
int
memicmp( const char *a, const char *b, size_t n )
{
    for( ; n; n--, a++, b++ )
	if( *a != *b  && toupper(*(const byte*)a) != toupper(*(const byte*)b) )
	    return *(const byte *)a - *(const byte*)b;
    return 0;
}
#endif