/* vi: set ts=2:
 *
 *	$Id: base36.c,v 1.1 2001/01/25 09:37:58 enno Exp $
 *	Eressea PB(E)M host Copyright (C) 1998-2000
 *      Christian Schlittchen (corwin@amber.kn-bremen.de)
 *      Katja Zedel (katze@felidae.kn-bremen.de)
 *      Henning Peters (faroul@beyond.kn-bremen.de)
 *      Enno Rehling (enno@eressea-pbem.de)
 *      Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de)
 *
 *  based on:
 *
 * Atlantis v1.0  13 September 1993 Copyright 1993 by Russell Wallace
 * Atlantis v1.7                    Copyright 1996 by Alex Schröder
 *
 * This program may not be used, modified or distributed without
 * prior permission by the authors of Eressea.
 * This program may not be sold or used commercially without prior written
 * permission from the authors.
 */

#include <config.h>
#include "base36.h"

#include <stdlib.h>

#ifdef HAVE_STRTOL
int
atoi36(const char * s)
{
	return (int)(strtol(s, NULL, 36));
}
#else
#include <ctype.h>
int
atoi36(const char * s)
{
	int i = 0;

	if(!(*s)) return 0;

	while(!isalnum((int)*s)) ++s;
	while(isalnum((int)*s)) {
		if (isupper((int)*s)) i = i*36 + (*s)-'A' + 10;
		else if (islower((int)*s)) i=i*36 + (*s)-'a' + 10;
		else if (isdigit((int)*s)) i=i*36 + (*s)-'0';
		++s;
	}
	if (i<0) return 0;
	return i;
}
#endif

const char*
itoab(int i, int base)
{
	static char **as = NULL;
	char * s, * dst;
	static int index = 0;
	int neg = 0;

	if (!as) {
		int i;
		char * x = calloc(sizeof(char), 8*4);
		as = calloc(sizeof(char*), 4);
		for (i=0;i!=4;++i) as[i] = x+i*8;
	}
	s = as[index];
	index = (index+1) % 4;
	dst = s+6;

	if (i!=0) {
		if (i<0) {
			i=-i;
			neg = 1;
		}
		while (i) {
			int x = i % base;
			i = i / base;
			if (x<10) *(dst--) = (char)('0' + x);
			else if ('a' + x - 10 == 'l') *(dst--) = 'L';
			else *(dst--) = (char)('a' + (x-10));
		}
		if (neg) *(dst) = '-';
		else ++dst;
	}
	else *dst = '0';

	return dst;
}

const char*
itoa36(int i)
{
	return itoab(i, 36);
}

const char*
itoa10(int i)
{
	return itoab(i, 10);
}

int
i10toi36(int i)
{
	int r = 0;
	while(i) {
		r = r*36 + i % 10;
		i = i / 10;
	}
	return r;
}