/*
  This file is part of libpsyc.
  Copyright (C) 2011,2012 Carlo v. Loesch, Gabor X Toth, Mathias L. Baumann,
  and other contributing authors.

  libpsyc is free software: you can redistribute it and/or modify it under the
  terms of the GNU Affero General Public License as published by the Free
  Software Foundation, either version 3 of the License, or (at your option) any
  later version. As a special exception, libpsyc is distributed with additional
  permissions to link libpsyc libraries with non-AGPL works.

  libpsyc 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 Affero General Public License for more
  details.

  You should have received a copy of the GNU Affero General Public License and
  the linking exception along with libpsyc in a COPYING file.
*/

#define ALPHANUMS "zyxwvutsrqponmlkjihgfedcba9876543210123456789abcdefghijklmnopqrstuvwxyz"

/**
 * Converts an integer to a string, using a base of 10 by default.
 *
 * If you NULL out the output buffer it will return the expected
 * output string length anyway.
 */
int
itoa (int number, char *out, int base)
{
    int t, count;
    char *p, *q;
    char c;

    p = q = out;
    if (base < 2 || base > 36)
	base = 10;

    do {
	t = number;
	number /= base;
	if (out)
	    *p = ALPHANUMS[t + 35 - number * base];
	p++;
    } while (number);

    if (t < 0) {
	if (out)
	    *p = '-';
	p++;
    }
    count = p - out;
    if (out) {
	*p-- = '\0';
	while (q < p) {
	    c = *p;
	    *p-- = *q;
	    *q++ = c;
	}
    }
    return count;
}

/* This little test program shows that itoa() is roughly 3 times faster
 * than sprintf  --lynX
 */
#ifdef CMDTOOL

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

int
main (int argc, char **argv)
{
    char out[4404];
    int in[44];
    int c, i, j;

    if (argc < 3 || argc > sizeof(in)) {
	printf("Usage: %s <times> <numbers>+\n\n"
	       "Example: %s 999999 123 234 345 -49 -21892\n",
	       argv[0], argv[0]);
	return -1;
    }
    for (j = argc - 1; j; j--) {
	//printf("Looking at arg #%d: %s\n", j, argv[j]);
	in[j] = atoi(argv[j]);
	//printf("Got %d: %d\n", j, in[j]);
    }
    for (i = in[1]; i; i--) {
	c = 0;
	for (j = argc - 1; j > 1; j--) {
#if 0
	    // use good old sprintf
	    c += sprintf(&out[c], " %d", in[j]);
#else
#if 1
	    // use the itoa implementation
	    out[c++] = ' ';
	    c += itoa(in[j], &out[c], 10);
#else
	    // just count the needed space
	    c += itoa(in[j], NULL, 10) + 1;
#endif
#endif
	}
    }
    printf("%d times, %d count, buffer len: %d, buffer: %s\n",
	   in[1], c, strlen(out), "<omitted>");	// out
    return 0;
}
#endif