/*
 * Copyright (c) 2016 Nordic Semiconductor ASA
 * Copyright (c) 2016 Vinayak Kariappa Chettimada
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdint.h>
#include "util.h"

/* Convert the integer D to a string and save the string in BUF. If
 * BASE is equal to 'd', interpret that D is decimal, and if BASE is
 * equal to 'x', interpret that D is hexadecimal.
 */
void util_itoa(char *buf, int base, int d)
{
	char *p = buf;
	char *p1, *p2;
	unsigned long ud = d;
	int divisor = 10;

	/* If %d is specified and D is minus, put `-' in the head. */
	if (base == 'd' && d < 0) {
		*p++ = '-';
		buf++;
		ud = -d;
	} else if (base == 'x')
		divisor = 16;

	/* Divide UD by DIVISOR until UD == 0. */
	do {
		int remainder = ud % divisor;
		*p++ =
		    (remainder < 10) ? remainder + '0' : remainder + 'a' - 10;
	} while (ud /= divisor);

	/* Terminate BUF. */
	*p = 0;

	/* Reverse BUF. */
	p1 = buf;
	p2 = p - 1;
	while (p1 < p2) {
		char tmp = *p1;
		*p1 = *p2;
		*p2 = tmp;
		p1++;
		p2--;
	}
}

int util_atoi(char *s)
{
	int val = 0;

	while (*s) {
		if (*s < '0' || *s > '9')
			return val;
		val = (val * 10) + (*s - '0');
		s++;
	}
	return val;
}

/* Format a string and print it on the screen, just like the libc
 *         function printf.
 */
void util_sprintf(char *str, const char *format, ...)
{
	char **arg = (char **)&format;
	int c;
	char buf[20];

	arg++;

	while ((c = *format++)) {
		if (c != '%')
			*str++ = c;
		else {
			char *p;

			c = *format++;
			switch (c) {
			case 'd':
			case 'u':
			case 'x':
				util_itoa(buf, c, *((int *)arg++));
				p = buf;
				goto string;
			case 's':
				p = *arg++;
				if (!p)
					p = "(null)";
string:
				while (*p)
					*str++ = *p++;
				break;
			default:
				*str++ = (*((int *)arg++));
				break;
			}
		}
	}

	*str = 0;
}

uint8_t util_ones_count_get(uint8_t *octets, uint8_t octets_len)
{
	uint8_t one_count = 0;

	while (octets_len--) {
		uint8_t bite;

		bite = *octets;
		while (bite) {
			bite &= (bite - 1);
			one_count++;
		}
		octets++;
	}

	return one_count;
}