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/*

 * Copyright (C) 2006 Martin Decky

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "printf.h"

#include "stdarg.h"

#include <types.h>

typedef char *char_ptr;

static char digits[] = "0123456789abcdef";  /**< Hexadecimal characters */

void puts(const char *str)

{

	int len = 0;

	while (str[len] != 0)

		len++;

	write(str, len);

}

/** Print hexadecimal digits

 *

 * Print fixed count of hexadecimal digits from

 * the number num. The digits are printed in

 * natural left-to-right order starting with

 * the width-th digit.

 *

 * @param num   Number containing digits.

 * @param width Count of digits to print.

 *

 */

static void print_fixed_hex(const __u64 num, const int width)

{

	int i;

	for (i = width * 8 - 4; i >= 0; i -= 4)

	    write(digits + ((num >> i) & 0xf), 1);

}

/** Print number in given base

 *

 * Print significant digits of a number in given

 * base.

 *

 * @param num  Number to print.

 * @param base Base to print the number in (should

 *             be in range 2 .. 16).

 *

 */

static void print_number(const __native num, const unsigned int base)

{

	int val = num;

	char d[sizeof(__native) * 8 + 1];		/* this is good enough even for base == 2 */

	int i = sizeof(__native) * 8 - 1;

	do {

		d[i--] = digits[val % base];

	} while (val /= base);

	d[sizeof(__native) * 8] = 0;	

	puts(&d[i + 1]);

}

/** General formatted text print

 *

 * Print text formatted according the fmt parameter

 * and variant arguments. Each formatting directive

 * begins with \% (percentage) character and one of the

 * following character:

 *

 * \%    Prints the percentage character.

 *

 * s    The next variant argument is treated as char*

 *      and printed as a NULL terminated string.

 *

 * c    The next variant argument is treated as a single char.

 *

 * p    The next variant argument is treated as a maximum

 *      bit-width integer with respect to architecture

 *      and printed in full hexadecimal width.

 *

 * P    As with 'p', but '0x' is prefixed.

 *

 * q    The next variant argument is treated as a 64b integer

 *      and printed in full hexadecimal width.

 *

 * Q    As with 'q', but '0x' is prefixed.

 *

 * l    The next variant argument is treated as a 32b integer

 *      and printed in full hexadecimal width.

 *

 * L    As with 'l', but '0x' is prefixed.

 *

 * w    The next variant argument is treated as a 16b integer

 *      and printed in full hexadecimal width.

 *

 * W    As with 'w', but '0x' is prefixed.

 *

 * b    The next variant argument is treated as a 8b integer

 *      and printed in full hexadecimal width.

 *

 * B    As with 'b', but '0x' is prefixed.

 *

 * d    The next variant argument is treated as integer

 *      and printed in standard decimal format (only significant

 *      digits).

 *

 * x    The next variant argument is treated as integer

 *      and printed in standard hexadecimal format (only significant

 *      digits).

 *

 * X    As with 'x', but '0x' is prefixed.

 *

 * All other characters from fmt except the formatting directives

 * are printed in verbatim.

 *

 * @param fmt Formatting NULL terminated string.

 */

void printf(const char *fmt, ...)

{

	int i = 0;

	va_list ap;

	char c;	

	va_start(ap, fmt);

	while ((c = fmt[i++])) {

		switch (c) {

			/* control character */

			case '%':

				switch (c = fmt[i++]) {

					/* percentile itself */

					case '%':

						break;

					/*

					 * String and character conversions.

					 */

					case 's':

						puts(va_arg(ap, char_ptr));

						goto loop;

					case 'c':

						c = (char) va_arg(ap, int);

						break;

					/*

					 * Hexadecimal conversions with fixed width.

					 */

					case 'P': 

						puts("0x");

					case 'p':

						print_fixed_hex(va_arg(ap, __native), sizeof(__native));

						goto loop;

					case 'Q':

						puts("0x");

					case 'q':

						print_fixed_hex(va_arg(ap, __u64), INT64);

						goto loop;

					case 'L': 

						puts("0x");

					case 'l':

						print_fixed_hex(va_arg(ap, __native), INT32);

						goto loop;

					case 'W':

						puts("0x");

					case 'w':

						print_fixed_hex(va_arg(ap, __native), INT16);

						goto loop;

					case 'B':

						puts("0x");

					case 'b':

						print_fixed_hex(va_arg(ap, __native), INT8);

						goto loop;

					/*

					 * Decimal and hexadecimal conversions.

					 */

					case 'd':

						print_number(va_arg(ap, __native), 10);

						goto loop;

					case 'X':

						puts("0x");

					case 'x':

						print_number(va_arg(ap, __native), 16);

						goto loop;

					/*

					 * Bad formatting.

					 */

					default:

						goto out;

			}

			default:

				write(&c, 1);

		}

loop:

		;

	}

out:

	va_end(ap);

}