/*
 ****************************************************************************
 * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
 ****************************************************************************
 *
 *        File: printf.c
 *      Author: Rolf Neugebauer (neugebar@dcs.gla.ac.uk)
 *     Changes: Grzegorz Milos (gm281@cam.ac.uk)
 *
 *        Date: Aug 2003, Aug 2005
 *
 * Environment: Xen Minimal OS
 * Description: Library functions for printing
 *              (freebsd port, mainly sys/subr_prf.c)
 *
 ****************************************************************************
 *
 *-
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 * $FreeBSD: src/sys/libkern/divdi3.c,v 1.6 1999/08/28 00:46:31 peter Exp $
 */

#include "ctype.h"
#include "kernel.h"
#include "limits.h"

#include "util/debug.h"
#include "util/string.h"

/**
 * simple_strtoul - convert a string to an unsigned long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
{
    unsigned long result = 0, value;

    if (!base)
    {
        base = 10;
        if (*cp == '0')
        {
            base = 8;
            cp++;
            if ((*cp == 'x') && isxdigit(cp[1]))
            {
                cp++;
                base = 16;
            }
        }
    }
    while (isxdigit(*cp) &&
           (value = isdigit(*cp) ? *cp - '0' : toupper(*cp) - 'A' + 10) <
               base)
    {
        result = result * base + value;
        cp++;
    }
    if (endp)
    {
        *endp = (char *)cp;
    }
    return result;
}

/**
 * simple_strtol - convert a string to a signed long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
long simple_strtol(const char *cp, char **endp, unsigned int base)
{
    if (*cp == '-')
    {
        return -simple_strtoul(cp + 1, endp, base);
    }
    return simple_strtoul(cp, endp, base);
}

/**
 * simple_strtoull - convert a string to an unsigned long long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
unsigned long long simple_strtoull(const char *cp, char **endp,
                                   unsigned int base)
{
    unsigned long long result = 0, value;

    if (!base)
    {
        base = 10;
        if (*cp == '0')
        {
            base = 8;
            cp++;
            if ((*cp == 'x') && isxdigit(cp[1]))
            {
                cp++;
                base = 16;
            }
        }
    }
    while (isxdigit(*cp) &&
           (value = isdigit(*cp) ? *cp - '0'
                                 : (islower(*cp) ? toupper(*cp) : *cp) - 'A' +
                                       10) < base)
    {
        result = result * base + value;
        cp++;
    }
    if (endp)
    {
        *endp = (char *)cp;
    }
    return result;
}

/**
 * simple_strtoll - convert a string to a signed long long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
long long simple_strtoll(const char *cp, char **endp, unsigned int base)
{
    if (*cp == '-')
    {
        return -simple_strtoull(cp + 1, endp, base);
    }
    return simple_strtoull(cp, endp, base);
}

static int skip_atoi(const char **s)
{
    int i = 0;

    while (isdigit(**s))
        i = i * 10 + *((*s)++) - '0';
    return i;
}

#define ZEROPAD 1  /* pad with zero */
#define SIGN 2     /* unsigned/signed long */
#define PLUS 4     /* show plus */
#define SPACE 8    /* space if plus */
#define LEFT 16    /* left justified */
#define SPECIAL 32 /* 0x */
#define LARGE 64   /* use 'ABCDEF' instead of 'abcdef' */

static char *number(char *buf, char *end, long long num, int base, int size,
                    int precision, int type)
{
    char c, sign, tmp[66];
    const char *digits;
    const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
    const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    int i;

    digits = (type & LARGE) ? large_digits : small_digits;
    if (type & LEFT)
    {
        type &= ~ZEROPAD;
    }
    if (base < 2 || base > 36)
    {
        return buf;
    }
    c = (type & ZEROPAD) ? '0' : ' ';
    sign = 0;
    if (type & SIGN)
    {
        if (num < 0)
        {
            sign = '-';
            num = -num;
            size--;
        }
        else if (type & PLUS)
        {
            sign = '+';
            size--;
        }
        else if (type & SPACE)
        {
            sign = ' ';
            size--;
        }
    }
    if (type & SPECIAL)
    {
        if (base == 16)
        {
            size -= 2;
        }
        else if (base == 8)
        {
            size--;
        }
    }
    i = 0;
    if (num == 0)
    {
        tmp[i++] = '0';
    }
    else
    {
        /* XXX KAF: force unsigned mod and div. */
        /* XXX kernel does not support long long division */
        unsigned long long num2 = (unsigned long long)num;
        unsigned int base2 = (unsigned int)base;
        while (num2 != 0)
        {
            tmp[i++] = digits[num2 % base2];
            num2 /= base2;
        }
    }
    if (i > precision)
    {
        precision = i;
    }
    size -= precision;
    if (!(type & (ZEROPAD + LEFT)))
    {
        while (size-- > 0)
        {
            if (buf <= end)
            {
                *buf = ' ';
            }
            ++buf;
        }
    }
    if (sign)
    {
        if (buf <= end)
        {
            *buf = sign;
        }
        ++buf;
    }
    if (type & SPECIAL)
    {
        if (base == 8)
        {
            if (buf <= end)
            {
                *buf = '0';
            }
            ++buf;
        }
        else if (base == 16)
        {
            if (buf <= end)
            {
                *buf = '0';
            }
            ++buf;
            if (buf <= end)
            {
                *buf = digits[33];
            }
            ++buf;
        }
    }
    if (!(type & LEFT))
    {
        while (size-- > 0)
        {
            if (buf <= end)
            {
                *buf = c;
            }
            ++buf;
        }
    }
    while (i < precision--)
    {
        if (buf <= end)
        {
            *buf = '0';
        }
        ++buf;
    }
    while (i-- > 0)
    {
        if (buf <= end)
        {
            *buf = tmp[i];
        }
        ++buf;
    }
    while (size-- > 0)
    {
        if (buf <= end)
        {
            *buf = ' ';
        }
        ++buf;
    }
    return buf;
}

/**
 * vsnprintf - Format a string and place it in a buffer
 * @buf: The buffer to place the result into
 * @size: The size of the buffer, including the trailing null space
 * @fmt: The format string to use
 * @args: Arguments for the format string
 *
 * Call this function if you are already dealing with a va_list.
 * You probably want snprintf instead.
 */
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
    int len;
    unsigned long long num;
    int i, base;
    char *str, *end, c;
    const char *s;

    int flags; /* flags to number() */

    int field_width; /* width of output field */
    int precision;   /* min. # of digits for integers; max
                                   number of chars for from string */
    int qualifier;   /* 'h', 'l', or 'L' for integer fields */
    /* 'z' support added 23/7/1999 S.H.    */
    /* 'z' changed to 'Z' --davidm 1/25/99 */

    str = buf;
    end = buf + size - 1;

    if (end < buf - 1)
    {
        end = ((void *)-1);
        size = end - buf + 1;
    }

    for (; *fmt; ++fmt)
    {
        if (*fmt != '%')
        {
            if (str <= end)
            {
                *str = *fmt;
            }
            ++str;
            continue;
        }

        /* process flags */
        flags = 0;
    repeat:
        ++fmt; /* this also skips first '%' */
        switch (*fmt)
        {
        case '-':
            flags |= LEFT;
            goto repeat;
        case '+':
            flags |= PLUS;
            goto repeat;
        case ' ':
            flags |= SPACE;
            goto repeat;
        case '#':
            flags |= SPECIAL;
            goto repeat;
        case '0':
            flags |= ZEROPAD;
            goto repeat;
        }

        /* get field width */
        field_width = -1;
        if (isdigit(*fmt))
        {
            field_width = skip_atoi(&fmt);
        }
        else if (*fmt == '*')
        {
            ++fmt;
            /* it's the next argument */
            field_width = va_arg(args, int);
            if (field_width < 0)
            {
                field_width = -field_width;
                flags |= LEFT;
            }
        }

        /* get the precision */
        precision = -1;
        if (*fmt == '.')
        {
            ++fmt;
            if (isdigit(*fmt))
            {
                precision = skip_atoi(&fmt);
            }
            else if (*fmt == '*')
            {
                ++fmt;
                /* it's the next argument */
                precision = va_arg(args, int);
            }
            if (precision < 0)
            {
                precision = 0;
            }
        }

        /* get the conversion qualifier */
        qualifier = -1;
        if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || *fmt == 'Z')
        {
            qualifier = *fmt;
            ++fmt;
            if (qualifier == 'l' && *fmt == 'l')
            {
                qualifier = 'L';
                ++fmt;
            }
        }
        if (*fmt == 'q')
        {
            qualifier = 'L';
            ++fmt;
        }

        /* default base */
        base = 10;

        switch (*fmt)
        {
        case 'c':
            if (!(flags & LEFT))
            {
                while (--field_width > 0)
                {
                    if (str <= end)
                    {
                        *str = ' ';
                    }
                    ++str;
                }
            }
            c = (unsigned char)va_arg(args, int);
            if (str <= end)
            {
                *str = c;
            }
            ++str;
            while (--field_width > 0)
            {
                if (str <= end)
                {
                    *str = ' ';
                }
                ++str;
            }
            continue;

        case 's':
            s = va_arg(args, char *);
            if (!s)
            {
                s = "<NULL>";
            }

            len = strnlen(s, precision);

            if (!(flags & LEFT))
            {
                while (len < field_width--)
                {
                    if (str <= end)
                    {
                        *str = ' ';
                    }
                    ++str;
                }
            }
            for (i = 0; i < len; ++i)
            {
                if (str <= end)
                {
                    *str = *s;
                }
                ++str;
                ++s;
            }
            while (len < field_width--)
            {
                if (str <= end)
                {
                    *str = ' ';
                }
                ++str;
            }
            continue;

        case 'p':
            if (field_width == -1)
            {
                field_width = 2 * sizeof(void *);
                flags |= ZEROPAD;
            }
            str = number(str, end, (unsigned long)va_arg(args, void *), 16,
                         field_width, precision, flags);
            continue;

        case 'n':
            /* FIXME:
                 * What does C99 say about the overflow case here? */
            if (qualifier == 'l')
            {
                long *ip = va_arg(args, long *);
                *ip = (str - buf);
            }
            else if (qualifier == 'Z')
            {
                size_t *ip = va_arg(args, size_t *);
                *ip = (str - buf);
            }
            else
            {
                int *ip = va_arg(args, int *);
                *ip = (str - buf);
            }
            continue;

        case '%':
            if (str <= end)
            {
                *str = '%';
            }
            ++str;
            continue;

            /* integer number formats - set up the flags and "break" */
        case 'o':
            base = 8;
            break;

        case 'X':
            flags |= LARGE;
            base = 16;
            break;
        case 'x':
            base = 16;
            break;

        case 'd':
        case 'i':
            flags |= SIGN;
        case 'u':
            break;

        default:
            if (str <= end)
            {
                *str = '%';
            }
            ++str;
            if (*fmt)
            {
                if (str <= end)
                {
                    *str = *fmt;
                }
                ++str;
            }
            else
            {
                --fmt;
            }
            continue;
        }
        if (qualifier == 'L')
        {
            num = va_arg(args, long long);
        }
        else if (qualifier == 'l')
        {
            num = va_arg(args, unsigned long);
            if (flags & SIGN)
            {
                num = (signed long)num;
            }
        }
        else if (qualifier == 'Z')
        {
            num = va_arg(args, size_t);
        }
        else if (qualifier == 'h')
        {
            num = (unsigned short)va_arg(args, int);
            if (flags & SIGN)
            {
                num = (signed short)num;
            }
        }
        else
        {
            num = va_arg(args, unsigned int);
            if (flags & SIGN)
            {
                num = (signed int)num;
            }
        }

        str = number(str, end, num, base, field_width, precision, flags);
    }
    if (str <= end)
    {
        *str = '\0';
    }
    else if (size > 0)
    {
        /* don't write out a null byte if the buf size is zero */
        *end = '\0';
    }
    /* the trailing null byte doesn't count towards the total
     * ++str;
     */
    return str - buf;
}

/**
 * snprintf - Format a string and place it in a buffer
 * @buf: The buffer to place the result into
 * @size: The size of the buffer, including the trailing null space
 * @fmt: The format string to use
 * @...: Arguments for the format string
 */
int snprintf(char *buf, size_t size, const char *fmt, ...)
{
    va_list args;
    int i;

    va_start(args, fmt);
    i = vsnprintf(buf, size, fmt, args);
    va_end(args);
    return i;
}

size_t iprintf(char **str, size_t *size, char *fmt, ...)
{
    va_list args;
    int len;

    va_start(args, fmt);
    len = vsnprintf(*str, *size, fmt, args);
    va_end(args);

    /* The way the "iprintf system" works, we're never going to catch
     * an error anywhere else. The size of the buffer will appear to have
     * increased, and it will appear to start farther to the left -> bad!
     * (However, kernel vsnprintf should never fail...) */
    KASSERT(len >= 0);

    len = MIN(len, (int)(*size - 1));

    *str += len;
    *size -= len;

    return *size - 1;
}

/**
 * vsscanf - Unformat a buffer into a list of arguments
 * @buf:        input buffer
 * @fmt:        format of buffer
 * @args:       arguments
 */
int vsscanf(const char *buf, const char *fmt, va_list args)
{
    const char *str = buf;
    char *next;
    char digit;
    int num = 0;
    int qualifier;
    int base;
    int field_width;
    int is_sign = 0;

    while (*fmt && *str)
    {
        /* skip any white space in format */
        /* white space in format matchs any amount of
         * white space, including none, in the input.
         */
        if (isspace(*fmt))
        {
            while (isspace(*fmt))
                ++fmt;
            while (isspace(*str))
                ++str;
        }

        /* anything that is not a conversion must match exactly */
        if (*fmt != '%' && *fmt)
        {
            if (*fmt++ != *str++)
            {
                break;
            }
            continue;
        }

        if (!*fmt)
        {
            break;
        }
        ++fmt;

        /* skip this conversion.
         * advance both strings to next white space
         */
        if (*fmt == '*')
        {
            while (!isspace(*fmt) && *fmt)
                fmt++;
            while (!isspace(*str) && *str)
                str++;
            continue;
        }

        /* get field width */
        field_width = -1;
        if (isdigit(*fmt))
        {
            field_width = skip_atoi(&fmt);
        }

        /* get conversion qualifier */
        qualifier = -1;
        if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || *fmt == 'Z' ||
            *fmt == 'z')
        {
            qualifier = *fmt++;
            if (qualifier == *fmt)
            {
                if (qualifier == 'h')
                {
                    qualifier = 'H';
                    fmt++;
                }
                else if (qualifier == 'l')
                {
                    qualifier = 'L';
                    fmt++;
                }
            }
        }
        base = 10;
        is_sign = 0;

        if (!*fmt || !*str)
        {
            break;
        }

        switch (*fmt++)
        {
        case 'c':
        {
            char *s = (char *)va_arg(args, char *);
            if (field_width == -1)
            {
                field_width = 1;
            }
            do
            {
                *s++ = *str++;
            } while (--field_width > 0 && *str);
            num++;
        }
            continue;
        case 's':
        {
            char *s = (char *)va_arg(args, char *);
            if (field_width == -1)
            {
                field_width = INT_MAX;
            }
            /* first, skip leading white space in buffer */
            while (isspace(*str))
                str++;

            /* now copy until next white space */
            while (*str && !isspace(*str) && field_width--)
            {
                *s++ = *str++;
            }
            *s = '\0';
            num++;
        }
            continue;
        case 'n':
            /* return number of characters read so far */
            {
                int *i = (int *)va_arg(args, int *);
                *i = str - buf;
            }
            continue;
        case 'o':
            base = 8;
            break;
        case 'x':
        case 'X':
            base = 16;
            break;
        case 'i':
            base = 0;
            is_sign = 1;
            break;
        case 'd':
            is_sign = 1;
            break;
        case 'u':
            break;
        case '%':
            /* looking for '%' in str */
            if (*str++ != '%')
            {
                return num;
            }
            continue;
        default:
            /* invalid format; stop here */
            return num;
        }

        /* have some sort of integer conversion.
         * first, skip white space in buffer.
         */
        while (isspace(*str))
            str++;

        digit = *str;
        if (is_sign && digit == '-')
        {
            digit = *(str + 1);
        }

        if (!digit || (base == 16 && !isxdigit(digit)) ||
            (base == 10 && !isdigit(digit)) ||
            (base == 8 && (!isdigit(digit) || digit > '7')) ||
            (base == 0 && !isdigit(digit)))
        {
            break;
        }

        switch (qualifier)
        {
        case 'H': /* that's 'hh' in format */
            if (is_sign)
            {
                signed char *s = (signed char *)va_arg(args, signed char *);
                *s = (signed char)simple_strtol(str, &next, base);
            }
            else
            {
                unsigned char *s =
                    (unsigned char *)va_arg(args, unsigned char *);
                *s = (unsigned char)simple_strtoul(str, &next, base);
            }
            break;
        case 'h':
            if (is_sign)
            {
                short *s = (short *)va_arg(args, short *);
                *s = (short)simple_strtol(str, &next, base);
            }
            else
            {
                unsigned short *s =
                    (unsigned short *)va_arg(args, unsigned short *);
                *s = (unsigned short)simple_strtoul(str, &next, base);
            }
            break;
        case 'l':
            if (is_sign)
            {
                long *l = (long *)va_arg(args, long *);
                *l = simple_strtol(str, &next, base);
            }
            else
            {
                unsigned long *l =
                    (unsigned long *)va_arg(args, unsigned long *);
                *l = simple_strtoul(str, &next, base);
            }
            break;
        case 'L':
            if (is_sign)
            {
                long long *l = (long long *)va_arg(args, long long *);
                *l = simple_strtoll(str, &next, base);
            }
            else
            {
                unsigned long long *l = (unsigned long long *)va_arg(
                    args, unsigned long long *);
                *l = simple_strtoull(str, &next, base);
            }
            break;
        case 'Z':
        case 'z':
        {
            size_t *s = (size_t *)va_arg(args, size_t *);
            *s = (size_t)simple_strtoul(str, &next, base);
        }
        break;
        default:
            if (is_sign)
            {
                int *i = (int *)va_arg(args, int *);
                *i = (int)simple_strtol(str, &next, base);
            }
            else
            {
                unsigned int *i =
                    (unsigned int *)va_arg(args, unsigned int *);
                *i = (unsigned int)simple_strtoul(str, &next, base);
            }
            break;
        }
        num++;

        if (!next)
        {
            break;
        }
        str = next;
    }
    return num;
}

/**
 * sscanf - Unformat a buffer into a list of arguments
 * @buf:        input buffer
 * @fmt:        formatting of buffer
 * @...:        resulting arguments
 */
int sscanf(const char *buf, const char *fmt, ...)
{
    va_list args;
    int i;

    va_start(args, fmt);
    i = vsscanf(buf, fmt, args);
    va_end(args);
    return i;
}