/* File : barebones/ee_printf.c
    This file contains an implementation of ee_printf that only 
  requires a method to output a char to a UART without pulling in library code.

This code is based on a file that contains the following:
 Copyright (C) 2002 Michael Ringgaard. All rights reserved.

 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. Neither the name of the project 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.

*/

#include <stddef.h>
#include <stdarg.h>
#include <debug.h>
#include <stdint.h>

#define ZEROPAD     (1<<0)  /* Pad with zero */
#define SIGN        (1<<1)  /* Unsigned/signed long */
#define PLUS        (1<<2)  /* Show plus */
#define SPACE       (1<<3)  /* Spacer */
#define LEFT        (1<<4)  /* Left justified */
#define HEX_PREP    (1<<5)  /* 0x */
#define UPPERCASE   (1<<6)  /* 'ABCDEF' */

#define is_digit(c) ((c) >= '0' && (c) <= '9')

const char lower_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
const char upper_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

/**
 * Determines the length of a string, scanning at most max characters.
 */
size_t strnlen(const char *s, size_t max)
{
    size_t n = 0;

    while(*s) {
        ++n;
        ++s;

        if(n == max)
            return n;
    }

    return n;
}


/**
 * Determines the length of a string.
 */
size_t strlen(const char *s)
{
    return strnlen(s, SIZE_MAX);
}


static int ee_skip_atoi(const char **s)
{
  int i = 0;
  while (is_digit(**s)) i = i*10 + *((*s)++) - '0';
  return i;
}

static char *ee_number(char *str, long num, int base, int size, int precision, int type)
{
  char c, sign, tmp[66];

  const char *dig = lower_digits;
  int i;

  if (type & UPPERCASE)  dig = upper_digits;
  if (type & LEFT) type &= ~ZEROPAD;
  if (base < 2 || base > 36) return 0;

  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 & HEX_PREP)
  {
    if (base == 16)
      size -= 2;
    else if (base == 8)
      size--;
  }

  i = 0;

  if (num == 0)
    tmp[i++] = '0';
  else
  {
    while (num != 0)
    {
      tmp[i++] = dig[((unsigned long) num) % (unsigned) base];
      num = ((unsigned long) num) / (unsigned) base;
    }
  }

  if (i > precision) precision = i;
  size -= precision;
  if (!(type & (ZEROPAD | LEFT))) while (size-- > 0) *str++ = ' ';
  if (sign) *str++ = sign;
  
  if (type & HEX_PREP)
  {
    if (base == 8)
      *str++ = '0';
    else if (base == 16)
    {
      *str++ = '0';
      *str++ = lower_digits[33];
    }
  }

  if (!(type & LEFT)) while (size-- > 0) *str++ = c;
  while (i < precision--) *str++ = '0';
  while (i-- > 0) *str++ = tmp[i];
  while (size-- > 0) *str++ = ' ';

  return str;
}

static char *eaddr(char *str, unsigned char *addr, int size, int precision, int type)
{
  char tmp[24];
  const char *dig = lower_digits;
  int i, len;

  (void)precision;

  if (type & UPPERCASE)  dig = upper_digits;
  len = 0;
  for (i = 0; i < 6; i++)
  {
    if (i != 0) tmp[len++] = ':';
    tmp[len++] = dig[addr[i] >> 4];
    tmp[len++] = dig[addr[i] & 0x0F];
  }

  if (!(type & LEFT)) while (len < size--) *str++ = ' ';
  for (i = 0; i < len; ++i) *str++ = tmp[i];
  while (len < size--) *str++ = ' ';

  return str;
}

static char *iaddr(char *str, unsigned char *addr, int size, int precision, int type)
{
  char tmp[24];
  int i, n, len;

  (void)precision;

  len = 0;
  for (i = 0; i < 4; i++)
  {
    if (i != 0) tmp[len++] = '.';
    n = addr[i];
    
    if (n == 0)
      tmp[len++] = lower_digits[0];
    else
    {
      if (n >= 100) 
      {
        tmp[len++] = lower_digits[n / 100];
        n = n % 100;
        tmp[len++] = lower_digits[n / 10];
        n = n % 10;
      }
      else if (n >= 10) 
      {
        tmp[len++] = lower_digits[n / 10];
        n = n % 10;
      }

      tmp[len++] = lower_digits[n];
    }
  }

  if (!(type & LEFT)) while (len < size--) *str++ = ' ';
  for (i = 0; i < len; ++i) *str++ = tmp[i];
  while (len < size--) *str++ = ' ';

  return str;
}

#ifdef HAS_FLOAT

char *ecvtbuf(double arg, int ndigits, int *decpt, int *sign, char *buf);
char *fcvtbuf(double arg, int ndigits, int *decpt, int *sign, char *buf);
static void ee_bufcpy(char *d, char *s, int count); 
 
void ee_bufcpy(char *pd, char *ps, int count) {
    char *pe=ps+count;
    while (ps!=pe)
        *pd++=*ps++;
}

static void parse_float(double value, char *buffer, char fmt, int precision)
{
  int decpt, sign, exp, pos;
  char *fdigits = NULL;
  char cvtbuf[80];
  int capexp = 0;
  int magnitude;

  if (fmt == 'G' || fmt == 'E')
  {
    capexp = 1;
    fmt += 'a' - 'A';
  }

  if (fmt == 'g')
  {
    fdigits = ecvtbuf(value, precision, &decpt, &sign, cvtbuf);
    magnitude = decpt - 1;
    if (magnitude < -4  ||  magnitude > precision - 1)
    {
      fmt = 'e';
      precision -= 1;
    }
    else
    {
      fmt = 'f';
      precision -= decpt;
    }
  }

  if (fmt == 'e')
  {
    fdigits = ecvtbuf(value, precision + 1, &decpt, &sign, cvtbuf);

    if (sign) *buffer++ = '-';
    *buffer++ = *fdigits;
    if (precision > 0) *buffer++ = '.';
    ee_bufcpy(buffer, fdigits + 1, precision);
    buffer += precision;
    *buffer++ = capexp ? 'E' : 'e';

    if (decpt == 0)
    {
      if (value == 0.0)
        exp = 0;
      else
        exp = -1;
    }
    else
      exp = decpt - 1;

    if (exp < 0)
    {
      *buffer++ = '-';
      exp = -exp;
    }
    else
      *buffer++ = '+';

    buffer[2] = (exp % 10) + '0';
    exp = exp / 10;
    buffer[1] = (exp % 10) + '0';
    exp = exp / 10;
    buffer[0] = (exp % 10) + '0';
    buffer += 3;
  }
  else if (fmt == 'f')
  {
    fdigits = fcvtbuf(value, precision, &decpt, &sign, cvtbuf);
    if (sign) *buffer++ = '-';
    if (*fdigits)
    {
      if (decpt <= 0)
      {
        *buffer++ = '0';
        *buffer++ = '.';
        for (pos = 0; pos < -decpt; pos++) *buffer++ = '0';
        while (*fdigits) *buffer++ = *fdigits++;
      }
      else
      {
        pos = 0;
        while (*fdigits)
        {
          if (pos++ == decpt) *buffer++ = '.';
          *buffer++ = *fdigits++;
        }
      }
    }
    else
    {
      *buffer++ = '0';
      if (precision > 0)
      {
        *buffer++ = '.';
        for (pos = 0; pos < precision; pos++) *buffer++ = '0';
      }
    }
  }

  *buffer = '\0';
}

static void decimal_point(char *buffer)
{
  while (*buffer)
  {
    if (*buffer == '.') return;
    if (*buffer == 'e' || *buffer == 'E') break;
    buffer++;
  }

  if (*buffer)
  {
    int n = strnlen(buffer,256);
    while (n > 0) 
    {
      buffer[n + 1] = buffer[n];
      n--;
    }

    *buffer = '.';
  }
  else
  {
    *buffer++ = '.';
    *buffer = '\0';
  }
}

static void cropzeros(char *buffer)
{
  char *stop;

  while (*buffer && *buffer != '.') buffer++;
  if (*buffer++)
  {
    while (*buffer && *buffer != 'e' && *buffer != 'E') buffer++;
    stop = buffer--;
    while (*buffer == '0') buffer--;
    if (*buffer == '.') buffer--;
    while (buffer!=stop)
        *++buffer=0;
  }
}

static char *flt(char *str, double num, int size, int precision, char fmt, int flags)
{
  char tmp[80];
  char c, sign;
  int n, i;

  // Left align means no zero padding
  if (flags & LEFT) flags &= ~ZEROPAD;

  // Determine padding and sign char
  c = (flags & ZEROPAD) ? '0' : ' ';
  sign = 0;
  if (flags & SIGN)
  {
    if (num < 0.0)
    {
      sign = '-';
      num = -num;
      size--;
    }
    else if (flags & PLUS)
    {
      sign = '+';
      size--;
    }
    else if (flags & SPACE)
    {
      sign = ' ';
      size--;
    }
  }

  // Compute the precision value
  if (precision < 0)
    precision = 6; // Default precision: 6

  // Convert floating point number to text
  parse_float(num, tmp, fmt, precision);

  if ((flags & HEX_PREP) && precision == 0) decimal_point(tmp);
  if (fmt == 'g' && !(flags & HEX_PREP)) cropzeros(tmp);

  n = strnlen(tmp,256);

  // Output number with alignment and padding
  size -= n;
  if (!(flags & (ZEROPAD | LEFT))) while (size-- > 0) *str++ = ' ';
  if (sign) *str++ = sign;
  if (!(flags & LEFT)) while (size-- > 0) *str++ = c;
  for (i = 0; i < n; i++) *str++ = tmp[i];
  while (size-- > 0) *str++ = ' ';

  return str;
}

#endif

static int ee_vsprintf(char *buf, const char *fmt, va_list args)
{
  int len;
  unsigned long num;
  int i, base;
  char *str;
  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

  for (str = buf; *fmt; fmt++)
  {
    if (*fmt != '%')
    {
      *str++ = *fmt;
      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 |= HEX_PREP; goto repeat;
      case '0': flags |= ZEROPAD; goto repeat;
    }

    // Get field width
    field_width = -1;
    if (is_digit(*fmt))
      field_width = ee_skip_atoi(&fmt);
    else if (*fmt == '*')
    {
      fmt++;
      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 (is_digit(*fmt))
        precision = ee_skip_atoi(&fmt);
      else if (*fmt == '*')
      {
        ++fmt;
        precision = va_arg(args, int);
      }
      if (precision < 0) precision = 0;
    }

    // Get the conversion qualifier
    qualifier = -1;
    if (*fmt == 'l' || *fmt == 'L')
    {
      qualifier = *fmt;
      fmt++;
    }

    // Default base
    base = 10;

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

      case 's':
        s = va_arg(args, char *);
        if (!s) s = "<NULL>";
        len = strnlen(s, precision);

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

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

      case 'A':
        flags |= UPPERCASE;

      case 'a':
        if (qualifier == 'l')
          str = eaddr(str, va_arg(args, unsigned char *), field_width, precision, flags);
        else
          str = iaddr(str, va_arg(args, unsigned char *), field_width, precision, flags);
        continue;

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

      case 'X':
        flags |= UPPERCASE;

      case 'x':
        base = 16;
        break;

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

      case 'u':
        break;

#ifdef HAS_FLOAT

      case 'f':
        str = flt(str, va_arg(args, double), field_width, precision, *fmt, flags | SIGN);
        continue;

#endif

      default:
        if (*fmt != '%') *str++ = '%';
        if (*fmt)
          *str++ = *fmt;
        else
          --fmt;
        continue;
    }

    if (qualifier == 'l')
      num = va_arg(args, unsigned long);
    else if (flags & SIGN)
      num = va_arg(args, int);
    else
      num = va_arg(args, unsigned int);

    str = ee_number(str, num, base, field_width, precision, flags);
  }

  *str = '\0';
  return str - buf;
}


int vprintf(const char *fmt, va_list args)
{
  char buf[1024], *p;
  int n=0;

  ee_vsprintf(buf, fmt, args);
  p=buf;

  debug_puts(p);
  while (*p) {
    n++;
	p++;
  }

  return n;
}




int printf(const char *fmt, ...)
{
  va_list args;
  int n=0;

  va_start(args, fmt);
  n = vprintf(fmt, args);
  va_end(args);

  return n;
}


