/*
 * snprintf.c - a portable implementation of snprintf and vsnprintf
 *
 */
/*
 * Portions Copyright (C) 2000-2026 The Xastir Group
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
  #include "config.h"
#endif  // HAVE_CONFIG_H

#include "snprintf.h"


/*
 * Copyright Patrick Powell 1995
 * This code is based on code written by Patrick Powell (papowell@astart.com)
 * It may be used for any purpose as long as this notice remains intact
 * on all source code distributions
 */

/**************************************************************
 * Original:
 * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
 * A bombproof version of doprnt (dopr) included.
 * Sigh.  This sort of thing is always nasty do deal with.  Note that
 * the version here does not include floating point...
 *
 * snprintf() is used instead of sprintf() as it does limit checks
 * for string length.  This covers a nasty loophole.
 *
 * The other functions are there to prevent NULL pointers from
 * causing nast effects.
 *
 * More Recently:
 *  Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
 *  This was ugly.  It is still ugly.  I opted out of floating point
 *  numbers, but the formatter understands just about everything
 *  from the normal C string format, at least as far as I can tell from
 *  the Solaris 2.5 printf(3S) man page.
 *
 *  Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
 *    Ok, added some minimal floating point support, which means this
 *    probably requires libm on most operating systems.  Don't yet
 *    support the exponent (e,E) and sigfig (g,G).  Also, fmtint()
 *    was pretty badly broken, it just wasn't being exercised in ways
 *    which showed it, so that's been fixed.  Also, formated the code
 *    to mutt conventions, and removed dead code left over from the
 *    original.  Also, there is now a builtin-test, just compile with:
 *           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
 *    and run snprintf for results.
 *
 *  Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
 *    The PGP code was using unsigned hexadecimal formats.
 *    Unfortunately, unsigned formats simply didn't work.
 *
 *  Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
 *    The original code assumed that both snprintf() and vsnprintf() were
 *    missing.  Some systems only have snprintf() but not vsnprintf(), so
 *    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
 *
 *  Andrew Tridgell (tridge@samba.org) Oct 1998
 *    fixed handling of %.0f
 *    added test for HAVE_LONG_DOUBLE
 *
 *
 **************************************************************/

#include <string.h>
#include <ctype.h>
#include <sys/types.h>

#ifndef HAVE_VSNPRINTF

/* varargs declarations: */

#if defined(__STDC__)
  #ifdef HAVE_STDARG_H
    #include <stdarg.h>
  #else // HAVE_STDARG_H
    #ifdef HAVE_STD_ARGS_H
      #include <std_args.h>
    #endif  // HAVE_STD_ARGS_H
  #endif    // HAVE_STDARG_H
  #include <stdarg.h>
  #define HAVE_STDARGS  /* let's hope that works everywhere (mj) */
  #define VA_LOCAL_DECL va_list ap
  #define VA_START(f) va_start(ap, f)
  #define VA_SHIFT(v,t); /* no-op for ANSI */
  #define VA_END va_end(ap)
#else   // __STDC__
  #include <varargs.h>
  #undef HAVE_STDARGS
  #define VA_LOCAL_DECL va_list ap
  #define VA_START(f) va_start(ap)      /* f is ignored! */
  #define VA_SHIFT(v,t) v = va_arg(ap,t)
  #define VA_END va_end(ap)
#endif  // __STDC__


// Must be last include file
#include "leak_detection.h"



#ifdef HAVE_LONG_DOUBLE
  #define LDOUBLE long double
#else   // HAVE_LONG_DOUBLE
  #define LDOUBLE double
#endif  // HAVE_LONG_DOUBLE

static void dopr(char *buffer, size_t maxlen, const char *format, va_list args);
static void fmtstr(char *buffer, size_t * currlen, size_t maxlen, char *value,
                   int flags, int min, int max);
static void fmtint(char *buffer, size_t * currlen, size_t maxlen, long value,
                   int base, int min, int max, int flags);
static void fmtfp(char *buffer, size_t * currlen, size_t maxlen,
                  LDOUBLE fvalue, int min, int max, int flags);
static void dopr_outch(char *buffer, size_t * currlen, size_t maxlen, char c);

/*
 * dopr(): poor man's version of doprintf
 */

/* format read states */
#define DP_S_DEFAULT 0
#define DP_S_FLAGS   1
#define DP_S_MIN     2
#define DP_S_DOT     3
#define DP_S_MAX     4
#define DP_S_MOD     5
#define DP_S_CONV    6
#define DP_S_DONE    7

/* format flags - Bits */
#define DP_F_MINUS      (1 << 0)
#define DP_F_PLUS       (1 << 1)
#define DP_F_SPACE      (1 << 2)
#define DP_F_NUM        (1 << 3)
#define DP_F_ZERO       (1 << 4)
#define DP_F_UP         (1 << 5)
#define DP_F_UNSIGNED   (1 << 6)

/* Conversion Flags */
#define DP_C_SHORT   1
#define DP_C_LONG    2
#define DP_C_LDOUBLE 3

#define char_to_int(p) (p - '0')
#define MAX(p, q) ((p >= q) ? p : q)

static void dopr(char *buffer, size_t maxlen, const char *format, va_list args)
{
  char ch;
  long value;
  LDOUBLE fvalue;
  char *strvalue;
  int min;
  int max;
  int state;
  int flags;
  int cflags;
  size_t currlen;

  state = DP_S_DEFAULT;
  currlen = flags = cflags = min = 0;
  max = -1;
  ch = *format++;

  while (state != DP_S_DONE)
  {
    if ((ch == '\0') || (currlen >= maxlen))
    {
      state = DP_S_DONE;
    }

    switch (state)
    {
      case DP_S_DEFAULT:
        if (ch == '%')
        {
          state = DP_S_FLAGS;
        }
        else
        {
          dopr_outch(buffer, &currlen, maxlen, ch);
        }

        ch = *format++;
        break;
      case DP_S_FLAGS:
        switch (ch)
        {
          case '-':
            flags |= DP_F_MINUS;
            ch = *format++;
            break;
          case '+':
            flags |= DP_F_PLUS;
            ch = *format++;
            break;
          case ' ':
            flags |= DP_F_SPACE;
            ch = *format++;
            break;
          case '#':
            flags |= DP_F_NUM;
            ch = *format++;
            break;
          case '0':
            flags |= DP_F_ZERO;
            ch = *format++;
            break;
          default:
            state = DP_S_MIN;
            break;
        }
        break;
      case DP_S_MIN:
        if (isdigit(ch))
        {
          min = 10 * min + char_to_int(ch);
          ch = *format++;
        }
        else if (ch == '*')
        {
          min = va_arg(args, int);
          ch = *format++;
          state = DP_S_DOT;
        }
        else
        {
          state = DP_S_DOT;
        }

        break;
      case DP_S_DOT:
        if (ch == '.')
        {
          state = DP_S_MAX;
          ch = *format++;
        }
        else
        {
          state = DP_S_MOD;
        }

        break;
      case DP_S_MAX:
        if (isdigit(ch))
        {
          if (max < 0)
          {
            max = 0;
          }

          max = 10 * max + char_to_int(ch);
          ch = *format++;
        }
        else if (ch == '*')
        {
          max = va_arg(args, int);
          ch = *format++;
          state = DP_S_MOD;
        }
        else
        {
          state = DP_S_MOD;
        }

        break;
      case DP_S_MOD:
        /* Currently, we don't support Long Long, bummer */
        switch (ch)
        {
          case 'h':
            cflags = DP_C_SHORT;
            ch = *format++;
            break;
          case 'l':
            cflags = DP_C_LONG;
            ch = *format++;
            break;
          case 'L':
            cflags = DP_C_LDOUBLE;
            ch = *format++;
            break;
          default:
            break;
        }
        state = DP_S_CONV;
        break;
      case DP_S_CONV:
        switch (ch)
        {
          case 'd':
          case 'i':
            if (cflags == DP_C_SHORT)
            {
              value = va_arg(args, short int);
            }
            else if (cflags == DP_C_LONG)
            {
              value = va_arg(args, long int);
            }
            else
            {
              value = va_arg(args, int);
            }

            fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags);
            break;
          case 'o':
            flags |= DP_F_UNSIGNED;
            if (cflags == DP_C_SHORT)
            {
              value = va_arg(args, unsigned short int);
            }
            else if (cflags == DP_C_LONG)
            {
              value = va_arg(args, unsigned long int);
            }
            else
            {
              value = va_arg(args, unsigned int);
            }

            fmtint(buffer, &currlen, maxlen, value, 8, min, max, flags);
            break;
          case 'u':
            flags |= DP_F_UNSIGNED;
            if (cflags == DP_C_SHORT)
            {
              value = va_arg(args, unsigned short int);
            }
            else if (cflags == DP_C_LONG)
            {
              value = va_arg(args, unsigned long int);
            }
            else
            {
              value = va_arg(args, unsigned int);
            }

            fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags);
            break;
          case 'X':
            flags |= DP_F_UP;
          case 'x':
            flags |= DP_F_UNSIGNED;
            if (cflags == DP_C_SHORT)
            {
              value = va_arg(args, unsigned short int);
            }
            else if (cflags == DP_C_LONG)
            {
              value = va_arg(args, unsigned long int);
            }
            else
            {
              value = va_arg(args, unsigned int);
            }

            fmtint(buffer, &currlen, maxlen, value, 16, min, max, flags);
            break;
          case 'f':
            if (cflags == DP_C_LDOUBLE)
            {
              fvalue = va_arg(args, LDOUBLE);
            }
            else
            {
              fvalue = va_arg(args, double);
            }

            /* um, floating point? */
            fmtfp(buffer, &currlen, maxlen, fvalue, min, max, flags);
            break;
          case 'E':
            flags |= DP_F_UP;
          case 'e':
            if (cflags == DP_C_LDOUBLE)
            {
              fvalue = va_arg(args, LDOUBLE);
            }
            else
            {
              fvalue = va_arg(args, double);
            }
            break;
          case 'G':
            flags |= DP_F_UP;
          case 'g':
            if (cflags == DP_C_LDOUBLE)
            {
              fvalue = va_arg(args, LDOUBLE);
            }
            else
            {
              fvalue = va_arg(args, double);
            }

            break;
          case 'c':
            dopr_outch(buffer, &currlen, maxlen, va_arg(args, int));
            break;
          case 's':
            strvalue = va_arg(args, char *);
            if (max < 0)
            {
              max = maxlen;  /* ie, no max */
            }

            fmtstr(buffer, &currlen, maxlen, strvalue, flags, min, max);
            break;
          case 'p':
            strvalue = va_arg(args, void *);
            fmtint(buffer, &currlen, maxlen, (long) strvalue, 16, min,
                   max, flags);
            break;
          case 'n':
            if (cflags == DP_C_SHORT)
            {
              short int *num;
              num = va_arg(args, short int *);
              *num = currlen;
            }
            else if (cflags == DP_C_LONG)
            {
              long int *num;
              num = va_arg(args, long int *);
              *num = currlen;
            }
            else
            {
              int *num;
              num = va_arg(args, int *);
              *num = currlen;
            }
            break;
          case '%':
            dopr_outch(buffer, &currlen, maxlen, ch);
            break;
          case 'w':
            /* not supported yet, treat as next char */
            ch = *format++;
            break;
          default:
            /* Unknown, skip */
            break;
        }
        ch = *format++;
        state = DP_S_DEFAULT;
        flags = cflags = min = 0;
        max = -1;
        break;
      case DP_S_DONE:
        break;
      default:
        /* hmm? */
        break;  /* some picky compilers need this */
    }
  }
  if (currlen < maxlen - 1)
  {
    buffer[currlen] = '\0';
  }
  else
  {
    buffer[maxlen - 1] = '\0';
  }
}

static void fmtstr(char *buffer, size_t * currlen, size_t maxlen,
                   char *value, int flags, int min, int max)
{
  int padlen, strln; /* amount to pad */
  int cnt = 0;

  if (value == 0)
  {
    value = "<NULL>";
  }

  for (strln = 0; value[strln]; ++strln); /* strlen */
  padlen = min - strln;
  if (padlen < 0)
  {
    padlen = 0;
  }

  if (flags & DP_F_MINUS)
  {
    padlen = -padlen;  /* Left Justify */
  }

  while ((padlen > 0) && (cnt < max))
  {
    dopr_outch(buffer, currlen, maxlen, ' ');
    --padlen;
    ++cnt;
  }

  while (*value && (cnt < max))
  {
    dopr_outch(buffer, currlen, maxlen, *value++);
    ++cnt;
  }

  while ((padlen < 0) && (cnt < max))
  {
    dopr_outch(buffer, currlen, maxlen, ' ');
    ++padlen;
    ++cnt;
  }
}

/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */

static void fmtint(char *buffer, size_t * currlen, size_t maxlen,
                   long value, int base, int min, int max, int flags)
{
  int signvalue = 0;
  unsigned long uvalue;
  char convert[20];
  int place = 0;
  int spadlen = 0; /* amount to space pad */
  int zpadlen = 0; /* amount to zero pad */
  int caps = 0;

  if (max < 0)
  {
    max = 0;
  }

  uvalue = value;

  if (!(flags & DP_F_UNSIGNED))
  {
    if (value < 0)
    {
      signvalue = '-';
      uvalue = -value;
    }
    else if (flags & DP_F_PLUS)     /* Do a sign (+/i) */
    {
      signvalue = '+';
    }
    else if (flags & DP_F_SPACE)
    {
      signvalue = ' ';
    }
  }

  if (flags & DP_F_UP)
  {
    caps = 1;  /* Should characters be upper case? */
  }

  do
  {
    convert[place++] = (caps ? "0123456789ABCDEF" : "0123456789abcdef")
                       [uvalue % (unsigned) base];

    uvalue = (uvalue / (unsigned) base);
  }

  while (uvalue && (place < 20));
  if (place == 20)
  {
    place--;
  }

  convert[place] = 0;

  zpadlen = max - place;
  spadlen = min - MAX(max, place) - (signvalue ? 1 : 0);

  if (zpadlen < 0)
  {
    zpadlen = 0;
  }

  if (spadlen < 0)
  {
    spadlen = 0;
  }

  if (flags & DP_F_ZERO)
  {
    zpadlen = MAX(zpadlen, spadlen);
    spadlen = 0;
  }

  if (flags & DP_F_MINUS)
  {
    spadlen = -spadlen;  /* Left Justifty */
  }

#ifdef DEBUG_SNPRINTF
  dprint(1, (debugfile, "zpad: %d, spad: %d, min: %d, max: %d, place: %d\n",
             zpadlen, spadlen, min, max, place));
#endif  // DEBUG_SNPRINTF

  /* Spaces */
  while (spadlen > 0)
  {
    dopr_outch(buffer, currlen, maxlen, ' ');
    --spadlen;
  }

  /* Sign */
  if (signvalue)
  {
    dopr_outch(buffer, currlen, maxlen, signvalue);
  }

  /* Zeros */
  if (zpadlen > 0)
  {
    while (zpadlen > 0)
    {
      dopr_outch(buffer, currlen, maxlen, '0');
      --zpadlen;
    }
  }

  /* Digits */
  while (place > 0)
  {
    dopr_outch(buffer, currlen, maxlen, convert[--place]);
  }

  /* Left Justified spaces */
  while (spadlen < 0)
  {
    dopr_outch(buffer, currlen, maxlen, ' ');
    ++spadlen;
  }
}

static LDOUBLE abs_val(LDOUBLE value)
{
  LDOUBLE result = value;

  if (value < 0)
  {
    result = -value;
  }

  return result;
}

static LDOUBLE pow10(int exp)
{
  LDOUBLE result = 1;

  while (exp)
  {
    result *= 10;
    exp--;
  }

  return result;
}

static long round(LDOUBLE value)
{
  long intpart;

  intpart = value;
  value = value - intpart;
  if (value >= 0.5)
  {
    intpart++;
  }

  return intpart;
}

static void fmtfp(char *buffer, size_t * currlen, size_t maxlen,
                  LDOUBLE fvalue, int min, int max, int flags)
{
  int signvalue = 0;
  LDOUBLE ufvalue;
  char iconvert[20];
  char fconvert[20];
  int iplace = 0;
  int fplace = 0;
  int padlen = 0; /* amount to pad */
  int zpadlen = 0;
  int caps = 0;
  long intpart;
  long fracpart;

  /*
  * AIX manpage says the default is 0, but Solaris says the default
  * is 6, and sprintf on AIX defaults to 6
  */
  if (max < 0)
  {
    max = 6;
  }

  ufvalue = abs_val(fvalue);

  if (fvalue < 0)
  {
    signvalue = '-';
  }
  else if (flags & DP_F_PLUS) /* Do a sign (+/i) */
  {
    signvalue = '+';
  }
  else if (flags & DP_F_SPACE)
  {
    signvalue = ' ';
  }

#if 0
  if (flags & DP_F_UP)
  {
    caps = 1;  /* Should characters be upper case? */
  }
#endif  // 0

  intpart = ufvalue;

  /*
  * Sorry, we only support 9 digits past the decimal because of our
  * conversion method
  */
  if (max > 9)
  {
    max = 9;
  }

  /* We "cheat" by converting the fractional part to integer by
  * multiplying by a factor of 10
  */
  fracpart = round((pow10(max)) * (ufvalue - intpart));

  if (fracpart >= pow10(max))
  {
    intpart++;
    fracpart -= pow10(max);
  }

  /* Convert integer part */
  do
  {
    iconvert[iplace++] = (caps ? "0123456789ABCDEF" : "0123456789abcdef")[intpart % 10];
    intpart = (intpart / 10);
  }
  while (intpart && (iplace < 20));

  if (iplace == 20)
  {
    iplace--;
  }

  iconvert[iplace] = 0;

  /* Convert fractional part */
  do
  {
    fconvert[fplace++] = (caps ? "0123456789ABCDEF" : "0123456789abcdef")[fracpart % 10];
    fracpart = (fracpart / 10);
  }
  while (fracpart && (fplace < 20));

  if (fplace == 20)
  {
    fplace--;
  }

  fconvert[fplace] = 0;

  /* -1 for decimal point, another -1 if we are printing a sign */
  padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0);
  zpadlen = max - fplace;

  if (zpadlen < 0)
  {
    zpadlen = 0;
  }

  if (padlen < 0)
  {
    padlen = 0;
  }

  if (flags & DP_F_MINUS)
  {
    padlen = -padlen;  /* Left Justifty */
  }

  if ((flags & DP_F_ZERO) && (padlen > 0))
  {
    if (signvalue)
    {
      dopr_outch(buffer, currlen, maxlen, signvalue);
      --padlen;
      signvalue = 0;
    }
    while (padlen > 0)
    {
      dopr_outch(buffer, currlen, maxlen, '0');
      --padlen;
    }
  }

  while (padlen > 0)
  {
    dopr_outch(buffer, currlen, maxlen, ' ');
    --padlen;
  }

  if (signvalue)
  {
    dopr_outch(buffer, currlen, maxlen, signvalue);
  }

  while (iplace > 0)
  {
    dopr_outch(buffer, currlen, maxlen, iconvert[--iplace]);
  }

  /*
  * Decimal point.  This should probably use locale to find the correct
  * char to print out.
  */
  if (max > 0)
  {
    dopr_outch(buffer, currlen, maxlen, '.');

    while (fplace > 0)
    {
      dopr_outch(buffer, currlen, maxlen, fconvert[--fplace]);
    }
  }

  while (zpadlen > 0)
  {
    dopr_outch(buffer, currlen, maxlen, '0');
    --zpadlen;
  }

  while (padlen < 0)
  {
    dopr_outch(buffer, currlen, maxlen, ' ');
    ++padlen;
  }
}

static void dopr_outch(char *buffer, size_t * currlen, size_t maxlen, char c)
{
  if (*currlen < maxlen)
  {
    buffer[(*currlen)++] = c;
  }
}

int xastir_vsnprintf(char *str, size_t count, const char *fmt, va_list args)
{
  str[0] = 0;
  dopr(str, count, fmt, args);
  return (strlen(str));
}
#endif /* !HAVE_VSNPRINTF */

#ifndef HAVE_SNPRINTF
#ifdef HAVE_STDARGS
  int xastir_snprintf(char *str, size_t count, const char *fmt, ...)
#else // HAVE_STDARGS
  int xastir_snprintf(va_alist) va_dcl
#endif    // HAVE_STDARGS
{
#  ifndef HAVE_STDARGS
  char *str;
  size_t count;
  char *fmt;
#  endif    // HAVE_STDARGS
  VA_LOCAL_DECL;

  VA_START(fmt);
  VA_SHIFT(str, char *);
  VA_SHIFT(count, size_t);
  VA_SHIFT(fmt, char *);
  (void) xastir_vsnprintf(str, count, fmt, ap);
  VA_END;
  return (strlen(str));
}
#endif /* !HAVE_SNPRINTF */


