/* misc.c - definitions of misc functions */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007,2008  Free Software Foundation, Inc.
 *
 *  GRUB 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <grub/misc.h>
#include <grub/err.h>
#include <grub/mm.h>
#include <stdarg.h>
#include <grub/term.h>
#include <grub/env.h>
#include <grub/time.h>

void *
grub_memmove (void *dest, const void *src, grub_size_t n)
{
  char *d = (char *) dest;
  const char *s = (const char *) src;

  if (d < s)
    while (n--)
      *d++ = *s++;
  else
    {
      d += n;
      s += n;
      
      while (n--)
	*--d = *--s;
    }
  
  return dest;
}
void *memmove (void *dest, const void *src, grub_size_t n)
  __attribute__ ((alias ("grub_memmove")));
/* GCC emits references to memcpy() for struct copies etc.  */
void *memcpy (void *dest, const void *src, grub_size_t n)
  __attribute__ ((alias ("grub_memmove")));

char *
grub_strcpy (char *dest, const char *src)
{
  char *p = dest;

  while ((*p++ = *src++) != '\0')
    ;

  return dest;
}

char *
grub_strncpy (char *dest, const char *src, int c)
{
  char *p = dest;
  
  while ((*p++ = *src++) != '\0' && --c)
    ;

  return dest;
}

char *
grub_stpcpy (char *dest, const char *src)
{
  char *d = dest;
  const char *s = src;

  do
    *d++ = *s;
  while (*s++ != '\0');

  return d - 1;
}

char *
grub_strcat (char *dest, const char *src)
{
  char *p = dest;

  while (*p)
    p++;

  while ((*p = *src) != '\0')
    {
      p++;
      src++;
    }

  return dest;
}

char *
grub_strncat (char *dest, const char *src, int c)
{
  char *p = dest;

  while (*p)
    p++;

  while ((*p = *src) != '\0' && c--)
    {
      p++;
      src++;
    }

  *p = '\0';

  return dest;
}

int
grub_printf (const char *fmt, ...)
{
  va_list ap;
  int ret;
  
  va_start (ap, fmt);
  ret = grub_vprintf (fmt, ap);
  va_end (ap);

  return ret;
}  

void
grub_real_dprintf (const char *file, const int line, const char *condition,
		   const char *fmt, ...)
{
  va_list args;
  const char *debug = grub_env_get ("debug");
  
  if (! debug)
    return;
  
  if (grub_strword (debug, "all") || grub_strword (debug, condition))
    {
      grub_printf ("%s:%d: ", file, line);
      va_start (args, fmt);
      grub_vprintf (fmt, args);
      va_end (args);
    }
}

int
grub_vprintf (const char *fmt, va_list args)
{
  int ret;

  ret = grub_vsprintf (0, fmt, args);
  grub_refresh ();
  return ret;
}

int
grub_memcmp (const void *s1, const void *s2, grub_size_t n)
{
  const char *t1 = s1;
  const char *t2 = s2;
  
  while (n--)
    {
      if (*t1 != *t2)
	return (int) *t1 - (int) *t2;

      t1++;
      t2++;
    }

  return 0;
}
int memcmp (const void *s1, const void *s2, grub_size_t n)
  __attribute__ ((alias ("grub_memcmp")));

int
grub_strcmp (const char *s1, const char *s2)
{
  while (*s1 && *s2)
    {
      if (*s1 != *s2)
	return (int) *s1 - (int) *s2;
      
      s1++;
      s2++;
    }

  return (int) *s1 - (int) *s2;
}

int
grub_strncmp (const char *s1, const char *s2, grub_size_t n)
{
  if (n == 0)
    return 0;
  
  while (*s1 && *s2 && --n)
    {
      if (*s1 != *s2)
	return (int) *s1 - (int) *s2;
      
      s1++;
      s2++;
    }

  return (int) *s1 - (int) *s2;
}

int
grub_strncasecmp (const char *s1, const char *s2, int c)
{
  int p = 1;

  while (grub_tolower (*s1) && grub_tolower (*s2) && p < c)
    {
      if (grub_tolower (*s1) != grub_tolower (*s2))
	return (int) grub_tolower (*s1) - (int) grub_tolower (*s2);
      
      s1++;
      s2++;
      p++;
    }

  return (int) *s1 - (int) *s2;
}

char *
grub_strchr (const char *s, int c)
{
  while (*s)
    {
      if (*s == c)
	return (char *) s;
      s++;
    }

  return 0;
}

char *
grub_strrchr (const char *s, int c)
{
  char *p = 0;

  while (*s)
    {
      if (*s == c)
	p = (char *) s;
      s++;
    }

  return p;
}

/* Copied from gnulib.
   Written by Bruno Haible <bruno@clisp.org>, 2005. */
char *
grub_strstr (const char *haystack, const char *needle)
{
  /* Be careful not to look at the entire extent of haystack or needle
     until needed.  This is useful because of these two cases:
       - haystack may be very long, and a match of needle found early,
       - needle may be very long, and not even a short initial segment of
       needle may be found in haystack.  */
  if (*needle != '\0')
    {
      /* Speed up the following searches of needle by caching its first
	 character.  */
      char b = *needle++;
      
      for (;; haystack++)
	{
	  if (*haystack == '\0')
	    /* No match.  */
	    return NULL;
	  if (*haystack == b)
	    /* The first character matches.  */
	    {
	      const char *rhaystack = haystack + 1;
	      const char *rneedle = needle;

	      for (;; rhaystack++, rneedle++)
		{
		  if (*rneedle == '\0')
		    /* Found a match.  */
		    return (char *) haystack;
		  if (*rhaystack == '\0')
		    /* No match.  */
		    return NULL;
		  if (*rhaystack != *rneedle)
		    /* Nothing in this round.  */
		    break;
		}
	    }
	}
    }
  else
    return (char *) haystack;
}

int
grub_strword (const char *haystack, const char *needle)
{
  const char *n_pos = needle;

  while (grub_iswordseparator (*haystack))
    haystack++;

  while (*haystack)
    {
      /* Crawl both the needle and the haystack word we're on.  */
      while(*haystack && !grub_iswordseparator (*haystack)
            && *haystack == *n_pos)
        {
          haystack++;
          n_pos++;
        }

      /* If we reached the end of both words at the same time, the word
      is found. If not, eat everything in the haystack that isn't the
      next word (or the end of string) and "reset" the needle.  */
      if ( (!*haystack || grub_iswordseparator (*haystack))
         && (!*n_pos || grub_iswordseparator (*n_pos)))
        return 1;
      else
        {
          n_pos = needle;
          while (*haystack && !grub_iswordseparator (*haystack))
            haystack++;
          while (grub_iswordseparator (*haystack))
            haystack++;
        }
    }

  return 0;
}

int
grub_iswordseparator (int c)
{
  return (grub_isspace (c) || c == ',' || c == ';' || c == '|' || c == '&');
}

int
grub_isspace (int c)
{
  return (c == '\n' || c == '\r' || c == ' ' || c == '\t');
}

int
grub_isprint (int c)
{
  return (c >= ' ' && c <= '~');
}

int
grub_isalpha (int c)
{
  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
}

int
grub_isdigit (int c)
{
  return (c >= '0' && c <= '9');
}

int
grub_isgraph (int c)
{
  return (c >= '!' && c <= '~');
}

int
grub_tolower (int c)
{
  if (c >= 'A' && c <= 'Z')
    return c - 'A' + 'a';

  return c;
}


unsigned long
grub_strtoul (const char *str, char **end, int base)
{
  unsigned long long num;

  num = grub_strtoull (str, end, base);
  if (num > ~0UL)
    {
      grub_error (GRUB_ERR_OUT_OF_RANGE, "overflow is detected");
      return ~0UL;
    }

  return (unsigned long) num;
}

unsigned long long
grub_strtoull (const char *str, char **end, int base)
{
  unsigned long long num = 0;
  int found = 0;
  
  /* Skip white spaces.  */
  while (*str && grub_isspace (*str))
    str++;
  
  /* Guess the base, if not specified. The prefix `0x' means 16, and
     the prefix `0' means 8.  */
  if (base == 0 && str[0] == '0')
    {
      if (str[1] == 'x')
	{
	  if (base == 0 || base == 16)
	    {
	      base = 16;
	      str += 2;
	    }
	}
      else if (str[1] >= '0' && str[1] <= '7')
	base = 8;
    }
  
  if (base == 0)
    base = 10;

  while (*str)
    {
      unsigned long digit;

      digit = grub_tolower (*str) - '0';
      if (digit > 9)
	{
	  digit += '0' - 'a' + 10;
	  if (digit >= (unsigned long) base)
	    break;
	}

      found = 1;

      /* NUM * BASE + DIGIT > ~0ULL */
      if (num > grub_divmod64 (~0ULL - digit, base, 0))
	{
	  grub_error (GRUB_ERR_OUT_OF_RANGE, "overflow is detected");
	  return ~0ULL;
	}

      num = num * base + digit;
      str++;
    }

  if (! found)
    {
      grub_error (GRUB_ERR_BAD_NUMBER, "unrecognized number");
      return 0;
    }
  
  if (end)
    *end = (char *) str;

  return num;
}

char *
grub_strdup (const char *s)
{
  grub_size_t len;
  char *p;
  
  len = grub_strlen (s) + 1;
  p = (char *) grub_malloc (len);
  if (! p)
    return 0;

  return grub_memcpy (p, s, len);
}

char *
grub_strndup (const char *s, grub_size_t n)
{
  grub_size_t len;
  char *p;
  
  len = grub_strlen (s);
  if (len > n)
    len = n;
  p = (char *) grub_malloc (len + 1);
  if (! p)
    return 0;
  
  grub_memcpy (p, s, len);
  p[len] = '\0';
  return p;
}

void *
grub_memset (void *s, int c, grub_size_t n)
{
  unsigned char *p = (unsigned char *) s;

  while (n--)
    *p++ = (unsigned char) c;

  return s;
}
void *memset (void *s, int c, grub_size_t n)
  __attribute__ ((alias ("grub_memset")));

grub_size_t
grub_strlen (const char *s)
{
  const char *p = s;

  while (*p)
    p++;

  return p - s;
}

static inline void
grub_reverse (char *str)
{
  char *p = str + grub_strlen (str) - 1;

  while (str < p)
    {
      char tmp;

      tmp = *str;
      *str = *p;
      *p = tmp;
      str++;
      p--;
    }
}

static char *
grub_itoa (char *str, int c, unsigned n)
{
  unsigned base = (c == 'x') ? 16 : 10;
  char *p;
  
  if ((int) n < 0 && c == 'd')
    {
      n = (unsigned) (-((int) n));
      *str++ = '-';
    }

  p = str;
  do
    {
      unsigned d = n % base;
      *p++ = (d > 9) ? d + 'a' - 10 : d + '0';
    }
  while (n /= base);
  *p = 0;

  grub_reverse (str);
  return p;
}

/* Divide N by D, return the quotient, and store the remainder in *R.  */
grub_uint64_t
grub_divmod64 (grub_uint64_t n, grub_uint32_t d, grub_uint32_t *r)
{
  /* This algorithm is typically implemented by hardware. The idea
     is to get the highest bit in N, 64 times, by keeping
     upper(N * 2^i) = upper((Q * 10 + M) * 2^i), where upper
     represents the high 64 bits in 128-bits space.  */
  unsigned bits = 64;
  unsigned long long q = 0;
  unsigned m = 0;

  /* Skip the slow computation if 32-bit arithmetic is possible.  */
  if (n < 0xffffffff)
    {
      if (r)
	*r = ((grub_uint32_t) n) % d;

      return ((grub_uint32_t) n) / d;
    }
  
  while (bits--)
    {
      m <<= 1;
      
      if (n & (1ULL << 63))
	m |= 1;
      
      q <<= 1;
      n <<= 1;
      
      if (m >= d)
	{
	  q |= 1;
	  m -= d;
	}
    }

  if (r)
    *r = m;
  
  return q;
}

/* Convert a long long value to a string. This function avoids 64-bit
   modular arithmetic or divisions.  */
static char *
grub_lltoa (char *str, int c, unsigned long long n)
{
  unsigned base = (c == 'x') ? 16 : 10;
  char *p;
  
  if ((long long) n < 0 && c == 'd')
    {
      n = (unsigned long long) (-((long long) n));
      *str++ = '-';
    }

  p = str;

  if (base == 16)
    do
      {
	unsigned d = (unsigned) (n & 0xf);
	*p++ = (d > 9) ? d + 'a' - 10 : d + '0';
      }
    while (n >>= 4);
  else
    /* BASE == 10 */
    do
      {
	unsigned m;
	
	n = grub_divmod64 (n, 10, &m);
	*p++ = m + '0';
      }
    while (n);
  
  *p = 0;

  grub_reverse (str);
  return p;
}

int
grub_vsprintf (char *str, const char *fmt, va_list args)
{
  char c;
  int count = 0;
  auto void write_char (unsigned char ch);
  auto void write_str (const char *s);
  auto void write_fill (const char ch, int n);
  
  void write_char (unsigned char ch)
    {
      if (str)
	*str++ = ch;
      else
	grub_putchar (ch);

      count++;
    }

  void write_str (const char *s)
    {
      while (*s)
	write_char (*s++);
    }

  void write_fill (const char ch, int n)
    {
      int i;
      for (i = 0; i < n; i++)
	write_char (ch);
    }
  
  while ((c = *fmt++) != 0)
    {
      if (c != '%')
	write_char (c);
      else
	{
	  char tmp[32];
	  char *p;
	  unsigned int format1 = 0;
	  unsigned int format2 = 3;
	  char zerofill = ' ';
	  int rightfill = 0;
	  int n;
	  int longfmt = 0;
	  int longlongfmt = 0;

	  if (*fmt && *fmt =='-')
	    {
	      rightfill = 1;
	      fmt++;
	    }

	  p = (char *) fmt;
	  /* Read formatting parameters.  */
	  while (*p && grub_isdigit (*p))
	    p++;

	  if (p > fmt)
	    {
	      char s[p - fmt + 1];
	      grub_strncpy (s, fmt, p - fmt);
	      s[p - fmt] = 0;
	      if (s[0] == '0')
		zerofill = '0';
	      format1 = grub_strtoul (s, 0, 10);
	      fmt = p;
	      if (*p && *p == '.')
		{
		  p++;
		  fmt++;
		  while (*p && grub_isdigit (*p))
		    p++;
		  
		  if (p > fmt)
		    {
		      char fstr[p - fmt];
		      grub_strncpy (fstr, fmt, p - fmt);
		      format2 = grub_strtoul (fstr, 0, 10);
		      fmt = p;
		    }
		}
	    }

	  c = *fmt++;
	  if (c == 'l')
	    {
	      longfmt = 1;
	      c = *fmt++;
	      if (c == 'l')
		{
		  longlongfmt = 1;
		  c = *fmt++;
		}
	    }

	  switch (c)
	    {
	    case 'p':
	      write_str ("0x");
	      c = 'x';
	      longlongfmt |= (sizeof (void *) == sizeof (long long));
	      /* fall through */
	    case 'x':
	    case 'u':
	    case 'd':
	      if (longlongfmt)
		{
		  long long ll;

		  ll = va_arg (args, long long);
		  grub_lltoa (tmp, c, ll);
		}
	      else
		{
		  if (longfmt)
		    n = va_arg (args, long);
		  else
		    n = va_arg (args, int);
		  grub_itoa (tmp, c, n);
		}
	      if (! rightfill && grub_strlen (tmp) < format1)
		write_fill (zerofill, format1 - grub_strlen (tmp));
	      write_str (tmp);
	      if (rightfill && grub_strlen (tmp) < format1)
		write_fill (zerofill, format1 - grub_strlen (tmp));
	      break;
	      
	    case 'c':
	      n = va_arg (args, int);
	      write_char (n & 0xff);
	      break;

	    case 'C':
	      {
		grub_uint32_t code = va_arg (args, grub_uint32_t);
		int shift;
		unsigned mask;
		
		if (code <= 0x7f)
		  {
		    shift = 0;
		    mask = 0;
		  }
		else if (code <= 0x7ff)
		  {
		    shift = 6;
		    mask = 0xc0;
		  }
		else if (code <= 0xffff)
		  {
		    shift = 12;
		    mask = 0xe0;
		  }
		else if (code <= 0x1fffff)
		  {
		    shift = 18;
		    mask = 0xf0;
		  }
		else if (code <= 0x3ffffff)
		  {
		    shift = 24;
		    mask = 0xf8;
		  }
		else if (code <= 0x7fffffff)
		  {
		    shift = 30;
		    mask = 0xfc;
		  }
		else
		  {
		    code = '?';
		    shift = 0;
		    mask = 0;
		  }

		write_char (mask | (code >> shift));
		
		for (shift -= 6; shift >= 0; shift -= 6)
		  write_char (0x80 | (0x3f & (code >> shift)));
	      }
	      break;

	    case 's':
	      p = va_arg (args, char *);
	      if (p)
		{
		  if (!rightfill && grub_strlen (p) < format1)
		    write_fill (zerofill, format1 - grub_strlen (p));
		  
		  write_str (p);
		  
		  if (rightfill && grub_strlen (p) < format1)
		    write_fill (zerofill, format1 - grub_strlen (p));
		}
	      else
		write_str ("(null)");
	      
	      break;

	    default:
	      write_char (c);
	      break;
	    }
	}
    }

  if (str)
    *str = '\0';

  if (count && !str)
    grub_refresh ();
  
  return count;
}

int
grub_sprintf (char *str, const char *fmt, ...)
{
  va_list ap;
  int ret;
  
  va_start (ap, fmt);
  ret = grub_vsprintf (str, fmt, ap);
  va_end (ap);

  return ret;
}

/* Convert UTF-16 to UTF-8.  */
grub_uint8_t *
grub_utf16_to_utf8 (grub_uint8_t *dest, grub_uint16_t *src,
		    grub_size_t size)
{
  grub_uint32_t code_high = 0;

  while (size--)
    {
      grub_uint32_t code = *src++;

      if (code_high)
	{
	  if (code >= 0xDC00 && code <= 0xDFFF)
	    {
	      /* Surrogate pair.  */
	      code = ((code_high - 0xD800) << 12) + (code - 0xDC00) + 0x10000;
	      
	      *dest++ = (code >> 18) | 0xF0;
	      *dest++ = ((code >> 12) & 0x3F) | 0x80;
	      *dest++ = ((code >> 6) & 0x3F) | 0x80;
	      *dest++ = (code & 0x3F) | 0x80;
	    }
	  else
	    {
	      /* Error...  */
	      *dest++ = '?';
	    }

	  code_high = 0;
	}
      else
	{
	  if (code <= 0x007F)
	    *dest++ = code;
	  else if (code <= 0x07FF)
	    {
	      *dest++ = (code >> 6) | 0xC0;
	      *dest++ = (code & 0x3F) | 0x80;
	    }
	  else if (code >= 0xD800 && code <= 0xDBFF)
	    {
	      code_high = code;
	      continue;
	    }
	  else if (code >= 0xDC00 && code <= 0xDFFF)
	    {
	      /* Error... */
	      *dest++ = '?';
	    }
	  else
	    {
	      *dest++ = (code >> 12) | 0xE0;
	      *dest++ = ((code >> 6) & 0x3F) | 0x80;
	      *dest++ = (code & 0x3F) | 0x80;
	    }
	}
    }

  return dest;
}

/* Convert an UTF-8 string to an UCS-4 string. Return the number of
   characters converted. DEST must be able to hold at least SIZE
   characters (when the input is unknown). If an invalid sequence is found,
   return -1.  */
grub_ssize_t
grub_utf8_to_ucs4 (grub_uint32_t *dest, const grub_uint8_t *src,
		   grub_size_t size)
{
  grub_uint32_t *p = dest;
  int count = 0;
  grub_uint32_t code = 0;
  
  while (size--)
    {
      grub_uint32_t c = *src++;
      
      if (count)
	{
	  if ((c & 0xc0) != 0x80)
	    {
	      /* invalid */
	      return -1;
	    }
	  else
	    {
	      code <<= 6;
	      code |= (c & 0x3f);
	      count--;
	    }
	}
      else
	{
	  if ((c & 0x80) == 0x00)
	    code = c;
	  else if ((c & 0xe0) == 0xc0)
	    {
	      count = 1;
	      code = c & 0x1f;
	    }
	  else if ((c & 0xf0) == 0xe0)
	    {
	      count = 2;
	      code = c & 0x0f;
	    }
	  else if ((c & 0xf8) == 0xf0)
	    {
	      count = 3;
	      code = c & 0x07;
	    }
	  else if ((c & 0xfc) == 0xf8)
	    {
	      count = 4;
	      code = c & 0x03;
	    }
	  else if ((c & 0xfe) == 0xfc)
	    {
	      count = 5;
	      code = c & 0x01;
	    }
	  else
	    /* invalid */
	    return -1;
	}

      if (count == 0)
	*p++ = code;
    }

  return p - dest;
}

void
grub_millisleep_generic (grub_uint32_t ms)
{
  grub_uint32_t end_at;

  end_at = grub_get_rtc () + grub_div_roundup (ms * GRUB_TICKS_PER_SECOND, 1000);

  while (grub_get_rtc () < end_at)
    grub_cpu_idle ();
}

/* Abort GRUB. This function does not return.  */
void
grub_abort (void)
{
  if (grub_term_get_current ())
    {
      grub_printf ("\nAborted. Press any key to exit.");
      grub_getkey ();
    }

  grub_exit ();
}
/* GCC emits references to abort().  */
void abort (void) __attribute__ ((alias ("grub_abort")));