/* mbutil.c -- readline multibyte character utility functions */

/* Copyright (C) 2001-2009 Free Software Foundation, Inc.

   This file is part of the GNU Readline Library (Readline), a library

   for reading lines of text with interactive input and history editing.      

   Readline 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.

   Readline 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 Readline.  If not, see <http://www.gnu.org/licenses/>.

*/

#define READLINE_LIBRARY

#if defined (HAVE_CONFIG_H)

#  include <config.h>

#endif

#include <sys/types.h>

#include <fcntl.h>

#include "posixjmp.h"

#if defined (HAVE_UNISTD_H)

#  include <unistd.h>	   /* for _POSIX_VERSION */

#endif /* HAVE_UNISTD_H */

#if defined (HAVE_STDLIB_H)

#  include <stdlib.h>

#else

#  include "ansi_stdlib.h"

#endif /* HAVE_STDLIB_H */

#include <stdio.h>

#include <ctype.h>

/* System-specific feature definitions and include files. */

#include "rldefs.h"

#include "rlmbutil.h"

#if defined (TIOCSTAT_IN_SYS_IOCTL)

#  include <sys/ioctl.h>

#endif /* TIOCSTAT_IN_SYS_IOCTL */

/* Some standard library routines. */

#include "readline.h"

#include "rlprivate.h"

#include "xmalloc.h"

/* Declared here so it can be shared between the readline and history

   libraries. */

#if defined (HANDLE_MULTIBYTE)

int rl_byte_oriented = 0;

#else

int rl_byte_oriented = 1;

#endif

/* **************************************************************** */

/*								    */

/*		Multibyte Character Utility Functions		    */

/*								    */

/* **************************************************************** */

#if defined(HANDLE_MULTIBYTE)

static int

_rl_find_next_mbchar_internal (string, seed, count, find_non_zero)

     char *string;

     int seed, count, find_non_zero;

{

  size_t tmp, len;

  mbstate_t ps;

  int point;

  wchar_t wc;

  tmp = 0;

  memset(&ps, 0, sizeof (mbstate_t));

  if (seed < 0)

    seed = 0;

  if (count <= 0)

    return seed;

  point = seed + _rl_adjust_point (string, seed, &ps);

  /* if this is true, means that seed was not pointing to a byte indicating

     the beginning of a multibyte character.  Correct the point and consume

     one char. */

  if (seed < point)

    count--;

  while (count > 0)  

    {

      len = strlen (string + point);

      if (len == 0)

	break;

      tmp = mbrtowc (&wc, string+point, len, &ps);

      if (MB_INVALIDCH ((size_t)tmp))

	{

	  /* invalid bytes. assume a byte represents a character */

	  point++;

	  count--;

	  /* reset states. */

	  memset(&ps, 0, sizeof(mbstate_t));

	}

      else if (MB_NULLWCH (tmp))

	break;			/* found wide '\0' */

      else

	{

	  /* valid bytes */

	  point += tmp;

	  if (find_non_zero)

	    {

	      if (wcwidth (wc) == 0)

		continue;

	      else

		count--;

	    }

	  else

	    count--;

	}

    }

  if (find_non_zero)

    {

      tmp = mbrtowc (&wc, string + point, strlen (string + point), &ps);

      while (MB_NULLWCH (tmp) == 0 && MB_INVALIDCH (tmp) == 0 && wcwidth (wc) == 0)

	{

	  point += tmp;

	  tmp = mbrtowc (&wc, string + point, strlen (string + point), &ps);

	}

    }

  return point;

}

static int

_rl_find_prev_mbchar_internal (string, seed, find_non_zero)

     char *string;

     int seed, find_non_zero;

{

  mbstate_t ps;

  int prev, non_zero_prev, point, length;

  size_t tmp;

  wchar_t wc;

  memset(&ps, 0, sizeof(mbstate_t));

  length = strlen(string);

  if (seed < 0)

    return 0;

  else if (length < seed)

    return length;

  prev = non_zero_prev = point = 0;

  while (point < seed)

    {

      tmp = mbrtowc (&wc, string + point, length - point, &ps);

      if (MB_INVALIDCH ((size_t)tmp))

	{

	  /* in this case, bytes are invalid or shorted to compose

	     multibyte char, so assume that the first byte represents

	     a single character anyway. */

	  tmp = 1;

	  /* clear the state of the byte sequence, because

	     in this case effect of mbstate is undefined  */

	  memset(&ps, 0, sizeof (mbstate_t));

	  /* Since we're assuming that this byte represents a single

	     non-zero-width character, don't forget about it. */

	  prev = point;

	}

      else if (MB_NULLWCH (tmp))

	break;			/* Found '\0' char.  Can this happen? */

      else

	{

	  if (find_non_zero)

	    {

	      if (wcwidth (wc) != 0)

		prev = point;

	    }

	  else

	    prev = point;  

	}

      point += tmp;

    }

  return prev;

}

/* return the number of bytes parsed from the multibyte sequence starting

   at src, if a non-L'\0' wide character was recognized. It returns 0, 

   if a L'\0' wide character was recognized. It  returns (size_t)(-1), 

   if an invalid multibyte sequence was encountered. It returns (size_t)(-2) 

   if it couldn't parse a complete  multibyte character.  */

int

_rl_get_char_len (src, ps)

     char *src;

     mbstate_t *ps;

{

  size_t tmp;

  tmp = mbrlen((const char *)src, (size_t)strlen (src), ps);

  if (tmp == (size_t)(-2))

    {

      /* shorted to compose multibyte char */

      if (ps)

	memset (ps, 0, sizeof(mbstate_t));

      return -2;

    }

  else if (tmp == (size_t)(-1))

    {

      /* invalid to compose multibyte char */

      /* initialize the conversion state */

      if (ps)

	memset (ps, 0, sizeof(mbstate_t));

      return -1;

    }

  else if (tmp == (size_t)0)

    return 0;

  else

    return (int)tmp;

}

/* compare the specified two characters. If the characters matched,

   return 1. Otherwise return 0. */

int

_rl_compare_chars (buf1, pos1, ps1, buf2, pos2, ps2)

     char *buf1;

     int pos1;

     mbstate_t *ps1;

     char *buf2;

     int pos2;

     mbstate_t *ps2;

{

  int i, w1, w2;

  if ((w1 = _rl_get_char_len (&buf1[pos1], ps1)) <= 0 || 

	(w2 = _rl_get_char_len (&buf2[pos2], ps2)) <= 0 ||

	(w1 != w2) ||

	(buf1[pos1] != buf2[pos2]))

    return 0;

  for (i = 1; i < w1; i++)

    if (buf1[pos1+i] != buf2[pos2+i])

      return 0;

  return 1;

}

/* adjust pointed byte and find mbstate of the point of string.

   adjusted point will be point <= adjusted_point, and returns

   differences of the byte(adjusted_point - point).

   if point is invalied (point < 0 || more than string length),

   it returns -1 */

int

_rl_adjust_point(string, point, ps)

     char *string;

     int point;

     mbstate_t *ps;

{

  size_t tmp = 0;

  int length;

  int pos = 0;

  length = strlen(string);

  if (point < 0)

    return -1;

  if (length < point)

    return -1;

  while (pos < point)

    {

      tmp = mbrlen (string + pos, length - pos, ps);

      if (MB_INVALIDCH ((size_t)tmp))

	{

	  /* in this case, bytes are invalid or shorted to compose

	     multibyte char, so assume that the first byte represents

	     a single character anyway. */

	  pos++;

	  /* clear the state of the byte sequence, because

	     in this case effect of mbstate is undefined  */

	  if (ps)

	    memset (ps, 0, sizeof (mbstate_t));

	}

      else if (MB_NULLWCH (tmp))

	pos++;

      else

	pos += tmp;

    }

  return (pos - point);

}

int

_rl_is_mbchar_matched (string, seed, end, mbchar, length)

     char *string;

     int seed, end;

     char *mbchar;

     int length;

{

  int i;

  if ((end - seed) < length)

    return 0;

  for (i = 0; i < length; i++)

    if (string[seed + i] != mbchar[i])

      return 0;

  return 1;

}

wchar_t

_rl_char_value (buf, ind)

     char *buf;

     int ind;

{

  size_t tmp;

  wchar_t wc;

  mbstate_t ps;

  int l;

  if (MB_LEN_MAX == 1 || rl_byte_oriented)

    return ((wchar_t) buf[ind]);

  l = strlen (buf);

  if (ind >= l - 1)

    return ((wchar_t) buf[ind]);

  memset (&ps, 0, sizeof (mbstate_t));

  tmp = mbrtowc (&wc, buf + ind, l - ind, &ps);

  if (MB_INVALIDCH (tmp) || MB_NULLWCH (tmp))  

    return ((wchar_t) buf[ind]);

  return wc;

}

#endif /* HANDLE_MULTIBYTE */

/* Find next `count' characters started byte point of the specified seed.

   If flags is MB_FIND_NONZERO, we look for non-zero-width multibyte

   characters. */

#undef _rl_find_next_mbchar

int

_rl_find_next_mbchar (string, seed, count, flags)

     char *string;

     int seed, count, flags;

{

#if defined (HANDLE_MULTIBYTE)

  return _rl_find_next_mbchar_internal (string, seed, count, flags);

#else

  return (seed + count);

#endif

}

/* Find previous character started byte point of the specified seed.

   Returned point will be point <= seed.  If flags is MB_FIND_NONZERO,

   we look for non-zero-width multibyte characters. */

#undef _rl_find_prev_mbchar

int

_rl_find_prev_mbchar (string, seed, flags)

     char *string;

     int seed, flags;

{

#if defined (HANDLE_MULTIBYTE)

  return _rl_find_prev_mbchar_internal (string, seed, flags);

#else

  return ((seed == 0) ? seed : seed - 1);

#endif

}