/* Access functions for KS C 5601-1992 based encoding conversion.

   Copyright (C) 1998-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#ifndef _KSC5601_H

#define _KSC5601_H	1

#define KSC5601_HANGUL 2350

#define KSC5601_HANJA  4888

#define KSC5601_SYMBOL  989

#include <gconv.h>

#include <stdint.h>

/* Structure to map from UCS to KSC.  This structure should be packed

   on all platforms.  */

struct map

{

  uint16_t ucs;

  char val[2];

};

/* Conversion table.  */

extern const uint16_t __ksc5601_hangul_to_ucs[KSC5601_HANGUL];

extern const uint16_t __ksc5601_sym_to_ucs[];

extern const struct map __ksc5601_sym_from_ucs[KSC5601_SYMBOL];

extern const uint16_t __ksc5601_hanja_to_ucs[KSC5601_HANJA];

extern const struct map __ksc5601_hanja_from_ucs[KSC5601_HANJA];

static inline uint32_t

__attribute ((always_inline))

ksc5601_to_ucs4 (const unsigned char **s, size_t avail, unsigned char offset)

{

  unsigned char ch = **s;

  unsigned char ch2;

  int idx;

  if (avail < 2)

    return 0;

  /* row 94(0x7e) and row 41(0x49) are user-defined area in KS C 5601 */

  if (ch < offset || (ch - offset) <= 0x20 || (ch - offset) >= 0x7e

      || (ch - offset) == 0x49)

    return __UNKNOWN_10646_CHAR;

  ch2 = (*s)[1];

  if (ch2 < offset || (ch2 - offset) <= 0x20 || (ch2 - offset) >= 0x7f)

    return __UNKNOWN_10646_CHAR;

  idx = (ch - offset - 0x21) * 94 + (ch2 - offset - 0x21);

  /* 1410 = 15 * 94 , 3760 = 40 * 94

     Hangul in KS C 5601 : row 16 - row 40 */

  *s += 2;

  if (idx >= 1410 && idx < 1410 + KSC5601_HANGUL)

    return (__ksc5601_hangul_to_ucs[idx - 1410]

	    ?: (*s -= 2, __UNKNOWN_10646_CHAR));

  else if (idx >= 3854)

    /* Hanja : row 42 - row 93 : 3854 = 94 * (42-1) */

   return (__ksc5601_hanja_to_ucs[idx - 3854]

	   ?: (*s -= 2, __UNKNOWN_10646_CHAR));

  else if (idx <= 1114)

    return __ksc5601_sym_to_ucs[idx] ?: (*s -= 2, __UNKNOWN_10646_CHAR);

  *s -= 2;

  return __UNKNOWN_10646_CHAR;

}

static inline size_t

__attribute ((always_inline))

ucs4_to_ksc5601_hangul (uint32_t wch, unsigned char *s, size_t avail)

{

  int l = 0;

  int u = KSC5601_HANGUL - 1;

  uint32_t try;

  while (l <= u)

    {

      int m = (l + u) / 2;

      try = (uint32_t) __ksc5601_hangul_to_ucs[m];

      if (try > wch)

	u = m - 1;

      else if (try < wch)

	l= m + 1;

      else

	{

	  if (avail < 2)

	    return 0;

	  s[0] = (m / 94) + 0x30;

	  s[1] = (m % 94) + 0x21;

	  return 2;

	}

    }

  return __UNKNOWN_10646_CHAR;

}

static inline size_t

__attribute ((always_inline))

ucs4_to_ksc5601_hanja (uint32_t wch, unsigned char *s, size_t avail)

{

  int l = 0;

  int u = KSC5601_HANJA - 1;

  uint32_t try;

  while (l <= u)

    {

      int m = (l + u) / 2;

      try = (uint32_t) __ksc5601_hanja_from_ucs[m].ucs;

      if (try > wch)

	u=m-1;

      else if (try < wch)

	l = m + 1;

      else

	{

	  if (avail < 2)

	    return 0;

	  s[0] = __ksc5601_hanja_from_ucs[m].val[0];

	  s[1] = __ksc5601_hanja_from_ucs[m].val[1];

	  return 2;

	}

    }

  return __UNKNOWN_10646_CHAR;

}

static inline  size_t

__attribute ((always_inline))

ucs4_to_ksc5601_sym (uint32_t wch, unsigned char *s, size_t avail)

{

  int l = 0;

  int u = KSC5601_SYMBOL - 1;

  uint32_t try;

  while (l <= u)

    {

      int m = (l + u) / 2;

      try = __ksc5601_sym_from_ucs[m].ucs;

      if (try > wch)

	u = m - 1;

      else if (try < wch)

	l = m + 1;

      else

	{

	  if (avail < 2)

	    return 0;

	  s[0] = __ksc5601_sym_from_ucs[m].val[0];

	  s[1] = __ksc5601_sym_from_ucs[m].val[1];

	  return 2;

	}

    }

  return __UNKNOWN_10646_CHAR;

}

static inline size_t

__attribute ((always_inline))

ucs4_to_ksc5601 (uint32_t wch, unsigned char *s, size_t avail)

{

  if (wch >= 0xac00 && wch <= 0xd7a3)

    return ucs4_to_ksc5601_hangul (wch, s, avail);

  else if ((wch >= 0x4e00 && wch <= 0x9fff)

	   || (wch >= 0xf900 && wch <= 0xfa0b))

    return ucs4_to_ksc5601_hanja (wch, s, avail);

  else

    return ucs4_to_ksc5601_sym (wch, s, avail);

}

#endif /* ksc5601.h */