/* -*- mode: c; c-basic-offset: 2; tab-width: 2; indent-tabs-mode: nil -*- */

/*

 *  Copyright (c) 2014-2021 Steven G. Johnson, Jiahao Chen, Peter Colberg, Tony Kelman, Scott P. Jones, and other contributors.

 *  Copyright (c) 2009 Public Software Group e. V., Berlin, Germany

 *

 *  Permission is hereby granted, free of charge, to any person obtaining a

 *  copy of this software and associated documentation files (the "Software"),

 *  to deal in the Software without restriction, including without limitation

 *  the rights to use, copy, modify, merge, publish, distribute, sublicense,

 *  and/or sell copies of the Software, and to permit persons to whom the

 *  Software is furnished to do so, subject to the following conditions:

 *

 *  The above copyright notice and this permission notice shall be included in

 *  all copies or substantial portions of the Software.

 *

 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 *  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

 *  DEALINGS IN THE SOFTWARE.

 */

/*

 *  This library contains derived data from a modified version of the

 *  Unicode data files.

 *

 *  The original data files are available at

 *  https://www.unicode.org/Public/UNIDATA/

 *

 *  Please notice the copyright statement in the file "utf8proc_data.c".

 */

/*

 *  File name:    utf8proc.c

 *

 *  Description:

 *  Implementation of libutf8proc.

 */

#include "utf8proc.h"

#ifndef SSIZE_MAX

#define SSIZE_MAX ((size_t)SIZE_MAX/2)

#endif

#ifndef UINT16_MAX

#  define UINT16_MAX 65535U

#endif

#include "utf8proc_data.c"

UTF8PROC_DLLEXPORT const utf8proc_int8_t utf8proc_utf8class[256] = {

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,

  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,

  3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,

  4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0 };

#define UTF8PROC_HANGUL_SBASE 0xAC00

#define UTF8PROC_HANGUL_LBASE 0x1100

#define UTF8PROC_HANGUL_VBASE 0x1161

#define UTF8PROC_HANGUL_TBASE 0x11A7

#define UTF8PROC_HANGUL_LCOUNT 19

#define UTF8PROC_HANGUL_VCOUNT 21

#define UTF8PROC_HANGUL_TCOUNT 28

#define UTF8PROC_HANGUL_NCOUNT 588

#define UTF8PROC_HANGUL_SCOUNT 11172

/* END is exclusive */

#define UTF8PROC_HANGUL_L_START  0x1100

#define UTF8PROC_HANGUL_L_END    0x115A

#define UTF8PROC_HANGUL_L_FILLER 0x115F

#define UTF8PROC_HANGUL_V_START  0x1160

#define UTF8PROC_HANGUL_V_END    0x11A3

#define UTF8PROC_HANGUL_T_START  0x11A8

#define UTF8PROC_HANGUL_T_END    0x11FA

#define UTF8PROC_HANGUL_S_START  0xAC00

#define UTF8PROC_HANGUL_S_END    0xD7A4

/* Should follow semantic-versioning rules (semver.org) based on API

   compatibility.  (Note that the shared-library version number will

   be different, being based on ABI compatibility.): */

#define STRINGIZEx(x) #x

#define STRINGIZE(x) STRINGIZEx(x)

UTF8PROC_DLLEXPORT const char *utf8proc_version(void) {

  return STRINGIZE(UTF8PROC_VERSION_MAJOR) "." STRINGIZE(UTF8PROC_VERSION_MINOR) "." STRINGIZE(UTF8PROC_VERSION_PATCH) "";

}

UTF8PROC_DLLEXPORT const char *utf8proc_unicode_version(void) {

  return "17.0.0";

}

UTF8PROC_DLLEXPORT const char *utf8proc_errmsg(utf8proc_ssize_t errcode) {

  switch (errcode) {

    case UTF8PROC_ERROR_NOMEM:

    return "Memory for processing UTF-8 data could not be allocated.";

    case UTF8PROC_ERROR_OVERFLOW:

    return "UTF-8 string is too long to be processed.";

    case UTF8PROC_ERROR_INVALIDUTF8:

    return "Invalid UTF-8 string";

    case UTF8PROC_ERROR_NOTASSIGNED:

    return "Unassigned Unicode code point found in UTF-8 string.";

    case UTF8PROC_ERROR_INVALIDOPTS:

    return "Invalid options for UTF-8 processing chosen.";

    default:

    return "An unknown error occurred while processing UTF-8 data.";

  }

}

#define utf_cont(ch)  (((ch) & 0xc0) == 0x80)

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_iterate(

  const utf8proc_uint8_t *str, utf8proc_ssize_t strlen, utf8proc_int32_t *dst

) {

  utf8proc_int32_t uc;

  const utf8proc_uint8_t *end;

  *dst = -1;

  if (!strlen) return 0;

  end = str + ((strlen < 0) ? 4 : strlen);

  uc = *str++;

  if (uc < 0x80) {

    *dst = uc;

    return 1;

  }

  // Must be between 0xc2 and 0xf4 inclusive to be valid

  if ((utf8proc_uint32_t)(uc - 0xc2) > (0xf4-0xc2)) return UTF8PROC_ERROR_INVALIDUTF8;

  if (uc < 0xe0) {         // 2-byte sequence

     // Must have valid continuation character

     if (str >= end || !utf_cont(*str)) return UTF8PROC_ERROR_INVALIDUTF8;

     *dst = ((uc & 0x1f)<<6) | (*str & 0x3f);

     return 2;

  }

  if (uc < 0xf0) {        // 3-byte sequence

     if ((str + 1 >= end) || !utf_cont(*str) || !utf_cont(str[1]))

        return UTF8PROC_ERROR_INVALIDUTF8;

     // Check for surrogate chars

     if (uc == 0xed && *str > 0x9f)

         return UTF8PROC_ERROR_INVALIDUTF8;

     uc = ((uc & 0xf)<<12) | ((*str & 0x3f)<<6) | (str[1] & 0x3f);

     if (uc < 0x800)

         return UTF8PROC_ERROR_INVALIDUTF8;

     *dst = uc;

     return 3;

  }

  // 4-byte sequence

  // Must have 3 valid continuation characters

  if ((str + 2 >= end) || !utf_cont(*str) || !utf_cont(str[1]) || !utf_cont(str[2]))

     return UTF8PROC_ERROR_INVALIDUTF8;

  // Make sure in correct range (0x10000 - 0x10ffff)

  if (uc == 0xf0) {

    if (*str < 0x90) return UTF8PROC_ERROR_INVALIDUTF8;

  } else if (uc == 0xf4) {

    if (*str > 0x8f) return UTF8PROC_ERROR_INVALIDUTF8;

  }

  *dst = ((uc & 7)<<18) | ((*str & 0x3f)<<12) | ((str[1] & 0x3f)<<6) | (str[2] & 0x3f);

  return 4;

}

UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_codepoint_valid(utf8proc_int32_t uc) {

    return (((utf8proc_uint32_t)uc)-0xd800 > 0x07ff) && ((utf8proc_uint32_t)uc < 0x110000);

}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_encode_char(utf8proc_int32_t uc, utf8proc_uint8_t *dst) {

  if (uc < 0x00) {

    return 0;

  } else if (uc < 0x80) {

    dst[0] = (utf8proc_uint8_t) uc;

    return 1;

  } else if (uc < 0x800) {

    dst[0] = (utf8proc_uint8_t)(0xC0 + (uc >> 6));

    dst[1] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));

    return 2;

  // Note: we allow encoding 0xd800-0xdfff here, so as not to change

  // the API, however, these are actually invalid in UTF-8

  } else if (uc < 0x10000) {

    dst[0] = (utf8proc_uint8_t)(0xE0 + (uc >> 12));

    dst[1] = (utf8proc_uint8_t)(0x80 + ((uc >> 6) & 0x3F));

    dst[2] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));

    return 3;

  } else if (uc < 0x110000) {

    dst[0] = (utf8proc_uint8_t)(0xF0 + (uc >> 18));

    dst[1] = (utf8proc_uint8_t)(0x80 + ((uc >> 12) & 0x3F));

    dst[2] = (utf8proc_uint8_t)(0x80 + ((uc >> 6) & 0x3F));

    dst[3] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));

    return 4;

  } else return 0;

}

/* internal version used for inserting 0xff bytes between graphemes */

static utf8proc_ssize_t charbound_encode_char(utf8proc_int32_t uc, utf8proc_uint8_t *dst) {

   if (uc < 0x00) {

      if (uc == -1) { /* internal value used for grapheme breaks */

        dst[0] = (utf8proc_uint8_t)0xFF;

        return 1;

      }

      return 0;

   } else if (uc < 0x80) {

      dst[0] = (utf8proc_uint8_t)uc;

      return 1;

   } else if (uc < 0x800) {

      dst[0] = (utf8proc_uint8_t)(0xC0 + (uc >> 6));

      dst[1] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));

      return 2;

   } else if (uc < 0x10000) {

      dst[0] = (utf8proc_uint8_t)(0xE0 + (uc >> 12));

      dst[1] = (utf8proc_uint8_t)(0x80 + ((uc >> 6) & 0x3F));

      dst[2] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));

      return 3;

   } else if (uc < 0x110000) {

      dst[0] = (utf8proc_uint8_t)(0xF0 + (uc >> 18));

      dst[1] = (utf8proc_uint8_t)(0x80 + ((uc >> 12) & 0x3F));

      dst[2] = (utf8proc_uint8_t)(0x80 + ((uc >> 6) & 0x3F));

      dst[3] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));

      return 4;

   } else return 0;

}

/* internal "unsafe" version that does not check whether uc is in range */

static const utf8proc_property_t *unsafe_get_property(utf8proc_int32_t uc) {

  /* ASSERT: uc >= 0 && uc < 0x110000 */

  return utf8proc_properties + (

    utf8proc_stage2table[

      utf8proc_stage1table[uc >> 8] + (uc & 0xFF)

    ]

  );

}

UTF8PROC_DLLEXPORT const utf8proc_property_t *utf8proc_get_property(utf8proc_int32_t uc) {

  return uc < 0 || uc >= 0x110000 ? utf8proc_properties : unsafe_get_property(uc);

}

/* return whether there is a grapheme break between boundclasses lbc and tbc

   (according to the definition of extended grapheme clusters)

  Rule numbering refers to TR29 Version 29 (Unicode 9.0.0):

  http://www.unicode.org/reports/tr29/tr29-29.html

  CAVEATS:

   Please note that evaluation of GB10 (grapheme breaks between emoji zwj sequences)

   and GB 12/13 (regional indicator code points) require knowledge of previous characters

   and are thus not handled by this function. This may result in an incorrect break before

   an E_Modifier class codepoint and an incorrectly missing break between two

   REGIONAL_INDICATOR class code points if such support does not exist in the caller.

   See the special support in grapheme_break_extended, for required bookkeeping by the caller.

*/

static utf8proc_bool grapheme_break_simple(int lbc, int tbc) {

  return

    (lbc == UTF8PROC_BOUNDCLASS_START) ? true :       // GB1

    (lbc == UTF8PROC_BOUNDCLASS_CR &&                 // GB3

     tbc == UTF8PROC_BOUNDCLASS_LF) ? false :         // ---

    (lbc >= UTF8PROC_BOUNDCLASS_CR && lbc <= UTF8PROC_BOUNDCLASS_CONTROL) ? true :  // GB4

    (tbc >= UTF8PROC_BOUNDCLASS_CR && tbc <= UTF8PROC_BOUNDCLASS_CONTROL) ? true :  // GB5

    (lbc == UTF8PROC_BOUNDCLASS_L &&                  // GB6

     (tbc == UTF8PROC_BOUNDCLASS_L ||                 // ---

      tbc == UTF8PROC_BOUNDCLASS_V ||                 // ---

      tbc == UTF8PROC_BOUNDCLASS_LV ||                // ---

      tbc == UTF8PROC_BOUNDCLASS_LVT)) ? false :      // ---

    ((lbc == UTF8PROC_BOUNDCLASS_LV ||                // GB7

      lbc == UTF8PROC_BOUNDCLASS_V) &&                // ---

     (tbc == UTF8PROC_BOUNDCLASS_V ||                 // ---

      tbc == UTF8PROC_BOUNDCLASS_T)) ? false :        // ---

    ((lbc == UTF8PROC_BOUNDCLASS_LVT ||               // GB8

      lbc == UTF8PROC_BOUNDCLASS_T) &&                // ---

     tbc == UTF8PROC_BOUNDCLASS_T) ? false :          // ---

    (tbc == UTF8PROC_BOUNDCLASS_EXTEND ||             // GB9

     tbc == UTF8PROC_BOUNDCLASS_ZWJ ||                // ---

     tbc == UTF8PROC_BOUNDCLASS_SPACINGMARK ||        // GB9a

     lbc == UTF8PROC_BOUNDCLASS_PREPEND) ? false :    // GB9b

    (lbc == UTF8PROC_BOUNDCLASS_E_ZWG &&              // GB11 (requires additional handling below)

     tbc == UTF8PROC_BOUNDCLASS_EXTENDED_PICTOGRAPHIC) ? false : // ----

    (lbc == UTF8PROC_BOUNDCLASS_REGIONAL_INDICATOR &&          // GB12/13 (requires additional handling below)

     tbc == UTF8PROC_BOUNDCLASS_REGIONAL_INDICATOR) ? false :  // ----

    true; // GB999

}

static utf8proc_bool grapheme_break_extended(int lbc, int tbc, int licb, int ticb, utf8proc_int32_t *state)

{

  if (state) {

    int state_bc, state_icb; /* boundclass and indic_conjunct_break state */

    if (*state == 0) { /* state initialization */

      state_bc = lbc;

      state_icb = licb == UTF8PROC_INDIC_CONJUNCT_BREAK_CONSONANT ? licb : UTF8PROC_INDIC_CONJUNCT_BREAK_NONE;

    }

    else { /* lbc and licb are already encoded in *state */

      state_bc = *state & 0xff;  // 1st byte of state is bound class

      state_icb = *state >> 8;   // 2nd byte of state is indic conjunct break

    }

    utf8proc_bool break_permitted = grapheme_break_simple(state_bc, tbc) &&

       !(state_icb == UTF8PROC_INDIC_CONJUNCT_BREAK_LINKER

        && ticb == UTF8PROC_INDIC_CONJUNCT_BREAK_CONSONANT); // GB9c

    // Special support for GB9c.  Don't break between two consonants

    // separated 1+ linker characters and 0+ extend characters in any order.

    // After a consonant, we enter LINKER state after at least one linker.

    if (ticb == UTF8PROC_INDIC_CONJUNCT_BREAK_CONSONANT

        || state_icb == UTF8PROC_INDIC_CONJUNCT_BREAK_CONSONANT

        || state_icb == UTF8PROC_INDIC_CONJUNCT_BREAK_EXTEND)

      state_icb = ticb;

    else if (state_icb == UTF8PROC_INDIC_CONJUNCT_BREAK_LINKER)

      state_icb = ticb == UTF8PROC_INDIC_CONJUNCT_BREAK_EXTEND ?

                  UTF8PROC_INDIC_CONJUNCT_BREAK_LINKER : ticb;

    // Special support for GB 12/13 made possible by GB999. After two RI

    // class codepoints we want to force a break. Do this by resetting the

    // second RI's bound class to UTF8PROC_BOUNDCLASS_OTHER, to force a break

    // after that character according to GB999 (unless of course such a break is

    // forbidden by a different rule such as GB9).

    if (state_bc == tbc && tbc == UTF8PROC_BOUNDCLASS_REGIONAL_INDICATOR)

      state_bc = UTF8PROC_BOUNDCLASS_OTHER;

    // Special support for GB11 (emoji extend* zwj / emoji)

    else if (state_bc == UTF8PROC_BOUNDCLASS_EXTENDED_PICTOGRAPHIC) {

      if (tbc == UTF8PROC_BOUNDCLASS_EXTEND) // fold EXTEND codepoints into emoji

        state_bc = UTF8PROC_BOUNDCLASS_EXTENDED_PICTOGRAPHIC;

      else if (tbc == UTF8PROC_BOUNDCLASS_ZWJ)

        state_bc = UTF8PROC_BOUNDCLASS_E_ZWG; // state to record emoji+zwg combo

      else

        state_bc = tbc;

    }

    else

      state_bc = tbc;

    *state = state_bc + (state_icb << 8);

    return break_permitted;

  }

  else

    return grapheme_break_simple(lbc, tbc);

}

UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_grapheme_break_stateful(

    utf8proc_int32_t c1, utf8proc_int32_t c2, utf8proc_int32_t *state) {

  const utf8proc_property_t *p1 = utf8proc_get_property(c1);

  const utf8proc_property_t *p2 = utf8proc_get_property(c2);

  return grapheme_break_extended(p1->boundclass,

                                 p2->boundclass,

                                 p1->indic_conjunct_break,

                                 p2->indic_conjunct_break,

                                 state);

}

UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_grapheme_break(

    utf8proc_int32_t c1, utf8proc_int32_t c2) {

  return utf8proc_grapheme_break_stateful(c1, c2, NULL);

}

static utf8proc_int32_t seqindex_decode_entry(const utf8proc_uint16_t **entry)

{

  utf8proc_int32_t entry_cp = **entry;

  if ((entry_cp & 0xF800) == 0xD800) {

    *entry = *entry + 1;

    entry_cp = ((entry_cp & 0x03FF) << 10) | (**entry & 0x03FF);

    entry_cp += 0x10000;

  }

  return entry_cp;

}

static utf8proc_int32_t seqindex_decode_index(const utf8proc_uint32_t seqindex)

{

  const utf8proc_uint16_t *entry = &utf8proc_sequences[seqindex];

  return seqindex_decode_entry(&entry);

}

static utf8proc_ssize_t seqindex_write_char_decomposed(utf8proc_uint16_t seqindex, utf8proc_int32_t *dst, utf8proc_ssize_t bufsize, utf8proc_option_t options, int *last_boundclass) {

  utf8proc_ssize_t written = 0;

  const utf8proc_uint16_t *entry = &utf8proc_sequences[seqindex & 0x3FFF];

  int len = seqindex >> 14;

  if (len >= 3) {

    len = *entry;

    entry++;

  }

  for (; len >= 0; entry++, len--) {

    utf8proc_int32_t entry_cp = seqindex_decode_entry(&entry);

    written += utf8proc_decompose_char(entry_cp, dst ? dst+written : dst,

      (bufsize > written) ? (bufsize - written) : 0, options,

    last_boundclass);

    if (written < 0) return UTF8PROC_ERROR_OVERFLOW;

  }

  return written;

}

UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_tolower(utf8proc_int32_t c)

{

  utf8proc_int32_t cl = utf8proc_get_property(c)->lowercase_seqindex;

  return cl != UINT16_MAX ? seqindex_decode_index((utf8proc_uint32_t)cl) : c;

}

UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_toupper(utf8proc_int32_t c)

{

  utf8proc_int32_t cu = utf8proc_get_property(c)->uppercase_seqindex;

  return cu != UINT16_MAX ? seqindex_decode_index((utf8proc_uint32_t)cu) : c;

}

UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_totitle(utf8proc_int32_t c)

{

  utf8proc_int32_t cu = utf8proc_get_property(c)->titlecase_seqindex;

  return cu != UINT16_MAX ? seqindex_decode_index((utf8proc_uint32_t)cu) : c;

}

UTF8PROC_DLLEXPORT int utf8proc_islower(utf8proc_int32_t c)

{

  const utf8proc_property_t *p = utf8proc_get_property(c);

  return p->lowercase_seqindex != p->uppercase_seqindex && p->lowercase_seqindex == UINT16_MAX;

}

UTF8PROC_DLLEXPORT int utf8proc_isupper(utf8proc_int32_t c)

{

  const utf8proc_property_t *p = utf8proc_get_property(c);

  return p->lowercase_seqindex != p->uppercase_seqindex && p->uppercase_seqindex == UINT16_MAX && p->category != UTF8PROC_CATEGORY_LT;

}

/* return a character width analogous to wcwidth (except portable and

   hopefully less buggy than most system wcwidth functions). */

UTF8PROC_DLLEXPORT int utf8proc_charwidth(utf8proc_int32_t c) {

  return utf8proc_get_property(c)->charwidth;

}

UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_charwidth_ambiguous(utf8proc_int32_t c) {

  return utf8proc_get_property(c)->ambiguous_width;

}

UTF8PROC_DLLEXPORT utf8proc_category_t utf8proc_category(utf8proc_int32_t c) {

  return (utf8proc_category_t) utf8proc_get_property(c)->category;

}

UTF8PROC_DLLEXPORT const char *utf8proc_category_string(utf8proc_int32_t c) {

  static const char s[][3] = {"Cn","Lu","Ll","Lt","Lm","Lo","Mn","Mc","Me","Nd","Nl","No","Pc","Pd","Ps","Pe","Pi","Pf","Po","Sm","Sc","Sk","So","Zs","Zl","Zp","Cc","Cf","Cs","Co"};

  return s[utf8proc_category(c)];

}

#define utf8proc_decompose_lump(replacement_uc) \

  return utf8proc_decompose_char((replacement_uc), dst, bufsize, \

  options & ~(unsigned int)UTF8PROC_LUMP, last_boundclass)

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose_char(utf8proc_int32_t uc, utf8proc_int32_t *dst, utf8proc_ssize_t bufsize, utf8proc_option_t options, int *last_boundclass) {

  const utf8proc_property_t *property;

  utf8proc_propval_t category;

  utf8proc_int32_t hangul_sindex;

  if (uc < 0 || uc >= 0x110000) return UTF8PROC_ERROR_NOTASSIGNED;

  property = unsafe_get_property(uc);

  category = property->category;

  hangul_sindex = uc - UTF8PROC_HANGUL_SBASE;

  if (options & (UTF8PROC_COMPOSE|UTF8PROC_DECOMPOSE)) {

    if (hangul_sindex >= 0 && hangul_sindex < UTF8PROC_HANGUL_SCOUNT) {

      utf8proc_int32_t hangul_tindex;

      if (bufsize >= 1) {

        dst[0] = UTF8PROC_HANGUL_LBASE +

          hangul_sindex / UTF8PROC_HANGUL_NCOUNT;

        if (bufsize >= 2) dst[1] = UTF8PROC_HANGUL_VBASE +

          (hangul_sindex % UTF8PROC_HANGUL_NCOUNT) / UTF8PROC_HANGUL_TCOUNT;

      }

      hangul_tindex = hangul_sindex % UTF8PROC_HANGUL_TCOUNT;

      if (!hangul_tindex) return 2;

      if (bufsize >= 3) dst[2] = UTF8PROC_HANGUL_TBASE + hangul_tindex;

      return 3;

    }

  }

  if (options & UTF8PROC_REJECTNA) {

    if (!category) return UTF8PROC_ERROR_NOTASSIGNED;

  }

  if (options & UTF8PROC_IGNORE) {

    if (property->ignorable) return 0;

  }

  if (options & UTF8PROC_STRIPNA) {

    if (!category) return 0;

  }

  if (options & UTF8PROC_LUMP) {

    if (category == UTF8PROC_CATEGORY_ZS) utf8proc_decompose_lump(0x0020);

    if (uc == 0x2018 || uc == 0x2019 || uc == 0x02BC || uc == 0x02C8)

      utf8proc_decompose_lump(0x0027);

    if (category == UTF8PROC_CATEGORY_PD || uc == 0x2212)

      utf8proc_decompose_lump(0x002D);

    if (uc == 0x2044 || uc == 0x2215) utf8proc_decompose_lump(0x002F);

    if (uc == 0x2236) utf8proc_decompose_lump(0x003A);

    if (uc == 0x2039 || uc == 0x2329 || uc == 0x3008)

      utf8proc_decompose_lump(0x003C);

    if (uc == 0x203A || uc == 0x232A || uc == 0x3009)

      utf8proc_decompose_lump(0x003E);

    if (uc == 0x2216) utf8proc_decompose_lump(0x005C);

    if (uc == 0x02C4 || uc == 0x02C6 || uc == 0x2038 || uc == 0x2303)

      utf8proc_decompose_lump(0x005E);

    if (category == UTF8PROC_CATEGORY_PC || uc == 0x02CD)

      utf8proc_decompose_lump(0x005F);

    if (uc == 0x02CB) utf8proc_decompose_lump(0x0060);

    if (uc == 0x2223) utf8proc_decompose_lump(0x007C);

    if (uc == 0x223C) utf8proc_decompose_lump(0x007E);

    if ((options & UTF8PROC_NLF2LS) && (options & UTF8PROC_NLF2PS)) {

      if (category == UTF8PROC_CATEGORY_ZL ||

          category == UTF8PROC_CATEGORY_ZP)

        utf8proc_decompose_lump(0x000A);

    }

  }

  if (options & UTF8PROC_STRIPMARK) {

    if (category == UTF8PROC_CATEGORY_MN ||

      category == UTF8PROC_CATEGORY_MC ||

      category == UTF8PROC_CATEGORY_ME) return 0;

  }

  if (options & UTF8PROC_CASEFOLD) {

    if (property->casefold_seqindex != UINT16_MAX) {

      return seqindex_write_char_decomposed(property->casefold_seqindex, dst, bufsize, options, last_boundclass);

    }

  }

  if (options & (UTF8PROC_COMPOSE|UTF8PROC_DECOMPOSE)) {

    if (property->decomp_seqindex != UINT16_MAX &&

        (!property->decomp_type || (options & UTF8PROC_COMPAT))) {

      return seqindex_write_char_decomposed(property->decomp_seqindex, dst, bufsize, options, last_boundclass);

    }

  }

  if (options & UTF8PROC_CHARBOUND) {

    utf8proc_bool boundary;

    boundary = grapheme_break_extended(0, property->boundclass, 0, property->indic_conjunct_break,

                                       last_boundclass);

    if (boundary) {

      if (bufsize >= 1) dst[0] = -1; /* sentinel value for grapheme break */

      if (bufsize >= 2) dst[1] = uc;

      return 2;

    }

  }

  if (bufsize >= 1) *dst = uc;

  return 1;

}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose(

  const utf8proc_uint8_t *str, utf8proc_ssize_t strlen,

  utf8proc_int32_t *buffer, utf8proc_ssize_t bufsize, utf8proc_option_t options

) {

    return utf8proc_decompose_custom(str, strlen, buffer, bufsize, options, NULL, NULL);

}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose_custom(

  const utf8proc_uint8_t *str, utf8proc_ssize_t strlen,

  utf8proc_int32_t *buffer, utf8proc_ssize_t bufsize, utf8proc_option_t options,

  utf8proc_custom_func custom_func, void *custom_data

) {

  /* strlen will be ignored, if UTF8PROC_NULLTERM is set in options */

  utf8proc_ssize_t wpos = 0;

  if ((options & UTF8PROC_COMPOSE) && (options & UTF8PROC_DECOMPOSE))

    return UTF8PROC_ERROR_INVALIDOPTS;

  if ((options & UTF8PROC_STRIPMARK) &&

      !(options & UTF8PROC_COMPOSE) && !(options & UTF8PROC_DECOMPOSE))

    return UTF8PROC_ERROR_INVALIDOPTS;

  {

    utf8proc_int32_t uc;

    utf8proc_ssize_t rpos = 0;

    utf8proc_ssize_t decomp_result;

    int boundclass = UTF8PROC_BOUNDCLASS_START;

    while (1) {

      if (options & UTF8PROC_NULLTERM) {

        rpos += utf8proc_iterate(str + rpos, -1, &uc);

        /* checking of return value is not necessary,

           as 'uc' is < 0 in case of error */

        if (uc < 0) return UTF8PROC_ERROR_INVALIDUTF8;

        if (rpos < 0) return UTF8PROC_ERROR_OVERFLOW;

        if (uc == 0) break;

      } else {

        if (rpos >= strlen) break;

        rpos += utf8proc_iterate(str + rpos, strlen - rpos, &uc);

        if (uc < 0) return UTF8PROC_ERROR_INVALIDUTF8;

      }

      if (custom_func != NULL) {

        uc = custom_func(uc, custom_data);   /* user-specified custom mapping */

      }

      decomp_result = utf8proc_decompose_char(

        uc, buffer ? buffer+wpos : buffer, (bufsize > wpos) ? (bufsize - wpos) : 0, options,

        &boundclass

      );

      if (decomp_result < 0) return decomp_result;

      wpos += decomp_result;

      /* prohibiting integer overflows due to too long strings: */

      if (wpos < 0 ||

          wpos > (utf8proc_ssize_t)(SSIZE_MAX/sizeof(utf8proc_int32_t)/2))

        return UTF8PROC_ERROR_OVERFLOW;

    }

  }

  if ((options & (UTF8PROC_COMPOSE|UTF8PROC_DECOMPOSE)) && bufsize >= wpos) {

    utf8proc_ssize_t pos = 0;

    while (pos < wpos-1) {

      utf8proc_int32_t uc1, uc2;

      const utf8proc_property_t *property1, *property2;

      uc1 = buffer[pos];

      uc2 = buffer[pos+1];

      property1 = unsafe_get_property(uc1);

      property2 = unsafe_get_property(uc2);

      if (property1->combining_class > property2->combining_class &&

          property2->combining_class > 0) {

        buffer[pos] = uc2;

        buffer[pos+1] = uc1;

        if (pos > 0) pos--; else pos++;

      } else {

        pos++;

      }

    }

  }

  return wpos;

}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_normalize_utf32(utf8proc_int32_t *buffer, utf8proc_ssize_t length, utf8proc_option_t options) {

  /* UTF8PROC_NULLTERM option will be ignored, 'length' is never ignored */

  if (options & (UTF8PROC_NLF2LS | UTF8PROC_NLF2PS | UTF8PROC_STRIPCC)) {

    utf8proc_ssize_t rpos;

    utf8proc_ssize_t wpos = 0;

    utf8proc_int32_t uc;

    for (rpos = 0; rpos < length; rpos++) {

      uc = buffer[rpos];

      if (uc == 0x000D && rpos < length-1 && buffer[rpos+1] == 0x000A) rpos++;

      if (uc == 0x000A || uc == 0x000D || uc == 0x0085 ||

          ((options & UTF8PROC_STRIPCC) && (uc == 0x000B || uc == 0x000C))) {

        if (options & UTF8PROC_NLF2LS) {

          if (options & UTF8PROC_NLF2PS) {

            buffer[wpos++] = 0x000A;

          } else {

            buffer[wpos++] = 0x2028;

          }

        } else {

          if (options & UTF8PROC_NLF2PS) {

            buffer[wpos++] = 0x2029;

          } else {

            buffer[wpos++] = 0x0020;

          }

        }

      } else if ((options & UTF8PROC_STRIPCC) &&

          (uc < 0x0020 || (uc >= 0x007F && uc < 0x00A0))) {

        if (uc == 0x0009) buffer[wpos++] = 0x0020;

      } else {

        buffer[wpos++] = uc;

      }

    }

    length = wpos;

  }

  if (options & UTF8PROC_COMPOSE) {

    utf8proc_int32_t *starter = NULL;

    const utf8proc_property_t *starter_property = NULL;

    utf8proc_propval_t max_combining_class = -1;

    utf8proc_ssize_t rpos;

    utf8proc_ssize_t wpos = 0;

    for (rpos = 0; rpos < length; rpos++) {

      utf8proc_int32_t current_char = buffer[rpos];

      const utf8proc_property_t *current_property = unsafe_get_property(current_char);

      if (starter && current_property->combining_class > max_combining_class) {

        /* combination perhaps possible */

        utf8proc_int32_t hangul_lindex;

        utf8proc_int32_t hangul_sindex;

        hangul_lindex = *starter - UTF8PROC_HANGUL_LBASE;

        if (hangul_lindex >= 0 && hangul_lindex < UTF8PROC_HANGUL_LCOUNT) {

          utf8proc_int32_t hangul_vindex;

          hangul_vindex = current_char - UTF8PROC_HANGUL_VBASE;

          if (hangul_vindex >= 0 && hangul_vindex < UTF8PROC_HANGUL_VCOUNT) {

            *starter = UTF8PROC_HANGUL_SBASE +

              (hangul_lindex * UTF8PROC_HANGUL_VCOUNT + hangul_vindex) *

              UTF8PROC_HANGUL_TCOUNT;

            starter_property = NULL;

            continue;

          }

        }

        hangul_sindex = *starter - UTF8PROC_HANGUL_SBASE;

        if (hangul_sindex >= 0 && hangul_sindex < UTF8PROC_HANGUL_SCOUNT &&

            (hangul_sindex % UTF8PROC_HANGUL_TCOUNT) == 0) {

          utf8proc_int32_t hangul_tindex;

          hangul_tindex = current_char - UTF8PROC_HANGUL_TBASE;

          if (hangul_tindex >= 0 && hangul_tindex < UTF8PROC_HANGUL_TCOUNT) {

            *starter += hangul_tindex;

            starter_property = NULL;

            continue;

          }

        }

        if (!starter_property) {

          starter_property = unsafe_get_property(*starter);

        }

        int idx = starter_property->comb_index;

        if (idx < 0x3FF && current_property->comb_issecond) {

          int len = starter_property->comb_length;

          utf8proc_int32_t max_second = utf8proc_combinations_second[idx + len - 1];

          if (current_char <= max_second) {

            int off;

            // TODO: binary search? arithmetic search?

            for (off = 0; off < len; ++off) {

              utf8proc_int32_t second = utf8proc_combinations_second[idx + off];

              if (current_char < second) {

                /* not found */

                break;

              }

              if (current_char == second) {

                /* found */

                utf8proc_int32_t composition = utf8proc_combinations_combined[idx + off];

                *starter = composition;

                starter_property = NULL;

                break;

              }

            }

            if (starter_property == NULL) {

              /* found */

              continue;

            }

          }

        }

      }

      buffer[wpos] = current_char;

      if (current_property->combining_class) {

        if (current_property->combining_class > max_combining_class) {

          max_combining_class = current_property->combining_class;

        }

      } else {

        starter = buffer + wpos;

        starter_property = NULL;

        max_combining_class = -1;

      }

      wpos++;

    }

    length = wpos;

  }

  return length;

}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_reencode(utf8proc_int32_t *buffer, utf8proc_ssize_t length, utf8proc_option_t options) {

  /* UTF8PROC_NULLTERM option will be ignored, 'length' is never ignored

     ASSERT: 'buffer' has one spare byte of free space at the end! */

  length = utf8proc_normalize_utf32(buffer, length, options);

  if (length < 0) return length;

  {

    utf8proc_ssize_t rpos, wpos = 0;

    utf8proc_int32_t uc;

    if (options & UTF8PROC_CHARBOUND) {

        for (rpos = 0; rpos < length; rpos++) {

            uc = buffer[rpos];

            wpos += charbound_encode_char(uc, ((utf8proc_uint8_t *)buffer) + wpos);

        }

    } else {

        for (rpos = 0; rpos < length; rpos++) {

            uc = buffer[rpos];

            wpos += utf8proc_encode_char(uc, ((utf8proc_uint8_t *)buffer) + wpos);

        }

    }

    ((utf8proc_uint8_t *)buffer)[wpos] = 0;

    return wpos;

  }

}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_map(

  const utf8proc_uint8_t *str, utf8proc_ssize_t strlen, utf8proc_uint8_t **dstptr, utf8proc_option_t options

) {

    return utf8proc_map_custom(str, strlen, dstptr, options, NULL, NULL);

}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_map_custom(

  const utf8proc_uint8_t *str, utf8proc_ssize_t strlen, utf8proc_uint8_t **dstptr, utf8proc_option_t options,

  utf8proc_custom_func custom_func, void *custom_data

) {

  utf8proc_int32_t *buffer;

  utf8proc_ssize_t result;

  *dstptr = NULL;

  result = utf8proc_decompose_custom(str, strlen, NULL, 0, options, custom_func, custom_data);

  if (result < 0) return result;

  buffer = (utf8proc_int32_t *) malloc(((utf8proc_size_t)result) * sizeof(utf8proc_int32_t) + 1);

  if (!buffer) return UTF8PROC_ERROR_NOMEM;

  result = utf8proc_decompose_custom(str, strlen, buffer, result, options, custom_func, custom_data);

  if (result < 0) {

    free(buffer);

    return result;

  }

  result = utf8proc_reencode(buffer, result, options);

  if (result < 0) {

    free(buffer);

    return result;

  }

  {

    utf8proc_int32_t *newptr;

    newptr = (utf8proc_int32_t *) realloc(buffer, (size_t)result+1);

    if (newptr) buffer = newptr;

  }

  *dstptr = (utf8proc_uint8_t *)buffer;

  return result;

}

UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFD(const utf8proc_uint8_t *str) {

  utf8proc_uint8_t *retval;

  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |

    UTF8PROC_DECOMPOSE);

  return retval;

}

UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFC(const utf8proc_uint8_t *str) {

  utf8proc_uint8_t *retval;

  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |

    UTF8PROC_COMPOSE);

  return retval;

}

UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKD(const utf8proc_uint8_t *str) {

  utf8proc_uint8_t *retval;

  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |

    UTF8PROC_DECOMPOSE | UTF8PROC_COMPAT);

  return retval;

}

UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKC(const utf8proc_uint8_t *str) {

  utf8proc_uint8_t *retval;

  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |

    UTF8PROC_COMPOSE | UTF8PROC_COMPAT);

  return retval;

}

UTF8PROC_DLLEXPORT utf8proc_uint8_t *utf8proc_NFKC_Casefold(const utf8proc_uint8_t *str) {

  utf8proc_uint8_t *retval;

  utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE |

    UTF8PROC_COMPOSE | UTF8PROC_COMPAT | UTF8PROC_CASEFOLD | UTF8PROC_IGNORE);

  return retval;

}