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

/*  LibreDWG - free implementation of the DWG file format                    */

/*                                                                           */

/*  Copyright (C) 2023-2025 Free Software Foundation, Inc.                   */

/*                                                                           */

/*  This library is free software, licensed 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.  */

/*  You should have received a copy of the GNU General Public License        */

/*  along with this program.  If not, see <http://www.gnu.org/licenses/>.    */

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

/*

 * codepages.c: preR2007 codepages support via iconv

 * written by Reini Urban

 *

 * See also the src mappings from https://www.unicode.org/Public/MAPPINGS/

 * or the libdxfrw/src/intern/drw_textcodec.cpp mappings.

 */

#include "config.h"

#include <string.h>

#include <stdint.h>

#include <stdlib.h>

#include <errno.h>

#include <ctype.h>

#include <assert.h>

#if defined HAVE_ICONV && defined HAVE_ICONV_H

#  include <iconv.h>

#endif

#if defined HAVE_WCTYPE_H

#  include <wctype.h>

#endif

// #define CODEPAGES_C

#include "common.h"

#include "codepages.h"

#include "codepages/ISO-8859-2.h"

#include "codepages/ISO-8859-3.h"

#include "codepages/ISO-8859-4.h"

#include "codepages/ISO-8859-5.h"

#include "codepages/ISO-8859-6.h"

#include "codepages/ISO-8859-7.h"

#include "codepages/ISO-8859-8.h"

#include "codepages/ISO-8859-9.h"

#include "codepages/CP437.h"

#include "codepages/CP850.h"

#include "codepages/CP852.h"

#include "codepages/CP855.h"

#include "codepages/CP857.h"

#include "codepages/CP860.h"

#include "codepages/CP861.h"

#include "codepages/CP863.h"

#include "codepages/CP864.h"

#include "codepages/CP865.h"

#include "codepages/CP869.h"

#include "codepages/CP932.h"

#include "codepages/MACINTOSH.h"

#include "codepages/BIG5.h"

#include "codepages/CP949.h"

#include "codepages/JOHAB.h"

#include "codepages/CP866.h"

#include "codepages/WINDOWS-1250.h"

#include "codepages/WINDOWS-1251.h"

#include "codepages/WINDOWS-1252.h"

#include "codepages/GB2312.h"

#include "codepages/WINDOWS-1253.h"

#include "codepages/WINDOWS-1254.h"

#include "codepages/WINDOWS-1255.h"

#include "codepages/WINDOWS-1256.h"

#include "codepages/WINDOWS-1257.h"

#include "codepages/WINDOWS-874.h"

#include "codepages/WINDOWS-932.h"

#include "codepages/WINDOWS-936.h"

#include "codepages/WINDOWS-949.h"

#include "codepages/WINDOWS-950.h"

#include "codepages/WINDOWS-1361.h"

#include "codepages/WINDOWS-1258.h"

static const uint16_t *cp_fntbl[] = { NULL, // UTF8

                                      NULL, // US-ASCII

                                      NULL, // ISO-8859-1

                                      cptbl_iso_8859_2,

                                      cptbl_iso_8859_3,

                                      cptbl_iso_8859_4,

                                      cptbl_iso_8859_5,

                                      cptbl_iso_8859_6,

                                      cptbl_iso_8859_7,

                                      cptbl_iso_8859_8,

                                      cptbl_iso_8859_9,

                                      cptbl_cp437,

                                      cptbl_cp850,

                                      cptbl_cp852,

                                      cptbl_cp855,

                                      cptbl_cp857,

                                      cptbl_cp860,

                                      cptbl_cp861,

                                      cptbl_cp863,

                                      cptbl_cp864,

                                      cptbl_cp865,

                                      cptbl_cp869,

                                      cptbl_cp932, /* original shiftjis */

                                      cptbl_macintosh,

                                      cptbl_big5,

                                      cptbl_cp949, /* 25 */

                                      cptbl_johab, /* 26 */

                                      cptbl_cp866,

                                      cptbl_windows_1250,

                                      cptbl_windows_1251, /* 29 */

                                      cptbl_windows_1252, /* 30 */

                                      cptbl_gb2312,

                                      cptbl_windows_1253,

                                      cptbl_windows_1254,

                                      cptbl_windows_1255,

                                      cptbl_windows_1256,

                                      cptbl_windows_1257,

                                      cptbl_windows_874,

                                      cptbl_windows_932, /* windows-31j */

                                      cptbl_windows_936,

                                      cptbl_windows_949,

                                      cptbl_windows_950,

                                      cptbl_windows_1361, /* 42 */

                                      NULL,               /* 43 UTF16 */

                                      cptbl_windows_1258,

                                      NULL };

static const uint8_t *cp_alnumtbl[]

    = { NULL, // UTF8

        NULL, // US-ASCII

        NULL, // ISO-8859-1

        cptbl_alnum_iso_8859_2,

        cptbl_alnum_iso_8859_3,

        cptbl_alnum_iso_8859_4,

        cptbl_alnum_iso_8859_5,

        cptbl_alnum_iso_8859_6,

        cptbl_alnum_iso_8859_7,

        cptbl_alnum_iso_8859_8,

        cptbl_alnum_iso_8859_9,

        cptbl_alnum_cp437,

        cptbl_alnum_cp850,

        cptbl_alnum_cp852,

        cptbl_alnum_cp855,

        cptbl_alnum_cp857,

        cptbl_alnum_cp860,

        cptbl_alnum_cp861,

        cptbl_alnum_cp863,

        cptbl_alnum_cp864,

        cptbl_alnum_cp865,

        cptbl_alnum_cp869,

        NULL, // cptbl_alnum_cp932, /* original shiftjis */

        cptbl_alnum_macintosh,

        NULL, // cptbl_alnum_big5,

        NULL, // cptbl_alnum_cp949, /* 25 */

        NULL, // cptbl_alnum_johab, /* 26 */

        cptbl_alnum_cp866,

        cptbl_alnum_windows_1250,

        cptbl_alnum_windows_1251, /* 29 */

        cptbl_alnum_windows_1252, /* 30 */

        NULL,                     // cptbl_alnum_gb2312,

        cptbl_alnum_windows_1253,

        cptbl_alnum_windows_1254,

        cptbl_alnum_windows_1255,

        cptbl_alnum_windows_1256,

        cptbl_alnum_windows_1257,

        cptbl_alnum_windows_874,

        NULL, // cptbl_alnum_windows_932, /* windows-31j */

        NULL, // cptbl_alnum_windows_936,

        NULL, // cptbl_alnum_windows_949,

        NULL, // cptbl_alnum_windows_950,

        NULL, // cptbl_alnum_windows_1361, /* 42 */

        NULL, /* 43 UTF16 */

        cptbl_alnum_windows_1258,

        NULL };

static const uint16_t *cp_alnum16tbl[]

    = { NULL,              // UTF8

        NULL,              // US-ASCII

        NULL,              // ISO-8859-1

        NULL,              // cptbl_alnum_iso_8859_2,

        NULL,              // cptbl_alnum_iso_8859_3,

        NULL,              // cptbl_alnum_iso_8859_4,

        NULL,              // cptbl_alnum_iso_8859_5,

        NULL,              // cptbl_alnum_iso_8859_6,

        NULL,              // cptbl_alnum_iso_8859_7,

        NULL,              // cptbl_alnum_iso_8859_8,

        NULL,              // cptbl_alnum_iso_8859_9,

        NULL,              // cptbl_alnum_cp437,

        NULL,              // cptbl_alnum_cp850,

        NULL,              // cptbl_alnum_cp852,

        NULL,              // cptbl_alnum_cp855,

        NULL,              // cptbl_alnum_cp857,

        NULL,              // cptbl_alnum_cp860,

        NULL,              // cptbl_alnum_cp861,

        NULL,              // cptbl_alnum_cp863,

        NULL,              // cptbl_alnum_cp864,

        NULL,              // cptbl_alnum_cp865,

        NULL,              // cptbl_alnum_cp869,

        cptbl_alnum_cp932, /* original shiftjis */

        NULL,              // cptbl_alnum_macintosh,

        cptbl_alnum_big5,

        cptbl_alnum_cp949, /* 25 */

        cptbl_alnum_johab, /* 26 */

        NULL,              // cptbl_alnum_cp866,

        NULL,              // cptbl_alnum_windows_1250,

        NULL,              // cptbl_alnum_windows_1251, /* 29 */

        NULL,              // cptbl_alnum_windows_1252, /* 30 */

        cptbl_alnum_gb2312,

        NULL,                    // cptbl_alnum_windows_1253,

        NULL,                    // cptbl_alnum_windows_1254,

        NULL,                    // cptbl_alnum_windows_1255,

        NULL,                    // cptbl_alnum_windows_1256,

        NULL,                    // cptbl_alnum_windows_1257,

        NULL,                    // cptbl_alnum_windows_874,

        cptbl_alnum_windows_932, /* windows-31j */

        cptbl_alnum_windows_936,

        cptbl_alnum_windows_949,

        cptbl_alnum_windows_950,

        cptbl_alnum_windows_1361, /* 42 */

        NULL,                     /* 43 UTF16 */

        NULL,                     // cptbl_alnum_windows_1258,

        NULL };

// synced with typedef enum _dwg_codepage in codepages.h

#ifdef HAVE_ICONV

const char *

dwg_codepage_iconvstr (Dwg_Codepage cp)

{

  // for iconv

  const char *_codepage_iconvstr[] = { "UTF8",         "US-ASCII",

                                       "ISO-8859-1",   "ISO-8859-2",

                                       "ISO-8859-3",   "ISO-8859-4",

                                       "ISO-8859-5",   "ISO-8859-6",

                                       "ISO-8859-7",   "ISO-8859-8",

                                       "ISO-8859-9",   "CP437",

                                       "CP850",        "CP852",

                                       "CP855",        "CP857",

                                       "CP860",        "CP861",

                                       "CP863",        "CP864",

                                       "CP865",        "CP869",

                                       "CP932",        "MACINTOSH",

                                       "BIG5",         "CP949", /* 25 */

                                       "JOHAB",        "CP866",

                                       "WINDOWS-1250", "WINDOWS-1251", /* 29 */

                                       "WINDOWS-1252",                 /* 30 */

                                       "GB2312",       "WINDOWS-1253",

                                       "WINDOWS-1254", "WINDOWS-1255",

                                       "WINDOWS-1256", "WINDOWS-1257",

                                       "WINDOWS-874",  "WINDOWS-932",

                                       "WINDOWS-936",  "WINDOWS-949",

                                       "WINDOWS-950",  "WINDOWS-1361",

                                       "UTF16", /* 43 */

                                       "WINDOWS-1258", NULL };

  if (cp <= CP_ANSI_1258)

    return _codepage_iconvstr[cp];

  else

    return NULL;

}

#endif

const char *_codepage_dxfstr[]

    = { "UTF8",       "US_ASCII",   "ISO-8859-1", "ISO-8859-2", "ISO-8859-3",

        "ISO-8859-4", "ISO-8859-5", "ISO-8859-6", "ISO-8859-7", "ISO-8859-8",

        "ISO-8859-9", "CP437",      "CP850",      "CP852",      "CP855",

        "CP857",      "CP860",      "CP861",      "CP863",      "CP864",

        "CP865",      "CP869",      "CP932",      "MACINTOSH",  "BIG5",

        "CP949",                                               /* 25 */

        "JOHAB",      "CP866",      "ANSI_1250",  "ANSI_1251", /* 29 */

        "ANSI_1252", /* 30 WesternEurope Windows */

        "GB2312",     "ANSI_1253",  "ANSI_1254",  "ANSI_1255",  "ANSI_1256",

        "ANSI_1257",  "ANSI_874",   "ANSI_932",   "ANSI_936",   "ANSI_949",

        "ANSI_950",   "ANSI_1361",  "UTF16", /* 43 */

        "ANSI_1258",  NULL };

const char *

dwg_codepage_dxfstr (Dwg_Codepage cp)

{

  if (cp <= CP_ANSI_1258)

    return _codepage_dxfstr[cp];

  else if (cp == CP_UNDEFINED)

    return "undefined";

  else

    return NULL;

}

Dwg_Codepage

dwg_codepage_int (const char *s)

{

  for (int i = 0; i <= (int)CP_ANSI_1258; i++)

    {

      if (strEQ (s, _codepage_dxfstr[i]))

        return (Dwg_Codepage)i;

      if (islower (*s) && 0 == strcasecmp (s, _codepage_dxfstr[i]))

        return (Dwg_Codepage)i;

    }

  return CP_UNDEFINED;

}

/* helper to check if a codepoint exists in the codepage,

   and convert it to/from unicode.

   dir = 1: from unicode wc to charset

   asian = 1: 2-byte CJK charset, else 1-byte (0-255)

*/

static wchar_t

codepage_helper (const Dwg_Codepage codepage, const wchar_t wc, const int dir,

                 const int asian)

{

  const uint16_t *fntbl;

  uint16_t maxc;

  assert (codepage != CP_UTF8 && codepage != CP_UTF16

          && codepage != CP_US_ASCII && codepage != CP_ISO_8859_1);

  fntbl = cp_fntbl[codepage];

  maxc = fntbl[0];

  assert (maxc);

  if (dir) // from unicode to charset.

    {      // reverse lookup. unsorted rhs values so we cannot bsearch.

      for (uint16_t i = 0x80; i < maxc; i++)

        {

          if (wc == fntbl[i])

            return i;

        }

      return 0;

    }

  else

    {

      if (wc < maxc)

        return fntbl[wc];

      else

        return 0;

    }

}

// returns the matching unicode codepoint,

// or 0 if the codepage does not contain the character

wchar_t

dwg_codepage_uc (Dwg_Codepage cp, unsigned char c)

{

  if (c < 128)

    return (wchar_t)c;

  else if (cp == CP_US_ASCII)

    return 0;

  if (cp == CP_ISO_8859_1 || cp == CP_UTF8 || cp == CP_UTF16)

    return (wchar_t)c;

  return codepage_helper (cp, (wchar_t)c, 0, 0);

}

// for wide asian chars

wchar_t

dwg_codepage_uwc (Dwg_Codepage cp, uint16_t c)

{

  if (cp == CP_CP864 && c == 0x25)

    return 0x066a;

  else if (cp == CP_CP932 && c == 0x5c)

    return 0x00A5;

  else if (cp == CP_CP932 && c == 0x7e)

    return 0x203E;

  else if (cp == CP_JOHAB && c == 0x5c)

    return 0x20A9;

  else if (c < 128 || cp == CP_UTF8 || cp == CP_UTF16)

    return (wchar_t)c;

  return codepage_helper (cp, (wchar_t)c, 0, 1);

}

// returns the matching codepoint,

// or 0 if the codepage does not contain the wide character

unsigned char

dwg_codepage_c (Dwg_Codepage cp, wchar_t wc)

{

  if (wc < 128)

    {

      if (cp == CP_US_ASCII || cp == CP_UTF8 || cp == CP_UTF16)

        return wc & 0xff;

    }

  else if (cp == CP_US_ASCII)

    return 0;

  if (cp == CP_ISO_8859_1 || cp == CP_UTF8)

    return wc < 256 ? wc : 0;

  return (unsigned char)codepage_helper (cp, wc, 1, 0);

}

// for wide asian chars

uint16_t

dwg_codepage_wc (Dwg_Codepage cp, wchar_t wc)

{

  if (wc < 128 || cp == CP_UTF8 || cp == CP_UTF16)

    return wc & 0xffff;

  return (uint16_t)codepage_helper (cp, wc, 1, 1);

}

/* for possible wide asian chars:

   932 is single-byte for most chars, but 0x8*, 0x9*, 0xE* and 0xF* lead bytes

   CP949, JOHAB, ANSI_949, 936, 950 for all > 0x8* lead bytes

   1361 for all but 0x8[0123], 0xD[4567F], 0xF[A-F] lead bytes

   BIG5, GB2312 are two-byte only.

   none have valid 0x00 bytes, so strlen works as before in the TV case.

*/

bool

dwg_codepage_isasian (const Dwg_Codepage cp)

{

  if (cp >= CP_BIG5 && cp <= CP_JOHAB)

    return true;

  else if (cp >= CP_ANSI_932 && cp <= CP_ANSI_1258)

    return true;

  else if (cp == CP_GB2312)

    return true;

  else

    return false;

}

static int

b8_cmp (const void *a, const void *b)

{

  return *(uint8_t *)a < *(uint8_t *)b   ? -1

         : *(uint8_t *)a > *(uint8_t *)b ? 1

                                         : 0;

}

static int

b16_cmp (const void *a, const void *b)

{

  return *(uint16_t *)a < *(uint16_t *)b   ? -1

         : *(uint16_t *)a > *(uint16_t *)b ? 1

                                           : 0;

}

bool

dwg_codepage_isalnum (const Dwg_Codepage cp, const wchar_t c)

{

  if (c < 128)

    return isalnum ((int)c);

  switch (cp)

    {

    case CP_US_ASCII:

      return false;

    case CP_ISO_8859_1:

      return (c >= 0xC0 && c <= 0xD6) || (c >= 0xD8 && c <= 0xFF);

    case CP_UTF8:

    case CP_UTF16: // fallthru

#if defined HAVE_WCTYPE_H

      return iswalnum ((int)c);

#else

                   // TODO panic?

      return false;

#endif

    default:

      {

        const uint8_t *fntbl = cp_alnumtbl[cp];

        assert (cp != CP_UTF8 && cp != CP_UTF16 && cp != CP_US_ASCII

                && cp != CP_ISO_8859_1);

        // 8 or 16bit?

        if (fntbl)

          {

            const uint8_t key = c & 0xff;

            const uint8_t sz8 = fntbl[0];

            const size_t sz = (size_t)sz8;

            uint8_t *found

                = (uint8_t *)bsearch (&key, &fntbl[1], sz, 1, b8_cmp);

            if (!found || found == &fntbl[0])

              return false;

            else

              return true;

          }

        else

          {

            const uint16_t key = c & 0xffff;

            const uint16_t *fntbl16 = cp_alnum16tbl[cp];

            const uint16_t sz16 = fntbl16[0];

            const size_t sz = (size_t)sz16;

            uint16_t *found

                = (uint16_t *)bsearch (&key, &fntbl16[1], sz, 2, b16_cmp);

            if (!found || found == &fntbl16[0])

              return false;

            else

              return true;

          }

        return false;

      }

    }

}

bool

dwg_codepage_is_twobyte (const Dwg_Codepage cp, const unsigned char c)

{

  if (cp == CP_CP932 || cp == CP_ANSI_932)

    return (c >= 0x80 && c <= 0x9F) || (c >= 0xE0);

  else if (cp == CP_CP949 || cp == CP_ANSI_949 || cp == CP_ANSI_936

           || cp == CP_ANSI_950)

    return c & 0x80;

  else if (cp == CP_ANSI_1361)

    return (c >= 0x80 && c <= 0x83) || (c >= 0xD4 && c <= 0xD7) || (c == 0xDF)

           || (c >= 0xFA);

  else if (cp == CP_GB2312 || cp == CP_BIG5)

    return true;

  else

    return false;

}