/*-------------------------------------------------------------------------

 *

 * encnames.c

 *    Encoding names and routines for working with them.

 *

 * Portions Copyright (c) 2001-2025, PostgreSQL Global Development Group

 *

 * IDENTIFICATION

 *    src/common/encnames.c

 *

 *-------------------------------------------------------------------------

 */

#include "c.h"

#include <ctype.h>

#include <unistd.h>

#include "mb/pg_wchar.h"

/* ----------

 * All encoding names, sorted:     *** A L P H A B E T I C ***

 *

 * All names must be without irrelevant chars, search routines use

 * isalnum() chars only. It means ISO-8859-1, iso_8859-1 and Iso8859_1

 * are always converted to 'iso88591'. All must be lower case.

 *

 * The table doesn't contain 'cs' aliases (like csISOLatin1). It's needed?

 *

 * Karel Zak, Aug 2001

 * ----------

 */

typedef struct pg_encname

{

  const char *name;

  pg_enc    encoding;

} pg_encname;

static const pg_encname pg_encname_tbl[] =

{

  {

    "abc", PG_WIN1258

  },              /* alias for WIN1258 */

  {

    "alt", PG_WIN866

  },              /* IBM866 */

  {

    "big5", PG_BIG5

  },              /* Big5; Chinese for Taiwan multibyte set */

  {

    "euccn", PG_EUC_CN

  },              /* EUC-CN; Extended Unix Code for simplified

                 * Chinese */

  {

    "eucjis2004", PG_EUC_JIS_2004

  },              /* EUC-JIS-2004; Extended UNIX Code fixed

                 * Width for Japanese, standard JIS X 0213 */

  {

    "eucjp", PG_EUC_JP

  },              /* EUC-JP; Extended UNIX Code fixed Width for

                 * Japanese, standard OSF */

  {

    "euckr", PG_EUC_KR

  },              /* EUC-KR; Extended Unix Code for Korean , KS

                 * X 1001 standard */

  {

    "euctw", PG_EUC_TW

  },              /* EUC-TW; Extended Unix Code for

                 *

                 * traditional Chinese */

  {

    "gb18030", PG_GB18030

  },              /* GB18030;GB18030 */

  {

    "gbk", PG_GBK

  },              /* GBK; Chinese Windows CodePage 936

                 * simplified Chinese */

  {

    "iso88591", PG_LATIN1

  },              /* ISO-8859-1; RFC1345,KXS2 */

  {

    "iso885910", PG_LATIN6

  },              /* ISO-8859-10; RFC1345,KXS2 */

  {

    "iso885913", PG_LATIN7

  },              /* ISO-8859-13; RFC1345,KXS2 */

  {

    "iso885914", PG_LATIN8

  },              /* ISO-8859-14; RFC1345,KXS2 */

  {

    "iso885915", PG_LATIN9

  },              /* ISO-8859-15; RFC1345,KXS2 */

  {

    "iso885916", PG_LATIN10

  },              /* ISO-8859-16; RFC1345,KXS2 */

  {

    "iso88592", PG_LATIN2

  },              /* ISO-8859-2; RFC1345,KXS2 */

  {

    "iso88593", PG_LATIN3

  },              /* ISO-8859-3; RFC1345,KXS2 */

  {

    "iso88594", PG_LATIN4

  },              /* ISO-8859-4; RFC1345,KXS2 */

  {

    "iso88595", PG_ISO_8859_5

  },              /* ISO-8859-5; RFC1345,KXS2 */

  {

    "iso88596", PG_ISO_8859_6

  },              /* ISO-8859-6; RFC1345,KXS2 */

  {

    "iso88597", PG_ISO_8859_7

  },              /* ISO-8859-7; RFC1345,KXS2 */

  {

    "iso88598", PG_ISO_8859_8

  },              /* ISO-8859-8; RFC1345,KXS2 */

  {

    "iso88599", PG_LATIN5

  },              /* ISO-8859-9; RFC1345,KXS2 */

  {

    "johab", PG_JOHAB

  },              /* JOHAB; Extended Unix Code for simplified

                 * Chinese */

  {

    "koi8", PG_KOI8R

  },              /* _dirty_ alias for KOI8-R (backward

                 * compatibility) */

  {

    "koi8r", PG_KOI8R

  },              /* KOI8-R; RFC1489 */

  {

    "koi8u", PG_KOI8U

  },              /* KOI8-U; RFC2319 */

  {

    "latin1", PG_LATIN1

  },              /* alias for ISO-8859-1 */

  {

    "latin10", PG_LATIN10

  },              /* alias for ISO-8859-16 */

  {

    "latin2", PG_LATIN2

  },              /* alias for ISO-8859-2 */

  {

    "latin3", PG_LATIN3

  },              /* alias for ISO-8859-3 */

  {

    "latin4", PG_LATIN4

  },              /* alias for ISO-8859-4 */

  {

    "latin5", PG_LATIN5

  },              /* alias for ISO-8859-9 */

  {

    "latin6", PG_LATIN6

  },              /* alias for ISO-8859-10 */

  {

    "latin7", PG_LATIN7

  },              /* alias for ISO-8859-13 */

  {

    "latin8", PG_LATIN8

  },              /* alias for ISO-8859-14 */

  {

    "latin9", PG_LATIN9

  },              /* alias for ISO-8859-15 */

  {

    "mskanji", PG_SJIS

  },              /* alias for Shift_JIS */

  {

    "muleinternal", PG_MULE_INTERNAL

  },

  {

    "shiftjis", PG_SJIS

  },              /* Shift_JIS; JIS X 0202-1991 */

  {

    "shiftjis2004", PG_SHIFT_JIS_2004

  },              /* SHIFT-JIS-2004; Shift JIS for Japanese,

                 * standard JIS X 0213 */

  {

    "sjis", PG_SJIS

  },              /* alias for Shift_JIS */

  {

    "sqlascii", PG_SQL_ASCII

  },

  {

    "tcvn", PG_WIN1258

  },              /* alias for WIN1258 */

  {

    "tcvn5712", PG_WIN1258

  },              /* alias for WIN1258 */

  {

    "uhc", PG_UHC

  },              /* UHC; Korean Windows CodePage 949 */

  {

    "unicode", PG_UTF8

  },              /* alias for UTF8 */

  {

    "utf8", PG_UTF8

  },              /* alias for UTF8 */

  {

    "vscii", PG_WIN1258

  },              /* alias for WIN1258 */

  {

    "win", PG_WIN1251

  },              /* _dirty_ alias for windows-1251 (backward

                 * compatibility) */

  {

    "win1250", PG_WIN1250

  },              /* alias for Windows-1250 */

  {

    "win1251", PG_WIN1251

  },              /* alias for Windows-1251 */

  {

    "win1252", PG_WIN1252

  },              /* alias for Windows-1252 */

  {

    "win1253", PG_WIN1253

  },              /* alias for Windows-1253 */

  {

    "win1254", PG_WIN1254

  },              /* alias for Windows-1254 */

  {

    "win1255", PG_WIN1255

  },              /* alias for Windows-1255 */

  {

    "win1256", PG_WIN1256

  },              /* alias for Windows-1256 */

  {

    "win1257", PG_WIN1257

  },              /* alias for Windows-1257 */

  {

    "win1258", PG_WIN1258

  },              /* alias for Windows-1258 */

  {

    "win866", PG_WIN866

  },              /* IBM866 */

  {

    "win874", PG_WIN874

  },              /* alias for Windows-874 */

  {

    "win932", PG_SJIS

  },              /* alias for Shift_JIS */

  {

    "win936", PG_GBK

  },              /* alias for GBK */

  {

    "win949", PG_UHC

  },              /* alias for UHC */

  {

    "win950", PG_BIG5

  },              /* alias for BIG5 */

  {

    "windows1250", PG_WIN1250

  },              /* Windows-1251; Microsoft */

  {

    "windows1251", PG_WIN1251

  },              /* Windows-1251; Microsoft */

  {

    "windows1252", PG_WIN1252

  },              /* Windows-1252; Microsoft */

  {

    "windows1253", PG_WIN1253

  },              /* Windows-1253; Microsoft */

  {

    "windows1254", PG_WIN1254

  },              /* Windows-1254; Microsoft */

  {

    "windows1255", PG_WIN1255

  },              /* Windows-1255; Microsoft */

  {

    "windows1256", PG_WIN1256

  },              /* Windows-1256; Microsoft */

  {

    "windows1257", PG_WIN1257

  },              /* Windows-1257; Microsoft */

  {

    "windows1258", PG_WIN1258

  },              /* Windows-1258; Microsoft */

  {

    "windows866", PG_WIN866

  },              /* IBM866 */

  {

    "windows874", PG_WIN874

  },              /* Windows-874; Microsoft */

  {

    "windows932", PG_SJIS

  },              /* alias for Shift_JIS */

  {

    "windows936", PG_GBK

  },              /* alias for GBK */

  {

    "windows949", PG_UHC

  },              /* alias for UHC */

  {

    "windows950", PG_BIG5

  }             /* alias for BIG5 */

};

/* ----------

 * These are "official" encoding names.

 * ----------

 */

#ifndef WIN32

#define DEF_ENC2NAME(name, codepage) { #name, PG_##name }

#else

#define DEF_ENC2NAME(name, codepage) { #name, PG_##name, codepage }

#endif

const pg_enc2name pg_enc2name_tbl[] =

{

  [PG_SQL_ASCII] = DEF_ENC2NAME(SQL_ASCII, 0),

  [PG_EUC_JP] = DEF_ENC2NAME(EUC_JP, 20932),

  [PG_EUC_CN] = DEF_ENC2NAME(EUC_CN, 20936),

  [PG_EUC_KR] = DEF_ENC2NAME(EUC_KR, 51949),

  [PG_EUC_TW] = DEF_ENC2NAME(EUC_TW, 0),

  [PG_EUC_JIS_2004] = DEF_ENC2NAME(EUC_JIS_2004, 20932),

  [PG_UTF8] = DEF_ENC2NAME(UTF8, 65001),

  [PG_MULE_INTERNAL] = DEF_ENC2NAME(MULE_INTERNAL, 0),

  [PG_LATIN1] = DEF_ENC2NAME(LATIN1, 28591),

  [PG_LATIN2] = DEF_ENC2NAME(LATIN2, 28592),

  [PG_LATIN3] = DEF_ENC2NAME(LATIN3, 28593),

  [PG_LATIN4] = DEF_ENC2NAME(LATIN4, 28594),

  [PG_LATIN5] = DEF_ENC2NAME(LATIN5, 28599),

  [PG_LATIN6] = DEF_ENC2NAME(LATIN6, 0),

  [PG_LATIN7] = DEF_ENC2NAME(LATIN7, 0),

  [PG_LATIN8] = DEF_ENC2NAME(LATIN8, 0),

  [PG_LATIN9] = DEF_ENC2NAME(LATIN9, 28605),

  [PG_LATIN10] = DEF_ENC2NAME(LATIN10, 0),

  [PG_WIN1256] = DEF_ENC2NAME(WIN1256, 1256),

  [PG_WIN1258] = DEF_ENC2NAME(WIN1258, 1258),

  [PG_WIN866] = DEF_ENC2NAME(WIN866, 866),

  [PG_WIN874] = DEF_ENC2NAME(WIN874, 874),

  [PG_KOI8R] = DEF_ENC2NAME(KOI8R, 20866),

  [PG_WIN1251] = DEF_ENC2NAME(WIN1251, 1251),

  [PG_WIN1252] = DEF_ENC2NAME(WIN1252, 1252),

  [PG_ISO_8859_5] = DEF_ENC2NAME(ISO_8859_5, 28595),

  [PG_ISO_8859_6] = DEF_ENC2NAME(ISO_8859_6, 28596),

  [PG_ISO_8859_7] = DEF_ENC2NAME(ISO_8859_7, 28597),

  [PG_ISO_8859_8] = DEF_ENC2NAME(ISO_8859_8, 28598),

  [PG_WIN1250] = DEF_ENC2NAME(WIN1250, 1250),

  [PG_WIN1253] = DEF_ENC2NAME(WIN1253, 1253),

  [PG_WIN1254] = DEF_ENC2NAME(WIN1254, 1254),

  [PG_WIN1255] = DEF_ENC2NAME(WIN1255, 1255),

  [PG_WIN1257] = DEF_ENC2NAME(WIN1257, 1257),

  [PG_KOI8U] = DEF_ENC2NAME(KOI8U, 21866),

  [PG_SJIS] = DEF_ENC2NAME(SJIS, 932),

  [PG_BIG5] = DEF_ENC2NAME(BIG5, 950),

  [PG_GBK] = DEF_ENC2NAME(GBK, 936),

  [PG_UHC] = DEF_ENC2NAME(UHC, 949),

  [PG_GB18030] = DEF_ENC2NAME(GB18030, 54936),

  [PG_JOHAB] = DEF_ENC2NAME(JOHAB, 0),

  [PG_SHIFT_JIS_2004] = DEF_ENC2NAME(SHIFT_JIS_2004, 932),

};

/* ----------

 * These are encoding names for gettext.

 *

 * This covers all encodings except MULE_INTERNAL, which is alien to gettext.

 * ----------

 */

const char *pg_enc2gettext_tbl[] =

{

  [PG_SQL_ASCII] = "US-ASCII",

  [PG_UTF8] = "UTF-8",

  [PG_MULE_INTERNAL] = NULL,

  [PG_LATIN1] = "LATIN1",

  [PG_LATIN2] = "LATIN2",

  [PG_LATIN3] = "LATIN3",

  [PG_LATIN4] = "LATIN4",

  [PG_ISO_8859_5] = "ISO-8859-5",

  [PG_ISO_8859_6] = "ISO_8859-6",

  [PG_ISO_8859_7] = "ISO-8859-7",

  [PG_ISO_8859_8] = "ISO-8859-8",

  [PG_LATIN5] = "LATIN5",

  [PG_LATIN6] = "LATIN6",

  [PG_LATIN7] = "LATIN7",

  [PG_LATIN8] = "LATIN8",

  [PG_LATIN9] = "LATIN-9",

  [PG_LATIN10] = "LATIN10",

  [PG_KOI8R] = "KOI8-R",

  [PG_KOI8U] = "KOI8-U",

  [PG_WIN1250] = "CP1250",

  [PG_WIN1251] = "CP1251",

  [PG_WIN1252] = "CP1252",

  [PG_WIN1253] = "CP1253",

  [PG_WIN1254] = "CP1254",

  [PG_WIN1255] = "CP1255",

  [PG_WIN1256] = "CP1256",

  [PG_WIN1257] = "CP1257",

  [PG_WIN1258] = "CP1258",

  [PG_WIN866] = "CP866",

  [PG_WIN874] = "CP874",

  [PG_EUC_CN] = "EUC-CN",

  [PG_EUC_JP] = "EUC-JP",

  [PG_EUC_KR] = "EUC-KR",

  [PG_EUC_TW] = "EUC-TW",

  [PG_EUC_JIS_2004] = "EUC-JP",

  [PG_SJIS] = "SHIFT-JIS",

  [PG_BIG5] = "BIG5",

  [PG_GBK] = "GBK",

  [PG_UHC] = "UHC",

  [PG_GB18030] = "GB18030",

  [PG_JOHAB] = "JOHAB",

  [PG_SHIFT_JIS_2004] = "SHIFT_JISX0213",

};

/*

 * Table of encoding names for ICU (currently covers backend encodings only)

 *

 * Reference: <https://ssl.icu-project.org/icu-bin/convexp>

 *

 * NULL entries are not supported by ICU, or their mapping is unclear.

 */

static const char *const pg_enc2icu_tbl[] =

{

  [PG_SQL_ASCII] = NULL,

  [PG_EUC_JP] = "EUC-JP",

  [PG_EUC_CN] = "EUC-CN",

  [PG_EUC_KR] = "EUC-KR",

  [PG_EUC_TW] = "EUC-TW",

  [PG_EUC_JIS_2004] = NULL,

  [PG_UTF8] = "UTF-8",

  [PG_MULE_INTERNAL] = NULL,

  [PG_LATIN1] = "ISO-8859-1",

  [PG_LATIN2] = "ISO-8859-2",

  [PG_LATIN3] = "ISO-8859-3",

  [PG_LATIN4] = "ISO-8859-4",

  [PG_LATIN5] = "ISO-8859-9",

  [PG_LATIN6] = "ISO-8859-10",

  [PG_LATIN7] = "ISO-8859-13",

  [PG_LATIN8] = "ISO-8859-14",

  [PG_LATIN9] = "ISO-8859-15",

  [PG_LATIN10] = NULL,

  [PG_WIN1256] = "CP1256",

  [PG_WIN1258] = "CP1258",

  [PG_WIN866] = "CP866",

  [PG_WIN874] = NULL,

  [PG_KOI8R] = "KOI8-R",

  [PG_WIN1251] = "CP1251",

  [PG_WIN1252] = "CP1252",

  [PG_ISO_8859_5] = "ISO-8859-5",

  [PG_ISO_8859_6] = "ISO-8859-6",

  [PG_ISO_8859_7] = "ISO-8859-7",

  [PG_ISO_8859_8] = "ISO-8859-8",

  [PG_WIN1250] = "CP1250",

  [PG_WIN1253] = "CP1253",

  [PG_WIN1254] = "CP1254",

  [PG_WIN1255] = "CP1255",

  [PG_WIN1257] = "CP1257",

  [PG_KOI8U] = "KOI8-U",

};

StaticAssertDecl(lengthof(pg_enc2icu_tbl) == PG_ENCODING_BE_LAST + 1,

         "pg_enc2icu_tbl incomplete");

/*

 * Is this encoding supported by ICU?

 */

bool

is_encoding_supported_by_icu(int encoding)

{

  if (!PG_VALID_BE_ENCODING(encoding))

    return false;

  return (pg_enc2icu_tbl[encoding] != NULL);

}

/*

 * Returns ICU's name for encoding, or NULL if not supported

 */

const char *

get_encoding_name_for_icu(int encoding)

{

  if (!PG_VALID_BE_ENCODING(encoding))

    return NULL;

  return pg_enc2icu_tbl[encoding];

}

/* ----------

 * Encoding checks, for error returns -1 else encoding id

 * ----------

 */

int

pg_valid_client_encoding(const char *name)

{

  int     enc;

  if ((enc = pg_char_to_encoding(name)) < 0)

    return -1;

  if (!PG_VALID_FE_ENCODING(enc))

    return -1;

  return enc;

}

int

pg_valid_server_encoding(const char *name)

{

  int     enc;

  if ((enc = pg_char_to_encoding(name)) < 0)

    return -1;

  if (!PG_VALID_BE_ENCODING(enc))

    return -1;

  return enc;

}

int

pg_valid_server_encoding_id(int encoding)

{

  return PG_VALID_BE_ENCODING(encoding);

}

/*

 * Remove irrelevant chars from encoding name, store at *newkey

 *

 * (Caller's responsibility to provide a large enough buffer)

 */

static char *

clean_encoding_name(const char *key, char *newkey)

{

  const char *p;

  char     *np;

  for (p = key, np = newkey; *p != '\0'; p++)

  {

    if (isalnum((unsigned char) *p))

    {

      if (*p >= 'A' && *p <= 'Z')

        *np++ = *p + 'a' - 'A';

      else

        *np++ = *p;

    }

  }

  *np = '\0';

  return newkey;

}

/*

 * Search encoding by encoding name

 *

 * Returns encoding ID, or -1 if not recognized

 */

int

pg_char_to_encoding(const char *name)

{

  unsigned int nel = lengthof(pg_encname_tbl);

  const pg_encname *base = pg_encname_tbl,

         *last = base + nel - 1,

         *position;

  int     result;

  char    buff[NAMEDATALEN],

         *key;

  if (name == NULL || *name == '\0')

    return -1;

  if (strlen(name) >= NAMEDATALEN)

    return -1;       /* it's certainly not in the table */

  key = clean_encoding_name(name, buff);

  while (last >= base)

  {

    position = base + ((last - base) >> 1);

    result = key[0] - position->name[0];

    if (result == 0)

    {

      result = strcmp(key, position->name);

      if (result == 0)

        return position->encoding;

    }

    if (result < 0)

      last = position - 1;

    else

      base = position + 1;

  }

  return -1;

}

const char *

pg_encoding_to_char(int encoding)

{

  if (PG_VALID_ENCODING(encoding))

  {

    const pg_enc2name *p = &pg_enc2name_tbl[encoding];

    Assert(encoding == p->encoding);

    return p->name;

  }

  return "";

}