/*
 * This is an implementation of wcwidth() and wcswidth() (defined in
 * IEEE Std 1002.1-2001) for Unicode.
 *
 * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
 * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
 *
 * In fixed-width output devices, Latin characters all occupy a single
 * "cell" position of equal width, whereas ideographic CJK characters
 * occupy two such cells. Interoperability between terminal-line
 * applications and (teletype-style) character terminals using the
 * UTF-8 encoding requires agreement on which character should advance
 * the cursor by how many cell positions. No established formal
 * standards exist at present on which Unicode character shall occupy
 * how many cell positions on character terminals. These routines are
 * a first attempt of defining such behavior based on simple rules
 * applied to data provided by the Unicode Consortium.
 *
 * For some graphical characters, the Unicode standard explicitly
 * defines a character-cell width via the definition of the East Asian
 * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
 * In all these cases, there is no ambiguity about which width a
 * terminal shall use. For characters in the East Asian Ambiguous (A)
 * class, the width choice depends purely on a preference of backward
 * compatibility with either historic CJK or Western practice.
 * Choosing single-width for these characters is easy to justify as
 * the appropriate long-term solution, as the CJK practice of
 * displaying these characters as double-width comes from historic
 * implementation simplicity (8-bit encoded characters were displayed
 * single-width and 16-bit ones double-width, even for Greek,
 * Cyrillic, etc.) and not any typographic considerations.
 *
 * Much less clear is the choice of width for the Not East Asian
 * (Neutral) class. Existing practice does not dictate a width for any
 * of these characters. It would nevertheless make sense
 * typographically to allocate two character cells to characters such
 * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
 * represented adequately with a single-width glyph. The following
 * routines at present merely assign a single-cell width to all
 * neutral characters, in the interest of simplicity. This is not
 * entirely satisfactory and should be reconsidered before
 * establishing a formal standard in this area. At the moment, the
 * decision which Not East Asian (Neutral) characters should be
 * represented by double-width glyphs cannot yet be answered by
 * applying a simple rule from the Unicode database content. Setting
 * up a proper standard for the behavior of UTF-8 character terminals
 * will require a careful analysis not only of each Unicode character,
 * but also of each presentation form, something the author of these
 * routines has avoided to do so far.
 *
 * http://www.unicode.org/unicode/reports/tr11/
 *
 * Markus Kuhn -- 2002-05-08 (Unicode 3.2)
 *
 * Permission to use, copy, modify, and distribute this software
 * for any purpose and without fee is hereby granted. The author
 * disclaims all warranties with regard to this software.
 *
 * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
 */

#include "fribidi_wcwidth.i"

struct interval
{
  int first;
  int last;
};

/* auxiliary function for binary search in interval table */
static int
bisearch (wchar_t ucs, const struct interval *table, int max)
{
  int min = 0;
  int mid;

  if (ucs < table[0].first || ucs > table[max].last)
    return 0;
  while (max >= min)
    {
      mid = (min + max) / 2;
      if (ucs > table[mid].last)
	min = mid + 1;
      else if (ucs < table[mid].first)
	max = mid - 1;
      else
	return 1;
    }

  return 0;
}


/* The following two functions define the column width of an ISO 10646
 * character as follows:
 *
 *    - The null character (U+0000) has a column width of 0.
 *
 *    - Other C0/C1 control characters and DEL will lead to a return
 *      value of -1.
 *
 *    - Non-spacing and enclosing combining characters (general
 *      category code Mn or Me in the Unicode database) have a
 *      column width of 0.
 *
 *    - Other format characters (general category code Cf in the Unicode
 *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
 *
 *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
 *      have a column width of 0.
 *
 *    - Spacing characters in the East Asian Wide (W) or East Asian
 *      Full-width (F) category as defined in Unicode Technical
 *      Report #11 have a column width of 2.
 *
 *    - All remaining characters (including all printable
 *      ISO 8859-1 and WGL4 characters, Unicode control characters,
 *      etc.) have a column width of 1.
 *
 * This implementation assumes that wchar_t characters are encoded
 * in ISO 10646.
 */

int
mk_wcwidth (wchar_t ucs)
{
  /* sorted list of non-overlapping intervals of non-spacing characters */
  /* generated with "uniset +cat=Me +cat=Mn +cat=Cf +1160-11FF +200B c" */
  static const struct interval combining[] = {
    {0x0300, 0x034F}, {0x0360, 0x036F}, {0x0483, 0x0486},
    {0x0488, 0x0489}, {0x0591, 0x05A1}, {0x05A3, 0x05B9},
    {0x05BB, 0x05BD}, {0x05BF, 0x05BF}, {0x05C1, 0x05C2},
    {0x05C4, 0x05C4}, {0x064B, 0x0655}, {0x0670, 0x0670},
    {0x06D6, 0x06E4}, {0x06E7, 0x06E8}, {0x06EA, 0x06ED},
    {0x070F, 0x070F}, {0x0711, 0x0711}, {0x0730, 0x074A},
    {0x07A6, 0x07B0}, {0x0901, 0x0902}, {0x093C, 0x093C},
    {0x0941, 0x0948}, {0x094D, 0x094D}, {0x0951, 0x0954},
    {0x0962, 0x0963}, {0x0981, 0x0981}, {0x09BC, 0x09BC},
    {0x09C1, 0x09C4}, {0x09CD, 0x09CD}, {0x09E2, 0x09E3},
    {0x0A02, 0x0A02}, {0x0A3C, 0x0A3C}, {0x0A41, 0x0A42},
    {0x0A47, 0x0A48}, {0x0A4B, 0x0A4D}, {0x0A70, 0x0A71},
    {0x0A81, 0x0A82}, {0x0ABC, 0x0ABC}, {0x0AC1, 0x0AC5},
    {0x0AC7, 0x0AC8}, {0x0ACD, 0x0ACD}, {0x0B01, 0x0B01},
    {0x0B3C, 0x0B3C}, {0x0B3F, 0x0B3F}, {0x0B41, 0x0B43},
    {0x0B4D, 0x0B4D}, {0x0B56, 0x0B56}, {0x0B82, 0x0B82},
    {0x0BC0, 0x0BC0}, {0x0BCD, 0x0BCD}, {0x0C3E, 0x0C40},
    {0x0C46, 0x0C48}, {0x0C4A, 0x0C4D}, {0x0C55, 0x0C56},
    {0x0CBF, 0x0CBF}, {0x0CC6, 0x0CC6}, {0x0CCC, 0x0CCD},
    {0x0D41, 0x0D43}, {0x0D4D, 0x0D4D}, {0x0DCA, 0x0DCA},
    {0x0DD2, 0x0DD4}, {0x0DD6, 0x0DD6}, {0x0E31, 0x0E31},
    {0x0E34, 0x0E3A}, {0x0E47, 0x0E4E}, {0x0EB1, 0x0EB1},
    {0x0EB4, 0x0EB9}, {0x0EBB, 0x0EBC}, {0x0EC8, 0x0ECD},
    {0x0F18, 0x0F19}, {0x0F35, 0x0F35}, {0x0F37, 0x0F37},
    {0x0F39, 0x0F39}, {0x0F71, 0x0F7E}, {0x0F80, 0x0F84},
    {0x0F86, 0x0F87}, {0x0F90, 0x0F97}, {0x0F99, 0x0FBC},
    {0x0FC6, 0x0FC6}, {0x102D, 0x1030}, {0x1032, 0x1032},
    {0x1036, 0x1037}, {0x1039, 0x1039}, {0x1058, 0x1059},
    {0x1160, 0x11FF}, {0x1712, 0x1714}, {0x1732, 0x1734},
    {0x1752, 0x1753}, {0x1772, 0x1773}, {0x17B7, 0x17BD},
    {0x17C6, 0x17C6}, {0x17C9, 0x17D3}, {0x180B, 0x180E},
    {0x18A9, 0x18A9}, {0x200B, 0x200F}, {0x202A, 0x202E},
    {0x2060, 0x2063}, {0x206A, 0x206F}, {0x20D0, 0x20EA},
    {0x302A, 0x302F}, {0x3099, 0x309A}, {0xFB1E, 0xFB1E},
    {0xFE00, 0xFE0F}, {0xFE20, 0xFE23}, {0xFEFF, 0xFEFF},
    {0xFFF9, 0xFFFB}, {0x1D167, 0x1D169}, {0x1D173, 0x1D182},
    {0x1D185, 0x1D18B}, {0x1D1AA, 0x1D1AD}, {0xE0001, 0xE0001},
    {0xE0020, 0xE007F}
  };

  /* test for 8-bit control characters */
  if (ucs == 0)
    return 0;
  if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
    return -1;

  /* binary search in table of non-spacing characters */
  if (bisearch (ucs, combining,
		sizeof (combining) / sizeof (struct interval) - 1))
    return 0;

  /* if we arrive here, ucs is not a combining or C0/C1 control character */

  return 1 + (ucs >= 0x1100 && (ucs <= 0x115f ||	/* Hangul Jamo init. consonants */
				ucs == 0x2329 || ucs == 0x232a || (ucs >= 0x2e80 && ucs <= 0xa4cf && ucs != 0x303f) ||	/* CJK ... Yi */
				(ucs >= 0xac00 && ucs <= 0xd7a3) ||	/* Hangul Syllables */
				(ucs >= 0xf900 && ucs <= 0xfaff) ||	/* CJK Compatibility Ideographs */
				(ucs >= 0xfe30 && ucs <= 0xfe6f) ||	/* CJK Compatibility Forms */
				(ucs >= 0xff00 && ucs <= 0xff60) ||	/* Fullwidth Forms */
				(ucs >= 0xffe0 && ucs <= 0xffe6) ||
				(ucs >= 0x20000 && ucs <= 0x2ffff)));
}


int
mk_wcswidth (const wchar_t * pwcs, size_t n)
{
  int w, width = 0;

  for (; *pwcs && n-- > 0; pwcs++)
    if ((w = mk_wcwidth (*pwcs)) < 0)
      return -1;
    else
      width += w;

  return width;
}


/*
 * The following functions are the same as mk_wcwidth() and
 * mk_wcwidth_cjk(), except that spacing characters in the East Asian
 * Ambiguous (A) category as defined in Unicode Technical Report #11
 * have a column width of 2. This variant might be useful for users of
 * CJK legacy encodings who want to migrate to UCS without changing
 * the traditional terminal character-width behaviour. It is not
 * otherwise recommended for general use.
 */
static int
mk_wcwidth_cjk (wchar_t ucs)
{
  /* sorted list of non-overlapping intervals of East Asian Ambiguous
   * characters, generated with "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
  static const struct interval ambiguous[] = {
    {0x00A1, 0x00A1}, {0x00A4, 0x00A4}, {0x00A7, 0x00A8},
    {0x00AA, 0x00AA}, {0x00AD, 0x00AE}, {0x00B0, 0x00B4},
    {0x00B6, 0x00BA}, {0x00BC, 0x00BF}, {0x00C6, 0x00C6},
    {0x00D0, 0x00D0}, {0x00D7, 0x00D8}, {0x00DE, 0x00E1},
    {0x00E6, 0x00E6}, {0x00E8, 0x00EA}, {0x00EC, 0x00ED},
    {0x00F0, 0x00F0}, {0x00F2, 0x00F3}, {0x00F7, 0x00FA},
    {0x00FC, 0x00FC}, {0x00FE, 0x00FE}, {0x0101, 0x0101},
    {0x0111, 0x0111}, {0x0113, 0x0113}, {0x011B, 0x011B},
    {0x0126, 0x0127}, {0x012B, 0x012B}, {0x0131, 0x0133},
    {0x0138, 0x0138}, {0x013F, 0x0142}, {0x0144, 0x0144},
    {0x0148, 0x014B}, {0x014D, 0x014D}, {0x0152, 0x0153},
    {0x0166, 0x0167}, {0x016B, 0x016B}, {0x01CE, 0x01CE},
    {0x01D0, 0x01D0}, {0x01D2, 0x01D2}, {0x01D4, 0x01D4},
    {0x01D6, 0x01D6}, {0x01D8, 0x01D8}, {0x01DA, 0x01DA},
    {0x01DC, 0x01DC}, {0x0251, 0x0251}, {0x0261, 0x0261},
    {0x02C4, 0x02C4}, {0x02C7, 0x02C7}, {0x02C9, 0x02CB},
    {0x02CD, 0x02CD}, {0x02D0, 0x02D0}, {0x02D8, 0x02DB},
    {0x02DD, 0x02DD}, {0x02DF, 0x02DF}, {0x0391, 0x03A1},
    {0x03A3, 0x03A9}, {0x03B1, 0x03C1}, {0x03C3, 0x03C9},
    {0x0401, 0x0401}, {0x0410, 0x044F}, {0x0451, 0x0451},
    {0x2010, 0x2010}, {0x2013, 0x2016}, {0x2018, 0x2019},
    {0x201C, 0x201D}, {0x2020, 0x2022}, {0x2024, 0x2027},
    {0x2030, 0x2030}, {0x2032, 0x2033}, {0x2035, 0x2035},
    {0x203B, 0x203B}, {0x203E, 0x203E}, {0x2074, 0x2074},
    {0x207F, 0x207F}, {0x2081, 0x2084}, {0x20AC, 0x20AC},
    {0x2103, 0x2103}, {0x2105, 0x2105}, {0x2109, 0x2109},
    {0x2113, 0x2113}, {0x2116, 0x2116}, {0x2121, 0x2122},
    {0x2126, 0x2126}, {0x212B, 0x212B}, {0x2153, 0x2154},
    {0x215B, 0x215E}, {0x2160, 0x216B}, {0x2170, 0x2179},
    {0x2190, 0x2199}, {0x21B8, 0x21B9}, {0x21D2, 0x21D2},
    {0x21D4, 0x21D4}, {0x21E7, 0x21E7}, {0x2200, 0x2200},
    {0x2202, 0x2203}, {0x2207, 0x2208}, {0x220B, 0x220B},
    {0x220F, 0x220F}, {0x2211, 0x2211}, {0x2215, 0x2215},
    {0x221A, 0x221A}, {0x221D, 0x2220}, {0x2223, 0x2223},
    {0x2225, 0x2225}, {0x2227, 0x222C}, {0x222E, 0x222E},
    {0x2234, 0x2237}, {0x223C, 0x223D}, {0x2248, 0x2248},
    {0x224C, 0x224C}, {0x2252, 0x2252}, {0x2260, 0x2261},
    {0x2264, 0x2267}, {0x226A, 0x226B}, {0x226E, 0x226F},
    {0x2282, 0x2283}, {0x2286, 0x2287}, {0x2295, 0x2295},
    {0x2299, 0x2299}, {0x22A5, 0x22A5}, {0x22BF, 0x22BF},
    {0x2312, 0x2312}, {0x2460, 0x24E9}, {0x24EB, 0x24FE},
    {0x2500, 0x254B}, {0x2550, 0x2573}, {0x2580, 0x258F},
    {0x2592, 0x2595}, {0x25A0, 0x25A1}, {0x25A3, 0x25A9},
    {0x25B2, 0x25B3}, {0x25B6, 0x25B7}, {0x25BC, 0x25BD},
    {0x25C0, 0x25C1}, {0x25C6, 0x25C8}, {0x25CB, 0x25CB},
    {0x25CE, 0x25D1}, {0x25E2, 0x25E5}, {0x25EF, 0x25EF},
    {0x2605, 0x2606}, {0x2609, 0x2609}, {0x260E, 0x260F},
    {0x261C, 0x261C}, {0x261E, 0x261E}, {0x2640, 0x2640},
    {0x2642, 0x2642}, {0x2660, 0x2661}, {0x2663, 0x2665},
    {0x2667, 0x266A}, {0x266C, 0x266D}, {0x266F, 0x266F},
    {0x273D, 0x273D}, {0x2776, 0x277F}, {0xFFFD, 0xFFFD}
  };

  /* binary search in table of non-spacing characters */
  if (bisearch (ucs, ambiguous,
		sizeof (ambiguous) / sizeof (struct interval) - 1))
    return 2;

  return mk_wcwidth (ucs);
}


int
mk_wcswidth_cjk (const wchar_t * pwcs, size_t n)
{
  int w, width = 0;

  for (; *pwcs && n-- > 0; pwcs++)
    if ((w = mk_wcwidth_cjk (*pwcs)) < 0)
      return -1;
    else
      width += w;

  return width;
}
