/*
 * 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
 *
 * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
 *
 * 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
 */

/*
 * Changes made for mutt:
 * - Adapted for Mutt by Edmund Grimley Evans.
 * - Changed 'first'/'last' members of combined[] to wchar_t from unsigned short to fix compiler warnings, 2007-11-13, Rocco Rutte
 */
module wcwidth_cjk_compat.wcwidth;


extern (C)
public struct wcwidth_cjk_option
{
	ubyte is_apple = 0;
	ubyte is_legacy_ja = 0;
	ubyte is_emoji = 1;
}

extern (C)
public static immutable wcwidth_cjk_option default_wcwidth_cjk_option =
{
	is_apple: 0,
	is_legacy_ja: 0,
	is_emoji: 1,
};

extern (C)
public static immutable wcwidth_cjk_option* default_wcwidth_cjk_option_ptr = &.default_wcwidth_cjk_option;

private struct interval
{
	uint first;
	uint last;
}

/* auxiliary function for binary search in interval table */
pure nothrow @safe @nogc @live
private bool bisearch(uint ucs, immutable ref .interval[] table, size_t max)

	in
	{
		//assert(table != null);
	}

	do
	{
		if ((ucs < table[0].first) || (ucs > table[max].last)) {
			return false;
		}

		size_t min = 0;

		while (max >= min) {
			size_t temp = min + max;
			size_t mid = temp / 2;

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

		return false;
	}

/*
 * 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.
 *
 *    - SOFT HYPHEN (U+00AD) has a column width of 1.
 *
 *    - 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.
 */

/* sorted list of non-overlapping intervals of non-spacing characters */
/* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
private static immutable .interval[] combining =
[
	{0x0300, 0x036F}, {0x0483, 0x0486}, {0x0488, 0x0489},
	{0x0591, 0x05BD}, {0x05BF, 0x05BF}, {0x05C1, 0x05C2},
	{0x05C4, 0x05C5}, {0x05C7, 0x05C7}, {0x0600, 0x0603},
	{0x0610, 0x0615}, {0x064B, 0x065E}, {0x0670, 0x0670},
	{0x06D6, 0x06E4}, {0x06E7, 0x06E8}, {0x06EA, 0x06ED},
	{0x070F, 0x070F}, {0x0711, 0x0711}, {0x0730, 0x074A},
	{0x07A6, 0x07B0}, {0x07EB, 0x07F3}, {0x0901, 0x0902},
	{0x093C, 0x093C}, {0x0941, 0x0948}, {0x094D, 0x094D},
	{0x0951, 0x0954}, {0x0962, 0x0963}, {0x0981, 0x0981},
	{0x09BC, 0x09BC}, {0x09C1, 0x09C4}, {0x09CD, 0x09CD},
	{0x09E2, 0x09E3}, {0x0A01, 0x0A02}, {0x0A3C, 0x0A3C},
	{0x0A41, 0x0A42}, {0x0A47, 0x0A48}, {0x0A4B, 0x0A4D},
	{0x0A70, 0x0A71}, {0x0A81, 0x0A82}, {0x0ABC, 0x0ABC},
	{0x0AC1, 0x0AC5}, {0x0AC7, 0x0AC8}, {0x0ACD, 0x0ACD},
	{0x0AE2, 0x0AE3}, {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}, {0x0CBC, 0x0CBC},
	{0x0CBF, 0x0CBF}, {0x0CC6, 0x0CC6}, {0x0CCC, 0x0CCD},
	{0x0CE2, 0x0CE3}, {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}, {0x135F, 0x135F},
	{0x1712, 0x1714}, {0x1732, 0x1734}, {0x1752, 0x1753},
	{0x1772, 0x1773}, {0x17B4, 0x17B5}, {0x17B7, 0x17BD},
	{0x17C6, 0x17C6}, {0x17C9, 0x17D3}, {0x17DD, 0x17DD},
	{0x180B, 0x180D}, {0x18A9, 0x18A9}, {0x1920, 0x1922},
	{0x1927, 0x1928}, {0x1932, 0x1932}, {0x1939, 0x193B},
	{0x1A17, 0x1A18}, {0x1B00, 0x1B03}, {0x1B34, 0x1B34},
	{0x1B36, 0x1B3A}, {0x1B3C, 0x1B3C}, {0x1B42, 0x1B42},
	{0x1B6B, 0x1B73}, {0x1DC0, 0x1DCA}, {0x1DFE, 0x1DFF},
	{0x200B, 0x200F}, {0x202A, 0x202E}, {0x2060, 0x2063},
	{0x206A, 0x206F}, {0x20D0, 0x20EF}, {0x302A, 0x302F},
		{0xA806, 0xA806}, {0xA80B, 0xA80B},
	{0xA825, 0xA826}, {0xFB1E, 0xFB1E}, {0xFE00, 0xFE0F},
	{0xFE20, 0xFE23}, {0xFEFF, 0xFEFF}, {0xFFF9, 0xFFFB},
	{0x010A01, 0x010A03}, {0x010A05, 0x010A06}, {0x010A0C, 0x010A0F},
	{0x010A38, 0x010A3A}, {0x010A3F, 0x010A3F}, {0x01D167, 0x01D169},
	{0x01D173, 0x01D182}, {0x01D185, 0x01D18B}, {0x01D1AA, 0x01D1AD},
	{0x01D242, 0x01D244}, {0x0E0001, 0x0E0001}, {0x0E0020, 0x0E007F},
	{0x0E0100, 0x0E01EF},
];

private static immutable .interval[] not_apple =
[
	{0x3099, 0x309A},
];

extern (C)
pure nothrow @safe @nogc @live
public int wcwidth_ucs(uint ucs, scope const wcwidth_cjk_option* option = default_wcwidth_cjk_option_ptr)

	in
	{
		assert(option != null);
	}

	do
	{
		if (option == null) {
			return 0;
		}

		/* test for 8-bit control characters */
		if (ucs == 0) {
			return 0;
		}

		if ((ucs < 32) || ((ucs >= 0x7F) && (ucs < 0xA0))) {
			return -1;
		}

		if (!option.is_apple) {
			if (.bisearch(ucs, .not_apple, .not_apple.length - 1)) {
				return 0;
			}
		}

		/* binary search in table of non-spacing characters */
		if (.bisearch(ucs, .combining, .combining.length - 1)) {
			return 0;
		}

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

		/* fast test for majority of non-wide scripts */
		if (ucs < 0x1100) {
			return 1;
		}

		return 1 +
				(
					(ucs >= 0x1100) &&
					(
						/* Hangul Jamo init. consonants */
						(ucs <= 0x115F) ||

						/* CJK ... Yi */
						(ucs == 0x2329) || (ucs == 0x232A) || ((ucs >= 0x2E80) && (ucs <= 0xA4CF) && (ucs != 0x303F)) ||

						/* Hangul Syllables */
						((ucs >= 0xAC00) && (ucs <= 0xD7A3)) ||

						/* CJK Compatibility Ideographs */
						((ucs >= 0xF900) && (ucs <= 0xFAFF)) ||

						/* Vertical forms */
						((ucs >= 0xFE10) && (ucs <= 0xFE19)) ||

						/* CJK Compatibility Forms */
						((ucs >= 0xFE30) && (ucs <= 0xFE6F)) ||

						/* Fullwidth Forms */
						((ucs >= 0xFF00) && (ucs <= 0xFF60)) ||

						((ucs >= 0xFFE0) && (ucs <= 0xFFE6)) || ((ucs >= 0x020000) && (ucs <= 0x02FFFD)) || ((ucs >= 0x030000) && (ucs <= 0x03FFFD))
					)
				);
	}

extern (C)
pure nothrow @trusted @nogc @live
public int wcswidth_ucs(scope const uint* pwcs, size_t n, scope const wcwidth_cjk_option* option = default_wcwidth_cjk_option_ptr)

	in
	{
		assert(pwcs != null);
		assert(option != null);
	}

	do
	{
		int width = 0;
		const (uint)* pwcs_ptr = pwcs;

		for (; (*pwcs_ptr != '\0') && (n-- != 0); pwcs_ptr++) {
			int w = .wcwidth_ucs(*pwcs_ptr, option);

			if (w < 0) {
				return -1;
			} else {
				width += w;
			}
		}

		return width;
	}

/*
 * The following functions are the same as wcwidth_ucs() and
 * 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.
 */
/*
 * In addition to the explanation mentioned above,
 * several characters in the East Asian Narrow (Na) and Not East Asian
 * (Neutral) category as defined in Unicode Technical Report #11
 * actually have a column width of 2 in CJK legacy encodings.
 */

//#define wcwidth_cjk wcwidth
//#define wcswidth_cjk wcswidth

/* For FreeBSD: wcwidth() is implemented as an inline function */
//#ifdef wcwidth
	//#undef wcwidth
//#endif

/*
 * sorted list of non-overlapping intervals of East Asian Ambiguous
 * characters, generated by "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c"
 */
private static immutable .interval[] ambiguous =
[
	{0x00A1, 0x00A1}, {0x00A4, 0x00A4}, {0x00A7, 0x00A8},
	{0x00AA, 0x00AA}, {0x00AE, 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, 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}, {0x2614, 0x2615},
	{0x261C, 0x261C}, {0x261E, 0x261E}, {0x2640, 0x2640},
	{0x2642, 0x2642}, {0x2660, 0x2661}, {0x2663, 0x2665},
	{0x2667, 0x266A}, {0x266C, 0x266D}, {0x266F, 0x266F},
	{0x273D, 0x273D}, {0x2776, 0x277F}, {0xE000, 0xF8FF},
	{0xFFFD, 0xFFFD}, {0x0F0000, 0x0FFFFD}, {0x100000, 0x10FFFD},
];

/* For Japanese legacy encodings, the following characters are added. */
private static immutable .interval[] legacy_ja = [{0x00A2, 0x00A3}, {0x00A5, 0x00A6}, {0x00AC, 0x00AC}, {0x00AF, 0x00AF}, {0x2212, 0x2212}];

private static immutable .interval[] emoji =
[
	{0x2600, 0x27BF},
	{0x01F300, 0x01F64F},
	{0x01F680, 0x01F6FF},
	{0x01F900, 0x01F9FF},
];

extern (C)
pure nothrow @safe @nogc @live
public int wcwidth_cjk(uint ucs, scope const wcwidth_cjk_option* option = default_wcwidth_cjk_option_ptr)

	in
	{
		assert(option != null);
	}

	do
	{
		/* binary search in table of non-spacing characters */
		if (.bisearch(ucs, .ambiguous, .ambiguous.length - 1)) {
			return 2;
		}

		if (option.is_legacy_ja) {
			if (.bisearch(ucs, .legacy_ja, .legacy_ja.length - 1)) {
				return 2;
			}
		}

		if (option.is_emoji) {
			if (.bisearch(ucs, .emoji, .emoji.length - 1)) {
				return 2;
			}
		}

		return .wcwidth_ucs(ucs, option);
	}

extern (C)
pure nothrow @trusted @nogc @live
public int wcswidth_cjk(scope const uint* pwcs, size_t n, scope const wcwidth_cjk_option* option = default_wcwidth_cjk_option_ptr)

	in
	{
		assert(pwcs != null);
		assert(option != null);
	}

	do
	{
		int width = 0;
		const (uint)* pwcs_ptr = pwcs;

		for (; (*pwcs_ptr != '\0') && (n-- != 0); pwcs_ptr++) {
			int w = .wcwidth_cjk(*pwcs_ptr, option);

			if (w < 0) {
				return -1;
			} else {
				width += w;
			}
		}

		return width;
	}