#include <libc.h>
#include <ctype.h>
#include <string.h>
#include <wchar.h>
#include <wctype.h>

/* From embeddedartistry/libc */
#define CASEMAP(u1, u2, l) { (u1), (l) - (u1), (u2) - (u1) + 1 }
#define CASELACE(u1, u2)   CASEMAP((u1), (u2), (u1) + 1)

static const struct {
	unsigned short upper;
	signed char lower;
	unsigned char len;
} casemaps[] = {
	CASEMAP(0xc0, 0xde, 0xe0),

	CASELACE(0x0100, 0x012e),	 CASELACE(0x0132, 0x0136),
	CASELACE(0x0139, 0x0147),	 CASELACE(0x014a, 0x0176),
	CASELACE(0x0179, 0x017d),

	CASELACE(0x370, 0x372),		 CASEMAP(0x391, 0x3a1, 0x3b1),
	CASEMAP(0x3a3, 0x3ab, 0x3c3),	 CASEMAP(0x400, 0x40f, 0x450),
	CASEMAP(0x410, 0x42f, 0x430),

	CASELACE(0x460, 0x480),		 CASELACE(0x48a, 0x4be),
	CASELACE(0x4c1, 0x4cd),		 CASELACE(0x4d0, 0x50e),

	CASELACE(0x514, 0x52e),		 CASEMAP(0x531, 0x556, 0x561),

	CASELACE(0x01a0, 0x01a4),	 CASELACE(0x01b3, 0x01b5),
	CASELACE(0x01cd, 0x01db),	 CASELACE(0x01de, 0x01ee),
	CASELACE(0x01f8, 0x021e),	 CASELACE(0x0222, 0x0232),
	CASELACE(0x03d8, 0x03ee),

	CASELACE(0x1e00, 0x1e94),	 CASELACE(0x1ea0, 0x1efe),

	CASEMAP(0x1f08, 0x1f0f, 0x1f00), CASEMAP(0x1f18, 0x1f1d, 0x1f10),
	CASEMAP(0x1f28, 0x1f2f, 0x1f20), CASEMAP(0x1f38, 0x1f3f, 0x1f30),
	CASEMAP(0x1f48, 0x1f4d, 0x1f40),

	CASEMAP(0x1f68, 0x1f6f, 0x1f60), CASEMAP(0x1f88, 0x1f8f, 0x1f80),
	CASEMAP(0x1f98, 0x1f9f, 0x1f90), CASEMAP(0x1fa8, 0x1faf, 0x1fa0),
	CASEMAP(0x1fb8, 0x1fb9, 0x1fb0), CASEMAP(0x1fba, 0x1fbb, 0x1f70),
	CASEMAP(0x1fc8, 0x1fcb, 0x1f72), CASEMAP(0x1fd8, 0x1fd9, 0x1fd0),
	CASEMAP(0x1fda, 0x1fdb, 0x1f76), CASEMAP(0x1fe8, 0x1fe9, 0x1fe0),
	CASEMAP(0x1fea, 0x1feb, 0x1f7a), CASEMAP(0x1ff8, 0x1ff9, 0x1f78),
	CASEMAP(0x1ffa, 0x1ffb, 0x1f7c),

	CASEMAP(0x13f0, 0x13f5, 0x13f8), CASELACE(0xa698, 0xa69a),
	CASELACE(0xa796, 0xa79e),

	CASELACE(0x246, 0x24e),		 CASELACE(0x510, 0x512),
	CASEMAP(0x2160, 0x216f, 0x2170), CASEMAP(0x2c00, 0x2c2e, 0x2c30),
	CASELACE(0x2c67, 0x2c6b),	 CASELACE(0x2c80, 0x2ce2),
	CASELACE(0x2ceb, 0x2ced),

	CASELACE(0xa640, 0xa66c),	 CASELACE(0xa680, 0xa696),

	CASELACE(0xa722, 0xa72e),	 CASELACE(0xa732, 0xa76e),
	CASELACE(0xa779, 0xa77b),	 CASELACE(0xa77e, 0xa786),

	CASELACE(0xa790, 0xa792),	 CASELACE(0xa7a0, 0xa7a8),

	CASELACE(0xa7b4, 0xa7b6),

	CASEMAP(0xff21, 0xff3a, 0xff41), { 0, 0, 0 }
};

static const unsigned short pairs[][2] = { { 'I', 0x0131 },
					   { 'S', 0x017f },
					   { 0x0130, 'i' },
					   { 0x0178, 0x00ff },
					   { 0x0181, 0x0253 },
					   { 0x0182, 0x0183 },
					   { 0x0184, 0x0185 },
					   { 0x0186, 0x0254 },
					   { 0x0187, 0x0188 },
					   { 0x0189, 0x0256 },
					   { 0x018a, 0x0257 },
					   { 0x018b, 0x018c },
					   { 0x018e, 0x01dd },
					   { 0x018f, 0x0259 },
					   { 0x0190, 0x025b },
					   { 0x0191, 0x0192 },
					   { 0x0193, 0x0260 },
					   { 0x0194, 0x0263 },
					   { 0x0196, 0x0269 },
					   { 0x0197, 0x0268 },
					   { 0x0198, 0x0199 },
					   { 0x019c, 0x026f },
					   { 0x019d, 0x0272 },
					   { 0x019f, 0x0275 },
					   { 0x01a6, 0x0280 },
					   { 0x01a7, 0x01a8 },
					   { 0x01a9, 0x0283 },
					   { 0x01ac, 0x01ad },
					   { 0x01ae, 0x0288 },
					   { 0x01af, 0x01b0 },
					   { 0x01b1, 0x028a },
					   { 0x01b2, 0x028b },
					   { 0x01b7, 0x0292 },
					   { 0x01b8, 0x01b9 },
					   { 0x01bc, 0x01bd },
					   { 0x01c4, 0x01c6 },
					   { 0x01c4, 0x01c5 },
					   { 0x01c5, 0x01c6 },
					   { 0x01c7, 0x01c9 },
					   { 0x01c7, 0x01c8 },
					   { 0x01c8, 0x01c9 },
					   { 0x01ca, 0x01cc },
					   { 0x01ca, 0x01cb },
					   { 0x01cb, 0x01cc },
					   { 0x01f1, 0x01f3 },
					   { 0x01f1, 0x01f2 },
					   { 0x01f2, 0x01f3 },
					   { 0x01f4, 0x01f5 },
					   { 0x01f6, 0x0195 },
					   { 0x01f7, 0x01bf },
					   { 0x0220, 0x019e },
					   { 0x0386, 0x03ac },
					   { 0x0388, 0x03ad },
					   { 0x0389, 0x03ae },
					   { 0x038a, 0x03af },
					   { 0x038c, 0x03cc },
					   { 0x038e, 0x03cd },
					   { 0x038f, 0x03ce },
					   { 0x0399, 0x0345 },
					   { 0x0399, 0x1fbe },
					   { 0x03a3, 0x03c2 },
					   { 0x03f7, 0x03f8 },
					   { 0x03fa, 0x03fb },
					   { 0x1e60, 0x1e9b },
					   { 0x1e9e, 0xdf },

					   { 0x1f59, 0x1f51 },
					   { 0x1f5b, 0x1f53 },
					   { 0x1f5d, 0x1f55 },
					   { 0x1f5f, 0x1f57 },
					   { 0x1fbc, 0x1fb3 },
					   { 0x1fcc, 0x1fc3 },
					   { 0x1fec, 0x1fe5 },
					   { 0x1ffc, 0x1ff3 },

					   { 0x23a, 0x2c65 },
					   { 0x23b, 0x23c },
					   { 0x23d, 0x19a },
					   { 0x23e, 0x2c66 },
					   { 0x241, 0x242 },
					   { 0x243, 0x180 },
					   { 0x244, 0x289 },
					   { 0x245, 0x28c },
					   { 0x3f4, 0x3b8 },
					   { 0x3f9, 0x3f2 },
					   { 0x3fd, 0x37b },
					   { 0x3fe, 0x37c },
					   { 0x3ff, 0x37d },
					   { 0x4c0, 0x4cf },

					   { 0x2126, 0x3c9 },
					   { 0x212a, 'k' },
					   { 0x212b, 0xe5 },
					   { 0x2132, 0x214e },
					   { 0x2183, 0x2184 },
					   { 0x2c60, 0x2c61 },
					   { 0x2c62, 0x26b },
					   { 0x2c63, 0x1d7d },
					   { 0x2c64, 0x27d },
					   { 0x2c6d, 0x251 },
					   { 0x2c6e, 0x271 },
					   { 0x2c6f, 0x250 },
					   { 0x2c70, 0x252 },
					   { 0x2c72, 0x2c73 },
					   { 0x2c75, 0x2c76 },
					   { 0x2c7e, 0x23f },
					   { 0x2c7f, 0x240 },
					   { 0x2cf2, 0x2cf3 },

					   { 0xa77d, 0x1d79 },
					   { 0xa78b, 0xa78c },
					   { 0xa78d, 0x265 },
					   { 0xa7aa, 0x266 },

					   { 0x10c7, 0x2d27 },
					   { 0x10cd, 0x2d2d },

					   /* bogus greek 'symbol' letters */
					   { 0x376, 0x377 },
					   { 0x39c, 0xb5 },
					   { 0x392, 0x3d0 },
					   { 0x398, 0x3d1 },
					   { 0x3a6, 0x3d5 },
					   { 0x3a0, 0x3d6 },
					   { 0x39a, 0x3f0 },
					   { 0x3a1, 0x3f1 },
					   { 0x395, 0x3f5 },
					   { 0x3cf, 0x3d7 },

					   { 0xa7ab, 0x25c },
					   { 0xa7ac, 0x261 },
					   { 0xa7ad, 0x26c },
					   { 0xa7ae, 0x26a },
					   { 0xa7b0, 0x29e },
					   { 0xa7b1, 0x287 },
					   { 0xa7b2, 0x29d },
					   { 0xa7b3, 0xab53 },

					   /* special cyrillic lowercase forms
					    */
					   { 0x412, 0x1c80 },
					   { 0x414, 0x1c81 },
					   { 0x41e, 0x1c82 },
					   { 0x421, 0x1c83 },
					   { 0x422, 0x1c84 },
					   { 0x422, 0x1c85 },
					   { 0x42a, 0x1c86 },
					   { 0x462, 0x1c87 },
					   { 0xa64a, 0x1c88 },

					   { 0, 0 } };

wchar_t __towcase(wchar_t wc, int lower)
{
	int i;
	int lmul = 2 * lower - 1;
	int lmask = lower - 1;
	/* no letters with case in these large ranges */
	if (!iswalpha((wint_t)wc) || (unsigned)wc - 0x0600 <= 0x0fff - 0x0600 ||
	    (unsigned)wc - 0x2e00 <= 0xa63f - 0x2e00 ||
	    (unsigned)wc - 0xa800 <= 0xab52 - 0xa800 ||
	    (unsigned)wc - 0xabc0 <= 0xfeff - 0xabc0) {
		return wc;
	}

	/* special case because the diff between upper/lower is too big */
	if (lower && (unsigned)wc - 0x10a0 < 0x2e) {
		if (wc > 0x10c5 && wc != 0x10c7 && wc != 0x10cd) {
			return wc;
		}

		return wc + 0x2d00 - 0x10a0;
	}

	if (!lower && (unsigned)wc - 0x2d00 < 0x26) {
		if (wc > 0x2d25 && wc != 0x2d27 && wc != 0x2d2d) {
			return wc;
		}

		return wc + 0x10a0 - 0x2d00;
	}

	if (lower && (unsigned)wc - 0x13a0 < 0x50) {
		return wc + 0xab70 - 0x13a0;
	}

	if (!lower && (unsigned)wc - 0xab70 < 0x50) {
		return wc + 0x13a0 - 0xab70;
	}

	for (i = 0; casemaps[i].len; i++) {
		int base = casemaps[i].upper + (lmask & casemaps[i].lower);
		if (wc - (wchar_t)base < casemaps[i].len) {
			if (casemaps[i].lower == 1) {
				return wc + (wchar_t)lower -
				       ((wc - casemaps[i].upper) & 1);
			}
			return wc + (wchar_t)(lmul * casemaps[i].lower);
		}
	}

	for (i = 0; pairs[i][1 - lower]; i++) {
		if (pairs[i][1 - lower] == wc) {
			return pairs[i][lower];
		}
	}

	if (wc - (wchar_t)(0x10428 - 0x28 * lower) < 0x28) {
		return wc - (wchar_t)(0x28 + 0x50 * lower);
	}

	if (wc - (wchar_t)(0x104d8 - 0x28 * lower) < 0x24) {
		return wc - (wchar_t)(0x28 + 0x50 * lower);
	}

	if (wc - (wchar_t)(0x10cc0 - 0x40 * lower) < 0x33) {
		return wc - (wchar_t)(0x40 + 0x80 * lower);
	}

	if (wc - (wchar_t)(0x118c0 - 0x20 * lower) < 0x20) {
		return wc - (wchar_t)(0x20 + 0x40 * lower);
	}

	if (wc - (wchar_t)(0x1e922 - 0x22 * lower) < 0x22) {
		return wc - (wchar_t)(0x22 + 0x44 * lower);
	}

	return wc;
}

wint_t towlower(wint_t wc)
{
	return (wint_t)(wc < 128 ? (wint_t)tolower((int)wc) :
				   (wint_t)__towcase((wchar_t)wc, 1));
}

weak wint_t towlower_l(wint_t wc, locale_t unused locale)
{
	return towlower(wc);
}

wint_t towupper(wint_t wc)
{
	return (wint_t)(wc < 128 ? (wint_t)toupper((int)wc) :
				   (wint_t)__towcase((wchar_t)wc, 0));
}

weak wint_t towupper_l(wint_t wc, locale_t unused locale)
{
	return towupper(wc);
}

wctrans_t wctrans(const char *class)
{
	if (!strcmp(class, "toupper"))
		return (wctrans_t)1;
	if (!strcmp(class, "tolower"))
		return (wctrans_t)2;
	return 0;
}

weak wctrans_t wctrans_l(const char *class, locale_t unused locale)
{
	return wctrans(class);
}

wint_t towctrans(wint_t wc, wctrans_t desc)
{
	if (desc == (wctrans_t)1)
		return towupper(wc);
	if (desc == (wctrans_t)2)
		return towlower(wc);
	return wc;
}

weak wint_t towctrans_l(wint_t wc, wctrans_t desc, locale_t unused locale)
{
	return towctrans(wc, desc);
}