#include <wchar.h>
#include <wctype.h>
#include <stdio.h>

#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('A','Z','a'),
	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),

	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),

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

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

	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 },

	{ 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 },
	{ 0x2c72, 0x2c73 },
	{ 0x2c75, 0x2c76 },

	{ 0xa77d, 0x1d79 },

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

	{ 0,0 }
};


static wchar_t __towcase(wchar_t wc, int lower)
{
	int i;
	int lmul = 2*lower-1;
	int lmask = lower-1;
	if ((unsigned)wc - 0x10400 < 0x50)
		return wc + lmul*0x28;
	/* no letters with case in these large ranges */
	if (!iswalpha(wc)
	 || (unsigned)wc - 0x0600 <= 0x0fff-0x0600
	 || (unsigned)wc - 0x2e00 <= 0xa6ff-0x2e00
	 || (unsigned)wc - 0xa800 <= 0xfeff-0xa800)
		return wc;
	/* special case because the diff between upper/lower is too big */
	if ((unsigned)wc - 0x10a0 < 0x26 || (unsigned)wc - 0x2d00 < 0x26)
		return wc + lmul*(0x2d00-0x10a0);
	for (i=0; casemaps[i].len; i++) {
		int base = casemaps[i].upper + (lmask & casemaps[i].lower);
		if ((unsigned)wc-base < casemaps[i].len) {
			if (casemaps[i].lower == 1)
				return wc + lower - ((wc-casemaps[i].upper)&1);
			return wc + lmul*casemaps[i].lower;
		}
	}
	for (i=0; pairs[i][1-lower]; i++) {
		if (pairs[i][1-lower] == wc)
			return pairs[i][lower];
	}
	if ((unsigned)wc - 0x10428 + (lower<<5) + (lower<<3) < 0x28)
		return wc - 0x28 + (lower<<10) + (lower<<6);
	return wc;
}

wint_t towupper(wint_t wc)
{
	return __towcase(wc, 0);
}

wint_t towlower(wint_t wc)
{
	return __towcase(wc, 1);
}