#include <u.h>
#include <libc.h>
#include <draw.h>

/*
 * The code makes two assumptions: strlen(ld) is 1 or 2; latintab[i].ld can be a
 * prefix of latintab[j].ld only when j<i.
 */
static struct cvlist
{
	char	*ld;		/* must be seen before using this conversion */
	char	*si;		/* options for last input characters */
	Rune	so[60];		/* the corresponding Rune for each si entry */
} latintab[] = {
	" ", " i",	{ 0x2423, 0x0131 },
	"!~", "-=~",	{ 0x2244, 0x2247, 0x2249 },
	"!", "!<=>?bmp",	{ 0x00a1, 0x226e, 0x2260, 0x226f, 0x203d, 0x2284, 0x2209, 0x2285 },
	"\"*", "IUiu",	{ 0x03aa, 0x03ab, 0x03ca, 0x03cb },
	"\"", "\"AEIOUYaeiouy",	{ 0x00a8, 0x00c4, 0x00cb, 0x00cf, 0x00d6, 0x00dc, 0x0178, 0x00e4, 0x00eb, 0x00ef, 0x00f6, 0x00fc, 0x00ff },
	"$*", "fhk",	{ 0x03d5, 0x03d1, 0x03f0 },
	"$", "BEFHILMRVaefglopv",	{ 0x212c, 0x2130, 0x2131, 0x210b, 0x2110, 0x2112, 0x2133, 0x211b, 0x01b2, 0x0251, 0x212f, 0x0192, 0x210a, 0x2113, 0x2134, 0x2118, 0x028b },
	"\'\"", "Uu",	{ 0x01d7, 0x01d8 },
	"\'", "\'ACEILNORSUYZacegilnorsuyz",	{ 0x00b4, 0x00c1, 0x0106, 0x00c9, 0x00cd, 0x0139, 0x0143, 0x00d3, 0x0154, 0x015a, 0x00da, 0x00dd, 0x0179, 0x00e1, 0x0107, 0x00e9, 0x0123, 0x00ed, 0x013a, 0x0144, 0x00f3, 0x0155, 0x015b, 0x00fa, 0x00fd, 0x017a },
	"*", "*ABCDEFGHIKLMNOPQRSTUWXYZabcdefghiklmnopqrstuwxyz",	{ 0x2217, 0x0391, 0x0392, 0x039e, 0x0394, 0x0395, 0x03a6, 0x0393, 0x0398, 0x0399, 0x039a, 0x039b, 0x039c, 0x039d, 0x039f, 0x03a0, 0x03a8, 0x03a1, 0x03a3, 0x03a4, 0x03a5, 0x03a9, 0x03a7, 0x0397, 0x0396, 0x03b1, 0x03b2, 0x03be, 0x03b4, 0x03b5, 0x03c6, 0x03b3, 0x03b8, 0x03b9, 0x03ba, 0x03bb, 0x03bc, 0x03bd, 0x03bf, 0x03c0, 0x03c8, 0x03c1, 0x03c3, 0x03c4, 0x03c5, 0x03c9, 0x03c7, 0x03b7, 0x03b6 },
	"+", "-O",	{ 0x00b1, 0x2295 },
	",", ",ACEGIKLNORSTUacegiklnorstu",	{ 0x00b8, 0x0104, 0x00c7, 0x0118, 0x0122, 0x012e, 0x0136, 0x013b, 0x0145, 0x01ea, 0x0156, 0x015e, 0x0162, 0x0172, 0x0105, 0x00e7, 0x0119, 0x0123, 0x012f, 0x0137, 0x013c, 0x0146, 0x01eb, 0x0157, 0x015f, 0x0163, 0x0173 },
	"-*", "l",	{ 0x019b },
	"-", "+-2:>DGHILOTZbdghiltuz~",	{ 0x2213, 0x00ad, 0x01bb, 0x00f7, 0x2192, 0x00d0, 0x01e4, 0x0126, 0x0197, 0x0141, 0x2296, 0x0166, 0x01b5, 0x0180, 0x00f0, 0x01e5, 0x210f, 0x0268, 0x0142, 0x0167, 0x0289, 0x01b6, 0x2242 },
	".", ".CEGILOZceglz",	{ 0x00b7, 0x010a, 0x0116, 0x0120, 0x0130, 0x013f, 0x2299, 0x017b, 0x010b, 0x0117, 0x0121, 0x0140, 0x017c },
	"/", "Oo",	{ 0x00d8, 0x00f8 },
	"1", "234568",	{ 0x00bd, 0x2153, 0x00bc, 0x2155, 0x2159, 0x215b },
	"2", "-35",	{ 0x01bb, 0x2154, 0x2156 },
	"3", "458",	{ 0x00be, 0x2157, 0x215c },
	"4", "5",	{ 0x2158 },
	"5", "68",	{ 0x215a, 0x215d },
	"7", "8",	{ 0x215e },
	":", "()-=",	{ 0x2639, 0x263a, 0x00f7, 0x2254 },
	"<!", "=~",	{ 0x2268, 0x22e6 },
	"<", "-<=>~",	{ 0x2190, 0x00ab, 0x2264, 0x2276, 0x2272 },
	"=", ":<=>OV",	{ 0x2255, 0x22dc, 0x2261, 0x22dd, 0x229c, 0x21d2 },
	">!", "=~",	{ 0x2269, 0x22e7 },
	">", "<=>~",	{ 0x2277, 0x2265, 0x00bb, 0x2273 },
	"?", "!?",	{ 0x203d, 0x00bf },
	"@\'", "\'",	{ 0x044a },
	"@@", "\'EKSTYZekstyz",	{ 0x044c, 0x0415, 0x041a, 0x0421, 0x0422, 0x042b, 0x0417, 0x0435, 0x043a, 0x0441, 0x0442, 0x044b, 0x0437 },
	"@C", "Hh",	{ 0x0427, 0x0427 },
	"@E", "Hh",	{ 0x042d, 0x042d },
	"@K", "Hh",	{ 0x0425, 0x0425 },
	"@S", "CHch",	{ 0x0429, 0x0428, 0x0429, 0x0428 },
	"@T", "Ss",	{ 0x0426, 0x0426 },
	"@Y", "AEOUaeou",	{ 0x042f, 0x0415, 0x0401, 0x042e, 0x042f, 0x0415, 0x0401, 0x042e },
	"@Z", "Hh",	{ 0x0416, 0x0416 },
	"@c", "h",	{ 0x0447 },
	"@e", "h",	{ 0x044d },
	"@k", "h",	{ 0x0445 },
	"@s", "ch",	{ 0x0449, 0x0448 },
	"@t", "s",	{ 0x0446 },
	"@y", "aeou",	{ 0x044f, 0x0435, 0x0451, 0x044e },
	"@z", "h",	{ 0x0436 },
	"@", "ABDFGIJLMNOPRUVXabdfgijlmnopruvx",	{ 0x0410, 0x0411, 0x0414, 0x0424, 0x0413, 0x0418, 0x0419, 0x041b, 0x041c, 0x041d, 0x041e, 0x041f, 0x0420, 0x0423, 0x0412, 0x0425, 0x0430, 0x0431, 0x0434, 0x0444, 0x0433, 0x0438, 0x0439, 0x043b, 0x043c, 0x043d, 0x043e, 0x043f, 0x0440, 0x0443, 0x0432, 0x0445 },
	"A", "E",	{ 0x00c6 },
	"C", "ACU",	{ 0x22c2, 0x2102, 0x22c3 },
	"Dv", "Zz",	{ 0x01c4, 0x01c5 },
	"D", "-e",	{ 0x00d0, 0x2206 },
	"G", "-",	{ 0x01e4 },
	"H", "-H",	{ 0x0126, 0x210d },
	"I", "-J",	{ 0x0197, 0x0132 },
	"L", "&-Jj|",	{ 0x22c0, 0x0141, 0x01c7, 0x01c8, 0x22c1 },
	"M", "#48bs",	{ 0x266e, 0x2669, 0x266a, 0x266d, 0x266f },
	"N", "JNj",	{ 0x01ca, 0x2115, 0x01cb },
	"O", "*+-./=EIcoprx",	{ 0x229b, 0x2295, 0x2296, 0x2299, 0x2298, 0x229c, 0x0152, 0x01a2, 0x00a9, 0x229a, 0x2117, 0x00ae, 0x2297 },
	"P", "P",	{ 0x2119 },
	"Q", "Q",	{ 0x211a },
	"R", "R",	{ 0x211d },
	"S", "123S",	{ 0x00b9, 0x00b2, 0x00b3, 0x00a7 },
	"T", "-u",	{ 0x0166, 0x22a8 },
	"V", "=",	{ 0x21d0 },
	"Y", "R",	{ 0x01a6 },
	"Z", "-ACSZ",	{ 0x01b5, 0xf015, 0xf017, 0xf016, 0x2124 },
	"^", "ACEGHIJOSUWYaceghijosuwy",	{ 0x00c2, 0x0108, 0x00ca, 0x011c, 0x0124, 0x00ce, 0x0134, 0x00d4, 0x015c, 0x00db, 0x0174, 0x0176, 0x00e2, 0x0109, 0x00ea, 0x011d, 0x0125, 0x00ee, 0x0135, 0x00f4, 0x015d, 0x00fb, 0x0175, 0x0177 },
	"_\"", "AUau",	{ 0x01de, 0x01d5, 0x01df, 0x01d6 },
	"_,", "Oo",	{ 0x01ec, 0x01ed },
	"_.", "Aa",	{ 0x01e0, 0x01e1 },
	"_", "AEIOU_aeiou",	{ 0x0100, 0x0112, 0x012a, 0x014c, 0x016a, 0x00af, 0x0101, 0x0113, 0x012b, 0x014d, 0x016b },
	"`\"", "Uu",	{ 0x01db, 0x01dc },
	"`", "AEIOUaeiou",	{ 0x00c0, 0x00c8, 0x00cc, 0x00d2, 0x00d9, 0x00e0, 0x00e8, 0x00ec, 0x00f2, 0x00f9 },
	"a", "ben",	{ 0x2194, 0x00e6, 0x2220 },
	"b", "()+-0123456789=bknpqru",	{ 0x208d, 0x208e, 0x208a, 0x208b, 0x2080, 0x2081, 0x2082, 0x2083, 0x2084, 0x2085, 0x2086, 0x2087, 0x2088, 0x2089, 0x208c, 0x265d, 0x265a, 0x265e, 0x265f, 0x265b, 0x265c, 0x2022 },
	"c", "$Oagu",	{ 0x00a2, 0x00a9, 0x2229, 0x2245, 0x222a },
	"dv", "z",	{ 0x01c6 },
	"d", "-adegz",	{ 0x00f0, 0x2193, 0x2021, 0x00b0, 0x2020, 0x02a3 },
	"e", "$lmns",	{ 0x20ac, 0x22ef, 0x2014, 0x2013, 0x2205 },
	"f", "a",	{ 0x2200 },
	"g", "$-r",	{ 0x00a4, 0x01e5, 0x2207 },
	"h", "-v",	{ 0x210f, 0x0195 },
	"i", "-bfjps",	{ 0x0268, 0x2286, 0x221e, 0x0133, 0x2287, 0x222b },
	"l", "\"$&\'-jz|",	{ 0x201c, 0x00a3, 0x2227, 0x2018, 0x0142, 0x01c9, 0x22c4, 0x2228 },
	"m", "iou",	{ 0x00b5, 0x2208, 0x00d7 },
	"n", "jo",	{ 0x01cc, 0x00ac },
	"o", "AOUaeiu",	{ 0x00c5, 0x229a, 0x016e, 0x00e5, 0x0153, 0x01a3, 0x016f },
	"p", "Odgrt",	{ 0x2117, 0x2202, 0x00b6, 0x220f, 0x221d },
	"r", "\"\'O",	{ 0x201d, 0x2019, 0x00ae },
	"s", "()+-0123456789=abnoprstu",	{ 0x207d, 0x207e, 0x207a, 0x207b, 0x2070, 0x2071, 0x2072, 0x2073, 0x2074, 0x2075, 0x2076, 0x2077, 0x2078, 0x2079, 0x207c, 0x00aa, 0x2282, 0x207f, 0x00ba, 0x2283, 0x221a, 0x00df, 0x220d, 0x2211 },
	"t", "-efmsu",	{ 0x0167, 0x2203, 0x2234, 0x2122, 0x03c2, 0x22a2 },
	"u", "-AEGIOUaegiou",	{ 0x0289, 0x0102, 0x0114, 0x011e, 0x012c, 0x014e, 0x016c, 0x2191, 0x0115, 0x011f, 0x012d, 0x014f, 0x016d },
	"v\"", "Uu",	{ 0x01d9, 0x01da },
	"v", "ACDEGIKLNORSTUZacdegijklnorstuz",	{ 0x01cd, 0x010c, 0x010e, 0x011a, 0x01e6, 0x01cf, 0x01e8, 0x013d, 0x0147, 0x01d1, 0x0158, 0x0160, 0x0164, 0x01d3, 0x017d, 0x01ce, 0x010d, 0x010f, 0x011b, 0x01e7, 0x01d0, 0x01f0, 0x01e9, 0x013e, 0x0148, 0x01d2, 0x0159, 0x0161, 0x0165, 0x01d4, 0x017e },
	"w", "bknpqr",	{ 0x2657, 0x2654, 0x2658, 0x2659, 0x2655, 0x2656 },
	"x", "O",	{ 0x2297 },
	"y", "$",	{ 0x00a5 },
	"z", "-",	{ 0x01b6 },
	"|", "Pp|",	{ 0x00de, 0x00fe, 0x00a6 },
	"~!", "=",	{ 0x2246 },
	"~", "-=AINOUainou~",	{ 0x2243, 0x2245, 0x00c3, 0x0128, 0x00d1, 0x00d5, 0x0168, 0x00e3, 0x0129, 0x00f1, 0x00f5, 0x0169, 0x2248 },
	0, 0, { 0 }
};

/*
 * Given 5 characters k[0]..k[4], find the rune or return -1 for failure.
 */
static long
unicode(Rune *k)
{
	long i, c;

	k++;	/* skip 'X' */
	c = 0;
	for(i=0; i<4; i++,k++){
		c <<= 4;
		if('0'<=*k && *k<='9')
			c += *k-'0';
		else if('a'<=*k && *k<='f')
			c += 10 + *k-'a';
		else if('A'<=*k && *k<='F')
			c += 10 + *k-'A';
		else
			return -1;
	}
	return c;
}

/*
 * Given n characters k[0]..k[n-1], find the corresponding rune or return -1 for
 * failure, or something < -1 if n is too small.  In the latter case, the result
 * is minus the required n.
 */
int
_latin1(Rune *k, int n)
{
	struct cvlist *l;
	int c;
	char* p;

	if(k[0] == 'X'){
		if(n>=5)
			return unicode(k);
		else
			return -5;
	}
	
	for(l=latintab; l->ld!=0; l++)
		if(k[0] == l->ld[0]){
			if(n == 1)
				return -2;
			if(l->ld[1] == 0)
				c = k[1];
			else if(l->ld[1] != k[1])
				continue;
			else if(n == 2)
				return -3;
			else
				c = k[2];
			for(p=l->si; *p!=0; p++)
				if(*p == c)
					return l->so[p - l->si];
			return -1;
		}
	return -1;
}