#include <stdlib.h>
#include <stdint.h>
#include <assert.h>

#include "utf8.h"

static const int8_t utf8proc_utf8class[256] = {
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
	4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0 };

static void encode_unknown(strbuf *buf)
{
	static const uint8_t repl[] = {239, 191, 189};
	strbuf_put(buf, repl, 3);
}

int utf8proc_charlen(const uint8_t *str, int str_len)
{
	int length, i;

	if (!str_len)
		return 0;

	length = utf8proc_utf8class[str[0]];

	if (!length)
		return -1;

	if (str_len >= 0 && length > str_len)
		return -str_len;

	for (i = 1; i < length; i++) {
		if ((str[i] & 0xC0) != 0x80)
			return -i;
	}

	return length;
}

void utf8proc_detab(strbuf *ob, const uint8_t *line, size_t size)
{
	static const uint8_t whitespace[] = "    ";

	size_t i = 0, tab = 0;

	while (i < size) {
		size_t org = i;

		while (i < size && line[i] != '\t' && line[i] <= 0x80) {
			i++; tab++;
		}

		if (i > org)
			strbuf_put(ob, line + org, i - org);

		if (i >= size)
			break;

		if (line[i] == '\t') {
			int numspaces = 4 - (tab % 4);
			strbuf_put(ob, whitespace, numspaces);
			i += 1;
			tab += numspaces;
		} else {
			int charlen = utf8proc_charlen(line + i, size - i);

			if (charlen >= 0) {
				strbuf_put(ob, line + i, charlen);
			} else {
				encode_unknown(ob);
				charlen = -charlen;
			}

			i += charlen;
			tab += 1;
		}
	}
}

int utf8proc_iterate(const uint8_t *str, int str_len, int32_t *dst)
{
	int length;
	int32_t uc = -1;

	*dst = -1;
	length = utf8proc_charlen(str, str_len);
	if (length < 0)
		return -1;

	switch (length) {
	case 1:
		uc = str[0];
		break;
	case 2:
		uc = ((str[0] & 0x1F) <<  6) + (str[1] & 0x3F);
		if (uc < 0x80) uc = -1;
		break;
	case 3:
		uc = ((str[0] & 0x0F) << 12) + ((str[1] & 0x3F) <<  6)
			+ (str[2] & 0x3F);
		if (uc < 0x800 || (uc >= 0xD800 && uc < 0xE000) ||
		    (uc >= 0xFDD0 && uc < 0xFDF0)) uc = -1;
		break;
	case 4:
		uc = ((str[0] & 0x07) << 18) + ((str[1] & 0x3F) << 12)
			+ ((str[2] & 0x3F) <<  6) + (str[3] & 0x3F);
		if (uc < 0x10000 || uc >= 0x110000) uc = -1;
		break;
	}

	if (uc < 0 || ((uc & 0xFFFF) >= 0xFFFE))
		return -1;

	*dst = uc;
	return length;
}

void utf8proc_encode_char(int32_t uc, strbuf *buf)
{
	uint8_t dst[4];
	int len = 0;

	assert(uc >= 0);

	if (uc < 0x80) {
		dst[0] = uc;
		len = 1;
	} else if (uc < 0x800) {
		dst[0] = 0xC0 + (uc >> 6);
		dst[1] = 0x80 + (uc & 0x3F);
		len = 2;
	} else if (uc == 0xFFFF) {
		dst[0] = 0xFF;
		len = 1;
	} else if (uc == 0xFFFE) {
		dst[0] = 0xFE;
		len = 1;
	} else if (uc < 0x10000) {
		dst[0] = 0xE0 + (uc >> 12);
		dst[1] = 0x80 + ((uc >> 6) & 0x3F);
		dst[2] = 0x80 + (uc & 0x3F);
		len = 3;
	} else if (uc < 0x110000) {
		dst[0] = 0xF0 + (uc >> 18);
		dst[1] = 0x80 + ((uc >> 12) & 0x3F);
		dst[2] = 0x80 + ((uc >> 6) & 0x3F);
		dst[3] = 0x80 + (uc & 0x3F);
		len = 4;
	} else {
		encode_unknown(buf);
		return;
	}

	strbuf_put(buf, dst, len);
}

void utf8proc_case_fold(strbuf *dest, const uint8_t *str, int len)
{
	int32_t c;

#define bufpush(x)				\
	utf8proc_encode_char(x, dest)

	while (len > 0) {
		int char_len = utf8proc_iterate(str, len, &c);

		if (char_len >= 0) {
#include "case_fold_switch.inc"
		} else {
			encode_unknown(dest);
			char_len = -char_len;
		}

		str += char_len;
		len -= char_len;
	}
}

// matches anything in the P[cdefios] classes.
int utf8proc_is_punctuation(int32_t uc)
{
	return ((uc >= 33 && uc <= 35) ||
		(uc >= 37 && uc <= 42) ||
		(uc >= 44 && uc <= 47) ||
		(uc >= 58 && uc <= 59) ||
		(uc >= 63 && uc <= 64) ||
		(uc >= 91 && uc <= 93) ||
		uc == 95 ||
		uc == 123 ||
		uc == 125 ||
		uc == 161 ||
		uc == 167 ||
		uc == 171 ||
		(uc >= 182 && uc <= 183) ||
		uc == 187 ||
		uc == 191 ||
		uc == 894 ||
		uc == 903 ||
		(uc >= 1370 && uc <= 1375) ||
		(uc >= 1417 && uc <= 1418) ||
		uc == 1470 ||
		uc == 1472 ||
		uc == 1475 ||
		uc == 1478 ||
		(uc >= 1523 && uc <= 1524) ||
		(uc >= 1545 && uc <= 1546) ||
		(uc >= 1548 && uc <= 1549) ||
		uc == 1563 ||
		(uc >= 1566 && uc <= 1567) ||
		(uc >= 1642 && uc <= 1645) ||
		uc == 1748 ||
		(uc >= 1792 && uc <= 1805) ||
		(uc >= 2039 && uc <= 2041) ||
		(uc >= 2096 && uc <= 2110) ||
		uc == 2142 ||
		(uc >= 2404 && uc <= 2405) ||
		uc == 2416 ||
		uc == 2800 ||
		uc == 3572 ||
		uc == 3663 ||
		(uc >= 3674 && uc <= 3675) ||
		(uc >= 3844 && uc <= 3858) ||
		uc == 3860 ||
		(uc >= 3898 && uc <= 3901) ||
		uc == 3973 ||
		(uc >= 4048 && uc <= 4052) ||
		(uc >= 4057 && uc <= 4058) ||
		(uc >= 4170 && uc <= 4175) ||
		uc == 4347 ||
		(uc >= 4960 && uc <= 4968) ||
		uc == 5120 ||
		(uc >= 5741 && uc <= 5742) ||
		(uc >= 5787 && uc <= 5788) ||
		(uc >= 5867 && uc <= 5869) ||
		(uc >= 5941 && uc <= 5942) ||
		(uc >= 6100 && uc <= 6102) ||
		(uc >= 6104 && uc <= 6106) ||
		(uc >= 6144 && uc <= 6154) ||
		(uc >= 6468 && uc <= 6469) ||
		(uc >= 6686 && uc <= 6687) ||
		(uc >= 6816 && uc <= 6822) ||
		(uc >= 6824 && uc <= 6829) ||
		(uc >= 7002 && uc <= 7008) ||
		(uc >= 7164 && uc <= 7167) ||
		(uc >= 7227 && uc <= 7231) ||
		(uc >= 7294 && uc <= 7295) ||
		(uc >= 7360 && uc <= 7367) ||
		uc == 7379 ||
		(uc >= 8208 && uc <= 8231) ||
		(uc >= 8240 && uc <= 8259) ||
		(uc >= 8261 && uc <= 8273) ||
		(uc >= 8275 && uc <= 8286) ||
		(uc >= 8317 && uc <= 8318) ||
		(uc >= 8333 && uc <= 8334) ||
		(uc >= 8968 && uc <= 8971) ||
		(uc >= 9001 && uc <= 9002) ||
		(uc >= 10088 && uc <= 10101) ||
		(uc >= 10181 && uc <= 10182) ||
		(uc >= 10214 && uc <= 10223) ||
		(uc >= 10627 && uc <= 10648) ||
		(uc >= 10712 && uc <= 10715) ||
		(uc >= 10748 && uc <= 10749) ||
		(uc >= 11513 && uc <= 11516) ||
		(uc >= 11518 && uc <= 11519) ||
		uc == 11632 ||
		(uc >= 11776 && uc <= 11822) ||
		(uc >= 11824 && uc <= 11842) ||
		(uc >= 12289 && uc <= 12291) ||
		(uc >= 12296 && uc <= 12305) ||
		(uc >= 12308 && uc <= 12319) ||
		uc == 12336 ||
		uc == 12349 ||
		uc == 12448 ||
		uc == 12539 ||
		(uc >= 42238 && uc <= 42239) ||
		(uc >= 42509 && uc <= 42511) ||
		uc == 42611 ||
		uc == 42622 ||
		(uc >= 42738 && uc <= 42743) ||
		(uc >= 43124 && uc <= 43127) ||
		(uc >= 43214 && uc <= 43215) ||
		(uc >= 43256 && uc <= 43258) ||
		(uc >= 43310 && uc <= 43311) ||
		uc == 43359 ||
		(uc >= 43457 && uc <= 43469) ||
		(uc >= 43486 && uc <= 43487) ||
		(uc >= 43612 && uc <= 43615) ||
		(uc >= 43742 && uc <= 43743) ||
		(uc >= 43760 && uc <= 43761) ||
		uc == 44011 ||
		(uc >= 64830 && uc <= 64831) ||
		(uc >= 65040 && uc <= 65049) ||
		(uc >= 65072 && uc <= 65106) ||
		(uc >= 65108 && uc <= 65121) ||
		uc == 65123 ||
		uc == 65128 ||
		(uc >= 65130 && uc <= 65131) ||
		(uc >= 65281 && uc <= 65283) ||
		(uc >= 65285 && uc <= 65290) ||
		(uc >= 65292 && uc <= 65295) ||
		(uc >= 65306 && uc <= 65307) ||
		(uc >= 65311 && uc <= 65312) ||
		(uc >= 65339 && uc <= 65341) ||
		uc == 65343 ||
		uc == 65371 ||
		uc == 65373 ||
		(uc >= 65375 && uc <= 65381) ||
		(uc >= 65792 && uc <= 65794) ||
		uc == 66463 ||
		uc == 66512 ||
		uc == 66927 ||
		uc == 67671 ||
		uc == 67871 ||
		uc == 67903 ||
		(uc >= 68176 && uc <= 68184) ||
		uc == 68223 ||
		(uc >= 68336 && uc <= 68342) ||
		(uc >= 68409 && uc <= 68415) ||
		(uc >= 68505 && uc <= 68508) ||
		(uc >= 69703 && uc <= 69709) ||
		(uc >= 69819 && uc <= 69820) ||
		(uc >= 69822 && uc <= 69825) ||
		(uc >= 69952 && uc <= 69955) ||
		(uc >= 70004 && uc <= 70005) ||
		(uc >= 70085 && uc <= 70088) ||
		uc == 70093 ||
		(uc >= 70200 && uc <= 70205) ||
		uc == 70854 ||
		(uc >= 71105 && uc <= 71113) ||
		(uc >= 71233 && uc <= 71235) ||
		(uc >= 74864 && uc <= 74868) ||
		(uc >= 92782 && uc <= 92783) ||
		uc == 92917 ||
		(uc >= 92983 && uc <= 92987) ||
		uc == 92996 ||
		uc == 113823);
}