/* See LICENSE file for copyright and license details. */
#include "lib-common.h"


enum libcharconv_result
libcharconv_buhid(const char *s, size_t slen, size_t *n, uint_least32_t *cp, size_t *ncp)
{
	uint_least32_t c;
	*n = 0;
	for (; slen--; s++) {
		switch (s[0]) {
		case 'A': case 'a': c = UINT32_C(0x1740); goto conv1;
		case 'I': case 'i': c = UINT32_C(0x1741); goto conv1;
		case 'U': case 'u': c = UINT32_C(0x1742); goto conv1;
		case '^':
			if (!slen)
				return LIBCHARCONV_INDETERMINATE;
			switch (s[1]) {
			case 'I': case 'i': c = UINT32_C(0x1752); goto conv2;
			case 'U': case 'u': c = UINT32_C(0x1753); goto conv2;
			default:
				goto no_match;
			}
			goto no_match;
		case 'B': case 'b': c = UINT32_C(0x174A); goto conv;
		case 'D': case 'd': c = UINT32_C(0x1747); goto conv;
		case 'G': case 'g': c = UINT32_C(0x1744); goto conv;
		case 'H': case 'h': c = UINT32_C(0x1751); goto conv;
		case 'K': case 'k': c = UINT32_C(0x1743); goto conv;
		case 'L': case 'l': c = UINT32_C(0x174E); goto conv;
		case 'M': case 'm': c = UINT32_C(0x174B); goto conv;
		case 'N': case 'n': c = UINT32_C(0x1748); goto conv;
		case 'P': case 'p': c = UINT32_C(0x1749); goto conv;
		case 'R': case 'r': c = UINT32_C(0x174D); goto conv;
		case 'S': case 's': c = UINT32_C(0x1750); goto conv;
		case 'T': case 't': c = UINT32_C(0x1746); goto conv;
		case 'Y': case 'y': c = UINT32_C(0x174C); goto conv;
		case 'W': case 'w': c = UINT32_C(0x174F); goto conv;
		default:
		no_match:
			*n += 1u;
			break;
		}
	}
no_conv:
	return LIBCHARCONV_NO_CONVERT;

conv:
	if (*n)
		goto no_conv;
conv_again:
	if (!slen)
		return LIBCHARCONV_INDETERMINATE;
	switch (s[1]) {
	case 'A': case 'a':
		if (*ncp >= 1u)
			cp[0] = c;
		*n += 2u;
		*ncp = 1u;
		return LIBCHARCONV_CONVERTED;
	case 'I': case 'i':
		if (*ncp >= 1u)
			cp[0] = c;
		if (*ncp >= 2u)
			cp[1] = UINT32_C(0x1752);
		*n += 2u;
		*ncp = 2u;
		return LIBCHARCONV_CONVERTED;
	case 'U': case 'u':
		if (*ncp >= 1u)
			cp[0] = c;
		if (*ncp >= 2u)
			cp[1] = UINT32_C(0x1753);
		*n += 2u;
		*ncp = 2u;
		return LIBCHARCONV_CONVERTED;
	case 'G': case 'g':
		if (c == UINT32_C(0x1745))
			goto no_match;
		if (s[0] != 'N' && s[0] != 'n')
			goto no_match;
		c = UINT32_C(0x1745);
		*n += 1u;
		slen--;
		s++;
		goto conv_again;
	default:
		goto no_match;
	}

conv1:
	if (*n)
		goto no_conv;
	if (*ncp)
		*cp = c;
	*n += 1u;
	*ncp = 1u;
	return LIBCHARCONV_CONVERTED;

conv2:
	if (*n)
		goto no_conv;
	if (*ncp)
		*cp = c;
	*n += 2u;
	*ncp = 1u;
	return LIBCHARCONV_CONVERTED;
}