/* 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++) {
		PLAIN_CASE_SINGLE('k', 0x1743);
		PLAIN_CASE_SINGLE('g', 0x1744);
		PLAIN_CASE_SELECT("tdnpbmyrlwsh", 0x1746);
		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;
		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;
}