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


enum libcharconv_result
libcharconv_marchen(const char *s, size_t slen, size_t *n, uint_least32_t *cp, size_t *ncp)
{
	static const char *const letters = "kKgGcCjYtTdnpPbmxXDwZz-yrlSsh";
	uint_least32_t c, c2, c3;
	size_t i;
	*n = 0;
	for (; slen--; s++) {
		PLAIN_SELECT(letters, 0x11C72);
		switch (s[0]) {
		case 'a': c = UINT32_C(0x11C8F); goto conv1_subjoinable;
		case 'A': c = UINT32_C(0x11CB0); goto conv_vowel;
		case 'i': c = UINT32_C(0x11CB1); goto conv_vowel;
		case 'u': c = UINT32_C(0x11CB2); goto conv_vowel;
		case 'e': c = UINT32_C(0x11CB3); goto conv_vowel;
		case 'o': c = UINT32_C(0x11CB4); goto conv_vowel;
		case '\'': c = UINT32_C(0x11CB5); goto conv1;
		case '\"': c = UINT32_C(0x11CB6); goto conv1;
		case '.': c = UINT32_C(0x11C70); goto conv1;
		case ':': c = UINT32_C(0x11C71); goto conv1;
		case '^':
			if (!slen)
				return LIBCHARCONV_INDETERMINATE;
			switch (s[1]) {
			case 'A': c = UINT32_C(0x11CB0); goto conv2;
			case 'i': c = UINT32_C(0x11CB1); goto conv2;
			case 'u': c = UINT32_C(0x11CB2); goto conv2;
			case 'e': c = UINT32_C(0x11CB3); goto conv2;
			case 'o': c = UINT32_C(0x11CB4); goto conv2;
			default:
				goto no_match;
			}
		case '_':
			if (*n)
				goto no_conv;
			*n += 1u;
			break;
		default:
		no_match:
			*n += 1u;
			break;
		}
	}
no_conv:
	return LIBCHARCONV_NO_CONVERT;

conv:
	if (*n == 1u && s[-1] == '_' && c != UINT32_C(0x11C88)) {
		c += 0x20u;
		goto conv1_prechecked;
	}
	if (*n)
		goto no_conv;
	if (!slen)
		return LIBCHARCONV_INDETERMINATE;
	for (i = 0u; letters[i]; i++)
		if (letters[i] == s[1])
			break;
	c3 = (letters[i] && letters[i] != '-') ? (uint_least32_t)(UINT32_C(0x11C92) + i) : 0u;
	if (c3 && slen == 1u)
		return LIBCHARCONV_INDETERMINATE;
	switch (s[c3 ? 2 : 1]) {
	case 'a':
		if (c3)
			goto conv3_prechecked;
		else
			goto conv2_prechecked;
	case 'A': c2 = UINT32_C(0x11CB0); break;
	case 'i': c2 = UINT32_C(0x11CB1); break;
	case 'u': c2 = UINT32_C(0x11CB2); break;
	case 'e': c2 = UINT32_C(0x11CB3); break;
	case 'o': c2 = UINT32_C(0x11CB4); break;
	default:
		goto no_match;
	}
	if (*ncp >= 1u)
		cp[0] = c;
	if (*ncp >= 2u)
		cp[1] = c2;
	if (c3 && *ncp >= 3u)
		cp[2] = c3;
	*n += c3 ? 3u : 2u;
	*ncp = c3 ? 3u : 2u;
	return LIBCHARCONV_CONVERTED;

conv1_subjoinable:
	if (*n == 1u && s[-1] == '_') {
		c += 0x20u;
	} else {
	conv1:
		if (*n)
			goto no_conv;
	}
conv1_prechecked:
	if (*ncp)
		*cp = c;
	*n += 1u;
	*ncp = 1u;
	return LIBCHARCONV_CONVERTED;

conv2:
	if (*n)
		goto no_conv;
conv2_prechecked:
	if (*ncp)
		cp[0] = c;
	*n += 2u;
	*ncp = 1u;
	return LIBCHARCONV_CONVERTED;

conv_vowel:
	if (*n)
		goto no_conv;
	if (*ncp >= 1u)
		cp[0] = UINT32_C(0x11C8F) + (s[-1] == '_' ? 0x20u : 0u);
	if (*ncp >= 2u)
		cp[1] = c;
	*n += 1u;
	*ncp = 2u;
	return LIBCHARCONV_CONVERTED;

conv3_prechecked:
	if (*ncp >= 1u)
		cp[0] = c;
	if (*ncp >= 2u)
		cp[1] = c3;
	*n += 3u;
	*ncp = 2u;
	return LIBCHARCONV_CONVERTED;
}