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


enum libcharconv_result
libcharconv_yijing_digrams(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++) {
		if ('1' <= s[0] && s[0] <= '3') {
			if (!slen)
				return LIBCHARCONV_INDETERMINATE;
			if (s[0] == '1' && s[1] == '1')
				c = UINT32_C(0x268C);
			else if (s[0] == '1' && s[1] == '2')
				c = UINT32_C(0x268E);
			else if (s[0] == '1' && s[1] == '3')
				c = UINT32_C(0x1D301);
			else if (s[0] == '2' && s[1] == '1')
				c = UINT32_C(0x268D);
			else if (s[0] == '2' && s[1] == '2')
				c = UINT32_C(0x268F);
			else if (s[0] == '2' && s[1] == '3')
				c = UINT32_C(0x1D302);
			else if (s[0] == '3' && s[1] == '1')
				c = UINT32_C(0x1D303);
			else if (s[0] == '3' && s[1] == '2')
				c = UINT32_C(0x1D304);
			else if (s[0] == '3' && s[1] == '3')
				c = UINT32_C(0x1D305);
			else
				goto no_match;
			goto conv;
		} else {
		no_match:
			*n += 1u;
		}
	}
no_conv:
	return LIBCHARCONV_NO_CONVERT;

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