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


enum libcharconv_result
libcharconv_box_drawing(const char *s, size_t slen, size_t *n, uint_least32_t *cp, size_t *ncp)
{
	uint_least32_t a, c;
	size_t i;
	*n = 0;
	for (; slen--; s++, ++*n) {
		PLAIN_CASE_SELECT("/\\X", 0x2571);
		if ('1' <= *s && *s <= '4') {
			c = (uint_least32_t)1 << (*s - '1');
			for (i = 1u;; i++) {
				if (slen < i)
					goto indeterminate;
				if ('1' <= s[i] && s[i] <= '4') {
					a = (uint_least32_t)1 << (s[i] - '1');
					if (a & c)
						goto next;
					c |= a;
				} else if (s[i] == 'O') {
					c = (uint_least32_t)" \x00\x01\x07\x02\x04\x09\x0D\x03\x08\x05\x0C\x06\x0B\x0A\x0E"[c];
					c |= UINT32_C(0x1FBA0);
					if (*n)
						goto no_conv;
					*n += i + 1u;
					goto conv_prechecked;
				}
			}
		}
	next:;
	}
no_conv:
	return LIBCHARCONV_NO_CONVERT;

indeterminate:
	if (*n)
		goto no_conv;
	return LIBCHARCONV_INDETERMINATE;

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