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


static struct {
	unsigned char cp_low;
	char latin;
} lisu[] = {
	{0xEE, 'a'},
	{0xD0, 'b'},
	{0xDA, 'c'},
	{0xD3, 'd'},
	{0xF0, 'e'},
	{0xDD, 'f'},
	{0xD6, 'g'},
	{0xE7, 'h'},
	{0xF2, 'i'},
	{0xD9, 'j'},
	{0xD7, 'k'},
	{0xE1, 'l'},
	{0xDF, 'm'},
	{0xE0, 'n'},
	{0xF3, 'o'},
	{0xD1, 'p'},
	{0xE3, 'r'},
	{0xE2, 's'},
	{0xD4, 't'},
	{0xF4, 'u'},
	{0xE6, 'v'},
	{0xEA, 'w'},
	{0xEB, 'x'},
	{0xEC, 'y'},
	{0xDC, 'z'},
	{0xEF, 'A'},
	{0xED, 'B'},
	{0xDB, 'C'},
	{0xF7, 'D'},
	{0xF1, 'E'},
	{0xDE, 'F'},
	{0xE8, 'G'},
	{0xE7, 'H'}, /* symmetry */
	{0xF2, 'I'}, /* symmetry */
	{0xE9, 'J'},
	{0xD8, 'K'},
	{0xF6, 'L'},
	{0xEA, 'M'}, /* W */
	{0xE0, 'N'}, /* symmetry */
	{0xF3, 'O'}, /* symmetry */
	{0xD2, 'P'},
	{0xE4, 'R'},
	{0xE2, 'S'}, /* symmetry */
	{0xD5, 'Y'},
	{0xF5, 'U'},
	{0xE5, 'V'},
	{0xDF, 'W'}, /* M */
	{0xEB, 'X'}, /* symmetry */
	{0xDC, 'Z'}, /* symmetry */
	{0xFE, '-'},
	{0xFF, '='},
	{0xFD, ':'},
	{0xFC, ';'},
	{0xF9, ','}
};


enum libcharconv_result
libcharconv_lisu(const char *s, size_t slen, size_t *n, uint_least32_t *cp, size_t *ncp)
{
	uint_least32_t c;
	size_t i;
	*n = 0;
	for (; slen--; s++) {
		if (*s == 'Y') {
			c = UINT32_C(0x11FB0);
			goto conv;
		} else if (*s == '.') {
			if (*n)
				goto no_conv;
			if (*ncp)
				*cp = UINT32_C(0xA4F8);
			*n += 1u;
			*ncp = 1u;
			if (!slen--)
				return LIBCHARCONV_CONVERT_IF_END;
			if (s[1] == '.') {
				if (*ncp)
					*cp = UINT32_C(0xA4FA);
				*n += 1u;
			} else if (s[1] == ',') {
				if (*ncp)
					*cp = UINT32_C(0xA4FB);
				*n += 1u;
			}
			return LIBCHARCONV_CONVERTED;
		} else {
			for (i = 0u; i < sizeof(lisu) / sizeof(*lisu); i++)
				if (*s == lisu[i].latin)
					goto conv_listed;
			*n += 1u;
		}
	}
no_conv:
	return LIBCHARCONV_NO_CONVERT;

conv_listed:
	c = (uint_least32_t)(UINT32_C(0xA400) | lisu[i].cp_low);
conv:
	if (*n)
		goto no_conv;
	if (*ncp)
		*cp = c;
	*n += 1u;
	*ncp = 1u;
	return LIBCHARCONV_CONVERTED;
}