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


static struct {
	uint_least32_t a;
	uint_least32_t b;
} pairs[] = {
	{UINT32_C(0x0020), UINT32_C(0x2588)},
	{UINT32_C(0x1FBA3), UINT32_C(0x1FBBE)},
	{UINT32_C(0x1FBAE), UINT32_C(0x1FBBF)},
	{UINT32_C(0x1FBBD), UINT32_C(0x2573)},
	{UINT32_C(0x1F030), UINT32_C(0x1F031)},
	{UINT32_C(0x1F062), UINT32_C(0x1F063)},
	{UINT32_C(0x2686), UINT32_C(0x2688)},
	{UINT32_C(0x2687), UINT32_C(0x2689)},
	{UINT32_C(0x2616), UINT32_C(0x26C9)},
	{UINT32_C(0x2617), UINT32_C(0x26CA)},
	{UINT32_C(0x26C0), UINT32_C(0x26C2)},
	{UINT32_C(0x26C1), UINT32_C(0x26C3)},
	{UINT32_C(0x1FA06), UINT32_C(0x1FA07)},
	{UINT32_C(0x1FA1B), UINT32_C(0x1FA1C)},
	{UINT32_C(0x1FA30), UINT32_C(0x1FA31)},
	{UINT32_C(0x1FA45), UINT32_C(0x1FA46)},
	{UINT32_C(0x1FA48), UINT32_C(0x1FA49)},
	{UINT32_C(0x1FA4B), UINT32_C(0x1FA4C)},
	{UINT32_C(0x24EA), UINT32_C(0x24FF)},
	{UINT32_C(0x1F10B), UINT32_C(0x1F10C)},
	{UINT32_C(0x2690), UINT32_C(0x2691)},
	{UINT32_C(0x1F3F3), UINT32_C(0x1F3F4)},
	{UINT32_C(0x1F3F1), UINT32_C(0x1F3F2)}
};


static struct {
	struct {uint_least32_t low, high;} low, high;
} range_pairs[] = {
	{{UINT32_C(0x2654), UINT32_C(0x2659)}, {UINT32_C(0x265A), UINT32_C(0x265F)}},
	{{UINT32_C(0x1FA60), UINT32_C(0x1FA66)}, {UINT32_C(0x1FA67), UINT32_C(0x1FA6D)}},
	{{UINT32_C(0x1FA09), UINT32_C(0x1FA0E)}, {UINT32_C(0x1FA0F), UINT32_C(0x1FA14)}},
	{{UINT32_C(0x1FA1E), UINT32_C(0x1FA23)}, {UINT32_C(0x1FA24), UINT32_C(0x1FA29)}},
	{{UINT32_C(0x1FA33), UINT32_C(0x1FA38)}, {UINT32_C(0x1FA39), UINT32_C(0x1FA3E)}},
	{{UINT32_C(0x1FA4E), UINT32_C(0x1FA50)}, {UINT32_C(0x1FA51), UINT32_C(0x1FA53)}},
	{{UINT32_C(0x2460), UINT32_C(0x2469)}, {UINT32_C(0x2776), UINT32_C(0x277F)}},
	{{UINT32_C(0x246A), UINT32_C(0x2473)}, {UINT32_C(0x24EB), UINT32_C(0x24F4)}},
	{{UINT32_C(0x24B6), UINT32_C(0x24CF)}, {UINT32_C(0x1F150), UINT32_C(0x1F169)}},
	{{UINT32_C(0x1F130), UINT32_C(0x1F149)}, {UINT32_C(0x1F170), UINT32_C(0x1F189)}},
	{{UINT32_C(0x2780), UINT32_C(0x2789)}, {UINT32_C(0x278A), UINT32_C(0x2793)}},
	{{UINT32_C(0x2660), UINT32_C(0x2663)}, {UINT32_C(0x2664), UINT32_C(0x2667)}}
};


enum libcharconv_result
libcharconv_negative(const char *s, size_t slen, size_t *n, uint_least32_t *cp, size_t *ncp)
{
	uint_least32_t c;
	size_t i, clen;
	*n = 0;
	while (slen) {
		clen = libcharconv_decode_utf8_(s, slen, &c);
		if (clen > slen) {
			if (*n)
				goto no_conv;
			return LIBCHARCONV_INDETERMINATE;
		}
		if (!clen) {
			*n += 1u;
			slen -= 1u;
			s = &s[1];
			continue;
		}

		for (i = 0u; i < sizeof(range_pairs) / sizeof(*range_pairs); i++) {
			if (range_pairs[i].low.low <= c && c <= range_pairs[i].low.high) {
				c += range_pairs[i].high.low - range_pairs[i].low.low;
				goto conv;
			}
			if (range_pairs[i].high.low <= c && c <= range_pairs[i].high.high) {
				c -= range_pairs[i].high.low - range_pairs[i].low.low;
				goto conv;
			}
		}
		for (i = 0u; i < sizeof(pairs) / sizeof(*pairs); i++) {
			if (c == pairs[i].a) {
				c = pairs[i].b;
				goto conv;
			}
			if (c == pairs[i].b) {
				c = pairs[i].a;
				goto conv;
			}
		}

		*n += clen;
		s = &s[clen];
		slen -= clen;
	}
no_conv:
	return LIBCHARCONV_NO_CONVERT;

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