/*
 * Copyright (C) 2022 Camden Dixie O'Brien
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this program.  If not, see
 * <https://www.gnu.org/licenses/>.
 */

#include "sud.h"

#include <stdio.h>

#define Q(x) #x
#define PRLUT(x) prlut(Q(x), x)

static void prlut(const char *name, unsigned lut[NCELLS][NDIGITS - 1])
{
	unsigned i, j;
	printf("const unsigned %s[NCELLS][NDIGITS - 1] = {\n", name);
	for (i = 0; i < NCELLS; ++i) {
		fputs("\t{ ", stdout);
		for (j = 0; j < NDIGITS - 1; ++j) {
			printf("%2u", lut[i][j]);
			if (j != NDIGITS - 2)
				putchar(',');
			putchar(' ');
		}
		fputs("},\n", stdout);
	}
	fputs("};\n", stdout);
}

int main(void)
{
	unsigned rowidx_lut[NCELLS][NDIGITS - 1];
	unsigned colidx_lut[NCELLS][NDIGITS - 1];
	unsigned segidx_lut[NCELLS][NDIGITS - 1];
	unsigned rowi, coli, segi, r, c, i, j, sr, sc;

	/* Populate tables. */
	for (r = 0; r < NDIGITS; ++r) {
		for (c = 0; c < NDIGITS; ++c) {
			/* Calculate row and column indices. */
			rowi = coli = 0;
			for (i = 0; i < NDIGITS; ++i) {
				if (i != c)
					rowidx_lut[r * NDIGITS + c][rowi++] = r * NDIGITS + i;
				if (i != r)
					colidx_lut[r * NDIGITS + c][coli++] = i * NDIGITS + c;
			}

			/* Calculate segment indices. */
			segi = 0;
			sr = SEGLEN * (r / SEGLEN);
			sc = SEGLEN * (c / SEGLEN);
			for (i = sr; i < sr + SEGLEN; ++i) {
				for (j = sc; j < sc + SEGLEN; ++j) {
					if (i == r && j == c)
						continue;
					segidx_lut[r * NDIGITS + c][segi++] = i * NDIGITS + j;
				}
			}
		}
	}

	printf("/*\n * This file is auto-generated; do not edit.\n */\n\n");
	printf("#include \"lut.h\"\n\n");
	PRLUT(rowidx_lut);
	putchar('\n');
	PRLUT(colidx_lut);
	putchar('\n');
	PRLUT(segidx_lut);

	return 0;
}