/*
 * 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 "solve.h"
#include "sud.h"

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

static uint32_t getseed(void)
{
	FILE *urandom = fopen("/dev/urandom", "rb");
	if (urandom == NULL)
		fprintf(stderr, "Failed to open /dev/urandom\n");

	uint32_t seed = 0;
	for (unsigned i = 0; i < 4; ++i)
		seed = seed << 8 | fgetc(urandom);

	fclose(urandom);

	return seed;
}

int main(void)
{
	uint32_t seed = getseed();
	printf("Seed: %u\n\n", seed);
	srand(seed);

	struct sudoku sud;
	gen(&sud);
	puts("Start:");
	print(&sud);
	putchar('\n');

	bool res = solve(&sud);
	if (!res) {
		puts("Solver encountered an error\n");
	} else {
		puts("End:");
		print(&sud);
	}

	return 0;
}