/**
 *
 * \section COPYRIGHT
 *
 * Copyright 2013-2014 The libLTE Developers. See the
 * COPYRIGHT file at the top-level directory of this distribution.
 *
 * \section LICENSE
 *
 * This file is part of the libLTE library.
 *
 * libLTE is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * libLTE 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 Lesser General Public License for more details.
 *
 * A copy of the GNU Lesser General Public License can be found in
 * the LICENSE file in the top-level directory of this distribution
 * and at http://www.gnu.org/licenses/.
 *
 */


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <math.h>
#include <time.h>

#include "lte.h"

#include "crc_test.h"

int num_bits = 1000, crc_length = 16;
unsigned int crc_poly = 0x11021;
unsigned int seed = 0;


void usage(char *prog) {
	printf("Usage: %s [nlps]\n", prog);
	printf("\t-n num_bits [Default %d]\n", num_bits);
	printf("\t-l crc_length [Default %d]\n", crc_length);
	printf("\t-p crc_poly (Hex) [Default 0x%x]\n", crc_poly);
	printf("\t-s seed [Default 0=time]\n");
}

void parse_args(int argc, char **argv) {
	int opt;
	while ((opt = getopt(argc, argv, "nlps")) != -1) {
		switch (opt) {
		case 'n':
			num_bits = atoi(argv[optind]);
			break;
		case 'l':
			crc_length = atoi(argv[optind]);
			break;
		case 'p':
			crc_poly = (unsigned int) strtoul(argv[optind], NULL, 16);
			break;
		case 's':
			seed = (unsigned int) strtoul(argv[optind], NULL, 0);
			break;
		default:
			usage(argv[0]);
			exit(-1);
		}
	}
}

int main(int argc, char **argv) {
	int i;
	char *data;
	unsigned int crc_word, expected_word;

	parse_args(argc, argv);

	data = malloc(sizeof(char) * (num_bits+crc_length));
	if (!data) {
		perror("malloc");
		exit(-1);
	}

	if (!seed) {
		seed = time(NULL);
	}
	srand(seed);

	// Generate data
	for (i=0;i<num_bits;i++) {
		data[i] = rand()%2;
	}

	// generate CRC word
	crc_word = crc(0, data, num_bits, crc_length, crc_poly, 1);

	// check if result is zero
	if (crc(0, data, num_bits + crc_length, crc_length, crc_poly, 0)) {
		printf("CRC check is non-zero\n");
		exit(-1);
	}

	free(data);

	printf("CRC word: 0x%x\n", crc_word);

	// check if generated word is as expected
	if (get_expected_word(num_bits, crc_length, crc_poly, seed, &expected_word)) {
		fprintf(stderr, "Test parameters not defined in test_results.h\n");
		exit(-1);
	}
	exit(expected_word != crc_word);
}