/*
 * Copyright (C) 2021  P. J. McDermott
 *
 * This file is part of @
 *
 * @ is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @ 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with @.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "datetime.h"

static char *
_concat_args(int argc, const char *argv[])
{
	int   buf_l;
	int   i;
	char *buf;
	int   buf_i;
	int   j;

	buf_l = 0;
	for (i = 0; i < argc; ++i) {
		buf_l += strlen(argv[i]) + 1;
	}

	buf = calloc(buf_l, sizeof(*buf));
	if (buf == NULL) {
		fprintf(stderr, "Failed to allocate buffer: %s\n",
				strerror(errno));
		return NULL;
	}

	buf_i = 0;
	for (i = 0; i < argc; ++i) {
		for (j = 0; argv[i][j] != '\0'; ++j) {
			buf[buf_i++] = argv[i][j];
		}
		buf[buf_i++] = ' ';
	}
	buf[--buf_i] = '\0';

	return buf;
}

int
main(int argc, const char *argv[])
{
	char   *buf;
	time_t  arg;
	time_t  now;
	time_t  dif;

	buf = _concat_args(argc - 1, argv + 1);
	if (buf == NULL) {
		return -1;
	}

	if (datetime_parse(buf, &arg) < 0) {
		free(buf);
		return EXIT_FAILURE;
	}
	free(buf);

	time(&now);
	dif = arg - now;
	if (dif >= 1000 * 24 * 60 * 60) {
		fputs("Date too far in the future\n", stderr);
		return EXIT_FAILURE;
	}

	setvbuf(stdout, NULL, _IONBF, 0);
	while (arg > now) {
		printf("\r%03d:%02d:%02d:%02d",
				(int) dif / 60 / 60 / 24,
				(int) dif / 60 / 60 % 24,
				(int) dif / 60 % 60,
				(int) dif % 60);
		sleep(1);
		time(&now);
		dif = arg - now;
	}
	printf("\r000:00:00:00\n");

	return EXIT_SUCCESS;
}