/*
   Copyright 2002 Mike Burns, Sean Proctor

   This program 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 2 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

   The license is at <http://www.gnu.org/licenses/gpl.txt>.
   */

/* original version copyright Mike Burns, 2001.  updated version copyright
 * Sean Proctor, 2002
 * original: 9/15/01 updated: 10/7/02
 * Mike Burns <mike@mike-burns.com>
 * Sean Proctor <sproctor@ccs.neu.edu>
 */

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

static const char *sneaker_colors[] = {"red", "orange", "yellow", "green",
	"blue", "khaki", "black"};

#define NUM_SNEAKERS (sizeof(sneaker_colors) / sizeof(char *))

int *make_sneakers(char *date)
{
	/* modifies sneakers */
	int *sneakers = malloc(sizeof(int) * 2);
	srand(atoi(date));

	sneakers[0] = (int)((NUM_SNEAKERS - 1.0) * rand() / RAND_MAX);
	sneakers[1] = (int)((NUM_SNEAKERS - 1.0) * rand() / RAND_MAX);
	if(sneakers[0] == sneakers[1]) {
		srand((unsigned int)(20.0 * rand()));
		sneakers[0] = (int)((NUM_SNEAKERS - 1.0) * rand() / RAND_MAX);
		sneakers[1] = (int)((NUM_SNEAKERS - 1.0) * rand() / RAND_MAX);
	}

	return sneakers;
}

void output_sneakers(char *date, int *sneakers)
{
	printf("Sneakers for %s: %s, %s\n", date, sneaker_colors[sneakers[0]],
			sneaker_colors[sneakers[1]]);
}

char *current_date(void)
{
	time_t t;
	struct tm *time_tm;
	char *date = malloc(sizeof(char) * 9);

	if((t = time(NULL)) == -1 || !(time_tm = localtime(&t))) {
		printf("Really weird error.");
		exit(1);
	}

	sprintf(date, "%4d%02d%02d", time_tm->tm_year + 1900, time_tm->tm_mon,
		time_tm->tm_mday);

	return date;
}

int check_input(char *date)
{
	int i;

	for(i = 0; i < 8; i++) if(!isdigit(date[i])) return 0;
	if(date[8]) return 0;

	return 1;
}

int main (int argc, char **argv)
{
	int *sneakers;
	char *date;

	switch(argc) {
		case 1:
			date = current_date();
			break;
		case 2:
			date = argv[1];
			if(check_input(date)) break;
		default:
			printf("usage: %s [YYYYMMDD]\n", argv[0]);
			exit(1);
	}

	sneakers = make_sneakers(date);
	output_sneakers(date, sneakers);

	free(sneakers);
	free(date);

	return 0;
}