/* client.c
 *
 * "Computer Player" for a simple 2D grid game by Robert Marmorstein.
 *
 * Copyright (c) 2012  Robert Marmorstein (marmorsteinrm@longwood.edu)
 * Released under the terms of the GPL, version 2.  See LICENSE file for details.
 *
 * For questions about the licensing of this software, contact me by mail: 
 * Ruffner 329, Longwood University, 201 High Street, Farmville, VA 23909
 */

#include <time.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>

#include "config.h"
#include "shmlib.h"
#include "commands.h"

int main(int argc, char* argv[])
{
	char* grid;
	int i, j;
	int fd;
	int x, y;

	int cmd;

	if (argc < 4) {
		printf("Syntax: client <fd> <x> <y>\n");
		exit(-1);
	}	

	//Parse command line arguments
	fd = atoi(argv[1]);
	x = atoi(argv[2]);
	y = atoi(argv[3]);

	//Initialize the random number generator -- make sure we use a different seed for each client by adding the arguments together.	
	srandom(fd + time(NULL) + x + y);

	//Attached to the shared memory
	grid = attach_map(0, WIDTH, HEIGHT);
	if (grid == (void *)-1) {
		perror("shmat");
		exit(-1);
	}

	//Main loop
	while(1) {	
		//Pick a random direction
		cmd = random() % 5;
	
		//But if we see the player next to us -- get him!
		if (grid[x-1 + y*WIDTH] == '+') {
			cmd = WEST;
		}
		if (grid[x + (y-1) * WIDTH] == '+') {
			cmd = NORTH;
		}
		if (grid[x + (y+1)*WIDTH] == '+') {
			cmd = SOUTH;
		}
		if (grid[x+1 + y*WIDTH] == '+') {
			cmd = EAST;
		}

		//Make sure we don't go out of bounds.
		if (cmd == NORTH && y > 2) {
			--y;
		}
		else if (cmd == SOUTH && y < HEIGHT-2) {
			++y;
		}
		else if (cmd == WEST && x > 2) {
			++x;
		}
		else if (cmd == EAST && x < WIDTH-2) {
			--x;
		}

		//Send the command to the server
		if ( write(fd, &cmd, sizeof(int)) < 0) {
			perror("write");
		}

		//Then sleep for a bit so the player has a chance!
		sleep(1);
	}
}