<?php
exec("stty -icanon min 0 time 0 -echo");
$continue=true;
$position=array('x'=>0,'y'=>0);

do {

	$position_change=false;
	$old_position=$position;
	$selection = fgetc(STDIN);
	echo "$selection";
	switch($selection){
		case 'q': //quit
			echo "Game end!\n";
			$continue=false;
			break;
		case 'a': //left
			$position['y']--;
			$position_change=true;
			break;
		case 'd': //right
			$position['y']++;
			$position_change=true;
			break;
		case 'w':
			$position['x']++;
			$position_change=true;
			break;
		case 's':
			$position['x']--;
			$position_change=true;
			break;
		case '': //NULL
			break;
		default:
			echo "Wrong key press\n";
	};
	if($position_change){
		passthru('clear');
		echo "Position: {$position['x']}x{$position['y']}\n";
		//Detect colission
		if($position['x']>=20){
			echo "Don't acceptable move. Do you go back!\n";
			$position=$old_position;
		};
	};
} while ($continue);
exec('stty +echo');