Santa's gifts

<?php
$number=readline();
$arr=explode(" ",readline());
$position=0;
for($i=1;$i<=$number;$i++)
{
    $command=explode(" ",readline());
    switch ($command[0])
    {
        case "Forward":
            if($command[1]+$position>=0&&$command[1]+$position<count($arr)&&$command[1]>=0&&$command[1]<count($arr))
            {
                $position += $command[1];
                array_splice($arr, $position, 1);
            }
            break;
        case "Back":
            if($position-$command[1]>=0&&$position-$command[1]<count($arr)&&$command[1]>=0&&$command[1]<count($arr))
            {
                $position -= $command[1];
                array_splice($arr, $position, 1);
            }
            break;
        case "Gift":
            if($command[1]>=0&&$command[1]<count($arr))
            {
                $position = $command[1];
                array_splice($arr, $position, 0, $command[2]);
            }
            break;
        case "Swap":
            $index1=array_search($command[1],$arr);
            $index2=array_search($command[2],$arr);
            if($index1!==false && $index2!==false)
            {
                $temp = $arr[$index1];
                $arr[$index1] = $arr[$index2];
                $arr[$index2] = $temp;
            }
            break;
    }
}
echo "Position: {$position}".PHP_EOL;
echo implode(", ",$arr);
?>