public function testMovement()
{
$d = new RoverPosition(new Coordinate(1, 2), 'E');
$newPosition = $d->evalCommand('M');
$this->assertTrue($newPosition->getCoordinates()->getX() == 2 && $newPosition->getCoordinates()->getY() == 2);
$d = new RoverPosition(new Coordinate(1, 2), 'W');
$newPosition = $d->evalCommand('M');
$this->assertTrue($newPosition->getCoordinates()->getX() == 0 && $newPosition->getCoordinates()->getY() == 2);
$d = new RoverPosition(new Coordinate(1, 2), 'S');
$newPosition = $d->evalCommand('M');
$this->assertTrue($newPosition->getCoordinates()->getX() == 1 && $newPosition->getCoordinates()->getY() == 1);
$d = new RoverPosition(new Coordinate(1, 2), 'N');
$newPosition = $d->evalCommand('M');
$this->assertTrue($newPosition->getCoordinates()->getX() == 1 && $newPosition->getCoordinates()->getY() == 3);
}
/**
* Eval command against current position
* @param $command
*
* @return RoverPosition new Position
*/
public function evalCommand($command)
{
$newPosition = new RoverPosition(new Coordinate($this->_coordinates->getX(), $this->_coordinates->getY()), $this->getDirection());
if ($command == CommandSequence::TURN_LEFT || $command == CommandSequence::TURN_RIGHT) {
$nextDirectionIndex = $this->_getCurrentDirectionIndex();
if ($command == CommandSequence::TURN_RIGHT) {
if ($nextDirectionIndex >= 3) {
$nextDirectionIndex = 0;
} else {
$nextDirectionIndex++;
}
} else {
if ($nextDirectionIndex <= 0) {
$nextDirectionIndex = 3;
} else {
$nextDirectionIndex--;
}
}
$newPosition->changeDirection($this->_getDirection($nextDirectionIndex));
} else {
if ($command == CommandSequence::MOVE_FORWARD) {
if ($newPosition->getDirection() == self::DIRECTION_EAST) {
$newPosition->getCoordinates()->moveAxis('x', 1);
} else {
if ($newPosition->getDirection() == self::DIRECTION_WEST) {
$newPosition->getCoordinates()->moveAxis('x', -1);
} else {
if ($newPosition->getDirection() == self::DIRECTION_SOUTH) {
$newPosition->getCoordinates()->moveAxis('y', -1);
} else {
if ($newPosition->getDirection() == self::DIRECTION_NORTH) {
$newPosition->getCoordinates()->moveAxis('y', 1);
}
}
}
}
}
}
return $newPosition;
}
private function _formatPosition(RoverPosition $position)
{
return sprintf('%d %d %s', $position->getCoordinates()->getX(), $position->getCoordinates()->getY(), $position->getDirection());
}