Woocommerce filtering shipping method in cart

Hey! I want to remove or add some shipping options depending on the category of product that is in cart. For example: I have one product from category X and I want to add shipping-method-X to cart. And if I have one product from category X and one from another category, then shipping-method-X is disabled.

For now I have this code:

function check_product_in_cart($shipping_in_cart) {

$shipping_NAME = 'flat_rate';

global $woocommerce;

foreach ($woocommerce->cart->cart_contents as $key => $values ) {

			$terms = get_the_terms( $values['product_id'], 'product_cat' );
			$tmp = array();

			foreach ($terms as $term) {

				array_push($tmp, $term->term_id);
			}

			array_unique($tmp); // usuniecie duplikatow

			if (sizeof($tmp) > 1 AND in_array('49', $tmp)) {
				unset($shipping_in_cart[$shipping_NAME]);
			}
		}

return $shipping_in_cart;
}

add_filter('woocommerce_shipping_methods','check_product_in_cart', 10, 1);

Whats wrong with this code?