_status_cancelled', 'wc_release_stock_for_order', 11 );
add_action( 'woocommerce_order_status_completed', 'wc_release_stock_for_order', 11 );
add_action( 'woocommerce_order_status_processing', 'wc_release_stock_for_order', 11 );
add_action( 'woocommerce_order_status_on-hold', 'wc_release_stock_for_order', 11 );

/**
 * Return low stock amount to determine if notification needs to be sent
 *
 * Since 5.2.0, this function no longer redirects from variation to its parent product.
 * Low stock amount can now be attached to the variation itself and if it isn't, only
 * then we check the parent product, and if it's not there, then we take the default
 * from the store-wide setting.
 *
 * @param  WC_Product $product Product to get data from.
 * @since  3.5.0
 * @return int
 */
function wc_get_low_stock_amount( WC_Product $product ) {
	$low_stock_amount = $product->get_low_stock_amount();

	if ( '' === $low_stock_amount && $product->is_type( 'variation' ) ) {
		$product          = wc_get_product( $product->get_parent_id() );
		$low_stock_amount = $product->get_low_stock_amount();
	}

	if ( '' === $low_stock_amount ) {
		$low_stock_amount = get_option( 'woocommerce_notify_low_stock_amount', 2 );
	}

	return (int) $low_stock_amount;
}