Calculate shipping methods/rates within an existing order in WooCommerce

Ok so thanks to @mujuonly, I was able to figure it out.

Here's how to get all calculated shipping rates, the same way it's shown on the cart page.

// Post variables$order_id   = isset($_POST['order_id'])?$_POST['order_id']:0;$country    = isset($_POST['country'])?$_POST['country']:0;$state      = isset($_POST['state'])?$_POST['state']:0;$postcode   = isset($_POST['postcode'])?$_POST['postcode']:0;$city       = isset($_POST['city'])?$_POST['city']:0;// Order and order items$order          = wc_get_order( $order_id );$order_items    = $order->get_items();// Reset shipping firstWC()->shipping()->reset_shipping();// Set correct temporary locationif ( $country != '' ) {    WC()->customer->set_billing_location( $country, $state, $postcode, $city );    WC()->customer->set_shipping_location( $country, $state, $postcode, $city );} else {    WC()->customer->set_billing_address_to_base();    WC()->customer->set_shipping_address_to_base();}// Remove all current items from cartif ( sizeof( WC()->cart->get_cart() ) > 0 ) {    WC()->cart->empty_cart();}// Add all items to cartforeach ($order_items as $order_item) {    WC()->cart->add_to_cart($order_item['product_id'], $order_item['qty']);}// Calculate shipping$packages = WC()->cart->get_shipping_packages();$shipping = WC()->shipping->calculate_shipping($packages);$available_methods = WC()->shipping->get_packages();

$available_methods[0]['rates'] will have all the shipping rates that are available to that location for products inside the order.

Try using:

// Calculate totalsWC()->cart->calculate_totals();WC()->cart->calculate_shipping();// Retrieve the shipping total$shipping_total = WC()->cart->get_shipping_total();

The WC_Cart class should have all of the methods you would need to recreate any cart functionality you might need. I suggest that you should read through and familiarize yourself with the class definition here...

https://docs.woocommerce.com/wc-apidocs/class-WC_Cart.html

Note: this is not an answer, I can't comment hence I'm writing here.In my case, there is a problem with the accepted answer:

If the customer has already added some items in the cart they will be lost because of the following line of code:

WC()->cart->empty_cart()

and instead, the cart is filled by the items in the past order.

So far it seems like using the cart is necessary to perform the properly calculate the shipping packages. If so is there a way I can create a clone of the current cart and then calculate the shipping packages? I don't want to affect my customer's original cart when doing this calculation.