[WordPress] [WooCommerce] [Bookings] Auto-Confirm Booking upon Order Complete

WP_WC_auto-confirm-bookings.php

<?php
	add_action( 'woocommerce_order_status_completed', 'mark_confirm_bookings', 20, 1 );
	
	function mark_confirm_bookings( $order_id ) {
		global $wpdb;

		$order    = new WC_Order( $order_id );
		$bookings = array();

		foreach ( $order->get_items() as $order_item_id => $item ) {
			if ( 'line_item' == $item['type'] ) {
				if ( !wc_booking_requires_confirmation( $item['product_id'] ) ) {
					$bookings = array_merge( $bookings, $wpdb->get_col( $wpdb->prepare( "SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key = '_booking_order_item_id' AND meta_value = %d", $order_item_id ) ) );
				}
			}
		}

		foreach ( $bookings as $booking_id ) {
			$booking = get_wc_booking( $booking_id );
			$booking->update_status('confirmed');
		}
	}
?>

Same issue with email being sent twice, I tried the method that @mzykin wrote, I deactivate the product as virtual, I change the function and when I perform the test the client's mail is not sent... Any suggestion?

Not totally related, but I was wondering how the opposite could be done.
Assuming a booking status changes to complete, and I'd want the order with that booking to also complete ?

Sorry guys... just saw all the comments (Github not sending me any notifications about comments on gists).
Keep in mind the code is from 2015, so things may have changed since then (actually, most likely, hence my snippet is not really compatible anymore).
Also, I have not used the Bookings plugin in years, so I can't really be helpful anymore about it.
If the email is now sending twice, maybe uncheck the "processing" email and only leave the completed one to be sent? or viceversa?
@mzykin About setting the product as non-virtual, not sure that's recommended, since it's a Booking and not a physical product?
@Xyala Sorry, I really wouldn't know, haven't used that plugin in years.