ETP + Woo > Autocomplete some orders

functions.php

<?php
/**
 * Set WooCommerce orders for Ticket products to 'completed' status automatically based on certain criteria.
 * 
 * You can further tweak the behavior by adjusting the snippet:
 * - based on order status: line 29
 * - based on payment gateway: line 36
 */
add_action( 'woocommerce_thankyou', function ( $order_id ) {
	// Bail if there is no order.
	if ( ! $order_id ) {
		return;
	}

	// Bail if there's no Event Tickets Plus.
	if ( ! class_exists( 'Tribe__Tickets_Plus__Main' ) ) {
		return;
	}

	// Get the order data.
	$order = wc_get_order( $order_id );

	/**
	 * Don't set the order status to 'completed' if the order is not set to 'processing' status. 
	 *
	 * Note: For some WooCommerce payment gateways (e.g. cheque), the order status is set to 'on-hold', for some to 'processing'.
	 * 
	 */
	if ( $order->get_status() != 'processing' ) {
		return;
	}

	/**
	 * Don't set the order status to 'completed' if the 'cheque' payment gateway has been used.
	 */
	if ( $order->get_payment_method() == 'cheque' ) {
		return;
	}

	$all_virtual = true;
	$all_tickets = true;

	foreach ( $order->get_items() as $item_id => $item ) {
		$product    = $item->get_product();
		$product_id = $product->get_id();

		if ( ! $product->is_virtual() ) {
			$all_virtual = false;
			break;
		}

		if ( ! function_exists( 'tribe_events_product_is_ticket' ) || ! tribe_events_product_is_ticket( $product_id ) ) {
			$all_tickets = false;
			break;
		}
	}

	if ( $all_virtual && $all_tickets ) {
		$order->update_status( 'completed' );
	}
} );