status rules used for backorders

I want to use your plugin to manage backorders. I’m syncing my woocommerce site with an external warehouse, so stock is updated automatically. I have created 2 rules:

1. processing -> backorder (custom status)
2. backorder  -> processing

I trigger the first one if order contains a product on backorder. Order will wait in this status for replenishment. I want to trigger second one, when all products in the order have stock quantity > 0. Can you please help me to create two alg_wc_order_status_rules_do_apply_rule filters?

filter for rule 1: do not trigger the rule if order had already been in “backorder” status. I need this condition, not to end up in an indefinite loop. I have turned on the option to record order status history in your plugin, so historical status should be somewhere in order’s meta.

filter for rule 2: I have altered your example 3 to trigger rule 2 only if all products in the order have stock higher than 0. Can you please confirm it’s ok?

add_filter( 'alg_wc_order_status_rules_do_apply_rule', function( $do_apply, $order, $rule_id, $args ) {
    /**
     * First we are checking:
     *     a) if it's the rule we need,
     *     b) if the rule's status, etc. conditions are fulfilled.
     */
    if ( 2 == $rule_id && $do_apply ) {
        /**
         * Now we check if any of the order's products have stock lower than 1.
         */
        foreach ( $order->get_items() as $item ) {
            $product = $item->get_product();
            if ( $product->get_stock_quantity() < 1 ) {
                /**
                 * We found a matching product - the rule will not be applied.
                 */
                return false;
            }
        }
        /**
         * We didn't find any matching products - the rule will be applied.
         */
        return true;
    }
    return $do_apply;
}, 10, 4 );