dynamically change product price/nextduedate during checkout

[jimlongo]

Hi, I want to align the billing cycle of a particular add-on item(s) that I will sell.

There is a nextduedate established by a productA that I sold. I can retrieve that date $dueDate

When I sell product B I want its nextduedate to be set to $dueDate, and its price to be prorated based on that date.

Trying to change price with PreShoppingCartCheckout, and to change the renewal with the ShoppingCartCheckoutCompletePage hook. 

add_hook('PreShoppingCartCheckout', 1, function($vars) {

    $pro_rated_amount = 22.50; // do some math here to get amount

    $command = 'UpdateInvoice';
    $postData = array(
        'invoiceid' => $vars['invoiceid'],
        'subtotal' => $pro_rated_amount,
    );
    $results = localAPI($command, $postData);
});

I think I could change the nextduedate IF i knew the serviceid, which unfortunately is not in $vars.

add_hook( 'ShoppingCartCheckoutCompletePage', 1, function ( $vars ) {

    $next_due_date = nextduedate of productA;

    $command = 'UpdateClientProduct';
    $postData = array(
        'serviceid' => $serviceid,
        'nextduedate' => date('Y-m-d', $next_due_date),
    );
    $results = localAPI($command, $postData);
});

Not sure if this is the best approach.  Open to ideas, if you think this would work, then how would you get the serviceid needed in step2

Edited May 24, 2019 by jimlongo

[jimlongo]

$invoiceid => $_SESSION['orderdetails']['invoiceID'],

$serviceid => $_SESSION['orderdetails']['ServiceIDs'][0],

found a couple things

 

[jimlongo]

this will change the nextorderdate 

add_hook( 'ShoppingCartCheckoutCompletePage', 1, function ( $vars ) {
	$next_due_date = date('Y-m-d', '1560132772');
	$serviceID = $_SESSION['orderdetails']['ServiceIDs'][0];

    $command = 'UpdateClientProduct';
    $postData = array(
        'serviceid' => $serviceID,
        'nextduedate' => $next_due_date,
    );
    $results = localAPI($command, $postData);
} );

 

But I am not having any luck changing the price.  Not clear if UpdateInvoice inside the PreShoppingCartCheckout hook is the best approach.  So far I have been unable to adjust the amount paid.

 

Edited May 27, 2019 by jimlongo

[jimlongo]

Prorata billing would work perfectly IF i could change the Prorata Date dynamically.

Still looking for ideas.   Do the APIs just not exist?