public function getNextBillingPeriod(BillingAgreementInterface $billingAgreement)
{
//Find out to which date the billing agreement was already executed (eg. a billing request was already made)
$startDate = $billingAgreement->getBilledToDate();
if (null == $startDate) {
//If never billed: use the initial billing date as starting point
$startDate = clone $billingAgreement->getInitialBillingDate();
} else {
//Increase last billed to with one day; that will be the start date of the next period
$startDate = clone $startDate->add(new \DateInterval('P1D'));
}
//Determine end date
$endDate = $this->addMonth($startDate, 1);
//TODO: allow more then just months
return array($startDate, $endDate);
}
