PHP Chained Payments - Kopfzerbrechen

<?php
private
function determine_status($id)
	{

	// user status in db can never be 2 or 3, those are calculated from payments

	if ($id == 1)
		{

		// get all payments to this user

		$payments_received = array();
		foreach($this->user->payments as $payment)
			{
			if ($payment->benefited_id == $this->user->id)
				{
				array_push($payments_received, $payment);
				}
			}

		// chain all payments

		$payment_chains = array();
		foreach($payments_received as $payment_received)
			{
			}
		}
	  else
		{
		return $id;
		}
	}

var end = 0;

//payments have to be sorted by confirmed
for (var i = 0; i < payments.length; i++) {
	var payment = payments[i];

	if(payment.confirmed == 0)
		continue;
	
	if (payment.confirmed > end) {
		end = payment.confirmed + (payment.duration * 365 * 24 * 60 * 60); //convert years to seconds for unix-timestamp
	}
	else {
		end += payment.duration * 365 * 24 * 60 * 60; //convert years to seconds for unix-timestamp
	}
}

if (end >= Date.now()){
//user is premium
}

select Betrag-(NOW()-Datum)*geld_pro_zeit>0 as Premium

update premium set Betrag=max(Betrag-(NOW()-Datum)*geld_pro_zeit,0)+neu_betrag

DateTime Premium-EndeMAX = Jetzt;
DateTime Premium-Ende = Jetzt;
foreach (var pmt in SQLQuery("Select Created, Confirmed, Duration from Payments where benifit_id = user.id")){
    if(pmt.Confirmed!=0){
        Premium-Ende += Premium-Ende - Created + Duration;
        if(Premium-Ende > Premium-EndeMAX) Premium-EndeMAX = Premium-Ende;
    }
}
return Premium-EndeMAX;

	private function determine_status($id) {
		//user status in db can never be 2 or 3, those are calculated from payments
		if ($id == 1) {
			else {
				if ($this -> expiration_date != false) {					
					return 2;
				} else {
					return $id;
				}
		} else {
			return $id;
		}
	}

private function get_expiration_date($payments) {
		//get all payments to this user
		$payments_received = array();
		foreach ($payments as $payment) {
			if ($payment -> benefited_id == $this -> user -> id) {
				array_push($payments_received, $payment);
			}
		}

		//sort all payments by date, ASC
		usort($payments_received, function($a, $b) {
			return $a -> confirmed - $b -> confirmed;
		});

		$expiration_date = false;

		foreach ($payments_received as $payment_received) {
			//check if is valid
			if ($payment_received -> confirmed <= time() + $payment_received -> duration * year) {
				//check if expiration date was set before
				if ($expiration_date != false) {
					//add the time to the expiration date
					$expiration_date += $payment_received -> duration * year;
				} else {
					//set the expiration date
					$expiration_date = $payment_received -> confirmed + ($payment_received -> duration * year);
				}
			}
		}
		return $expiration_date;
	}