MethodFactory.php

<?php 
abstract class PaymentType {
   abstract function pay();
}

class BitcoinPayment extends PaymentType {
  public function pay()
  {
    return 'Pay with Bitcoin';
  }
}
 
class MoneyPayment extends PaymentType {
  public function pay()
  {
    return 'pay with Money';
  }
}

class Factory {
  public static function create($name)
  {
    $className  = $name.'Payment';
    if (class_exists($className))
    {
      return new $className();
    }
  }
}

// injeção 

class PaymentsService {

//----- Recebe um tipo Payment independente de qual for
  public function payWith(PaymentType $payment)
  {
     return $payment->pay();
  }
}


class Controller {

  public function action()
  {
     
     $service =  new PaymentService();
     
     echo $service->payWith(Factory::create('Money'));
     echo $service->payWith(Factory::create('Bitcoin'));
     
  }
}
?>