<?php
interface EmailServiceInterface {
}

class PepipostEmailService extends EmailServiceInterface {
}

class MailgunEmailService extends EmailServiceInterface {
}


class EmailServiceFactory {
    public static function create(string $serviceName): EmailServiceInterface {
        switch ($serviceName) {
            case 'pepipost':
                return new PepipostEmailService();

            case 'mailgun':
                return MailgunEmailService();

            default:
                return new PepipostEmailService();
        }
    }
}

// Su dung
$emailService = EmailServiceFactory::create(config('email_service.service_name'));