PaymentProcessor.java

package com.example.payment;

import java.util.Objects;

public class PaymentProcessor {
    private final PaymentGateway paymentGateway;
    private final PaymentRepository paymentRepository;
    private final PaymentEmailSender emailSender;
    private final String apiKey;
    private final String confirmationEmailTo;

    public PaymentProcessor(PaymentGateway paymentGateway,
                            PaymentRepository paymentRepository,
                            PaymentEmailSender emailSender,
                            String apiKey,
                            String confirmationEmailTo) {
        this.paymentGateway = Objects.requireNonNull(paymentGateway, "paymentGateway");
        this.paymentRepository = Objects.requireNonNull(paymentRepository, "paymentRepository");
        this.emailSender = Objects.requireNonNull(emailSender, "emailSender");
        this.apiKey = Objects.requireNonNull(apiKey, "apiKey");
        this.confirmationEmailTo = Objects.requireNonNull(confirmationEmailTo, "confirmationEmailTo");
    }

    public boolean processPayment(double amount) {
        if (amount <= 0.0) {
            throw new IllegalArgumentException("amount måste vara > 0");
        }

        PaymentChargeResponse response = paymentGateway.charge(apiKey, amount);

        if (response.isSuccess()) {
            paymentRepository.saveSuccessfulPayment(amount);
            emailSender.sendPaymentConfirmation(confirmationEmailTo, amount);
            return true;
        }

        return false;
    }
}