Order Processing - Choreography - Email Service

email_service.kt

class EmailService(private val customerEmails: MutableMap<Int, String> = mutableMapOf()) {
    @KafkaListener(topics = [ORDERS, SHIPMENTS, PAYMENTS])
    fun onOrder(order: Order) {
        customerEmails[order.customerId]?.let { emailGateway.notify(it, "order now at status: ${order.status}") }
            ?: throw RuntimeException("Customer email not found")
    }

    @KafkaListener(topics = [CUSTOMERS])
    fun onCustomer(customer: Customer) {
        customerEmails[customer.id] = customer.email
    }
}