package drills.drill01.exercise4

import drills.drill01.exercise2.PrintService
import java.rmi.Remote
import java.rmi.RemoteException
import java.rmi.server.UnicastRemoteObject

interface Math : Remote {
    @Throws(RemoteException::class)
    fun getFactOf(n: Int): Long

    @Throws(RemoteException::class)
    fun getFactOf(n: Int, ps: PrintService)
}

class MathImpl : Math, UnicastRemoteObject() {
    override fun getFactOf(n: Int): Long = fact(n)

    override fun getFactOf(n: Int, ps: PrintService) {
        ps.print("The factorial of $n is ${fact(n)}")
    }

    private fun fact(n: Int): Long {
        return if (n <= 1) 1 else n * fact(n - 1)
    }
}