//In Kotlin there are no events type
interface GameListener {
    fun gameStarted(name: String)
}

class Game(val name: String) {
    private val listeners = arrayListOf<GameListener>()

    fun addListener(listener: GameListener) {
        listeners.add(listener)
    }

    fun start() {
        for (listener in listeners) {
            listener.gameStarted(name)
        }
    }
}

class Statistic: GameListener {
    var startsCount = 0
    var lastGame = ""

    override fun gameStarted(name: String) {
        startsCount++
        lastGame = name
    }
}

val statistic = Statistic()
val heroes = Game("Heroes")
val doom = Game("Doom")

//subscribe to events
heroes.addListener(statistic)
doom.addListener(statistic)

doom.start()
heroes.start()
//statistic.lastGame is "Heroes"
//statistic.startsCount is 2

println(statistic.lastGame)
println(statistic.startsCount)