import org.junit.jupiter.api.Test

interface CoffeeMachine {
    fun makeSmallCoffee()
    fun makeLargeCoffee()
}

class NormalCoffeeMachine : CoffeeMachine {
    override fun makeSmallCoffee() = println("Normal: Making small coffee")

    override fun makeLargeCoffee() = println("Normal: Making large coffee")
}

//Decorator:
class EnhancedCoffeeMachine(private val coffeeMachine: CoffeeMachine) : CoffeeMachine by coffeeMachine {

    // overriding behaviour
    override fun makeLargeCoffee() {
        println("Enhanced: Making large coffee")
    }

    // extended behaviour
    fun makeCoffeeWithMilk() {
        println("Enhanced: Making coffee with milk")
        coffeeMachine.makeSmallCoffee()
        addMilk()
    }

    private fun addMilk() {
        println("Enhanced: Adding milk")
    }
}

class DecoratorTest {

    @Test
    fun Decorator() {
        val normalMachine = NormalCoffeeMachine()
        val enhancedMachine = EnhancedCoffeeMachine(normalMachine)

        // non-overridden behaviour
        enhancedMachine.makeSmallCoffee()
        // overridden behaviour
        enhancedMachine.makeLargeCoffee()
        // extended behaviour
        enhancedMachine.makeCoffeeWithMilk()
    }
}