import java.util.*

fun main(args: Array<String>) {
    feedTheFish()
}

fun shouldChangeWater(
    day: String,
    temp: Int = 22,
    dirty: Int = 22
): Boolean {
    return when {
        isTooHot(temp) -> true
        isDirty(dirty) -> true
        isSunday(day) -> true
        else -> false
    }
}

fun isTooHot(temp: Int) = temp > 30
fun isDirty(dirty: Int) = dirty > 30
fun isSunday(day: String) = day == "Sunday"

fun dayOfWeek() {
    println("What day is it today?")
    var day: String? = null
    day = when(Calendar.getInstance().get(Calendar.DAY_OF_WEEK)) {
        1 -> "Sunday"
        2 -> "Monday"
        3 -> "Tuesday"
        4 -> "Wednesday"
        5 -> "Thursday"
        6 -> "Friday"
        7 -> "Saturday"
        else -> "wut?"
    }
    println("Today is: $day")
}

fun feedTheFish() {
    val day = randomDay()
    val food = fishFood(day)
    print("Today is $day and the fish eat $food")
    if (shouldChangeWater(day)) {
        println("Change the water today")
    }
}

fun fitMoreFish(
    tankSize: Double,
    currentFish: List<Int>,
    fishSize: Int = 2,
    hasDecorations: Boolean = true
): Boolean {
    val tankCap = tankSize.times(if(hasDecorations) 0.8 else 1.0)
    val currentTotalSize = if(currentFish.isNotEmpty()) currentFish.sum() else 0
    return tankCap.minus(currentTotalSize) >= fishSize
}

fun fishFood(day: String): String {
    return when(day) {
        "Monday" -> "flakes"
        "Tuesday" -> "pellets"
        "Wednesday" -> "redworms"
        "Thursday" -> "granules"
        "Friday" -> "mosquitoes"
        "Saturday" -> "lettuce"
        "Sunday" -> "plankton"
        else -> "fasting"
    }
}

fun randomDay() : String {
    val week = listOf<String>("Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday")
    return week[Random().nextInt(week.count())]
}