Coding challenge - String representation of time in seconds

readme.md

From an integer X representing a time duration in seconds produce a simplified string representation.
For example, given X=100, you should output:"1m40s"
Use the following abbreviation w,d,h,m,s to represent:

• 1w is 1 week
• 1d is 1 day
• 1h is 1 hour
• 1m is 1 minute
• 1s is 1 second

Only the two largest non-zero integers should be used. Round up the second unit if necessary
to produce only two units even though this might mean the output represents slightly more time than X seconds

Write a function

 fun solution(X: Int): String  

that, given an integer X, returns a string representing the duration

Examples:

1. Given X=100, return "1m40s"
2. Given X=7263, return "2hm2m". (7263s=2h1m3s, but this uses too many units, so we round the
   second-largest unit up to 2h2m)
3. Given X=3605, return 1h5s

main.kt

fun main(){
    print(solution(3600))
}
// output: 1h

fun solution(X: Int): String {
    var secondsValue = TimeUnit.SECONDS()
    var minutesValue = TimeUnit.MINUTES()
    var hoursValue = TimeUnit.HOURS()
    var daysValue = TimeUnit.DAYS()
    var weeksValue = TimeUnit.WEEKS()
    var remainder = X
    do {
        when {
            remainder < 60 -> {
                secondsValue = TimeUnit.SECONDS(remainder)
                remainder = 0
            }

            remainder < 3600 -> {
                minutesValue = TimeUnit.MINUTES(remainder / 60)
                remainder %= 60
            }

            remainder < 86400 -> {
                hoursValue = TimeUnit.HOURS(remainder / 3600)
                remainder %= 3600
            }

            remainder < 604800 -> {
                daysValue = TimeUnit.DAYS(remainder / 86400)
                remainder %= 86400
            }

            else -> {
                weeksValue = TimeUnit.WEEKS(remainder / 604800)
                remainder %= 604800
            }
        }
    } while (remainder != 0)
    val order = arrayOf(weeksValue, daysValue, hoursValue, minutesValue, secondsValue)
    order.sortBy { it.order }
    val selection = order.filter { it.value != 0 }.toMutableList()
    selection.getOrNull(2)?.let {
        selection[1] = selection[1].mCopy(selection[1].value + 1)
    }
    return "${selection.first().run { printRepresentation() }}${
        selection.getOrNull(1)?.run { printRepresentation() } ?: ""
    }"
}

sealed class TimeUnit(open val value:Int, private val abbreviation:String,val order:Int){
    fun printRepresentation():String = "$value$abbreviation"
    abstract  fun mCopy(value: Int = 0):TimeUnit
    data class SECONDS(override val value: Int = 0): TimeUnit(value,"s",5) {
        override fun mCopy(value: Int): TimeUnit {
            return copy(value = value)
        }
    }

    data class MINUTES(override val value: Int = 0): TimeUnit(value,"m",4){
        override fun mCopy(value: Int): TimeUnit {
            return copy(value = value)
        }
    }
    data class HOURS(override var value: Int = 0): TimeUnit(value,"h",3){
        override fun mCopy(value: Int): TimeUnit {
            return copy(value = value)
        }
    }
    data class DAYS(override val value: Int = 0): TimeUnit(value,"d",2){
        override fun mCopy(value: Int): TimeUnit {
            return copy(value = value)
        }
    }
    data class WEEKS(override val value: Int = 0): TimeUnit(value,"w",1){
        override fun mCopy(value: Int): TimeUnit {
            return copy(value = value)
        }
    }
}