Coverage Summary for Class: Hand (day07p1)

 package day07p1
 
 import day07p1.HandType.*
 
 fun List<HandBid>.totalWinning(): Long {
   return this.asSequence().sortedBy { it.hand }.mapIndexed { index, handBid -> (index + 1L) * handBid.bid }.sum()
 }
 
 fun String.toHandBidList(): List<HandBid> = lines().map { it.toHandBid() }
 
 fun String.toHandBid(): HandBid {
   val (hand, bid) = split(" ")
   return HandBid(hand.toHand(), bid.toInt())
 }
 
 data class HandBid(val hand: Hand, val bid: Int)
 
 enum class HandType {
   HighCard,
   OnePair,
   TwoPair,
   ThreeOfAKind,
   FullHouse,
   FourOfAKind,
   FiveOfAKind;
 
   companion object {
     fun allHandTypes(): List<HandType> = entries
   }
 }
 
 fun String.toHand(): Hand = Hand(map { it.toCard() }.toList())
 
 data class Hand(val cards: List<Card>) : Comparable<Hand> {
   val handType: HandType
 
   init {
     require(cards.size == 5) { cards }
     val cardsByType = cards.groupBy { it }
     handType = when (cardsByType.size) {
       5 -> HighCard
       4 -> OnePair
       3 -> {
         if (cardsByType.values.any { it.size == 2 }) TwoPair else ThreeOfAKind
       }
 
       2 -> {
         if (cardsByType.values.any { it.size == 3 }) FullHouse else FourOfAKind
       }
 
       else -> FiveOfAKind
     }
   }
 
   override fun compareTo(other: Hand): Int {
     val result = handType.compareTo(other.handType)
     if (result != 0) return result
 
     return cards.asSequence().zip(other.cards.asSequence())
       .filter { (a, b) -> a != b }
       .map { (a, b) -> a.compareTo(b) }
       .firstOrNull() ?: 0
   }
 }
 
 fun Char.toCard(): Card = Card[this]
 
 enum class Card(val shortId: Char) {
   Two('2'),
   Three('3'),
   Four('4'),
   Five('5'),
   Six('6'),
   Seven('7'),
   Eight('8'),
   Nine('9'),
   Ten('T'),
   Jack('J'),
   Queen('Q'),
   King('K'),
   Ace('A');
 
   companion object {
     fun allCards(): List<Card> = entries
 
     private val byShortId = entries.associateBy { it.shortId }
     operator fun get(shortId: Char): Card = byShortId.getValue(shortId)
   }
 }