🚀 3단계 - 로또(2등)

src/main/kotlin/lotto/LottoVendingMachine.kt

@@ -1,16 +1,19 @@
 package lotto
 
+import lotto.domain.Lotto
+import lotto.domain.Lottos
+
 object LottoVendingMachine {
     private const val LOTTO_PRICE = 1000
 
-    fun buyLotto(money: Int?): List<Lotto> {
+    fun buyLotto(money: Int?): Lottos {
         requireNotNull(money) {
             "구매 금액은 null이 아니어야 함"
         }
         require(money >= LOTTO_PRICE) {
             "구매 금액은 1000 보다 커야 함"
         }
 
-        return List(money / LOTTO_PRICE) { Lotto() }
+        return Lottos(List(money / LOTTO_PRICE) { Lotto() })
     }
 }

src/main/kotlin/lotto/application/LottoApplication.kt

@@ -1,8 +1,9 @@
 package lotto.application
 
-import lotto.Lotto
-import lotto.LottoResult
+import lotto.domain.Lotto
+import lotto.domain.LottoResult
 import lotto.LottoVendingMachine
+import lotto.domain.LottoNumber
 import lotto.view.InputView
 import lotto.view.OutputView
 
@@ -12,17 +13,17 @@ class LottoApplication(
 ) {
 
     fun run() {
-        outputView.showInputMoneyMessage()
         val money = inputView.inputMoney()
         val lotto = LottoVendingMachine.buyLotto(money)
         outputView.showLottoCount(lotto)
         outputView.showLotto(lotto)
 
-        outputView.showInputWinningNumbersMessage()
-        val winningNumbers: List<Int> = inputView.inputWinningNumbers()
+        val winningLotto: Lotto = inputView.inputWinningNumbers()
+        val bonusNumber: LottoNumber = inputView.inputBonusNumber()
 
         val lottoResult= LottoResult.makeLottoResult(
-            winningLotto = Lotto(*winningNumbers.toIntArray()),
+            winningLotto = winningLotto,
+            bonusLottoNumber = bonusNumber,
             lottos = lotto,
         )
         outputView.showResult(lottoResult, money)

src/main/kotlin/lotto/domain/Lotto.kt

@@ -0,0 +1,22 @@
+package lotto.domain
+
+class Lotto private constructor(val lottoNumbers: Set<LottoNumber>) {
+
+    init {
+        val lottoNumbersSize = lottoNumbers.size
+        require(lottoNumbersSize == LOTTO_SIZE)
+    }
+
+    constructor() : this(LottoPreset.shuffled().take(6).sortedBy { it.number }.toSet())
+
+    constructor(vararg number: Int) : this(number.map { LottoNumber(it) }.toSet())
+
+    fun countMatch(winningLotto: Lotto): Int {
+        return lottoNumbers.intersect(winningLotto.lottoNumbers).count()
+    }
+
+    companion object {
+        private val LottoPreset = List(LottoNumber.END_LOTTO_NUMBER) { LottoNumber(it + 1) }
+        private const val LOTTO_SIZE = 6
+    }
+}

src/main/kotlin/lotto/domain/LottoNumber.kt

@@ -0,0 +1,13 @@
+package lotto.domain
+
+@JvmInline
+value class LottoNumber(val number: Int) {
+    init {
+        require(number in START_LOTTO_NUMBER..END_LOTTO_NUMBER)
+    }
+
+    companion object {
+        const val START_LOTTO_NUMBER = 1
+        const val END_LOTTO_NUMBER = 45
+    }
+}

src/main/kotlin/lotto/domain/LottoResult.kt

@@ -0,0 +1,43 @@
+package lotto.domain
+
+class LottoResult private constructor(private val result: Map<Prize, Int>) : Map<Prize, Int> by result {
+    private val totalPrizeMoney: Long
+        get() {
+            return result.map {
+                it.key.money.toLong() * it.value
+            }.sum()
+        }
+
+    override fun get(key: Prize): Int {
+        return result[key] ?: 0
+    }
+
+    fun getRateOfReturn(money: Int): Float {
+        return totalPrizeMoney.toFloat() / money
+    }
+
+    companion object {
+        fun makeLottoResult(
+            winningLotto: Lotto,
+            bonusLottoNumber: LottoNumber,
+            lottos: Lottos,
+        ): LottoResult {
+            val result = lottos.lottos.groupingBy { lotto ->
+                val matchCount = lotto.countMatch(winningLotto)
+                when (matchCount) {
+                    6 -> Prize.FIRST
+                    5 -> if (bonusLottoNumber in lotto.lottoNumbers) {
+                        Prize.SECOND
+                    } else {
+                        Prize.THIRD
+                    }
+
+                    4 -> Prize.FOURTH
+                    3 -> Prize.FIFTH
+                    else -> Prize.NONE
+                }
+            }.eachCount()
+            return LottoResult(result)
+        }
+    }
+}

src/main/kotlin/lotto/domain/Lottos.kt

@@ -0,0 +1,5 @@
+package lotto.domain
+
+class Lottos(lottos: List<Lotto>) {
+    val lottos: List<Lotto> = lottos.toList()
+}

src/main/kotlin/lotto/domain/Prize.kt

@@ -0,0 +1,11 @@
+package lotto.domain
+
+enum class Prize(val money: Int, val count: Int) {
+    FIRST(2_000_000_000, 6),
+    SECOND(30_000_000, 5),
+    THIRD(1_500_000, 5),
+    FOURTH(50_000, 4),
+    FIFTH(5_000, 3),
+    NONE(0, 0),
+    ;
+}

src/main/kotlin/lotto/view/InputView.kt

@@ -1,13 +1,24 @@
 package lotto.view
 
+import lotto.domain.Lotto
+import lotto.domain.LottoNumber
+
 class InputView {
     fun inputMoney(): Int {
+        println("구입금액을 입력해 주세요.")
         val input = readlnOrNull()?.toIntOrNull()
         requireNotNull(input)
         return input
     }
 
-    fun inputWinningNumbers(): List<Int> {
-        return readlnOrNull()?.split(",")?.map { it.trim().toInt() } ?: emptyList()
+    fun inputWinningNumbers(): Lotto {
+        println("지난 주 당첨 번호를 입력해 주세요.")
+        val winningNumbers: List<Int> = readlnOrNull()?.split(",")?.map { it.trim().toInt() } ?: emptyList()
+        return Lotto(*winningNumbers.toIntArray())
+    }
+
+    fun inputBonusNumber(): LottoNumber {
+        println("보너스 볼을 입력해 주세요.")
+        return LottoNumber(readlnOrNull()?.toIntOrNull() ?: 0)
     }
 }

src/main/kotlin/lotto/view/OutputView.kt

@@ -1,36 +1,33 @@
 package lotto.view
 
-import lotto.Lotto
-import lotto.LottoResult
-import lotto.Prize
+import lotto.domain.LottoResult
+import lotto.domain.Lottos
+import lotto.domain.Prize
 
 class OutputView {
-    fun showInputMoneyMessage() {
-        println("구입금액을 입력해 주세요.")
+    fun showLottoCount(lottos: Lottos) {
+        println("${lottos.lottos.size}개를 구매했습니다.")
     }
 
-    fun showLottoCount(lotto: List<Lotto>) {
-        println("${lotto.size}개를 구매했습니다.")
-    }
-
-    fun showLotto(lotto: List<Lotto>) {
-        lotto.forEach {
-            println(it)
+    fun showLotto(lottos: Lottos) {
+        lottos.lottos.forEach {
+            println("[${it.lottoNumbers.map { lottoNumber -> lottoNumber.number }.joinToString(", ")}]")
         }
     }
 
-    fun showInputWinningNumbersMessage() {
-        println("지난 주 당첨 번호를 입력해 주세요.")
-    }
-
     fun showResult(lottoResult: LottoResult, money: Int) {
         println("당첨 통계")
         println("---------")
         Prize.entries
             .filter { it != Prize.NONE }
-            .sortedByDescending { it.count }
+            .reversed()
             .forEach { prize ->
-                println("${prize.count}개 일치 (${prize.money}원) - ${lottoResult[prize]}개")
+                val title = if (prize == Prize.SECOND) {
+                    "${prize.count}개 일치, 보너스 볼 일치 (${prize.money}원)"
+                } else {
+                    "${prize.count}개 일치 (${prize.money}원)"
+                }
+                println("$title - ${lottoResult[prize]}개")
             }
 
         println(String.format("총 수익률은 %.2f입니다.", lottoResult.getRateOfReturn(money)))

src/test/kotlin/lotto/LottoNumberTest.kt

@@ -2,6 +2,7 @@ package lotto
 
 import io.kotest.assertions.throwables.shouldNotThrow
 import io.kotest.assertions.throwables.shouldThrow
+import lotto.domain.LottoNumber
 import org.junit.jupiter.api.Test
 
 class LottoNumberTest {