From b42bacd4209a01515dc779dee658c69b32f45213 Mon Sep 17 00:00:00 2001
From: eunwoo song <presentsong@naver.com>
Date: Mon, 6 Nov 2023 01:54:21 +0900
Subject: [PATCH] =?UTF-8?q?feat:=20=EC=9A=B0=EC=8A=B9=EC=9E=90=EC=9D=98=20?=
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---
 README.md                               |  4 ++--
 src/main/kotlin/racingcar/Cars.kt       |  9 +++++++++
 src/main/kotlin/racingcar/Main.kt       | 17 ++++++++++++++---
 src/main/kotlin/racingcar/OutputView.kt |  5 +++++
 src/test/kotlin/racingcar/CarsTest.kt   |  6 ++++++
 5 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 49a3646e03..965c56a1ff 100644
--- a/README.md
+++ b/README.md
@@ -2,5 +2,5 @@
 
 ## 기능목록
 
-- [ ] 자동차 이름 입력받는다
-- [ ] 우승자를 선정한다
+- [x] 자동차 이름 입력받는다
+- [x] 우승자를 선정한다
diff --git a/src/main/kotlin/racingcar/Cars.kt b/src/main/kotlin/racingcar/Cars.kt
index adec065d09..1f872513c6 100644
--- a/src/main/kotlin/racingcar/Cars.kt
+++ b/src/main/kotlin/racingcar/Cars.kt
@@ -1,12 +1,21 @@
 package racingcar
 
 class Cars(val cars: List<Car>, private val powerGenerator: PowerGenerator) {
+    init {
+        require(cars.isNotEmpty()) { "자동차는 최소 한 대 이상 존재해야 합니다." }
+    }
+
     fun move(): Cars {
         val movedCars = mutableListOf<Car>()
         cars.forEach { movedCars.add(it.move(powerGenerator.generate())) }
         return Cars(movedCars, powerGenerator)
     }
 
+    fun findWinner(): List<Car> {
+        val maxPosition = cars.maxBy { it.position }.position
+        return cars.filter { it.position == maxPosition }
+    }
+
     companion object {
         fun initialize(numberOfCars: Int, names: List<String>, powerGenerator: PowerGenerator): Cars {
             val cars = mutableListOf<Car>()
diff --git a/src/main/kotlin/racingcar/Main.kt b/src/main/kotlin/racingcar/Main.kt
index b21814ff1b..b06b4089b5 100644
--- a/src/main/kotlin/racingcar/Main.kt
+++ b/src/main/kotlin/racingcar/Main.kt
@@ -1,10 +1,14 @@
 package racingcar
 
 fun main() {
-    val numberOfCars = InputView.inputNumberOfCars()
-    val namesOfCars = InputView.inputNameOfCars()
-    val cars = Cars.initialize(numberOfCars, namesOfCars, RandomPowerGenerator)
+    val cars = initializeCars()
+
+    val movedCars = moveCars(cars)
+    val winners = movedCars.findWinner()
+    OutputView.printWinners(winners)
+}
 
+private fun moveCars(cars: Cars): Cars {
     val numberOfMoves = InputView.inputNumberOfMoves()
 
     OutputView.printResultTitle()
@@ -14,4 +18,11 @@ fun main() {
         movedCars = movedCars.move()
         OutputView.printResult(movedCars.cars)
     }
+    return movedCars
+}
+
+private fun initializeCars(): Cars {
+    val numberOfCars = InputView.inputNumberOfCars()
+    val namesOfCars = InputView.inputNameOfCars()
+    return Cars.initialize(numberOfCars, namesOfCars, RandomPowerGenerator)
 }
diff --git a/src/main/kotlin/racingcar/OutputView.kt b/src/main/kotlin/racingcar/OutputView.kt
index 9ff5c624aa..2d1e9ee0df 100644
--- a/src/main/kotlin/racingcar/OutputView.kt
+++ b/src/main/kotlin/racingcar/OutputView.kt
@@ -12,4 +12,9 @@ object OutputView {
         }
         println()
     }
+
+    fun printWinners(winners: List<Car>) {
+        val winnerNames = winners.joinToString(", ") { it.name }
+        println("$winnerNames 가 최종 우승했습니다.")
+    }
 }
diff --git a/src/test/kotlin/racingcar/CarsTest.kt b/src/test/kotlin/racingcar/CarsTest.kt
index a4d1a319df..2f961c4c03 100644
--- a/src/test/kotlin/racingcar/CarsTest.kt
+++ b/src/test/kotlin/racingcar/CarsTest.kt
@@ -2,9 +2,15 @@ package racingcar
 
 import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
 
 internal class CarsTest {
 
+    @Test
+    fun `자동차들은 1대 이상 있어야 한다`() {
+        assertThrows<IllegalArgumentException> { Cars.initialize(0, listOf("a", "b", "c"), FixedPowerGenerator(5)) }
+    }
+
     @Test
     fun `자동차들은 특정 숫자 이상이 들어오면 움직인다`() {
         val cars = Cars.initialize(3, listOf("a", "b", "c"), FixedPowerGenerator(4))