[4장_양수진] 데이터 중심 설계 리팩토링

Author: yangsooplus

src/main/kotlin/yangsooplus/ch04/DiscountCondition.kt

@@ -1,15 +1,26 @@
 package yangsooplus.ch04
 
+import java.lang.IllegalArgumentException
 import java.time.DayOfWeek
 import java.time.LocalTime
 
 class DiscountCondition(
     val type: DiscountConditionType,
-    val sequence: Int,
-    val dayOfWeek: DayOfWeek,
-    val startTime: LocalTime,
-    val endTime: LocalTime
-)
+    private val sequence: Int,
+    private val dayOfWeek: DayOfWeek,
+    private val startTime: LocalTime,
+    private val endTime: LocalTime
+) {
+    fun isDiscountable(dayOfWeek: DayOfWeek, time: LocalTime): Boolean {
+        if (type != DiscountConditionType.PERIOD) throw IllegalArgumentException()
+        return this.dayOfWeek == dayOfWeek && startTime <= time && endTime >= time
+    }
+
+    fun isDiscountable(sequence: Int): Boolean {
+        if (type != DiscountConditionType.SEQUENCE) throw IllegalArgumentException()
+        return this.sequence == sequence
+    }
+}
 
 enum class DiscountConditionType{
     SEQUENCE, PERIOD

src/main/kotlin/yangsooplus/ch04/Movie.kt

@@ -2,17 +2,46 @@ package yangsooplus.ch04
 
 import yangsooplus.ch02.Money
 import java.time.Duration
+import java.time.LocalDateTime
 
 class Movie(
     val title: String,
     val runningTime: Duration,
-    val fee: Money,
+    private val fee: Money,
     val discountConditions: List<DiscountCondition>,
 
     val movieType: MovieType,
-    val discountAmount: Money,
-    val discountPercent: Double
-)
+    private val discountAmount: Money,
+    private val discountPercent: Double
+) {
+    fun calculateAmountDiscountedFee(): Money {
+        return fee.minus(discountAmount)
+    }
+
+    fun calculatePercentDiscountedFee(): Money {
+        return fee.minus(fee.times(discountPercent))
+    }
+
+    fun calculateNoneDiscountedFee(): Money = fee
+
+    fun isDiscountable(whenScreened: LocalDateTime, sequence: Int): Boolean {
+        discountConditions.forEach { condition ->
+            when (condition.type) {
+                DiscountConditionType.PERIOD -> {
+                    if (condition.isDiscountable(whenScreened.dayOfWeek, whenScreened.toLocalTime()))
+                        return true
+                }
+
+                DiscountConditionType.SEQUENCE -> {
+                    if (condition.isDiscountable(sequence))
+                        return true
+                }
+            }
+        }
+        return false
+    }
+
+}
 
 enum class MovieType {
     AMOUNT_DISCOUNT, PERCENT_DISCOUNT, NONE_DISCOUNT

src/main/kotlin/yangsooplus/ch04/ReservationAgency.kt

@@ -1,39 +1,10 @@
 package yangsooplus.ch04
 
-import yangsooplus.ch02.Money
+
 
 class ReservationAgency {
 
     fun reserve(screening: Screening, customer: Customer, audienceCnt: Int): Reservation {
-        val movie = screening.movie
-
-        var discountable = false
-        movie.discountConditions.forEach { condition ->
-            discountable = when (condition.type) {
-                DiscountConditionType.PERIOD -> {
-                    screening.whenScreened.dayOfWeek == condition.dayOfWeek &&
-                            condition.startTime <= screening.whenScreened.toLocalTime() &&
-                            condition.endTime >= screening.whenScreened.toLocalTime()
-                }
-                DiscountConditionType.SEQUENCE -> {
-                    condition.sequence == screening.sequence
-                }
-            }
-
-            if (discountable) return@forEach
-        }
-
-        val fee = if (discountable) {
-            val discountAmount = when(movie.movieType) {
-                MovieType.AMOUNT_DISCOUNT -> movie.discountAmount
-                MovieType.PERCENT_DISCOUNT -> movie.fee.times(movie.discountPercent)
-                MovieType.NONE_DISCOUNT -> Money.ZERO
-            }
-            movie.fee.minus(discountAmount)
-        } else {
-            movie.fee
-        }
-
-        return Reservation(customer, screening, fee, audienceCnt)
+        return Reservation(customer, screening, screening.calculateFee(audienceCnt), audienceCnt)
     }
 }

src/main/kotlin/yangsooplus/ch04/Screening.kt

@@ -1,9 +1,20 @@
 package yangsooplus.ch04
 
+import yangsooplus.ch02.Money
 import java.time.LocalDateTime
 
 class Screening(
-    val movie: Movie,
+    private val movie: Movie,
     val sequence: Int,
     val whenScreened: LocalDateTime
-)
+) {
+
+    fun calculateFee(audienceCnt: Int): Money {
+        return when (movie.movieType) {
+            MovieType.AMOUNT_DISCOUNT -> movie.calculateAmountDiscountedFee()
+            MovieType.PERCENT_DISCOUNT -> movie.calculatePercentDiscountedFee()
+            MovieType.NONE_DISCOUNT -> movie.calculateNoneDiscountedFee()
+        }.times(audienceCnt)
+    }
+
+}