[WM] refactor: add the interface for the discount strategies

GraceeFlower · Feb 17, 2020 · ea97232 · ea97232
1 parent 3490196
commit ea97232
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Showing 5 changed files with 62 additions and 50 deletions.
diff --git a/src/main/java/com/thoughtworks/DiscountStrategy.java b/src/main/java/com/thoughtworks/DiscountStrategy.java
@@ -0,0 +1,8 @@
+package com.thoughtworks;
+
+import java.util.ArrayList;
+
+public interface DiscountStrategy {
+
+  String getDiscountInfo(ArrayList<Dish> menu);
+}
diff --git a/src/main/java/com/thoughtworks/FullOffStrategy.java b/src/main/java/com/thoughtworks/FullOffStrategy.java
@@ -0,0 +1,15 @@
+package com.thoughtworks;
+
+import java.util.ArrayList;
+
+public class FullOffStrategy implements DiscountStrategy {
+
+  public int getDiscountMoney() {
+    return 6;
+  }
+
+  @Override
+  public String getDiscountInfo(ArrayList<Dish> menu) {
+    return "满30减6元，省6元\n";
+  }
+}
diff --git a/src/main/java/com/thoughtworks/HalfOffStrategy.java b/src/main/java/com/thoughtworks/HalfOffStrategy.java
@@ -0,0 +1,29 @@
+package com.thoughtworks;
+
+import java.util.ArrayList;
+
+public class HalfOffStrategy implements DiscountStrategy {
+
+  public int getDiscountMoney(ArrayList<Dish> menu) {
+    int reducePrice = 0;
+    for (Dish dish : menu) {
+      if (DataProvider.getHalfDishIds().contains(dish.getId())) {
+        reducePrice += (int) dish.getPrice() / 2;
+      }
+    }
+    return reducePrice;
+  }
+
+  @Override
+  public String getDiscountInfo(ArrayList<Dish> menu) {
+    StringBuilder strategy = new StringBuilder("指定菜品半价(");
+    for (Dish dish : menu) {
+      if (DataProvider.getHalfDishIds().contains(dish.getId())) {
+        strategy.append(dish.getName()).append("，");
+      }
+    }
+    strategy.deleteCharAt(strategy.length() - 1).append(")，省")
+      .append(this.getDiscountMoney(menu)).append("元\n");
+    return strategy.toString();
+  }
+}
diff --git a/src/main/java/com/thoughtworks/OrderRender.java b/src/main/java/com/thoughtworks/OrderRender.java
@@ -13,18 +13,6 @@ public OrderRender(ArrayList<Dish> menu, int[] subtotal, String strategy) {
     this.strategy = strategy;
   }
 
-//  public ArrayList<Dish> getMenu() {
-//    return menu;
-//  }
-//
-//  public int[] getSubtotal() {
-//    return subtotal;
-//  }
-//
-//  public String getStrategy() {
-//    return strategy;
-//  }
-
   public String renderReceipt() {
     StringBuilder receipt = new StringBuilder("============= 订餐明细 =============\n");
     for (int i = 0; i < menu.size(); i++) {

diff --git a/src/main/java/com/thoughtworks/Restaurant.java b/src/main/java/com/thoughtworks/Restaurant.java
@@ -20,26 +20,20 @@ public int[] getSubtotal(ArrayList<Dish> menu) {
   }
 
   public String getStrategy(ArrayList<Dish> menu, int[] subtotal) {
-    ArrayList<Integer> halfOffInfo = calculateHalfOff(menu);
     int total = calculateTotal(subtotal);
-    int discount = calculateFullOff(total);
     StringBuilder strategy = new StringBuilder();
-    if (discount > 0) {
+    FullOffStrategy fullOff = new FullOffStrategy();
+    HalfOffStrategy halfOff = new HalfOffStrategy();
+    if (30 <= total) {
       strategy.append("-----------------------------------\n").append("使用优惠:\n");
-      if (discount < halfOffInfo.get(halfOffInfo.size() - 1)) {
-        total -= halfOffInfo.get(halfOffInfo.size() - 1);
-        strategy.append("指定菜品半价(");
-        int infoLen = halfOffInfo.size();
-        for (int i = 0; i < infoLen - 1; i++) {
-          strategy.append(menu.get(halfOffInfo.get(i)).getName());
-          if (i != infoLen - 2) {
-            strategy.append("，");
-          }
-        }
-        strategy.append(")，省").append(halfOffInfo.get(infoLen - 1)).append("元\n");
+      int fullReduce = fullOff.getDiscountMoney();
+      int halfReduce = halfOff.getDiscountMoney(menu);
+      if (fullReduce < halfReduce) {
+        total -= halfReduce;
+        strategy.append(halfOff.getDiscountInfo(menu));
       } else {
-        total -= discount;
-        strategy.append("满30减6元，省6元\n");
+        total -= fullReduce;
+        strategy.append(fullOff.getDiscountInfo(menu));
       }
     }
     strategy.append("-----------------------------------\n总计：").append(total).append("元\n");
@@ -53,26 +47,4 @@ public int calculateTotal(int[] subtotal) {
     }
     return total;
   }
-
-  public ArrayList<Integer> calculateHalfOff(ArrayList<Dish> menu) {
-    ArrayList<Integer> halfOffInfo = new ArrayList<>();
-    int reducePrice = 0;
-    for (int i = 0; i < menu.size(); i++) {
-      Dish dish = menu.get(i);
-      if(DataProvider.getHalfDishIds().contains(dish.getId())) {
-        reducePrice += (int)dish.getPrice() / 2;
-        halfOffInfo.add(i);
-      }
-    }
-    halfOffInfo.add(reducePrice);
-    return halfOffInfo;
-  }
-
-  public int calculateFullOff(int total) {
-    int reducePrice = 0;
-    if (30 <= total) {
-      reducePrice = 6;
-    }
-    return reducePrice;
-  }
 }