tdd-java-demo

Discount.java

(1517B)

 package takehome.model;
 
 import com.google.common.collect.HashMultiset;
 import com.google.common.collect.Multiset;
 import com.google.common.collect.Multisets;
 
 import java.time.LocalDate;
 import java.util.Arrays;
 
 public class Discount {
     private final Multiset<Item> items;
     private final double amount;
     private final LocalDate startDate;
     private final LocalDate endDate;
 
     public Discount(double amount, Item ...items) {
         this(amount, LocalDate.MIN, LocalDate.MAX, items);
     }
 
     public Discount(double amount, LocalDate startDate, LocalDate endDate, Item... items) {
         this.amount = amount;
         this.startDate = startDate;
         this.endDate = endDate;
         this.items = HashMultiset.create(Arrays.asList(items));
     }
 
     public double getAmount() {
         return amount;
     }
 
     @SuppressWarnings("UnstableApiUsage")
     public double getDiscount(Basket basket) {
         Multiset<Item> basketSet = basket.getItems();
 
         int occurrences = 0;
         boolean occurrence = Multisets.containsOccurrences(basketSet, items);
 
         while (occurrence) {
             occurrences++;
             basketSet = Multisets.difference(basketSet, items);
             occurrence = Multisets.containsOccurrences(basketSet, items);
         }
 
         return amount * occurrences;
     }
 
     public boolean isValid(LocalDate date) {
         return date.equals(startDate) || date.equals(endDate) ||
                 (date.isAfter(startDate) && date.isBefore(endDate));
     }
 }