feat: add JoinQueueEvent

.gitignore

@@ -4,3 +4,4 @@ Lab1.pdf
 
 checkstyle.jar
 cs2030_checks.xml
+*.swp

ArrivalEvent.java

@@ -28,13 +28,7 @@ class ArrivalEvent extends Event {
       if (this.shop.isQueueFull()) {
         return new Event[] { new DepartureEvent(this.getTime(), customer, shop) };
       }
-      Queue queue = this.shop.getQueue();
-      System.out
-          .println(String.format("%s: %s joined queue %s",
-              super.toString(),
-              this.customer, queue));
-      queue.enq(customer);
-      return new Event[] {};
+      return new Event[] { new JoinQueueEvent(customer, shop) };
     }
     return new Event[] {
         new ServiceBeginEvent(this.getTime(), customer, shop, availableCounter) };
@@ -46,6 +40,6 @@ class ArrivalEvent extends Event {
     return String.format("%s: %s arrived %s",
         super.toString(),
         this.customer,
-        this.shop.getQueue());
+        this.shop.queueString());
   }
 }

DepartureEvent.java

@@ -32,10 +32,10 @@ class DepartureEvent extends Event {
   @Override
   public Event[] simulate() {
     // when customer departs, check if there are customers in queue
-    if (this.shop.getQueue().isEmpty() || this.counter == null) {
+    if (this.shop.isQueueEmpty() || this.counter == null) {
       return new Event[] {};
     }
-    Customer c = (Customer) this.shop.getQueue().deq();
+    Customer c = this.shop.leaveQueue();
     return new Event[] {
         new ServiceBeginEvent(this.getTime(), c, this.shop, this.counter),
     };

JoinQueueEvent.java

@@ -0,0 +1,24 @@
+
+class JoinQueueEvent extends Event {
+  private Customer customer;
+  private Shop shop;
+
+  public JoinQueueEvent(Customer customer, Shop shop) {
+    super(customer.getArrivalTIme());
+    this.customer = customer;
+    this.shop = shop;
+  }
+
+  @Override
+  public Event[] simulate() {
+    this.shop.joinQueue(customer);
+      return new Event[] {};
+  }
+
+  @Override
+  public String toString() {
+    return String.format("%s: %s joined queue %s",
+        super.toString(),
+        this.customer, this.shop.queueString());
+  }
+}

Shop.java

@@ -41,5 +41,20 @@ public class Shop {
   public boolean isQueueFull() {
     return this.queue.isFull();
   }
+  public boolean isQueueEmpty() {
+    return this.queue.isEmpty();
+  }
+
+  public void joinQueue(Customer customer) {
+    this.queue.enq(customer);
+  }
+
+  public Customer leaveQueue() {
+    return (Customer) this.queue.deq();
+  }
+
+  public String queueString() {
+    return this.queue.toString();
+  }
 
 }