updated smartplug

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/SmartPlug.java

@@ -1,5 +1,8 @@
 package ch.usi.inf.sa4.sanmarinoes.smarthut.models;
 
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.validation.constraints.NotNull;
@@ -8,11 +11,42 @@ import javax.validation.constraints.NotNull;
 @Entity
 public class SmartPlug extends Switchable {
 
+    /** The total amount of power that the smart plug has consumed represented in kW/h */
+    @Column @NotNull private static double totalConsumption;
+
     /** Whether the smart plug is on */
     @Column(name = "smart_plug_on", nullable = false)
     @NotNull
     private boolean on;
 
+    public double getTotalConsumption() {
+        return totalConsumption;
+    }
+
+    public void resetTotalConsumption() {
+        totalConsumption = 0;
+    }
+
+    /**
+     * Updates the consumption of a smart plug storing it in kW/h assuming that an average smart
+     * plug consumes 3W and by computing the conversion from watts to kW/h
+     */
+    private static void updateTotalConsumption() {
+        double averageConsumption = 3;
+        totalConsumption += (averageConsumption / 1000) * (1 / 3600);
+    }
+
+    /** Calls updateTotalConsumption every second */
+    public void updateConsumptionOverTime() {
+        final ScheduledExecutorService executorService =
+                Executors.newSingleThreadScheduledExecutor();
+
+        while (isOn()) {
+            executorService.scheduleAtFixedRate(
+                    SmartPlug::updateTotalConsumption, 0, 1, TimeUnit.SECONDS);
+        }
+    }
+
     @Override
     public boolean isOn() {
         return on;