control the well from a text-based cli

src/main/java/com/henrypump/poc/Measurement.java

@@ -1,5 +1,9 @@
 package com.henrypump.poc;
 
+import org.bson.Document;
+
+import java.time.ZonedDateTime;
+
 import static java.lang.Math.abs;
 
 /**
@@ -37,6 +41,26 @@ public class Measurement {
         this.sendDelta = sendDelta;
         this.lastSentValue = 0.0;
         this.sendTimeDelta = sendTimeDelta;
+
+        Document lastStored =  this.db.getLastStoredMeasurement(this.tagName);
+        try {
+            ZonedDateTime timestamp = ZonedDateTime.parse((CharSequence) lastStored.get("timestamp"));
+            if (isToday(timestamp)){
+                this.average = lastStored.getDouble("dailyAverage");
+                this.total = lastStored.getDouble("dailyTotal");
+                this.lastSentValue = lastStored.getDouble("currentValue");
+                this.dailyMax = lastStored.getDouble("maxDailyValue");
+                this.dailyMin = lastStored.getDouble("minDailyValue");
+                this.lastSentTimestamp = timestamp.toEpochSecond();
+                this.numMeasurements = lastStored.getLong("numMeasurements");
+                System.out.println("Using stored value from " + timestamp.toString() + " for " + this.tagName);
+            } else {
+                System.out.println("Cannot use stored value from " + timestamp.toString() + " for " + this.tagName);
+            }
+        } catch (NullPointerException e){
+            System.out.println("There was no previous measurement in the database for " + this.tagName);
+        }
+
     }
 
     Measurement(String tagName, boolean storeInDatabase){
@@ -83,9 +107,17 @@ public class Measurement {
         return dailyMin;
     }
 
+    public static boolean isToday(ZonedDateTime inpZDT){
+        ZonedDateTime now = ZonedDateTime.now();
+        if (now.toLocalDate().equals(inpZDT.toLocalDate())){
+            return true;
+        }
+        return false;
+    };
+
     public void update(double value)
     {
-        long currentTimestamp = System.currentTimeMillis();
+        long currentTimestamp = ZonedDateTime.now().toEpochSecond();
         lastValue = currentValue;
         currentValue = value;
 
@@ -101,6 +133,7 @@ public class Measurement {
                     currentTimestamp - lastSentTimestamp > (sendTimeDelta  * 1000)){
                 long l = db.newMeasurement(this);
                 lastSentValue = currentValue;
+                lastSentTimestamp = currentTimestamp;
             }
         }
     }