1 files changed, 21 insertions, 0 deletions
diff --git a/app/src/main/java/io/trygvis/soilmoisture/SmDevice.java b/app/src/main/java/io/trygvis/soilmoisture/SmDevice.java
index 1074dd9..d56f33e 100644
--- a/app/src/main/java/io/trygvis/soilmoisture/SmDevice.java
+++ b/app/src/main/java/io/trygvis/soilmoisture/SmDevice.java
@@ -6,8 +6,11 @@ import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.List;
 
+import io.trygvis.android.Optional;
 import io.trygvis.android.bt.BtDevice;
 
+import static io.trygvis.android.Optional.empty;
+import static io.trygvis.android.Optional.of;
 import static io.trygvis.soilmoisture.SmDevice.SmCmdCode.GET_SENSOR_COUNT;
 import static io.trygvis.soilmoisture.SmDevice.SmCmdCode.GET_SENSOR_NAME;
 import static io.trygvis.soilmoisture.SmDevice.SmCmdCode.GET_VALUE;
@@ -75,7 +78,25 @@ class SmDevice {
         return sensors;
     }
 
+    public Optional<SmSensor> getSensorByIndex(int index) {
+        if (!isUseful()) {
+            throw new IllegalStateException("Not a useful device");
+        }
+
+        for (SmSensor sensor : sensors) {
+            if (sensor.getIndex() == index) {
+                return of(sensor);
+            }
+        }
+
+        return empty();
+    }
+
     void addSensor(SmSensor sensor) {
+        if (getSensorByIndex(sensor.index).isPresent()) {
+            throw new IllegalStateException("This device already contains a sensor with index=" + sensor.index);
+        }
+
         sensors.add(sensor);
     }