add read sensor

internal/domains/sensors/repository.go

@@ -143,7 +143,15 @@ func (i *inMemory) UpdateSensor(s Sensor) error {
 }
 
 func (i *inMemory) ReadSensor(sensorID string) (Sensor, error) {
-	panic("unimplemented")
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	sensor, exists := i.sensors[sensorID]
+	if !exists {
+		return Sensor{}, ErrSensorNotFound
+	}
+
+	return *sensor, nil
 }
 
 func (i *inMemory) ReadSensorValues(sensorID string, from time.Time, to time.Time) ([]SensorData, error) {
@@ -234,10 +242,21 @@ func (d *DecoratorRepo) ReadSensorValues(sensorID string, from, to time.Time) ([
 }
 
 func (d *DecoratorRepo) ReadAllSensors() ([]Sensor, error) {
+	var sensors []Sensor
+
 	sensors, err := d.memory.ReadAllSensors()
 	if err == nil && len(sensors) > 0 {
 		return sensors, nil
 	}
 
-	return d.db.ReadAllSensors()
+	sensors, err = d.db.ReadAllSensors()
+	if err != nil {
+		return []Sensor{}, err
+	}
+
+	for _, s := range sensors {
+		_ = d.memory.CreateSensor(s)
+	}
+
+	return sensors, nil
 }