fix: cli temperature read

changes:
- fix: read temperature values without daemon
  Add subcommand to read temperature values without starting the daemon

- fix: implement measured value types
  Replace measured value types with constants

- fix: add sensor pipelines
  Add functions which returns a channel with measured values

- fix: filter measured values from a channel
  Add functions to filter measured values by sensor id or measured
  value types.

pkg/daemon/daemon.go

@@ -16,8 +16,6 @@ import (
 
 func Start(cnf *config.Config, flogger logger.Logger) error {
 
-	measuredValueChannel := make(chan *types.MeasuredValue, 0)
-
 	// load data source name (dsn)
 	dsnURL, err := url.Parse(cnf.DSN)
 	if err != nil {
@@ -69,7 +67,7 @@ func Start(cnf *config.Config, flogger logger.Logger) error {
 			continue
 		}
 
-		flogger.Debug("Found sensor %v", repoSensor.GetName())
+		flogger.Debug("Found sensor %v", repoSensor.Name)
 
 		sensor, err := sensor.New(repoSensor)
 		if err != nil {
@@ -85,25 +83,23 @@ func Start(cnf *config.Config, flogger logger.Logger) error {
 	parentCtx := context.Background()
 	ctx, cancel := context.WithCancel(parentCtx)
 
-	for _, s := range sensors {
-		go func(sensor sensor.Sensor) {
-			for {
-				select {
-				case <-ctx.Done():
+	measuredValueChannel, errorChannel := sensor.ReadTickingPipeline(ctx, sensors...)
+
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case err, open := <-errorChannel:
+				if !open {
 					return
-				case <-sensor.GetTicker().C:
-					measuredValues, err := sensor.Read()
-					if err != nil {
-						flogger.Error("%v", err)
-						continue
-					}
-					for _, measuredValue := range measuredValues {
-						measuredValueChannel <- measuredValue
-					}
+				}
+				if err != nil {
+					flogger.Error("%v", err)
 				}
 			}
-		}(s)
-	}
+		}
+	}()
 
 	measuredValues := make([]*types.MeasuredValue, 0, 10)
 	for {
@@ -123,7 +119,6 @@ func Start(cnf *config.Config, flogger logger.Logger) error {
 
 		case signal := <-interruptChannel:
 			cancel()
-			close(measuredValueChannel)
 
 			flogger.Info("Stopping daemon: Received process signal %v", signal.String())