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/sensor/bme280.go

@@ -66,21 +66,21 @@ func (bme280 *BME280) Read() ([]*types.MeasuredValue, error) {
 		{
 			ID:        uuid.NewV4().String(),
 			Value:     float64(humidityValue),
-			ValueType: "humidity",
+			ValueType: types.Humidity,
 			Date:      format.FormatedTime(),
 			SensorID:  bme280.ID,
 		},
 		{
 			ID:        uuid.NewV4().String(),
 			Value:     float64(pressureValue),
-			ValueType: "pressure",
+			ValueType: types.Pressure,
 			Date:      format.FormatedTime(),
 			SensorID:  bme280.ID,
 		},
 		{
 			ID:        uuid.NewV4().String(),
 			Value:     float64(temperatureValue),
-			ValueType: "temperature",
+			ValueType: types.Temperature,
 			Date:      format.FormatedTime(),
 			SensorID:  bme280.ID,
 		},

pkg/sensor/dht11.go

@@ -42,14 +42,14 @@ func (dht11 *DHT11) Read() ([]*types.MeasuredValue, error) {
 		{
 			ID:        uuid.NewV4().String(),
 			Value:     float64(humidityValue),
-			ValueType: "humidity",
+			ValueType: types.Humidity,
 			Date:      format.FormatedTime(),
 			SensorID:  dht11.ID,
 		},
 		{
 			ID:        uuid.NewV4().String(),
 			Value:     float64(temperatureValue),
-			ValueType: "temperature",
+			ValueType: types.Temperature,
 			Date:      format.FormatedTime(),
 			SensorID:  dht11.ID,
 		},

pkg/sensor/dht22.go

@@ -42,14 +42,14 @@ func (dht22 *DHT22) Read() ([]*types.MeasuredValue, error) {
 		{
 			ID:        uuid.NewV4().String(),
 			Value:     float64(humidityValue),
-			ValueType: "humidity",
+			ValueType: types.Humidity,
 			Date:      format.FormatedTime(),
 			SensorID:  dht22.ID,
 		},
 		{
 			ID:        uuid.NewV4().String(),
 			Value:     float64(temperatureValue),
-			ValueType: "temperature",
+			ValueType: types.Temperature,
 			Date:      format.FormatedTime(),
 			SensorID:  dht22.ID,
 		},

pkg/sensor/ds18b20.go

@@ -59,7 +59,7 @@ func (ds18b20 *DS18B20) Read() ([]*types.MeasuredValue, error) {
 		{
 			ID:        uuid.NewV4().String(),
 			Value:     float64(temperatureValue),
-			ValueType: "temperature",
+			ValueType: types.Temperature,
 			Date:      format.FormatedTime(),
 			SensorID:  ds18b20.ID,
 		},

pkg/sensor/interfaces.go

@@ -7,7 +7,8 @@ import (
 )
 
 type Sensor interface {
-	GetID() string
 	GetTicker() *time.Ticker
+
+	// Read single measured values from sensor
 	Read() ([]*types.MeasuredValue, error)
 }

pkg/sensor/sensor.go

@@ -1,6 +1,7 @@
 package sensor
 
 import (
+	"context"
 	"errors"
 	"sync"
 
@@ -11,6 +12,124 @@ var (
 	ErrSensorModelNotMatched = errors.New("Sensor model not matched")
 )
 
+// FilterMeasuredValuesByTypes filters measured values by type
+func FilterMeasuredValuesByTypes(ctx context.Context, inChannel <-chan *types.MeasuredValue, measuredValueTypes ...types.MeasuredValueType) <-chan *types.MeasuredValue {
+	outChannel := make(chan *types.MeasuredValue, 0)
+	go func() {
+	LOOP:
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case measuredValue, open := <-inChannel:
+				if !open {
+					return
+				}
+
+				for i := range measuredValueTypes {
+					if measuredValueTypes[i] == measuredValue.ValueType {
+						outChannel <- measuredValue
+						continue LOOP
+					}
+				}
+			}
+		}
+	}()
+	return outChannel
+}
+
+// FilterMeasuredValuesBySensorIDs filters measured values by sensor id
+func FilterMeasuredValuesBySensorIDs(ctx context.Context, inChannel <-chan *types.MeasuredValue, sensorIDs ...string) <-chan *types.MeasuredValue {
+	outChannel := make(chan *types.MeasuredValue, 0)
+	go func() {
+	LOOP:
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case measuredValue, open := <-inChannel:
+				if !open {
+					return
+				}
+
+				for i := range sensorIDs {
+					if sensorIDs[i] == measuredValue.SensorID {
+						outChannel <- measuredValue
+						continue LOOP
+					}
+				}
+			}
+		}
+	}()
+	return outChannel
+}
+
+// ReadPipeline pipes for each sensor measured values until the context has been
+// closed. The returned channels will be closed
+func ReadPipeline(ctx context.Context, sensors ...Sensor) (<-chan *types.MeasuredValue, <-chan error) {
+	var (
+		errorChannel         = make(chan error, 0)
+		measuredValueChannel = make(chan *types.MeasuredValue, 0)
+	)
+
+	go func() {
+		wg := new(sync.WaitGroup)
+		for i := range sensors {
+			wg.Add(1)
+
+			go func(s Sensor) {
+				defer wg.Done()
+				measuredValues, err := s.Read()
+				if err != nil {
+					errorChannel <- err
+					return
+				}
+				for i := range measuredValues {
+					measuredValueChannel <- measuredValues[i]
+				}
+			}(sensors[i])
+		}
+
+		wg.Wait()
+		close(errorChannel)
+		close(measuredValueChannel)
+	}()
+
+	return measuredValueChannel, errorChannel
+}
+
+// ReadTickingPipeline pipes for every tick on each sensor measured values until
+// the context has been closed
+func ReadTickingPipeline(ctx context.Context, sensors ...Sensor) (<-chan *types.MeasuredValue, <-chan error) {
+	var (
+		errorChannel         = make(chan error, 0)
+		measuredValueChannel = make(chan *types.MeasuredValue, 0)
+	)
+
+	for i := range sensors {
+		go func(s Sensor) {
+			for {
+				select {
+				case <-ctx.Done():
+					return
+				case <-s.GetTicker().C:
+					measuredValues, err := s.Read()
+					if err != nil {
+						errorChannel <- err
+						break
+					}
+
+					for i := range measuredValues {
+						measuredValueChannel <- measuredValues[i]
+					}
+				}
+			}
+		}(sensors[i])
+	}
+
+	return measuredValueChannel, errorChannel
+}
+
 // New returns a new sensor
 func New(sensor *types.Sensor) (Sensor, error) {
 	switch sensor.Model {