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.

cli/root.go

@@ -10,6 +10,7 @@ import (
 
 	"git.cryptic.systems/volker.raschek/flucky/cli/daemon"
 	"git.cryptic.systems/volker.raschek/flucky/cli/sensor"
+	"git.cryptic.systems/volker.raschek/flucky/cli/temperature"
 	"git.cryptic.systems/volker.raschek/flucky/pkg/config"
 	"github.com/Masterminds/semver"
 
@@ -38,6 +39,7 @@ func Execute(version *semver.Version) error {
 	subCommands := []func(cmd *cobra.Command) error{
 		daemon.InitCmd,
 		sensor.InitCmd,
+		temperature.InitCmd,
 	}
 
 	for _, subCommand := range subCommands {

cli/temperature/temperature.go

@@ -0,0 +1,133 @@
+package temperature
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"os"
+
+	"git.cryptic.systems/volker.raschek/flucky/pkg/cli"
+	"git.cryptic.systems/volker.raschek/flucky/pkg/config"
+	"git.cryptic.systems/volker.raschek/flucky/pkg/repository"
+	"git.cryptic.systems/volker.raschek/flucky/pkg/sensor"
+	"git.cryptic.systems/volker.raschek/flucky/pkg/types"
+	"git.cryptic.systems/volker.raschek/go-logger"
+	"github.com/spf13/cobra"
+)
+
+func InitCmd(cmd *cobra.Command) error {
+	temperatureCmd := &cobra.Command{
+		Use:   "temperature",
+		Short: "Read and list temperature values",
+	}
+
+	readTemperatureCmd := &cobra.Command{
+		Use:   "read",
+		Short: "Read temperature values from sensors",
+		RunE:  readTemperature,
+	}
+	readTemperatureCmd.Flags().Bool("persist", true, "Persist measured values to the repository")
+
+	temperatureCmd.AddCommand(readTemperatureCmd)
+	cmd.AddCommand(temperatureCmd)
+
+	return nil
+}
+
+func readTemperature(cmd *cobra.Command, args []string) error {
+	configFile, err := cmd.Flags().GetString("config")
+	if err != nil {
+		return fmt.Errorf("No config file defined")
+	}
+
+	persist, err := cmd.Flags().GetBool("persist")
+	if err != nil {
+		return fmt.Errorf("Flag persist not defined: %v", err)
+	}
+
+	cnf, err := config.Read(configFile)
+	if err != nil {
+		return err
+	}
+
+	dsnURL, err := url.Parse(cnf.DSN)
+	if err != nil {
+		return err
+	}
+
+	logLevelString, err := cmd.Flags().GetString("loglevel")
+	if err != nil {
+		return err
+	}
+
+	logLevel, err := logger.ParseLogLevel(logLevelString)
+	if err != nil {
+		return err
+	}
+
+	flogger := logger.NewLogger(logLevel)
+
+	repo, err := repository.New(dsnURL, flogger)
+	if err != nil {
+		return err
+	}
+
+	sensorTypes, err := repo.GetSensors()
+	if err != nil {
+		return err
+	}
+
+	sensorTypes, err = types.FilterSensorByMeasuredValueTypes(sensorTypes, types.Temperature)
+	if err != nil {
+		return err
+	}
+
+	sensors := make([]sensor.Sensor, 0)
+	for i := range sensorTypes {
+		s, err := sensor.New(sensorTypes[i])
+		if err != nil {
+			return err
+		}
+		sensors = append(sensors, s)
+	}
+
+	measuredValueChannel, errorChannel := sensor.ReadPipeline(context.TODO(), sensors...)
+
+	go func() {
+		for {
+			select {
+			case err, open := <-errorChannel:
+				if !open {
+					return
+				}
+				flogger.Error("%v", err)
+			}
+		}
+	}()
+
+	measuredValues := make([]*types.MeasuredValue, 0)
+LOOP:
+	for {
+		select {
+		case measuredValue, open := <-measuredValueChannel:
+			if !open {
+				break LOOP
+			}
+			measuredValues = append(measuredValues, measuredValue)
+		}
+	}
+
+	err = cli.PrintMeasuredValues(measuredValues, os.Stdout)
+	if err != nil {
+		return err
+	}
+
+	if persist {
+		err = repo.AddMeasuredValues(measuredValues...)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

pkg/cli/cli.go

@@ -8,6 +8,25 @@ import (
 	"git.cryptic.systems/volker.raschek/flucky/pkg/types"
 )
 
+func PrintMeasuredValues(measuredValues []*types.MeasuredValue, w io.Writer) error {
+
+	// declar tabwriter
+	tw := tabwriter.NewWriter(w, 0, 0, 3, ' ', 0)
+
+	fmt.Fprint(tw, "timestamp\ttype\tvalue\n")
+
+	for i := range measuredValues {
+		fmt.Fprintf(tw, "%v\t%v\t%v\n", measuredValues[i].Date.String(), measuredValues[i].ValueType, measuredValues[i].Value)
+	}
+
+	err := tw.Flush()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // PrintSensors displays a list with all configured sensors
 func PrintSensors(sensors []*types.Sensor, w io.Writer) error {
 
@@ -42,7 +61,10 @@ func PrintSensors(sensors []*types.Sensor, w io.Writer) error {
 		fmt.Fprintf(tw, "%v\t%v\n", sensor.TickDuration, sensor.Enabled)
 	}
 
-	tw.Flush()
+	err := tw.Flush()
+	if err != nil {
+		return err
+	}
 
 	return nil
 }

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) {
+	measuredValueChannel, errorChannel := sensor.ReadTickingPipeline(ctx, sensors...)
+
+	go func() {
 		for {
 			select {
 			case <-ctx.Done():
 				return
-				case <-sensor.GetTicker().C:
-					measuredValues, err := sensor.Read()
+			case err, open := <-errorChannel:
+				if !open {
+					return
+				}
 				if err != nil {
 					flogger.Error("%v", err)
-						continue
-					}
-					for _, measuredValue := range measuredValues {
-						measuredValueChannel <- measuredValue
 				}
 			}
 		}
-		}(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())
 

pkg/repository/db/postgres.go

@@ -115,7 +115,7 @@ func (postgres *Postgres) InsertDevices(ctx context.Context, devices ...*types.D
 
 // InsertMeasuredValues into the database
 func (postgres *Postgres) InsertMeasuredValues(ctx context.Context, measuredValues ...*types.MeasuredValue) error {
-	splittedMeasuredValues := make(map[string][]*types.MeasuredValue, 0)
+	splittedMeasuredValues := make(map[types.MeasuredValueType][]*types.MeasuredValue, 0)
 
 	for _, measuredValue := range measuredValues {
 		if _, ok := splittedMeasuredValues[measuredValue.ValueType]; !ok {
@@ -164,11 +164,11 @@ func (postgres *Postgres) InsertMeasuredValues(ctx context.Context, measuredValu
 		var queryFile string
 
 		switch measuredValueType {
-		case "humidity":
+		case types.Humidity:
 			queryFile = "insertHumidity.sql"
-		case "pressure":
+		case types.Pressure:
 			queryFile = "insertPressure.sql"
-		case "temperature":
+		case types.Temperature:
 			queryFile = "insertTemperature.sql"
 		default:
 			tx.Rollback()
@@ -361,7 +361,7 @@ func (postgres *Postgres) SelectHumidity(ctx context.Context, id string) (*types
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "humidity"
+		measuredValue.ValueType = types.Humidity
 	}
 
 	return measuredValues[0], nil
@@ -391,7 +391,7 @@ func (postgres *Postgres) SelectHumidities(ctx context.Context) ([]*types.Measur
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "humidity"
+		measuredValue.ValueType = types.Humidity
 	}
 
 	return measuredValues, nil
@@ -462,7 +462,7 @@ func (postgres *Postgres) SelectPressure(ctx context.Context, id string) (*types
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "pressure"
+		measuredValue.ValueType = types.Pressure
 	}
 
 	return measuredValues[0], nil
@@ -492,7 +492,7 @@ func (postgres *Postgres) SelectPressures(ctx context.Context) ([]*types.Measure
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "pressure"
+		measuredValue.ValueType = types.Pressure
 	}
 
 	return measuredValues, nil
@@ -622,7 +622,7 @@ func (postgres *Postgres) SelectTemperature(ctx context.Context, id string) (*ty
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "temperatures"
+		measuredValue.ValueType = types.Temperature
 	}
 
 	return measuredValues[0], nil
@@ -652,7 +652,7 @@ func (postgres *Postgres) SelectTemperatures(ctx context.Context) ([]*types.Meas
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "temperatures"
+		measuredValue.ValueType = types.Temperature
 	}
 
 	return measuredValues, nil

pkg/repository/db/sqlite.go

@@ -114,7 +114,7 @@ func (sqlite *SQLite) InsertDevices(ctx context.Context, devices ...*types.Devic
 
 // InsertMeasuredValues into the database
 func (sqlite *SQLite) InsertMeasuredValues(ctx context.Context, measuredValues ...*types.MeasuredValue) error {
-	splittedMeasuredValues := make(map[string][]*types.MeasuredValue, 0)
+	splittedMeasuredValues := make(map[types.MeasuredValueType][]*types.MeasuredValue, 0)
 
 	for _, measuredValue := range measuredValues {
 		if _, ok := splittedMeasuredValues[measuredValue.ValueType]; !ok {
@@ -163,11 +163,11 @@ func (sqlite *SQLite) InsertMeasuredValues(ctx context.Context, measuredValues .
 		var queryFile string
 
 		switch measuredValueType {
-		case "humidity":
+		case types.Humidity:
 			queryFile = "insertHumidity.sql"
-		case "pressure":
+		case types.Pressure:
 			queryFile = "insertPressure.sql"
-		case "temperature":
+		case types.Temperature:
 			queryFile = "insertTemperature.sql"
 		default:
 			tx.Rollback()
@@ -360,7 +360,7 @@ func (sqlite *SQLite) SelectHumidity(ctx context.Context, id string) (*types.Mea
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "humidity"
+		measuredValue.ValueType = types.Humidity
 	}
 
 	return measuredValues[0], nil
@@ -390,7 +390,7 @@ func (sqlite *SQLite) SelectHumidities(ctx context.Context) ([]*types.MeasuredVa
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "humidity"
+		measuredValue.ValueType = types.Humidity
 	}
 
 	return measuredValues, nil
@@ -461,7 +461,7 @@ func (sqlite *SQLite) SelectPressure(ctx context.Context, id string) (*types.Mea
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "pressure"
+		measuredValue.ValueType = types.Pressure
 	}
 
 	return measuredValues[0], nil
@@ -491,7 +491,7 @@ func (sqlite *SQLite) SelectPressures(ctx context.Context) ([]*types.MeasuredVal
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "pressure"
+		measuredValue.ValueType = types.Pressure
 	}
 
 	return measuredValues, nil
@@ -621,7 +621,7 @@ func (sqlite *SQLite) SelectTemperature(ctx context.Context, id string) (*types.
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "temperatures"
+		measuredValue.ValueType = types.Temperature
 	}
 
 	return measuredValues[0], nil
@@ -651,7 +651,7 @@ func (sqlite *SQLite) SelectTemperatures(ctx context.Context) ([]*types.Measured
 	}
 
 	for _, measuredValue := range measuredValues {
-		measuredValue.ValueType = "temperatures"
+		measuredValue.ValueType = types.Temperature
 	}
 
 	return measuredValues, nil

pkg/repository/repository.go

@@ -98,8 +98,28 @@ func (repo *Repository) GetSensor(sensorID string) (*types.Sensor, error) {
 
 // GetSensors returns all sensors. If no sensors has been found, the function
 // returns nil.
-func (repo *Repository) GetSensors() ([]*types.Sensor, error) {
-	return repo.database.SelectSensors(context.Background())
+func (repo *Repository) GetSensors(models ...string) ([]*types.Sensor, error) {
+	sensors, err := repo.database.SelectSensors(context.Background())
+	switch {
+	case err != nil:
+		return nil, err
+	case len(models) > 0:
+		cachedSensors := make([]*types.Sensor, 0)
+	LOOP:
+		for i := range sensors {
+			for j := range models {
+				if strings.ToLower(sensors[i].Model) == strings.ToLower(models[j]) {
+					cachedSensors = append(cachedSensors, sensors[i])
+					continue LOOP
+				}
+			}
+		}
+		return cachedSensors, nil
+	case len(models) <= 0:
+		fallthrough
+	default:
+		return sensors, err
+	}
 }
 
 // GetSensorsByDeviceID returns all sensors by a device id. If no sensor has

pkg/repository/repository_test.go

@@ -188,6 +188,26 @@ func testBackend(t *testing.T, repo *repository.Repository) {
 	require.NoError(err)
 	require.Len(sensors, len(expectedSensors))
 
+	sensors, err = repo.GetSensors("BME280")
+	require.NoError(err)
+	require.Len(sensors, 1)
+	require.JSONEq(jsonEncoder(expectedSensors[2]), jsonEncoder(sensors[0]))
+
+	sensors, err = repo.GetSensors("DS18B20")
+	require.NoError(err)
+	require.Len(sensors, 1)
+	require.JSONEq(jsonEncoder(expectedSensors[1]), jsonEncoder(sensors[0]))
+
+	sensors, err = repo.GetSensors("DHT11")
+	require.NoError(err)
+	require.Len(sensors, 1)
+	require.JSONEq(jsonEncoder(expectedSensors[0]), jsonEncoder(sensors[0]))
+
+	sensors, err = repo.GetSensors("DHT11", "DS18B20")
+	require.NoError(err)
+	require.Len(sensors, 2)
+	require.ElementsMatch(expectedSensors[0:2], sensors)
+
 	// Test: GetSensor
 	sensor, err := repo.GetSensor(expectedSensors[0].ID)
 	require.NoError(err)
@@ -278,7 +298,7 @@ func testBackend(t *testing.T, repo *repository.Repository) {
 			{
 				ID:           "2e5a297a-3da0-46ae-89d2-0fcab0f1d5f7",
 				Value:        32,
-				ValueType:    "humidity",
+				ValueType:    types.Humidity,
 				Date:         *timeNow(require),
 				SensorID:     "8c74397f-8e60-4c9d-960d-3197747cef9a",
 				CreationDate: *timeNow(require),
@@ -287,7 +307,7 @@ func testBackend(t *testing.T, repo *repository.Repository) {
 			{
 				ID:           "d69f1b62-0c6c-4058-b42c-4a2821bd220c",
 				Value:        38,
-				ValueType:    "pressure",
+				ValueType:    types.Pressure,
 				Date:         *timeNow(require),
 				SensorID:     "8c74397f-8e60-4c9d-960d-3197747cef9a",
 				CreationDate: *timeNow(require),
@@ -296,7 +316,7 @@ func testBackend(t *testing.T, repo *repository.Repository) {
 			{
 				ID:           "ea945ae0-412b-4561-a191-1f8f1f909fa4",
 				Value:        35.4,
-				ValueType:    "temperature",
+				ValueType:    types.Temperature,
 				Date:         *timeNow(require),
 				SensorID:     "8c74397f-8e60-4c9d-960d-3197747cef9a",
 				CreationDate: *timeNow(require),

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 {

pkg/types/measuredValue.go

@@ -10,9 +10,17 @@ import (
 type MeasuredValue struct {
 	ID           string            `json:"id" xml:"id"`
 	Value        float64           `json:"value,string" xml:"value,string"`
-	ValueType    string     `json:"value_type" xml:"value_type"`
+	ValueType    MeasuredValueType `json:"value_type" xml:"value_type"`
 	Date         time.Time         `json:"date" xml:"date"`
 	SensorID     string            `json:"sensor_id" xml:"sensor_id"`
 	CreationDate time.Time         `json:"creation_date" xml:"creation_date"`
 	UpdateDate   *time.Time        `json:"update_date" xml:"update_date"`
 }
+
+type MeasuredValueType string
+
+const (
+	Humidity    MeasuredValueType = "humidity"
+	Pressure                      = "pressure"
+	Temperature                   = "temperature"
+)

pkg/types/sensor.go

@@ -1,6 +1,7 @@
 package types
 
 import (
+	"fmt"
 	"time"
 )
 
@@ -22,21 +23,6 @@ type Sensor struct {
 	UpdateDate   *time.Time `json:"update_date" xml:"update_date"`
 }
 
-// GetID returns the UUID of the sensor.
-func (s *Sensor) GetID() string {
-	return s.ID
-}
-
-// GetDeviceID returns the UUID of the configured device.
-func (s *Sensor) GetDeviceID() string {
-	return s.DeviceID
-}
-
-// GetName returns the name of the sensor.
-func (s *Sensor) GetName() string {
-	return s.Name
-}
-
 // GetTicker returns a new ticker, which tick every when the sensor should be
 // read
 func (s *Sensor) GetTicker() *time.Ticker {
@@ -46,3 +32,34 @@ func (s *Sensor) GetTicker() *time.Ticker {
 	}
 	return time.NewTicker(duration)
 }
+
+// FilterSensorByMeasuredValueTypes filters sensors by the measured values types
+// which they measure
+func FilterSensorByMeasuredValueTypes(sensors []*Sensor, measuredValueTypes ...MeasuredValueType) ([]*Sensor, error) {
+	cachedSensors := make([]*Sensor, 0)
+
+	mapping := map[MeasuredValueType][]string{
+		Humidity:    {"BME280", "DHT11", "DHT22"},
+		Pressure:    {"BME280"},
+		Temperature: {"BME280", "DHT11", "DHT22", "DS18B20"},
+	}
+
+	for i := range measuredValueTypes {
+		mappedSensors, ok := mapping[measuredValueTypes[i]]
+		if !ok {
+			return nil, fmt.Errorf("No mapping for measured values type %v available", measuredValueTypes[i])
+		}
+
+	LOOP:
+		for j := range sensors {
+			for k := range mappedSensors {
+				if sensors[j].Model == mappedSensors[k] {
+					cachedSensors = append(cachedSensors, sensors[j])
+					continue LOOP
+				}
+			}
+		}
+	}
+
+	return cachedSensors, nil
+}

pkg/types/sensor_test.go

@@ -0,0 +1,67 @@
+package types_test
+
+import (
+	"testing"
+
+	"git.cryptic.systems/volker.raschek/flucky/pkg/types"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFilterSensorByMeasuredValueTypes(t *testing.T) {
+	require := require.New(t)
+
+	testCases := []struct {
+		sensors            []*types.Sensor
+		expectedSensors    []*types.Sensor
+		measuredValueTypes []types.MeasuredValueType
+	}{
+		{
+			sensors: []*types.Sensor{
+				{ID: "af7f845f-9a79-4638-8005-292754367d33", Model: "BME280"},
+				{ID: "2d2c20e4-2628-4660-9f8c-a301b4e5933b", Model: "DHT11"},
+				{ID: "30e69d52-c0cd-48a7-841a-3918b2ed5941", Model: "DHT22"},
+				{ID: "2d1ecf2e-2dc6-48f6-8158-822cab6e561b", Model: "DS18B20"},
+			},
+			expectedSensors: []*types.Sensor{
+				{ID: "af7f845f-9a79-4638-8005-292754367d33", Model: "BME280"},
+				{ID: "2d2c20e4-2628-4660-9f8c-a301b4e5933b", Model: "DHT11"},
+				{ID: "30e69d52-c0cd-48a7-841a-3918b2ed5941", Model: "DHT22"},
+				{ID: "2d1ecf2e-2dc6-48f6-8158-822cab6e561b", Model: "DS18B20"},
+			},
+			measuredValueTypes: []types.MeasuredValueType{types.Temperature},
+		},
+		{
+			sensors: []*types.Sensor{
+				{ID: "af7f845f-9a79-4638-8005-292754367d33", Model: "BME280"},
+				{ID: "2d2c20e4-2628-4660-9f8c-a301b4e5933b", Model: "DHT11"},
+				{ID: "30e69d52-c0cd-48a7-841a-3918b2ed5941", Model: "DHT22"},
+				{ID: "2d1ecf2e-2dc6-48f6-8158-822cab6e561b", Model: "DS18B20"},
+			},
+			expectedSensors: []*types.Sensor{
+				{ID: "af7f845f-9a79-4638-8005-292754367d33", Model: "BME280"},
+				{ID: "2d2c20e4-2628-4660-9f8c-a301b4e5933b", Model: "DHT11"},
+				{ID: "30e69d52-c0cd-48a7-841a-3918b2ed5941", Model: "DHT22"},
+			},
+			measuredValueTypes: []types.MeasuredValueType{types.Humidity},
+		},
+		{
+			sensors: []*types.Sensor{
+				{ID: "af7f845f-9a79-4638-8005-292754367d33", Model: "BME280"},
+				{ID: "2d2c20e4-2628-4660-9f8c-a301b4e5933b", Model: "DHT11"},
+				{ID: "30e69d52-c0cd-48a7-841a-3918b2ed5941", Model: "DHT22"},
+				{ID: "2d1ecf2e-2dc6-48f6-8158-822cab6e561b", Model: "DS18B20"},
+			},
+			expectedSensors: []*types.Sensor{
+				{ID: "af7f845f-9a79-4638-8005-292754367d33", Model: "BME280"},
+			},
+			measuredValueTypes: []types.MeasuredValueType{types.Pressure},
+		},
+	}
+
+	for i := range testCases {
+		s, err := types.FilterSensorByMeasuredValueTypes(testCases[i].sensors, testCases[i].measuredValueTypes...)
+		require.NoError(err)
+		require.ElementsMatch(testCases[i].expectedSensors, s)
+		require.Equal(len(testCases[i].expectedSensors), len(s))
+	}
+}