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/types/measuredValue.go

@@ -8,11 +8,19 @@ import (
 // example from a sensor. It can contains different types, for example humidity
 // or temperature.
 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"`
-	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"`
+	ID           string            `json:"id" xml:"id"`
+	Value        float64           `json:"value,string" xml:"value,string"`
+	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"
+)