Initial MVP commit

internal/application/units/converter.go

@@ -0,0 +1,35 @@
+package units
+
+import (
+	"math"
+
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/platform/constants"
+)
+
+type Converter interface {
+	TemperatureCToOutput(celsius *float64) *float64
+	SpeedKmhToOutput(kmh *float64) *float64
+}
+
+type USConverter struct{}
+
+func (USConverter) TemperatureCToOutput(celsius *float64) *float64 {
+	if celsius == nil {
+		return nil
+	}
+	f := round(constants.CelsiusToFahrenheit(*celsius), constants.TempFahrenheitPrecision)
+	return &f
+}
+
+func (USConverter) SpeedKmhToOutput(kmh *float64) *float64 {
+	if kmh == nil {
+		return nil
+	}
+	mph := round(constants.KmhToMph(*kmh), constants.WindMphPrecision)
+	return &mph
+}
+
+func round(v float64, precision int) float64 {
+	pow := math.Pow(10, float64(precision))
+	return math.Round(v*pow) / pow
+}