merge backend refactoring from main

1 files changed, 60 insertions, 0 deletions

diff --git a/temperature.go b/temperature.go
new file mode 100644
index 0000000..ac8cae0
--- /dev/null
+++ b/temperature.go
@@ -0,0 +1,60 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+)
+
+type TemperatureUnit int
+
+const (
+	Celcius TemperatureUnit = iota
+	Kelvin
+	Fahrenheit
+)
+
+var TemperatureUnits = []string{"°C", "°K", "°F"}
+
+func ParseTemperatureUnit(s string) (TemperatureUnit, error) {
+	// Each case corresponds to a value in UnitStrings().
+	switch s {
+	case "°C":
+		return Celcius, nil
+	case "°K":
+		return Kelvin, nil
+	case "°F":
+		return Fahrenheit, nil
+	default:
+		return *new(TemperatureUnit), errors.New(fmt.Sprintf("invalid unit: '%s'", s))
+	}
+}
+
+type Temperature struct {
+	Val  float32
+	Unit TemperatureUnit
+}
+
+func (t Temperature) AsUnit(u TemperatureUnit) (float32, error) {
+	// Convert to celcius
+	var c float32
+	switch t.Unit {
+	case Celcius:
+		c = t.Val
+	case Kelvin:
+		c = t.Val - 272.15
+	case Fahrenheit:
+		c = (t.Val - 32.0) * (5.0 / 9.0)
+	}
+
+	// Convert to desired unit
+	switch u {
+	case Celcius:
+		return c, nil
+	case Kelvin:
+		return c + 272.15, nil
+	case Fahrenheit:
+		return c*(9.0/5.0) + 32.0, nil
+	default:
+		return 0, errors.New(fmt.Sprintf("invalid unit: '%v'", u))
+	}
+}