Add time.Duration formatter

duration/time.go

@@ -0,0 +1,61 @@
+package duration
+
+import (
+	"bytes"
+	"math"
+	"strings"
+	"text/template"
+	"time"
+
+	"github.com/leekchan/gtf"
+)
+
+const defaultDurationFormat = `{{if gt .Years 0}}{{.Years}} year{{.Years|pluralize "s"}}, {{end}}` +
+	`{{if gt .Days 0}}{{.Days}} day{{.Days|pluralize "s"}}, {{end}}` +
+	`{{if gt .Hours 0}}{{.Hours}} hour{{.Hours|pluralize "s"}}, {{end}}` +
+	`{{if gt .Minutes 0}}{{.Minutes}} minute{{.Minutes|pluralize "s"}}, {{end}}` +
+	`{{if gt .Seconds 0}}{{.Seconds}} second{{.Seconds|pluralize "s"}}{{end}}`
+
+func HumanizeDuration(in time.Duration) string {
+	f, err := CustomHumanizeDuration(in, defaultDurationFormat)
+	if err != nil {
+		panic(err)
+	}
+	return strings.Trim(f, " ,")
+}
+
+func CustomHumanizeDuration(in time.Duration, tpl string) (string, error) {
+	result := struct{ Years, Days, Hours, Minutes, Seconds int64 }{}
+
+	in = time.Duration(math.Abs(float64(in)))
+
+	for in > 0 {
+		switch {
+		case in > 365.25*24*time.Hour:
+			result.Years = int64(in / (365 * 24 * time.Hour))
+			in = in - time.Duration(result.Years)*365*24*time.Hour
+		case in > 24*time.Hour:
+			result.Days = int64(in / (24 * time.Hour))
+			in = in - time.Duration(result.Days)*24*time.Hour
+		case in > time.Hour:
+			result.Hours = int64(in / time.Hour)
+			in = in - time.Duration(result.Hours)*time.Hour
+		case in > time.Minute:
+			result.Minutes = int64(in / time.Minute)
+			in = in - time.Duration(result.Minutes)*time.Minute
+		default:
+			result.Seconds = int64(in / time.Second)
+			in = 0
+		}
+	}
+
+	tmpl, err := template.New("timeformat").Funcs(template.FuncMap(gtf.GtfFuncMap)).Parse(tpl)
+	if err != nil {
+		return "", err
+	}
+
+	buf := bytes.NewBuffer([]byte{})
+	tmpl.Execute(buf, result)
+
+	return buf.String(), nil
+}

duration/time_test.go

@@ -0,0 +1,35 @@
+package duration
+
+import (
+	"testing"
+	"time"
+)
+
+func TestCustomFormat(t *testing.T) {
+	d := 389*24*time.Hour +
+		12*time.Hour +
+		31*time.Minute +
+		54*time.Second +
+		346*time.Millisecond
+
+	f := `{{.Years}} - {{.Days}} - {{.Hours}} - {{.Minutes}} - {{.Seconds}}`
+	e := `1 - 24 - 12 - 31 - 54`
+
+	if s, _ := CustomHumanizeDuration(d, f); s != e {
+		t.Errorf("Got unexpected result: expected=%q result=%q", e, s)
+	}
+}
+
+func TestDefaultFormat(t *testing.T) {
+	d := 389*24*time.Hour +
+		12*time.Hour +
+		31*time.Minute +
+		54*time.Second +
+		346*time.Millisecond
+
+	e := `1 year, 24 days, 12 hours, 31 minutes, 54 seconds`
+
+	if s := HumanizeDuration(d); s != e {
+		t.Errorf("Got unexpected result: expected=%q result=%q", e, s)
+	}
+}