1 files changed, 59 insertions, 0 deletions
diff --git a/internal/service/time.go b/internal/service/time.go
new file mode 100644
index 0000000..b275b82
--- /dev/null
+++ b/internal/service/time.go
@@ -0,0 +1,59 @@
+package service
+
+import (
+	"math/rand"
+	"time"
+)
+
+type Duration struct {
+	time.Duration
+}
+
+func DurationRef(v time.Duration) *Duration {
+	return &Duration{v}
+}
+
+func (s Duration) MarshalText() ([]byte, error) {
+	return []byte(s.Duration.String()), nil
+}
+
+func (s *Duration) Max(args ...*Duration) Duration {
+	m := s
+
+	for _, o := range args {
+		if m.Duration < o.Duration {
+			v := o
+			m = v
+		}
+	}
+
+	return *m
+}
+
+func (s *Duration) Min(args ...*Duration) Duration {
+	m := s
+
+	for _, o := range args {
+		if m.Duration > o.Duration {
+			v := o
+			m = v
+		}
+	}
+
+	return *m
+}
+
+func (s *Duration) UnmarshalText(text []byte) error {
+	v, err := time.ParseDuration(string(text))
+	if err != nil {
+		return err
+	}
+	*s = Duration{v}
+
+	return nil
+}
+
+func RandomDuration(from Duration, until Duration) Duration {
+	period := until.Duration - from.Duration
+	return Duration{from.Duration + time.Duration(rand.Intn(int(period)))}
+}