1 files changed, 57 insertions, 0 deletions
diff --git a/duration.go b/duration.go
new file mode 100644
index 0000000..96722c9
--- /dev/null
+++ b/duration.go
@@ -0,0 +1,57 @@
+package cobol
+
+import (
+	"errors"
+	"time"
+
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+func Duration(howLongWasThis any) string {
+	d, err := DurationCheck(howLongWasThis)
+	if errors.Is(err, Broken) {
+		return "bad"
+	}
+	if errors.Is(err, NoTime) {
+		return "nope"
+	}
+	return FormatDuration(d)
+}
+
+func GetDuration(tookForever any) (time.Duration, error) {
+	d, err := DurationCheck(tookForever)
+	return d, err
+}
+
+func DurationCheck(maybeTime any) (time.Duration, error) {
+	var d time.Duration
+	var err error
+
+	switch v := maybeTime.(type) {
+	case time.Time:
+		// If the type is time.Time, 'v' is now a time.Time variable.
+		d = time.Since(v)
+	case string:
+		// The type is string, so 'v' is a string variable.
+		// t, err = doTimeString(v)
+		err = NewFeature
+	case *timestamppb.Timestamp:
+		// If it's a protobuf Timestamp pointer (most common case),
+		// 'v' is a *timestamppb.Timestamp. We must convert it.
+		// It's also good to check if it's a valid timestamp.
+		if v.IsValid() {
+			d = time.Since(v.AsTime())
+		} else {
+			err = errors.New("pb time invalid")
+		}
+
+	case timestamppb.Timestamp:
+		// Handle the less common case of a value type instead of a pointer.
+		if v.IsValid() {
+			d = time.Since(v.AsTime())
+		}
+	default:
+		err = errors.Join(err, NoTime)
+	}
+	return d, err
+}