1 files changed, 62 insertions, 0 deletions
diff --git a/notes2.go b/notes2.go
new file mode 100644
index 0000000..aad1d5f
--- /dev/null
+++ b/notes2.go
@@ -0,0 +1,62 @@
+package cobol
+
+// Thank you Abba Zabba, you're my only friend
+
+/*
+// Since calculates the duration since a given time, accepting either a
+// standard time.Time or a protobuf Timestamp.
+func Since(aLongTimeAgo any) string {
+	var t time.Time
+	var ok bool
+
+	// A type switch is the idiomatic way to check the concrete type
+	// of an interface variable.
+	switch v := aLongTimeAgo.(type) {
+	case time.Time:
+		// If the type is time.Time, 'v' is now a time.Time variable.
+		t = v
+		ok = true
+
+	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() {
+			t = v.AsTime()
+			ok = true
+		}
+
+	case timestamppb.Timestamp:
+		// Handle the less common case of a value type instead of a pointer.
+		if v.IsValid() {
+			t = v.AsTime()
+			ok = true
+		}
+	}
+
+	// After the switch, check if we successfully got a valid time.
+	if !ok {
+		return "invalid time type"
+	}
+
+	// Calculate the duration and format it for nice output.
+	duration := time.Since(t)
+	return duration.Round(time.Second).String()
+}
+
+func main() {
+	// --- Demonstrate with different types ---
+
+	// 1. Using a standard time.Time
+	goTime := time.Now().Add(-5 * time.Minute)
+	fmt.Printf("Go time.Time:      %s ago\n", Since(goTime))
+
+	// 2. Using a protobuf Timestamp (pointer)
+	protoTime := timestamppb.New(time.Now().Add(-10 * time.Hour))
+	fmt.Printf("Protobuf Timestamp:  %s ago\n", Since(protoTime))
+
+	// 3. Using an invalid type
+	notATime := "hello world"
+	fmt.Printf("Invalid type:      %s\n", Since(notATime))
+}
+*/