Tidy up interfaces and pretty printing

usbid/describe.go

@@ -0,0 +1,48 @@
+package usbid
+
+import (
+	"fmt"
+
+	"github.com/kylelemons/gousb/usb"
+)
+
+// Describe one of the following:
+//   - *usb.Descriptor       Product (Vendor)
+func Describe(val interface{}) string {
+	switch val := val.(type) {
+	case *usb.Descriptor:
+		if v, ok := Vendors[val.Vendor]; ok {
+			if d, ok := v.Product[val.Product]; ok {
+				return fmt.Sprintf("%s (%s)", d, v)
+			}
+			return fmt.Sprintf("Unknown (%s)", v)
+		}
+		return fmt.Sprintf("Unknown %s:%s", val.Vendor, val.Product)
+	}
+	return fmt.Sprintf("Unknown (%T)", val)
+}
+
+// Classify one of the following:
+//   - *usb.Descriptor       Class SubClass Protocol
+func Classify(val interface{}) string {
+	var class, sub, proto uint8
+	switch val := val.(type) {
+	case *usb.Descriptor:
+		class, sub, proto = val.Class, val.SubClass, val.Protocol
+	case *usb.Interface:
+		class, sub, proto = val.IfClass, val.IfSubClass, val.IfProtocol
+	default:
+		return fmt.Sprintf("Unknown (%T)", val)
+	}
+
+	if c, ok := Classes[class]; ok {
+		if s, ok := c.SubClass[sub]; ok {
+			if p, ok := s.Protocol[proto]; ok {
+				return fmt.Sprintf("%s (%s) %s", c, s, p)
+			}
+			return fmt.Sprintf("%s (%s)", c, s)
+		}
+		return fmt.Sprintf("%s", c)
+	}
+	return fmt.Sprintf("Unknown %s.%s.%s", class, sub, proto)
+}