1 files changed, 59 insertions, 0 deletions
diff --git a/debInfo.go b/debInfo.go
new file mode 100644
index 0000000..98d0439
--- /dev/null
+++ b/debInfo.go
@@ -0,0 +1,59 @@
+package debian
+
+import (
+	"errors"
+	"fmt"
+
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+
+	"go.wit.com/lib/config"
+)
+
+func SetDebInfoString(pb proto.Message, varname string, varvalue string) error {
+	// 1. Get the reflection interface for the top-level message (e.g., Package).
+	msg := pb.ProtoReflect()
+	descriptor := msg.Descriptor()
+
+	// 2. Find the FieldDescriptor for the nested message field (named "debInfo").
+	//    This is the corrected line: call .Fields().ByName().
+	debInfoFieldDescriptor := descriptor.Fields().ByName("debInfo")
+	if debInfoFieldDescriptor == nil {
+		return fmt.Errorf("field 'debInfo' not found in message %s", descriptor.FullName())
+	}
+
+	// 3. From the field descriptor, get the MessageDescriptor for the DebInfo type.
+	//    This gives us the "schema" for the DebInfo message.
+	debInfoMsgDescriptor := debInfoFieldDescriptor.Message()
+	if debInfoMsgDescriptor == nil {
+		// This would happen if the 'debInfo' field was not a message type.
+		// return ErrFieldNotMessage
+		return errors.New("debInfo failed to turn into a message?")
+	}
+
+	// 4. Now, find the FieldDescriptor for the target string field (varname)
+	//    WITHIN the DebInfo message's schema.
+	fieldName := protoreflect.Name(varname)
+	fieldDescriptor := debInfoMsgDescriptor.Fields().ByName(fieldName)
+	if fieldDescriptor == nil {
+		return fmt.Errorf("field '%s' not found in nested message 'debInfo'", varname)
+	}
+
+	// 5. Validate that the target field is a string.
+	if fieldDescriptor.Kind() != protoreflect.StringKind {
+		return config.ErrProtoVarNotString
+	}
+
+	// 6. CRITICAL STEP: Get a mutable reference to the actual nested DebInfo message.
+	//    msg.Mutable() is perfect for this. It will:
+	//    a) Get the existing DebInfo message if it's already been set.
+	//    b) Create a NEW, empty DebInfo message if it's currently nil.
+	//    Then, we get the reflection interface for that nested message.
+	debInfoMsg := msg.Mutable(debInfoFieldDescriptor).Message()
+
+	// 7. Prepare the value and SET it on the nested message.
+	valueToSet := protoreflect.ValueOfString(varvalue)
+	debInfoMsg.Set(fieldDescriptor, valueToSet)
+
+	return nil
+}