added MessageType enum and concreteType to Message (#39)

lib/src/message.dart

@@ -5,30 +5,32 @@ import 'package:nostr/nostr.dart';
 // Used to deserialize any kind of message that a nostr client or relay can transmit.
 class Message {
  late String type;
+ late MessageType concreteType;
  late dynamic message;
 
 // nostr message deserializer
  Message.deserialize(String payload) {
  dynamic data = jsonDecode(payload);
- var messages = ["EVENT", "REQ", "CLOSE", "NOTICE", "EOSE", "OK", "AUTH"];
- if (messages.contains(data[0]) == false) {
+ if (MessageType.values.map<String>((e) => e.rawType).contains(data[0]) ==
+   false) {
  throw 'Unsupported payload (or NIP)';
  }
 
  type = data[0];
- switch (type) {
- case "EVENT":
+ concreteType = MessageType.byRawType(data[0]);
+ switch (concreteType) {
+ case MessageType.event:
  message = Event.deserialize(data);
  // ignore: deprecated_member_use_from_same_package
  if (message.kind == 4) message = EncryptedDirectMessage(message);
  break;
- case "OK":
+ case MessageType.ok:
  message = Nip20.deserialize(data);
  break;
- case "REQ":
+ case MessageType.req:
  message = Request.deserialize(data);
  break;
- case "CLOSE":
+ case MessageType.close:
  message = Close.deserialize(data);
  break;
  default:
@@ -37,3 +39,19 @@ class Message {
  }
  }
 }
+
+enum MessageType {
+ event("EVENT"),
+ req("REQ"),
+ close("CLOSE"),
+ notice("NOTICE"),
+ eose("EOSE"),
+ ok("OK"),
+ auth("AUTH");
+
+ const MessageType(this.rawType);
+ final String rawType;
+ static MessageType byRawType(String name) {
+ return MessageType.values.byName(name.toLowerCase());
+ }
+}