enum for event type

lib/models/content/content.dart

@@ -1,4 +1,5 @@
-import "package:nexus/models/content/encrypted.dart";
+import "package:collection/collection.dart";
+import "package:freezed_annotation/freezed_annotation.dart";
 import "package:nexus/models/content/membership.dart";
 import "package:nexus/models/content/message.dart";
 
@@ -8,10 +9,19 @@ class Content {
 
   Map<String, dynamic> toJson() => {};
   static Content fromEventJson(Map<String, dynamic> eventJson) =>
-      switch (eventJson["type"]) {
-        EncryptedContent.type => EncryptedContent.fromJson,
-        MembershipContent.type => MembershipContent.fromJson,
-        MessageContent.type => MessageContent.fromJson,
-        _ => Content.fromJson,
-      }(eventJson);
+      (EventType.values
+          .firstWhereOrNull((eventType) => eventType == eventJson["type"])
+          ?.contentFromJson ??
+      Content.fromJson)(eventJson);
+}
+
+@JsonEnum(valueField: "type")
+enum EventType {
+  encrypted("m.room.encrypted", Content.fromJson),
+  membership("m.room.member", MembershipContent.fromJson),
+  message("m.room.message", MessageContent.fromJson);
+
+  final String type;
+  final Content Function(Map<String, dynamic> json) contentFromJson;
+  const EventType(this.type, this.contentFromJson);
 }

lib/models/content/encrypted.dart

@@ -1,9 +0,0 @@
-import "package:nexus/models/content/content.dart";
-
-class EncryptedContent extends Content {
-  EncryptedContent();
-  factory EncryptedContent.fromJson(Map<String, dynamic> json) =>
-      EncryptedContent();
-
-  static const type = "m.room.encrypted";
-}

lib/models/content/membership.dart

@@ -6,8 +6,6 @@ part "membership.g.dart";
 
 @freezed
 abstract class MembershipContent extends Content with _$MembershipContent {
-  static const type = "m.room.membership";
-
   MembershipContent._();
   const factory MembershipContent({
     @JsonKey(name: "displayname") required String displayName,

lib/models/content/message.dart

@@ -8,8 +8,6 @@ part "message.g.dart";
 
 @Freezed(unionKey: "msgtype", fallbackUnion: "default")
 abstract class MessageContent extends Content with _$MessageContent {
-  static const type = "m.room.message";
-
   MessageContent._();
   const factory MessageContent({
     required String msgtype,