fix channels serializer

apps/api/serializers.py

@@ -171,18 +171,15 @@ class UniqueContentRuleSerializer(DynamicModelSerializer):
         fields = ("id", "name", "value")
 
 
-class DiscordChannelSerializer(DynamicModelSerializer):
-    class Meta:
-        model = DiscordChannel
-        fields = ("id", "channel_id")
-
-
 class SubscriptionSerializer(DynamicModelSerializer):
     filters = serializers.PrimaryKeyRelatedField(
         queryset=ContentFilter.objects.all(),
         many=True
     )
-    channels = DiscordChannelSerializer(many=True)
+    channels = serializers.PrimaryKeyRelatedField(
+        queryset=DiscordChannel.objects.all(),
+        many=True
+    )
     #  unique_rules = UniqueContentRuleSerializer(many=True)  # TODO: solve? causes issues with submission.
 
     class Meta:
@@ -203,22 +200,6 @@ class SubscriptionSerializer(DynamicModelSerializer):
             "unique_rules"
         )
 
-    def _delete_unused_channels(self):
-        referenced_channel_ids = set(Subscription.objects.values_list("channels__channel_id", flat=True))
-        del_count, _ = DiscordChannel.objects.exclude(channel_id__in=referenced_channel_ids).delete()
-        log.info("Deleted %s unreferenced DiscordChannel object(s).", del_count)
-
-    def update(self, instance, validated_data):
-        channels = validated_data.pop("channels")
-
-        instance.channels.clear()
-        for channel_id in channels:
-            channel, created = DiscordChannel.objects.get_or_create(channel_id=channel_id)
-            instance.channels.add(channel)
-
-        self._delete_unused_channels()
-        return super().update(instance, validated_data)
-
     def validate(self, data):
         server = data.get("server") or self.context.get("server")
         if not server: