Use existing power levels as base for user levels instead of hardcoded values

mautrix_telegram/portal/metadata.py

@@ -503,14 +503,15 @@ class PortalMetadata(BasePortal, ABC):
             levels.users[self.main_intent.mxid] = 100
         return levels
 
-    @staticmethod
-    def _get_level_from_participant(participant: TypeParticipant) -> int:
+    @classmethod
+    def _get_level_from_participant(cls, participant: TypeParticipant,
+                                    levels: PowerLevelStateEventContent) -> int:
         # TODO use the power level requirements to get better precision in channels
         if isinstance(participant, (ChatParticipantAdmin, ChannelParticipantAdmin)):
-            return 50
+            return levels.state_default or 50
         elif isinstance(participant, (ChatParticipantCreator, ChannelParticipantCreator)):
-            return 95
-        return 0
+            return levels.get_user_level(cls.az.bot_mxid) - 5
+        return levels.users_default or 0
 
     @staticmethod
     def _participant_to_power_levels(levels: PowerLevelStateEventContent,
@@ -541,7 +542,7 @@ class PortalMetadata(BasePortal, ABC):
 
             puppet = p.Puppet.get(TelegramID(participant.user_id))
             user = u.User.get_by_tgid(TelegramID(participant.user_id))
-            new_level = self._get_level_from_participant(participant)
+            new_level = self._get_level_from_participant(participant, levels)
 
             if user:
                 await user.register_portal(self)