Move ERType to Entrance.Type, fix typing imports

BaseClasses.py

@@ -17,7 +17,9 @@
 import NetUtils
 import Options
 import Utils
-from EntranceRando import ERType, ERPlacementState
+
+if typing.TYPE_CHECKING:
+    from EntranceRando import ERPlacementState
 
 
 class Group(TypedDict, total=False):
@@ -767,6 +769,9 @@ def remove(self, item: Item):
 
 
 class Entrance:
+    class Type(IntEnum):
+        ONE_WAY = 1
+        TWO_WAY = 2
 
     access_rule: Callable[[CollectionState], bool] = staticmethod(lambda state: True)
     hide_path: bool = False
@@ -775,13 +780,13 @@ class Entrance:
     parent_region: Optional[Region]
     connected_region: Optional[Region] = None
     er_group: str
-    er_type: ERType
+    er_type: Type
     # LttP specific, TODO: should make a LttPEntrance
     addresses = None
     target = None
 
     def __init__(self, player: int, name: str = '', parent: Region = None,
-                 er_group: str = 'Default', er_type: ERType = ERType.ONE_WAY):
+                 er_group: str = 'Default', er_type: Type = Type.ONE_WAY):
         self.name = name
         self.parent_region = parent
         self.player = player

EntranceRando.py

@@ -1,19 +1,12 @@
 import functools
 import queue
 import random
-from dataclasses import dataclass
-from enum import IntEnum
 from typing import Set, Tuple, List, Dict, Iterable, Callable, Union
 
 from BaseClasses import Region, Entrance, CollectionState
 from worlds.AutoWorld import World
 
 
-class ERType(IntEnum):
-    ONE_WAY = 1
-    TWO_WAY = 2
-
-
 class EntranceLookup:
     class GroupLookup:
         _lookup: Dict[str, List[Entrance]]
@@ -44,6 +37,7 @@ def __init__(self, rng: random.Random):
         self.dead_ends = EntranceLookup.GroupLookup()
         self.others = EntranceLookup.GroupLookup()
 
+    # todo - investigate whether this might leak memory (holds references to Entrances)?
     @staticmethod
     @functools.cache
     def _is_dead_end(entrance: Entrance):
@@ -192,7 +186,7 @@ def connect(self, source_exit: Entrance, target_entrance: Entrance) -> Iterable[
 
         self._connect_one_way(source_exit, target_entrance)
         # if we're doing coupled randomization place the reverse transition as well.
-        if self.coupled and source_exit.er_type == ERType.TWO_WAY:
+        if self.coupled and source_exit.er_type == Entrance.Type.TWO_WAY:
             # todo - better exceptions here
             for reverse_entrance in source_region.entrances:
                 if reverse_entrance.name == source_exit.name: