messagebus becomes a class, requires handlers [messagebus_as_class]

Author: hjwp

src/allocation/service_layer/messagebus.py

@@ -1,9 +1,8 @@
 # pylint: disable=broad-except
 from __future__ import annotations
 import logging
-from typing import Union, TYPE_CHECKING
+from typing import Callable, Dict, List, Union, Type, TYPE_CHECKING
 from allocation.domain import commands, events
-from . import handlers
 
 if TYPE_CHECKING:
     from . import unit_of_work
@@ -13,16 +12,27 @@
 Message = Union[commands.Command, events.Event]
 
 
-def handle(message: Message, uow: unit_of_work.AbstractUnitOfWork):
-    queue = [message]
-    while queue:
-        message = queue.pop(0)
-        if isinstance(message, events.Event):
-            handle_event(message, queue, uow)
-        elif isinstance(message, commands.Command):
-            handle_command(message, queue, uow)
-        else:
-            raise Exception(f"{message} was not an Event or Command")
+class MessageBus:
+    def __init__(
+        self,
+        uow: unit_of_work.AbstractUnitOfWork,
+        event_handlers: Dict[Type[events.Event], List[Callable]],
+        command_handlers: Dict[Type[commands.Command], Callable],
+    ):
+        self.uow = uow
+        self.event_handlers = event_handlers
+        self.command_handlers = command_handlers
+
+    def handle(self, message: Message):
+        self.queue = [message]
+        while self.queue:
+            message = self.queue.pop(0)
+            if isinstance(message, events.Event):
+                self.handle_event(message)
+            elif isinstance(message, commands.Command):
+                self.handle_command(message)
+            else:
+                raise Exception(f"{message} was not an Event or Command")
 
 
 def handle_event(