feat: Implement event service

src/viur/shop/modules/order.py

@@ -4,13 +4,12 @@
 
 from viur.core import current, db, errors as core_errors, exposed, force_post
 from viur.core.prototypes import List
-
 from .abstract import ShopModuleAbstract
 from .. import ClientError, exceptions as e
 from ..constants import AddressType
 from ..payment_providers import PaymentProviderAbstract
 from ..response_types import JsonResponse
-from ..services.hooks import Kind, hook_service
+from ..services import EVENT_SERVICE, Event, HOOK_SERVICE, Hook
 from ..skeletons.order import get_payment_providers
 
 if t.TYPE_CHECKING:
@@ -160,6 +159,7 @@ def checkout_start(
 
         order_skel = self.freeze_order(order_skel)
         order_skel.toDB()
+        EVENT_SERVICE.call(Event.ORDER_STARTED, order_skel=order_skel)
         return JsonResponse({
             "skel": order_skel,
             "payment": self.get_payment_provider_by_name(order_skel["payment_provider"]).get_checkout_start_data(
@@ -252,13 +252,15 @@ def checkout_order(
             }, status_code=400)
             raise e.InvalidStateError(", ".join(error_))
 
-        order_skel = hook_service.dispatch(Kind.ORDER_ASSIGN_UID, self.assign_uid)(order_skel)
-        order_skel["is_ordered"] = True
+        order_skel = HOOK_SERVICE.dispatch(Hook.ORDER_ASSIGN_UID, self.assign_uid)(order_skel)
+        # order_skel["is_ordered"] = True
         # TODO: call hooks
         # TODO: charge order if it should directly be charged
         pp_res = self.get_payment_provider_by_name(order_skel["payment_provider"]).checkout(order_skel)
         # TODO: write in transaction
-        order_skel.toDB()
+        # order_skel.toDB()
+        order_skel = self.set_ordered(order_skel, pp_res)
+        # EVENT_SERVICE.call(Event.ORDER_ORDERED, order_skel=order_skel, payment=pp_res)
         return JsonResponse({
             "skel": order_skel,
             "payment": pp_res,
@@ -285,6 +287,18 @@ def can_order(
         # TODO: ...
         return errors
 
+    def set_ordered(self, order_skel: "SkeletonInstance", payment: t.Any) -> "SkeletonInstance":
+        order_skel["is_ordered"] = True  # TODO: transaction
+        order_skel.toDB()
+        EVENT_SERVICE.call(Event.ORDER_ORDERED, order_skel=order_skel, payment=payment)
+        return order_skel
+
+    def set_paid(self, order_skel: "SkeletonInstance") -> "SkeletonInstance":
+        order_skel["is_paid"] = True  # TODO: transaction
+        order_skel.toDB()
+        EVENT_SERVICE.call(Event.ORDER_PAID, order_skel=order_skel)
+        return order_skel
+
     # --- Internal helpers  ----------------------------------------------------
     def get_payment_provider_by_name(
         self,

src/viur/shop/payment_providers/unzer_abstract.py

@@ -153,8 +153,9 @@ def return_handler(
             logger.info(f'Order {order_skel["key"]} already marked as paid. Nothing to do.')
         elif is_paid:
             logger.info(f'Mark order {order_skel["key"]} as paid')
-            order_skel["is_paid"] = True  # TODO: transaction
-            order_skel.toDB()
+            self.shop.order.set_paid(order_skel)
+            # order_skel["is_paid"] = True  # TODO: transaction
+            # order_skel.toDB()
         else:
             raise errors.NotImplemented("Order not paid")
         return "OKAY, paid"

src/viur/shop/services/__init__.py

@@ -0,0 +1,10 @@
+from .events import EVENT_SERVICE, Event, EventService, on_event
+from .hooks import HOOK_SERVICE, Hook
+
+__all__ = [
+    "EVENT_SERVICE",
+    "Event",
+    "on_event",
+    "HOOK_SERVICE",
+    "Hook",
+]

src/viur/shop/services/events.py

@@ -0,0 +1,58 @@
+import collections
+import enum
+import logging
+import typing as t
+
+logger = logging.getLogger("viur.shop").getChild(__name__)
+
+
+class Event(enum.IntEnum):
+    ORDER_STARTED = enum.auto()
+    ORDER_ORDERED = enum.auto()
+    ORDER_PAID = enum.auto()
+
+
+class EventService:
+    observer: t.Final[dict[[Event, list[t.Callable]]]] = collections.defaultdict(list)
+
+    def register(self, event: Event, func: t.Callable) -> t.Callable:
+        if not isinstance(event, Event):
+            raise TypeError(f"event must be of type Event")
+        EventService.observer[event].append(func)
+        return func
+
+    def unregister(self, func: t.Callable, event: Event = None) -> None:
+        for event_, funcs in EventService.observer:
+            if event is None or event_ == Event:
+                try:
+                    funcs.pop(func, )
+                except ValueError:
+                    pass
+
+    def call(
+        self,
+        _event: Event,
+        _raise_errors: bool = False,
+        *args, **kwargs
+    ) -> None:
+        for func in EventService.observer[_event]:
+            try:
+                func(*args, **kwargs)
+            except Exception as e:
+                logger.exception(f"Error while calling {func} at event {_event}: {e}")
+                if _raise_errors:
+                    raise e
+
+
+EVENT_SERVICE = EventService()
+
+
+def on_event(event: Event) -> t.Callable:
+    if not isinstance(event, Event):
+        raise TypeError
+
+    def outer_wrapper(func: t.Callable) -> t.Callable:
+        EVENT_SERVICE.register(event, func)
+        return func
+
+    return outer_wrapper

src/viur/shop/services/hooks.py

@@ -6,14 +6,14 @@
 logger = logging.getLogger("viur.shop").getChild(__name__)
 
 
-class Kind(enum.IntEnum):
+class Hook(enum.IntEnum):
     ORDER_ASSIGN_UID = enum.auto()
 
 
 class Customization(abc.ABC):
     @property
     @abc.abstractmethod
-    def kind(self) -> Kind:
+    def kind(self) -> Hook:
         ...
 
     @abc.abstractmethod
@@ -24,7 +24,7 @@ def __repr__(self) -> str:
         return f"<Customization {self.__class__.__name__} for {self.kind.name}>"
 
     @classmethod
-    def from_method(cls, func: t.Callable, kind: Kind) -> t.Self:
+    def from_method(cls, func: t.Callable, kind: Hook) -> t.Self:
         return type(
             f"{kind}_{func.__name__}{cls.__name__}",
             (cls,),
@@ -57,4 +57,4 @@ def dispatch(self, kind: Customization, default: t.Callable = None):
         return default
 
 
-hook_service = HookService()
+HOOK_SERVICE = HookService()

src/viur/shop/shop.py

@@ -9,7 +9,7 @@
 from viur.core.prototypes.instanced_module import InstancedModule
 from viur.core.skeleton import MetaSkel, Skeleton, skeletonByKind
 
-from .services.hooks import hook_service
+from .services.hooks import HOOK_SERVICE
 from .types import Supplier
 from .modules import Address, Api, Cart, Discount, DiscountCondition, Order, Shipping, ShippingConfig, Vat
 from .payment_providers import PaymentProviderAbstract
@@ -38,7 +38,7 @@ def __init__(
         *args, **kwargs,
     ):
         super().__init__()
-        self.hooks = hook_service
+        self.hooks = HOOK_SERVICE
 
         # Store arguments
         self.name: str = name