[D2C-45] 주문/결제 상태 이벤트 로그 발생 로직 구현

apps/api/backend/services/cart_item_service.py

@@ -9,13 +9,16 @@
     CartItemCreateRequest, 
     CartItemQuantityUpdateRequest,
 )
+from backend.services.event_log_service import record_domain_event_safely
+
 
 MAX_CART_ITEM_QUANTITY = 99
 
 def add_item_to_cart(cart_id: UUID, payload: CartItemCreateRequest) -> dict[str, Any]:
     cart_query = text("""
         SELECT
             cart_id,
+            user_id,
             cart_status
         FROM carts
         WHERE cart_id = :cart_id
@@ -157,6 +160,24 @@ def add_item_to_cart(cart_id: UUID, payload: CartItemCreateRequest) -> dict[str,
                     status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
                     detail="Failed to update cart item",
                 )
+
+            record_domain_event_safely(
+                event_name="cart_item_quantity_changed",
+                user_id=cart["user_id"],
+                entity_type="cart",
+                entity_id=updated_item["cart_id"],
+                properties={
+                    "cart_id": updated_item["cart_id"],
+                    "cart_item_id": updated_item["cart_item_id"],
+                    "product_id": updated_item["product_id"],
+                    "previous_quantity": existing_item["quantity"],
+                    "next_quantity": updated_item["quantity"],
+                    "quantity_delta": payload.quantity,
+                    "unit_price": updated_item["unit_price"],
+                    "currency": updated_item["currency"],
+                    "change_source": "add_item_to_cart",
+                },
+            )
 
             return {
                 "cart_item_id": updated_item["cart_item_id"],
@@ -185,6 +206,21 @@ def add_item_to_cart(cart_id: UUID, payload: CartItemCreateRequest) -> dict[str,
                 status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
                 detail="Failed to add item to cart",
             )
+
+        record_domain_event_safely(
+            event_name="cart_item_added",
+            user_id=cart["user_id"],
+            entity_type="cart",
+            entity_id=created_item["cart_id"],
+            properties={
+                "cart_id": created_item["cart_id"],
+                "cart_item_id": created_item["cart_item_id"],
+                "product_id": created_item["product_id"],
+                "quantity": created_item["quantity"],
+                "unit_price": created_item["unit_price"],
+                "currency": created_item["currency"],
+            },
+        )
 
         return {
             "cart_item_id": created_item["cart_item_id"],
@@ -201,7 +237,8 @@ def add_item_to_cart(cart_id: UUID, payload: CartItemCreateRequest) -> dict[str,
 def remove_item_from_cart(cart_id: UUID, cart_item_id: UUID) -> dict[str, Any]:
     cart_query = text("""
         SELECT
-            cart_id
+            cart_id,
+            user_id
         FROM carts
         WHERE cart_id = :cart_id
           AND cart_status = 'active'
@@ -214,7 +251,11 @@ def remove_item_from_cart(cart_id: UUID, cart_item_id: UUID) -> dict[str, Any]:
           AND cart_id = :cart_id
         RETURNING
             cart_item_id,
-            cart_id
+            cart_id,
+            product_id,
+            quantity,
+            unit_price,
+            currency
     """)
 
     with engine.begin() as connection:
@@ -242,6 +283,21 @@ def remove_item_from_cart(cart_id: UUID, cart_item_id: UUID) -> dict[str, Any]:
                 status_code=status.HTTP_404_NOT_FOUND,
                 detail="Cart item not found",
             )
+
+        record_domain_event_safely(
+            event_name="cart_item_removed",
+            user_id=cart["user_id"],
+            entity_type="cart",
+            entity_id=deleted_item["cart_id"],
+            properties={
+                "cart_id": deleted_item["cart_id"],
+                "cart_item_id": deleted_item["cart_item_id"],
+                "product_id": deleted_item["product_id"],
+                "quantity": deleted_item["quantity"],
+                "unit_price": deleted_item["unit_price"],
+                "currency": deleted_item["currency"],
+            },
+        )
 
         return {
             "cart_item_id": deleted_item["cart_item_id"],
@@ -257,6 +313,7 @@ def update_cart_item_quantity(
     cart_query = text("""
         SELECT
             cart_id,
+            user_id,
             cart_status
         FROM carts
         WHERE cart_id = :cart_id
@@ -269,6 +326,7 @@ def update_cart_item_quantity(
             cart_item_id,
             cart_id,
             product_id,
+            quantity,
             unit_price,
             currency
         FROM cart_items
@@ -335,6 +393,23 @@ def update_cart_item_quantity(
                 status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
                 detail="Failed to update cart item quantity",
             )
+
+    record_domain_event_safely(
+        event_name="cart_item_quantity_changed",
+        user_id=cart["user_id"],
+        entity_type="cart",
+        entity_id=updated_item["cart_id"],
+        properties={
+            "cart_id": updated_item["cart_id"],
+            "cart_item_id": updated_item["cart_item_id"],
+            "product_id": updated_item["product_id"],
+            "previous_quantity": item["quantity"],
+            "next_quantity": updated_item["quantity"],
+            "unit_price": updated_item["unit_price"],
+            "currency": updated_item["currency"],
+            "change_source": "update_cart_item_quantity",
+        },
+    )
 
     return {
         "cart_item_id": updated_item["cart_item_id"],

apps/api/backend/services/cart_service.py

@@ -7,6 +7,7 @@
 
 from backend.db.connection import engine
 from backend.schemas.cart import CartCreateRequest
+from backend.services.event_log_service import record_domain_event_safely
 
 
 def create_or_get_active_cart(payload: CartCreateRequest) -> dict[str, Any]:
@@ -49,42 +50,52 @@ def create_or_get_active_cart(payload: CartCreateRequest) -> dict[str, Any]:
             checked_out_at
     """)
 
+    is_created = False
+
     with engine.begin() as connection:
         existing = connection.execute(
             select_query,
             {"user_id": payload.user_id},
         ).mappings().first()
 
         if existing is not None:
-            return {
-                "cart_id": existing["cart_id"],
-                "user_id": existing["user_id"],
-                "cart_status": existing["cart_status"],
-                "created_at": existing["created_at"],
-                "updated_at": existing["updated_at"],
-                "checked_out_at": existing["checked_out_at"],
-            }
-
-        created = connection.execute(
-            insert_query,
-            {"user_id": payload.user_id},
-        ).mappings().first()
-
-        if created is None:
-            raise HTTPException(
-                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
-                detail="Failed to create cart",
-            )
-
-        return {
-            "cart_id": created["cart_id"],
-            "user_id": created["user_id"],
-            "cart_status": created["cart_status"],
-            "created_at": created["created_at"],
-            "updated_at": created["updated_at"],
-            "checked_out_at": created["checked_out_at"],
-        }
+            cart = existing
+        else:
+            created = connection.execute(
+                insert_query,
+                {"user_id": payload.user_id},
+            ).mappings().first()
+
+            if created is None:
+                raise HTTPException(
+                    status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+                    detail="Failed to create cart",
+                )
+
+            cart = created
+            is_created = True
+
+    if is_created:
+        record_domain_event_safely(
+            event_name="cart_created",
+            user_id=cart["user_id"],
+            entity_type="cart",
+            entity_id=cart["cart_id"],
+            properties={
+                "cart_id": cart["cart_id"],
+                "cart_status": cart["cart_status"],
+                "created_at": cart["created_at"],
+            },
+        )
 
+    return {
+        "cart_id": cart["cart_id"],
+        "user_id": cart["user_id"],
+        "cart_status": cart["cart_status"],
+        "created_at": cart["created_at"],
+        "updated_at": cart["updated_at"],
+        "checked_out_at": cart["checked_out_at"],
+    }
 
 def get_cart_detail(cart_id: UUID) -> dict[str, Any]:
     cart_query = text("""

apps/api/backend/services/coupon_service.py

@@ -1,3 +1,4 @@
+import logging
 from decimal import Decimal, ROUND_HALF_UP
 from typing import Any
 from uuid import UUID
@@ -7,8 +8,34 @@
 
 from backend.db.connection import engine
 from backend.schemas.coupon_apply import CouponApplyRequest
+from backend.services.event_log_service import record_event
 
 
+logger = logging.getLogger(__name__)
+
+
+def record_domain_event_safely(
+    *,
+    event_name: str,
+    user_id: UUID | None,
+    entity_type: str | None,
+    entity_id: UUID | None,
+    properties: dict[str, Any],
+) -> None:
+    try:
+        record_event(
+            event_name=event_name,
+            event_type="domain_event",
+            source="backend",
+            user_id=user_id,
+            session_id=None,
+            entity_type=entity_type,
+            entity_id=entity_id,
+            properties=properties,
+        )
+    except Exception:  # pylint: disable=broad-exception-caught
+        logger.exception("Failed to record domain event: %s", event_name)
+
 def apply_coupon_to_cart(cart_id: UUID, payload: CouponApplyRequest) -> dict[str, Any]:
     cart_query = text("""
         SELECT
@@ -136,6 +163,25 @@ def apply_coupon_to_cart(cart_id: UUID, payload: CouponApplyRequest) -> dict[str
 
     final_amount = total_amount - discount_amount
 
+    record_domain_event_safely(
+        event_name="coupon_applied",
+        user_id=cart["user_id"],
+        entity_type="coupon",
+        entity_id=coupon["coupon_id"],
+        properties={
+            "cart_id": cart_id,
+            "coupon_id": coupon["coupon_id"],
+            "coupon_name": coupon["coupon_name"],
+            "coupon_type": coupon["coupon_type"],
+            "discount_value": discount_value,
+            "minimum_order_amount": minimum_order_amount,
+            "total_amount": total_amount,
+            "discount_amount": discount_amount,
+            "final_amount": final_amount,
+            "currency": currency,
+        },
+    )
+
     return {
         "cart_id": cart_id,
         "coupon": {

apps/api/backend/services/event_log_service.py

@@ -1,4 +1,5 @@
 import json
+import logging
 from typing import Any
 from uuid import UUID, uuid4
 
@@ -11,6 +12,7 @@
 
 ALLOWED_EVENT_TYPES = {"user_behavior", "domain_event", "system_event"}
 ALLOWED_SOURCES = {"frontend", "backend", "script"}
+logger = logging.getLogger(__name__)
 
 
 def record_event(
@@ -108,6 +110,29 @@ def record_event(
     }
 
 
+def record_domain_event_safely(
+    *,
+    event_name: str,
+    user_id: UUID | None,
+    entity_type: str | None,
+    entity_id: UUID | None,
+    properties: dict[str, Any],
+) -> None:
+    try:
+        record_event(
+            event_name=event_name,
+            event_type="domain_event",
+            source="backend",
+            user_id=user_id,
+            session_id=None,
+            entity_type=entity_type,
+            entity_id=entity_id,
+            properties=properties,
+        )
+    except Exception:  # pylint: disable=broad-exception-caught
+        logger.exception("Failed to record domain event: %s", event_name)
+
+
 def create_event_log(payload: EventLogCreateRequest) -> dict[str, Any]:
     return record_event(
         event_name=payload.event_name,