sync(receiptwitness): copy latest standalone code to monorepo

Syncs receiptwitness standalone repo code into monorepo subdirectory.
Includes email parsing, notifications, queue, and worker modules.
Keeps monorepo Dockerfile (uses local common/).

Co-Authored-By: Paperclip <noreply@paperclip.ing>

receiptwitness/src/receiptwitness/events.py

@@ -2,12 +2,17 @@
 
 import json
 import logging
+import uuid
 from datetime import UTC, datetime
 from decimal import Decimal
 
 import redis.asyncio as aioredis
+from cartsnitch_common.database import get_async_session_factory
+from cartsnitch_common.models.user import User
+from sqlalchemy import select
 
 from receiptwitness.config import settings
+from receiptwitness.notifications.email import send_receipt_notification
 
 logger = logging.getLogger(__name__)
 
@@ -39,6 +44,36 @@ async def get_redis_client() -> aioredis.Redis:
     return aioredis.Redis(connection_pool=_get_pool())
 
 
+async def _send_notification_for_event(payload: dict) -> None:
+    """Look up user email and send receipt notification. Silently skips on error."""
+    try:
+        user_uuid = uuid.UUID(payload["user_id"])
+    except (ValueError, KeyError):
+        logger.warning("Invalid user_id in event payload: %s", payload.get("user_id"))
+        return
+
+    try:
+        session_factory = get_async_session_factory(settings.database_url)
+        async with session_factory() as session:
+            result = await session.execute(select(User.email).where(User.id == user_uuid))
+            row = result.scalar_one_or_none()
+            if not row:
+                logger.warning("User %s not found for notification", user_uuid)
+                return
+            user_email = row
+    except Exception:
+        logger.exception("Failed to look up user email for notification")
+        return
+
+    await send_receipt_notification(
+        user_email=user_email,
+        store_name=payload["store_slug"],
+        item_count=payload["item_count"],
+        total=payload["total"],
+        purchase_date=payload["purchase_date"],
+    )
+
+
 async def publish_receipt_ingested(
     user_id: str,
     store_slug: str,
@@ -48,18 +83,19 @@ async def publish_receipt_ingested(
     total: Decimal | float,
 ) -> None:
     """Publish a cartsnitch.receipts.ingested event after successful ingestion."""
+    payload = {
+        "user_id": user_id,
+        "store_slug": store_slug,
+        "purchase_id": purchase_id,
+        "purchase_date": purchase_date,
+        "item_count": item_count,
+        "total": float(total) if isinstance(total, Decimal) else total,
+    }
     event = {
         "event_type": CHANNEL_RECEIPTS_INGESTED,
         "timestamp": datetime.now(UTC).isoformat(),
         "service": "receiptwitness",
-        "payload": {
-            "user_id": user_id,
-            "store_slug": store_slug,
-            "purchase_id": purchase_id,
-            "purchase_date": purchase_date,
-            "item_count": item_count,
-            "total": float(total) if isinstance(total, Decimal) else total,
-        },
+        "payload": payload,
     }
 
     try:
@@ -73,3 +109,5 @@ async def publish_receipt_ingested(
     except aioredis.ConnectionError:
         logger.error("Failed to publish event — Redis/DragonflyDB connection error")
         raise
+    else:
+        await _send_notification_for_event(payload)