Mechanic's work place

app/services/notifications.py

@@ -1,27 +1,70 @@
+from datetime import UTC, datetime, timedelta
+
 import httpx
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.config import settings
+from app.models.car import ServiceNotification
 from app.models.user import User
 
 MODERATOR_ROLES = {"admin", "verifier", "moderator"}
 
 
-async def notify_user(user: User, text: str) -> None:
+async def notify_user(user: User, text: str) -> bool:
     if not settings.bot_token or settings.app_env == "test":
-        return
+        return False
     try:
         async with httpx.AsyncClient(timeout=5) as client:
-            await client.post(
+            response = await client.post(
                 f"https://api.telegram.org/bot{settings.bot_token}/sendMessage",
                 data={"chat_id": str(user.telegram_id), "text": text},
             )
+            return response.status_code < 400
     except Exception:
-        return
+        return False
 
 
 async def notify_platform_moderators(session: AsyncSession, text: str) -> None:
     result = await session.execute(select(User).where(User.platform_role.in_(MODERATOR_ROLES)))
     for user in result.scalars():
         await notify_user(user, text)
+
+
+async def retry_failed_notifications(session: AsyncSession, *, limit: int = 50) -> int:
+    return await process_notification_queue(session, limit=limit)
+
+
+async def process_notification_queue(session: AsyncSession, *, limit: int = 50) -> int:
+    now = datetime.now(UTC)
+    result = await session.execute(
+        select(ServiceNotification)
+        .where(
+            ServiceNotification.status.in_(["pending", "failed", "retrying"]),
+            ServiceNotification.retry_count < 5,
+        )
+        .order_by(ServiceNotification.created_at.asc())
+        .limit(limit)
+    )
+    delivered = 0
+    for notification in result.scalars():
+        if notification.status == "retrying" and notification.created_at > now - timedelta(seconds=30):
+            continue
+        notification.status = "processing"
+        user = await session.get(User, notification.recipient_user_id)
+        if user is None:
+            notification.status = "abandoned"
+            notification.last_error = "recipient_not_found"
+            continue
+        ok = await notify_user(user, f"{notification.title}\n{notification.body}" if notification.body else notification.title)
+        notification.retry_count += 1
+        if ok:
+            notification.status = "sent"
+            notification.sent_at = datetime.now(UTC)
+            notification.last_error = None
+            delivered += 1
+        else:
+            notification.status = "abandoned" if notification.retry_count >= 5 else "retrying"
+            notification.last_error = "telegram_delivery_failed"
+    await session.commit()
+    return delivered