backend: add push token API and FCM delivery pipeline

app/notifications/repository.py

@@ -1,6 +1,9 @@
+from datetime import datetime, timezone
+
+from sqlalchemy import delete, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.notifications.models import NotificationLog
+from app.notifications.models import NotificationLog, PushDeviceToken
 
 
 async def create_notification_log(db: AsyncSession, *, user_id: int, event_type: str, payload: str) -> None:
@@ -8,8 +11,6 @@ async def create_notification_log(db: AsyncSession, *, user_id: int, event_type:
 
 
 async def list_user_notifications(db: AsyncSession, *, user_id: int, limit: int = 50) -> list[NotificationLog]:
-    from sqlalchemy import select
-
     result = await db.execute(
         select(NotificationLog)
         .where(NotificationLog.user_id == user_id)
@@ -17,3 +18,63 @@ async def list_user_notifications(db: AsyncSession, *, user_id: int, limit: int
         .limit(limit)
     )
     return list(result.scalars().all())
+
+
+async def upsert_push_device_token(
+    db: AsyncSession,
+    *,
+    user_id: int,
+    platform: str,
+    token: str,
+    device_id: str | None,
+    app_version: str | None,
+) -> PushDeviceToken:
+    result = await db.execute(
+        select(PushDeviceToken).where(
+            PushDeviceToken.user_id == user_id,
+            PushDeviceToken.platform == platform,
+            PushDeviceToken.token == token,
+        )
+    )
+    existing = result.scalar_one_or_none()
+    if existing is not None:
+        existing.device_id = device_id
+        existing.app_version = app_version
+        existing.updated_at = datetime.now(timezone.utc)
+        await db.flush()
+        return existing
+
+    record = PushDeviceToken(
+        user_id=user_id,
+        platform=platform,
+        token=token,
+        device_id=device_id,
+        app_version=app_version,
+    )
+    db.add(record)
+    await db.flush()
+    return record
+
+
+async def delete_push_device_token(
+    db: AsyncSession,
+    *,
+    user_id: int,
+    platform: str,
+    token: str,
+) -> int:
+    result = await db.execute(
+        delete(PushDeviceToken).where(
+            PushDeviceToken.user_id == user_id,
+            PushDeviceToken.platform == platform,
+            PushDeviceToken.token == token,
+        )
+    )
+    return int(result.rowcount or 0)
+
+
+async def list_push_tokens_for_user(db: AsyncSession, *, user_id: int) -> list[PushDeviceToken]:
+    result = await db.execute(
+        select(PushDeviceToken).where(PushDeviceToken.user_id == user_id).order_by(PushDeviceToken.id.asc())
+    )
+    return list(result.scalars().all())