Add notification model

src/va_agent/notifications.py

@@ -78,7 +78,9 @@ class NotificationDocument(BaseModel):
 class NotificationBackend(Protocol):
     """Backend-agnostic interface for notification storage."""
 
-    async def get_recent_notifications(self, phone_number: str) -> list[Notification]:
+    async def get_recent_notifications(
+        self, phone_number: str
+    ) -> list[Notification]:
         """Return recent notifications for *phone_number*."""
         ...
 
@@ -111,7 +113,9 @@ class FirestoreNotificationBackend:
         self._max_to_notify = max_to_notify
         self._window_hours = window_hours
 
-    async def get_recent_notifications(self, phone_number: str) -> list[Notification]:
+    async def get_recent_notifications(
+        self, phone_number: str
+    ) -> list[Notification]:
         """Get recent notifications for a user.
 
         Retrieves notifications created within the configured time window,
@@ -144,7 +148,9 @@ class FirestoreNotificationBackend:
             cutoff = time.time() - (self._window_hours * 3600)
 
             parsed = [
-                n for n in document.notificaciones if n.timestamp_creacion >= cutoff
+                n
+                for n in document.notificaciones
+                if n.timestamp_creacion >= cutoff
             ]
 
             if not parsed:
@@ -206,7 +212,9 @@ class RedisNotificationBackend:
         self._max_to_notify = max_to_notify
         self._window_hours = window_hours
 
-    async def get_recent_notifications(self, phone_number: str) -> list[Notification]:
+    async def get_recent_notifications(
+        self, phone_number: str
+    ) -> list[Notification]:
         """Get recent notifications for a user from Redis.
 
         Reads from the ``notification:{phone}`` key, parses the JSON
@@ -238,7 +246,9 @@ class RedisNotificationBackend:
             cutoff = time.time() - (self._window_hours * 3600)
 
             parsed = [
-                n for n in document.notificaciones if n.timestamp_creacion >= cutoff
+                n
+                for n in document.notificaciones
+                if n.timestamp_creacion >= cutoff
             ]
 
             if not parsed:

src/va_agent/session.py

@@ -6,7 +6,6 @@ import asyncio
 import logging
 import time
 import uuid
-from datetime import UTC, datetime
 from typing import TYPE_CHECKING, Any, override
 
 from google.adk.errors.already_exists_error import AlreadyExistsError
@@ -103,24 +102,6 @@ class FirestoreSessionService(BaseSessionService):
     def _events_col(self, app_name: str, user_id: str, session_id: str) -> Any:
         return self._session_ref(app_name, user_id, session_id).collection("events")
 
-    @staticmethod
-    def _timestamp_to_float(value: Any, default: float = 0.0) -> float:
-        if value is None:
-            return default
-        if isinstance(value, (int, float)):
-            return float(value)
-        if hasattr(value, "timestamp"):
-            try:
-                return float(value.timestamp())
-            except (
-                TypeError,
-                ValueError,
-                OSError,
-                OverflowError,
-            ) as exc:  # pragma: no cover
-                logger.debug("Failed to convert timestamp %r: %s", value, exc)
-        return default
-
     # ------------------------------------------------------------------
     # State helpers
     # ------------------------------------------------------------------
@@ -190,7 +171,7 @@ class FirestoreSessionService(BaseSessionService):
                 )
             )
 
-        now = datetime.now(UTC)
+        now = time.time()
         write_coros.append(
             self._session_ref(app_name, user_id, session_id).set(
                 {
@@ -215,7 +196,7 @@ class FirestoreSessionService(BaseSessionService):
             user_id=user_id,
             id=session_id,
             state=merged,
-            last_update_time=now.timestamp(),
+            last_update_time=now,
         )
 
     @override
@@ -302,9 +283,7 @@ class FirestoreSessionService(BaseSessionService):
             id=session_id,
             state=merged,
             events=events,
-            last_update_time=self._timestamp_to_float(
-                session_data.get("last_update_time"), 0.0
-            ),
+            last_update_time=session_data.get("last_update_time", 0.0),
         )
 
     @override
@@ -347,9 +326,7 @@ class FirestoreSessionService(BaseSessionService):
                     id=data["session_id"],
                     state=merged,
                     events=[],
-                    last_update_time=self._timestamp_to_float(
-                        data.get("last_update_time"), 0.0
-                    ),
+                    last_update_time=data.get("last_update_time", 0.0),
                 )
             )
 
@@ -389,8 +366,6 @@ class FirestoreSessionService(BaseSessionService):
         # Persist state deltas
         session_ref = self._session_ref(app_name, user_id, session_id)
 
-        last_update_dt = datetime.fromtimestamp(event.timestamp, UTC)
-
         if event.actions and event.actions.state_delta:
             state_deltas = _session_util.extract_state_delta(event.actions.state_delta)
 
@@ -411,16 +386,16 @@ class FirestoreSessionService(BaseSessionService):
                     FieldPath("state", k).to_api_repr(): v
                     for k, v in state_deltas["session"].items()
                 }
-                field_updates["last_update_time"] = last_update_dt
+                field_updates["last_update_time"] = event.timestamp
                 write_coros.append(session_ref.update(field_updates))
             else:
                 write_coros.append(
-                    session_ref.update({"last_update_time": last_update_dt})
+                    session_ref.update({"last_update_time": event.timestamp})
                 )
 
             await asyncio.gather(*write_coros)
         else:
-            await session_ref.update({"last_update_time": last_update_dt})
+            await session_ref.update({"last_update_time": event.timestamp})
 
         # Log token usage
         if event.usage_metadata: