feat: schedule periodic user synchronization

app/sync/scheduler.py

@@ -0,0 +1,42 @@
+import asyncio
+import logging
+from datetime import datetime, timedelta, timezone
+
+logger = logging.getLogger(__name__)
+
+
+class SyncScheduler:
+    def __init__(self, manager, *, interval_seconds: float) -> None:
+        self.manager = manager
+        self.interval_seconds = interval_seconds
+        self._task: asyncio.Task | None = None
+        self._stop = asyncio.Event()
+        self.last_tick = None
+        self.next_tick = None
+
+    async def run_once(self) -> None:
+        self.last_tick = datetime.now(timezone.utc)
+        try:
+            await self.manager.sync_all_enabled()
+        except Exception:
+            logger.exception("sync_all_enabled failed during scheduled tick")
+        finally:
+            self.next_tick = datetime.now(timezone.utc) + timedelta(seconds=self.interval_seconds)
+
+    async def _run(self) -> None:
+        while not self._stop.is_set():
+            await self.run_once()
+            try:
+                await asyncio.wait_for(self._stop.wait(), timeout=self.interval_seconds)
+            except TimeoutError:
+                pass
+
+    async def start(self) -> None:
+        self._stop.clear()
+        self._task = asyncio.create_task(self._run())
+
+    async def stop(self) -> None:
+        self._stop.set()
+        if self._task is not None:
+            await self._task
+            self._task = None