feat: add poller with supervised restart loop

Made-with: Cursor

src/ntr_fetcher/poller.py

@@ -0,0 +1,69 @@
+import asyncio
+import logging
+from datetime import datetime, timezone
+
+from ntr_fetcher.db import Database
+from ntr_fetcher.soundcloud import SoundCloudClient
+from ntr_fetcher.week import get_show_week
+
+logger = logging.getLogger(__name__)
+
+
+class Poller:
+    def __init__(
+        self,
+        db: Database,
+        soundcloud: SoundCloudClient,
+        soundcloud_user: str,
+        show_day: int,
+        show_hour: int,
+        poll_interval: float,
+    ):
+        self._db = db
+        self._sc = soundcloud
+        self._user = soundcloud_user
+        self._show_day = show_day
+        self._show_hour = show_hour
+        self._poll_interval = poll_interval
+        self._user_id: int | None = None
+        self.last_fetch: datetime | None = None
+        self.alive = True
+
+    async def _get_user_id(self) -> int:
+        if self._user_id is None:
+            self._user_id = await self._sc.resolve_user(self._user)
+        return self._user_id
+
+    async def poll_once(self, full: bool = False) -> None:
+        user_id = await self._get_user_id()
+        now = datetime.now(timezone.utc)
+        week_start, week_end = get_show_week(now, self._show_day, self._show_hour)
+        show = self._db.get_or_create_show(week_start, week_end)
+
+        tracks = await self._sc.fetch_likes(
+            user_id=user_id,
+            since=week_start,
+            until=week_end,
+        )
+
+        for track in tracks:
+            self._db.upsert_track(track)
+
+        track_ids = [t.id for t in tracks]
+        self._db.set_show_tracks(show.id, track_ids)
+        self.last_fetch = datetime.now(timezone.utc)
+        logger.info("Fetched %d tracks for show %d", len(tracks), show.id)
+
+    async def run_supervised(self, restart_delay: float = 30.0) -> None:
+        while True:
+            try:
+                self.alive = True
+                await self.poll_once()
+                await asyncio.sleep(self._poll_interval)
+            except asyncio.CancelledError:
+                self.alive = False
+                raise
+            except Exception:
+                self.alive = False
+                logger.exception("Poller failed, restarting in %.1fs", restart_delay)
+                await asyncio.sleep(restart_delay)