Use celery tasks instead of systemd timers for periodic work; and add more tests

twitch/signals.py

@@ -0,0 +1,65 @@
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+logger = logging.getLogger("ttvdrops.signals")
+
+
+def _dispatch(task_fn: Any, pk: int) -> None:  # noqa: ANN401
+    """Dispatch a Celery task, logging rather than raising when the broker is unavailable."""
+    try:
+        task_fn.delay(pk)
+    except Exception:  # noqa: BLE001
+        logger.debug(
+            "Could not dispatch %s(%d) — broker may be unavailable.",
+            task_fn.name,
+            pk,
+        )
+
+
+def on_game_saved(sender: Any, instance: Any, created: bool, **kwargs: Any) -> None:  # noqa: ANN401, FBT001
+    """Dispatch a box-art download task when a new Game is created."""
+    if created:
+        from twitch.tasks import download_game_image  # noqa: PLC0415
+
+        _dispatch(download_game_image, instance.pk)
+
+
+def on_drop_campaign_saved(
+    sender: Any,  # noqa: ANN401
+    instance: Any,  # noqa: ANN401
+    created: bool,  # noqa: FBT001
+    **kwargs: Any,  # noqa: ANN401
+) -> None:
+    """Dispatch an image download task when a new DropCampaign is created."""
+    if created:
+        from twitch.tasks import download_campaign_image  # noqa: PLC0415
+
+        _dispatch(download_campaign_image, instance.pk)
+
+
+def on_drop_benefit_saved(
+    sender: Any,  # noqa: ANN401
+    instance: Any,  # noqa: ANN401
+    created: bool,  # noqa: FBT001
+    **kwargs: Any,  # noqa: ANN401
+) -> None:
+    """Dispatch an image download task when a new DropBenefit is created."""
+    if created:
+        from twitch.tasks import download_benefit_image  # noqa: PLC0415
+
+        _dispatch(download_benefit_image, instance.pk)
+
+
+def on_reward_campaign_saved(
+    sender: Any,  # noqa: ANN401
+    instance: Any,  # noqa: ANN401
+    created: bool,  # noqa: FBT001
+    **kwargs: Any,  # noqa: ANN401
+) -> None:
+    """Dispatch an image download task when a new RewardCampaign is created."""
+    if created:
+        from twitch.tasks import download_reward_campaign_image  # noqa: PLC0415
+
+        _dispatch(download_reward_campaign_image, instance.pk)