Refactor stream notifier

src/modules/stream_notifications/watcher.py

@@ -0,0 +1,95 @@
+from datetime import datetime, timezone, timedelta
+
+from twitchAPI.helper import first
+
+from core.redis import redis_manager
+from repositories.streamers import StreamerConfigRepository
+
+from .state import State, StateManager
+from .sent_notifications import SentNotificationRepository, SentNotificationType
+from .notification import notify
+from .twitch.authorize import authorize
+
+
+class StateWatcher:
+    START_STREAM_THRESHOLD = timedelta(minutes=15)
+
+    @classmethod
+    async def get_twitch_state(cls, streamer_id: int) -> State | None:
+        twitch = await authorize()
+
+        stream = await first(
+            twitch.get_streams(user_id=[str(streamer_id)])
+        )
+
+        if stream is None:
+            return None
+
+        return State(
+            title=stream.title,
+            category=stream.game_name,
+            last_live_at=datetime.now(timezone.utc)
+        )
+
+    @classmethod
+    async def notify_and_save(
+        cls,
+        streamer_id: int,
+        sent_notification_type: SentNotificationType,
+        state: State
+    ):
+        streamer = await StreamerConfigRepository.get_by_twitch_id(streamer_id)
+
+        sent_result = await notify(sent_notification_type, streamer, state)
+        await SentNotificationRepository.add(
+            streamer.twitch.id,
+            sent_notification_type,
+            state,
+            sent_result=sent_result
+        )
+
+    @classmethod
+    async def notify_start_stream(
+        cls,
+        streamer_id: int,
+        state: State
+    ):
+        await cls.notify_and_save(streamer_id, SentNotificationType.START_STREAM, state)
+
+    @classmethod
+    async def notify_change_category(
+        cls,
+        streamer_id: int,
+        state: State
+    ):
+        await cls.notify_and_save(streamer_id, SentNotificationType.CHANGE_CATEGORY, state)
+
+    @classmethod
+    async def _on_stream_state_change(cls, streamer_id: int):
+        current_state = await cls.get_twitch_state(streamer_id)
+        if current_state is None:
+            return
+
+        last_state = await StateManager.get(streamer_id)
+        if last_state is None:
+            await cls.notify_start_stream(streamer_id, current_state)
+            await StateManager.update(streamer_id, current_state)
+            return
+
+        if datetime.now(timezone.utc) - last_state.last_live_at > cls.START_STREAM_THRESHOLD:
+            await cls.notify_start_stream(streamer_id, current_state)
+            await StateManager.update(streamer_id, current_state)
+            return
+
+        if last_state.category != current_state.category:
+            await cls.notify_change_category(streamer_id, current_state)
+            await StateManager.update(streamer_id, current_state)
+            return
+
+        await StateManager.update(streamer_id, current_state)
+
+    @classmethod
+    async def on_stream_state_change(cls, streamer_id: int):
+        async with redis_manager.connect() as redis:
+            async with redis.lock(f"on_stream_state_change:{streamer_id}"):
+                await cls._on_stream_state_change(streamer_id)