feat: creatives and external channels

src/usecase/external_channel/delete_external_channel.py

@@ -0,0 +1,20 @@
+import logging
+from typing import TYPE_CHECKING
+
+from src import domain, dto
+
+if TYPE_CHECKING:
+    from .. import Usecase
+
+log = logging.getLogger(__name__)
+
+
+async def delete_external_channel(self: 'Usecase', input: dto.DeleteExternalChannelInput) -> None:
+    async with self.database.transaction():
+        channel = await self.database.get_external_channel(input.user_id, channel_id=input.channel_id)
+        if not channel:
+            log.warning('User %s attempted to delete unavailable external channel %s', input.user_id, input.channel_id)
+            raise domain.ExternalChannelNotFound(input.channel_id)
+
+        await self.database.delete_external_channel(input.channel_id)
+        log.info('User %s deleted external channel %s', input.user_id, input.channel_id)