feat: creatives and external channels

src/usecase/target_channel/get_user_target_chans.py

@@ -0,0 +1,24 @@
+from typing import TYPE_CHECKING
+
+from src import dto
+
+if TYPE_CHECKING:
+    from .. import Usecase
+
+
+async def get_user_target_chans(self: 'Usecase', input: dto.GetUserTargetChansInput) -> dto.GetUserTargetChansOutput:
+    async with self.database.transaction():
+        channels = await self.database.get_user_target_channels(input.user_id)
+
+    return dto.GetUserTargetChansOutput(
+        target_channels=[
+            dto.ConnectTargetChanOutput(
+                id=channel.id,
+                telegram_id=channel.telegram_id,
+                title=channel.title,
+                username=channel.username,
+                is_active=channel.is_active,
+            )
+            for channel in channels
+        ]
+    )