feat: creatives and external channels

src/usecase/creative/create_creative.py

@@ -0,0 +1,40 @@
+import logging
+import uuid
+from typing import TYPE_CHECKING
+
+from src import domain, dto
+
+if TYPE_CHECKING:
+    from .. import Usecase
+
+log = logging.getLogger(__name__)
+
+
+async def create_creative(self: 'Usecase', input: dto.CreateCreativeInput, user_id: uuid.UUID) -> dto.CreativeOutput:
+    async with self.database.transaction():
+        target_channel = await self.database.get_target_channel(user_id, channel_id=input.target_channel_id)
+        if not target_channel:
+            log.warning(
+                'User %s attempted to create creative for unavailable target %s', user_id, input.target_channel_id
+            )
+            raise domain.TargetChannelNotFound(input.target_channel_id)
+
+        creative = domain.Creative(
+            name=input.name,
+            text=input.text,
+            target_channel_id=target_channel.id,
+            user_id=user_id,
+        )
+
+        created = await self.database.create_creative(creative)
+
+    return dto.CreativeOutput(
+        id=created.id,
+        name=created.name,
+        text=created.text,
+        target_channel_id=created.target_channel_id,
+        target_channel_title=created.target_channel.title,
+        created_at=created.created_at,
+        status=created.status,
+        purchases_count=created.purchases_count,
+    )