feat: creatives and external channels

src/domain/external_channel.py

@@ -0,0 +1,33 @@
+import uuid
+from typing import TYPE_CHECKING
+
+from sqlalchemy import BigInteger, Column, ForeignKey, Table
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from src import domain
+
+if TYPE_CHECKING:
+    from . import TargetChannel
+
+# M2M association table between TargetChannel and ExternalChannel
+target_channel_external_channel = Table(
+    'target_channel_external_channels',
+    domain.Base.metadata,
+    Column('target_channel_id', ForeignKey('targetchannels.id', ondelete='CASCADE'), primary_key=True),
+    Column('external_channel_id', ForeignKey('externalchannels.id', ondelete='CASCADE'), primary_key=True),
+)
+
+
+class ExternalChannel(domain.Base):
+    telegram_id: Mapped[int] = mapped_column(BigInteger, unique=True, index=True)
+    title: Mapped[str]
+    username: Mapped[str | None] = mapped_column(index=True)
+    description: Mapped[str | None]
+    subscribers_count: Mapped[int | None]
+    user_id: Mapped[uuid.UUID] = mapped_column(ForeignKey('users.id'), index=True)
+
+    # M2M relationship with target channels
+    target_channels: Mapped[list['TargetChannel']] = relationship(
+        secondary=target_channel_external_channel,
+        back_populates='external_channels',
+    )