first commit

app/messages/repository.py

@@ -0,0 +1,41 @@
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.messages.models import Message, MessageType
+
+
+async def create_message(
+    db: AsyncSession,
+    *,
+    chat_id: int,
+    sender_id: int,
+    message_type: MessageType,
+    text: str | None,
+) -> Message:
+    message = Message(chat_id=chat_id, sender_id=sender_id, type=message_type, text=text)
+    db.add(message)
+    await db.flush()
+    return message
+
+
+async def get_message_by_id(db: AsyncSession, message_id: int) -> Message | None:
+    result = await db.execute(select(Message).where(Message.id == message_id))
+    return result.scalar_one_or_none()
+
+
+async def list_chat_messages(
+    db: AsyncSession,
+    chat_id: int,
+    *,
+    limit: int = 50,
+    before_id: int | None = None,
+) -> list[Message]:
+    query = select(Message).where(Message.chat_id == chat_id)
+    if before_id is not None:
+        query = query.where(Message.id < before_id)
+    result = await db.execute(query.order_by(Message.id.desc()).limit(limit))
+    return list(result.scalars().all())
+
+
+async def delete_message(db: AsyncSession, message: Message) -> None:
+    await db.delete(message)