wip: add import endpoint

app/api/nonsense.py

@@ -1,4 +1,7 @@
-from fastapi import APIRouter, Depends, status
+import io
+from fastapi import APIRouter, Depends, status, UploadFile, HTTPException
+from sqlalchemy.exc import SQLAlchemyError
+import polars as pl
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.database import get_db
@@ -48,3 +51,37 @@ async def merge_nonsense(
     nonsense = Nonsense(**payload.model_dump())
     await nonsense.save_or_update(db_session)
     return nonsense
+
+
+@router.post(
+    "/import",
+    status_code=status.HTTP_201_CREATED,
+)
+async def import_nonsense(
+    xlsx: UploadFile,
+    db_session: AsyncSession = Depends(get_db),
+):
+    file_bytes = await xlsx.read()
+
+    nonsense_data = pl.read_excel(
+        source=io.BytesIO(file_bytes),
+        sheet_name="New Nonsense",
+        engine="calamine",
+    )
+
+    try:
+        nonsense_records = [
+            Nonsense(
+                name=nonsense.get("name"),
+                description=nonsense.get("description"),
+            )
+            for nonsense in nonsense_data.to_dicts()
+        ]
+        db_session.add_all(nonsense_records)
+        await db_session.commit()
+        return {"filename": xlsx.filename, "nonsense_records": len(nonsense_records)}
+    except (SQLAlchemyError, HTTPException) as ex:
+        await db_session.rollback()
+        raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail=repr(ex)) from ex
+    finally:
+        await db_session.close()