minor adjustments

papermerge/core/db/exceptions.py

@@ -1,2 +1,6 @@
 class UserNotFound(Exception):
     pass
+
+
+class PageNotFound(Exception):
+    pass

papermerge/core/db/models.py

@@ -101,10 +101,10 @@ class DocumentVersion(Base):
 
     id: Mapped[UUID] = mapped_column(primary_key=True)
     number: Mapped[int]
+    file_name: Mapped[str]
     document_id: Mapped[UUID] = mapped_column(
         ForeignKey("core_document.basetreenode_ptr_id")
     )
-
     lang: Mapped[str]
     short_description: Mapped[str]
 

papermerge/core/db/pages.py

@@ -1,11 +1,13 @@
 from uuid import UUID
 
-from sqlalchemy import Engine, select
+from sqlalchemy import Engine, exc, select
 from sqlalchemy.orm import Session
 
 from papermerge.core import schemas
 from papermerge.core.db.models import Page
 
+from .exceptions import PageNotFound
+
 
 def get_first_page(
     engine: Engine,
@@ -21,7 +23,14 @@ def get_first_page(
         ).order_by(
             Page.number.asc()
         ).limit(1)
-        db_page = session.scalars(stmt).one()
+        try:
+            db_page = session.scalars(stmt).one()
+        except exc.NoResultFound:
+            session.close()
+            raise PageNotFound(
+                f"DocVerID={doc_ver_id} does not have pages."
+                " Maybe it does not have associated file yet?"
+            )
         model = schemas.Page.model_validate(db_page)
 
     return model

papermerge/core/routers/thumbnails.py

@@ -11,6 +11,7 @@
 from papermerge.core import schemas
 from papermerge.core.auth import get_current_user
 from papermerge.core.constants import DEFAULT_THUMBNAIL_SIZE
+from papermerge.core.db import exceptions as db_exc
 from papermerge.core.models import Document
 from papermerge.core.pathlib import rel2abs, thumbnail_path
 from papermerge.core.utils import image
@@ -116,10 +117,10 @@ def retrieve_document_thumbnail(
             doc_id=document_id
         )
         page = db.get_first_page(engine, doc_ver_id=doc_ver.id)
-    except Document.DoesNotExist:
+    except db_exc.PageNotFound as e:
         raise HTTPException(
             status_code=404,
-            detail="Page does not exist"
+            detail=f"DocID={document_id}: {e}"
         )
 
     if page is None: