feat: pdf reader

backend/apps/books/views.py

@@ -168,18 +168,23 @@ class EBookViewSet(viewsets.ModelViewSet):
 
     @action(detail=True, methods=["get"])
     def file(self, request: Request, pk: int | None = None) -> FileResponse | Response:
-        """Stream the EPUB file for authenticated in-browser reading."""
+        """Stream the ebook file for authenticated in-browser reading."""
         ebook = self.get_object()
-        if ebook.format != "epub":
+        content_types = {
+            "epub": "application/epub+zip",
+            "pdf": "application/pdf",
+        }
+        content_type = content_types.get(ebook.format)
+        if not content_type:
             return Response(
-                {"error": "Reader supports EPUB only."},
+                {"error": "Unsupported format for in-browser reading."},
                 status=status.HTTP_400_BAD_REQUEST,
             )
         if not ebook.file:
             return Response({"error": "No file found for this e-book."}, status=status.HTTP_400_BAD_REQUEST)
         return FileResponse(
             ebook.file.open("rb"),
-            content_type="application/epub+zip",
+            content_type=content_type,
             filename=ebook.filename(),
         )