feat: Create new API for uploading papers

src/paper/serializers/paper_upload_serializer.py

@@ -0,0 +1,10 @@
+from rest_framework import serializers
+
+
+class PaperUploadSerializer(serializers.Serializer):
+    """
+    Serializer for uploading a paper.
+    Used to validate request data.
+    """
+
+    filename = serializers.CharField(required=True)

src/paper/services/storage_service.py

@@ -0,0 +1,47 @@
+import uuid
+
+from boto3 import session
+
+from researchhub import settings
+
+
+class StorageService:
+    """
+    Service for interacting with S3 storage.
+    """
+
+    def create_presigned_url(
+        self,
+        filename: str,
+        user_id: str,
+        content_type: str = "application/pdf",
+        valid_for: int = 2,
+    ) -> str:
+        """
+        Create a presigned URL for uploading a file to S3 that is time-limited.
+        """
+
+        s3_filename = f"/uploads/{user_id}/{uuid.uuid4()}/{filename}"
+
+        boto3_session = session.Session()
+        s3_client = boto3_session.client(
+            "s3",
+            aws_access_key_id=settings.AWS_ACCESS_KEY_ID,
+            aws_secret_access_key=settings.AWS_SECRET_ACCESS_KEY,
+        )
+
+        url = s3_client.generate_presigned_url(
+            "put_object",
+            Params={
+                "Bucket": settings.AWS_STORAGE_BUCKET_NAME,
+                "Key": s3_filename,
+                "ContentType": content_type,
+                "Metadata": {
+                    "created-by-id": f"{user_id}",
+                    "file-name": filename,
+                },
+            },
+            ExpiresIn=60 * valid_for,
+        )
+
+        return url

src/paper/tests/test_paper_upload_view.py

@@ -0,0 +1,56 @@
+from unittest.mock import Mock
+
+from rest_framework.test import APIRequestFactory, APITestCase, force_authenticate
+
+from paper.views.paper_upload_views import PaperUploadView
+from user.tests.helpers import create_random_default_user
+
+
+class PaperUploadViewTest(APITestCase):
+
+    def setUp(self):
+        self.factory = APIRequestFactory()
+        self.view = PaperUploadView.as_view()
+        self.mock_storage_service = Mock()
+        self.user = create_random_default_user("user1")
+
+    def test_post(self):
+        # Arrange
+        request = self.factory.post(
+            "/paper/upload/",
+            {
+                "filename": "test.pdf",
+            },
+        )
+
+        force_authenticate(request, self.user)
+
+        # Act
+        response = self.view(request, storage_service=self.mock_storage_service)
+
+        # Assert
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(
+            response.data,
+            {
+                "presigned_url": self.mock_storage_service.create_presigned_url.return_value,
+            },
+        )
+        self.mock_storage_service.create_presigned_url.assert_called_once_with(
+            "test.pdf",
+            request.user.id,
+        )
+
+    def test_post_fails_with_validation_error(self):
+        # Arrange
+        request = self.factory.post("/paper/upload/", {})
+
+        force_authenticate(request, self.user)
+
+        # Act
+        response = self.view(request, storage_service=self.mock_storage_service)
+
+        # Assert
+        self.assertEqual(response.status_code, 400)
+        self.assertEqual(response.data, {"filename": ["This field is required."]})
+        self.mock_storage_service.create_presigned_url.assert_not_called()

src/paper/tests/test_storage_service.py

@@ -0,0 +1,43 @@
+import uuid
+from unittest import TestCase
+from unittest.mock import Mock, patch
+
+from paper.services.storage_service import StorageService
+from researchhub import settings
+
+
+class StorageServiceTest(TestCase):
+
+    @patch("paper.services.storage_service.session.Session")
+    @patch("paper.services.storage_service.uuid.uuid4")
+    def test_create_presigned_url(self, mock_uuid, mock_session):
+        # Arrange
+        uuid1 = uuid.uuid4()
+        mock_uuid.return_value = uuid1
+
+        mock_s3_client = Mock()
+        mock_session.return_value.client.return_value = mock_s3_client
+
+        mock_s3_client.generate_presigned_url.return_value = "https://presignedUrl1"
+
+        service = StorageService()
+
+        # Act
+        url = service.create_presigned_url("file1.pdf", "userId1", valid_for=2)
+
+        # Assert
+        mock_s3_client.generate_presigned_url.assert_called_once_with(
+            "put_object",
+            Params={
+                "Bucket": settings.AWS_STORAGE_BUCKET_NAME,
+                "Key": f"/uploads/userId1/{uuid1}/file1.pdf",
+                "ContentType": "application/pdf",
+                "Metadata": {
+                    "created-by-id": "userId1",
+                    "file-name": "file1.pdf",
+                },
+            },
+            ExpiresIn=60 * 2,
+        )
+
+        self.assertEqual(url, "https://presignedUrl1")

src/paper/views/paper_upload_views.py

@@ -0,0 +1,40 @@
+from rest_framework.permissions import IsAuthenticated
+from rest_framework.request import Request
+from rest_framework.response import Response
+from rest_framework.views import APIView
+
+from paper.serializers.paper_upload_serializer import PaperUploadSerializer
+from paper.services.storage_service import StorageService
+
+
+class PaperUploadView(APIView):
+    """
+    View for uploading papers.
+    """
+
+    permission_classes = [IsAuthenticated]
+
+    def dispatch(self, request, *args, **kwargs):
+        self.storage_service = kwargs.pop("storage_service", StorageService())
+        return super().dispatch(request, *args, **kwargs)
+
+    def post(self, request: Request, *args, **kwargs) -> Response:
+        """
+        Creates a presigned URL for uploading a paper and returns it.
+        """
+        user = request.user
+        data = request.data
+
+        # Validate request data
+        serializer = PaperUploadSerializer(data=request.data)
+        serializer.is_valid(raise_exception=True)
+
+        filename = data.get("filename")
+
+        presigned_url = self.storage_service.create_presigned_url(filename, user.id)
+
+        return Response(
+            {
+                "presigned_url": presigned_url,
+            }
+        )

src/researchhub/urls.py

@@ -34,6 +34,7 @@
 import search.urls
 import user.views
 from citation.views import CitationEntryViewSet, CitationProjectViewSet
+from paper.views import paper_upload_views
 from researchhub.settings import INSTALLED_APPS, USE_DEBUG_TOOLBAR
 from researchhub_comment.views.rh_comment_view import RhCommentViewSet
 from review.views.review_view import ReviewViewSet
@@ -252,6 +253,11 @@
     path("email_notifications/", mailing_list.views.email_notifications),
     path("health/", researchhub.views.healthcheck),
     path("", researchhub.views.index, name="index"),
+    path(
+        "paper/upload/",
+        paper_upload_views.PaperUploadView.as_view(),
+        name="paper_upload",
+    ),
     path("robots.txt", researchhub.views.robots_txt, name="robots_txt"),
     path(
         "webhooks/persona/",