✨(backend) configure lasuite.malware_detection module

We want to use the malware_detection module from lasuite library. We add
a new setting MALWARE_DETECTION to configure the backend we want to use.
The callback is also added. It removes the file if it is not safe or
change it's status in the metadata to set it as ready.

src/backend/core/malware_detection.py

@@ -0,0 +1,51 @@
+"""Malware detection callbacks"""
+
+import logging
+
+from django.core.files.storage import default_storage
+
+from lasuite.malware_detection.enums import ReportStatus
+
+from core.enums import DocumentAttachmentStatus
+from core.models import Document
+
+logger = logging.getLogger(__name__)
+
+
+def malware_detection_callback(file_path, status, error_info, **kwargs):
+    """Malware detection callback"""
+
+    if status == ReportStatus.SAFE:
+        logger.info("File %s is safe", file_path)
+        # Get existing metadata
+        s3_client = default_storage.connection.meta.client
+        bucket_name = default_storage.bucket_name
+        head_resp = s3_client.head_object(Bucket=bucket_name, Key=file_path)
+        metadata = head_resp.get("Metadata", {})
+        metadata.update({"status": DocumentAttachmentStatus.READY})
+        # Update status in metadata
+        s3_client.copy_object(
+            Bucket=bucket_name,
+            CopySource={"Bucket": bucket_name, "Key": file_path},
+            Key=file_path,
+            ContentType=head_resp.get("ContentType"),
+            Metadata=metadata,
+            MetadataDirective="REPLACE",
+        )
+        return
+
+    document_id = kwargs.get("document_id")
+    logger.error(
+        "File %s for document %s is infected with malware. Error info: %s",
+        file_path,
+        document_id,
+        error_info,
+    )
+
+    # Remove the file from the document and change the status to unsafe
+    document = Document.objects.get(pk=document_id)
+    document.attachments.remove(file_path)
+    document.save(update_fields=["attachments"])
+
+    # Delete the file from the storage
+    default_storage.delete(file_path)