Adds additional warnings during an import if it might fail due to reasons (#4814)

src/documents/management/commands/document_importer.py

@@ -7,6 +7,7 @@ from pathlib import Path
 import tqdm
 from django.conf import settings
 from django.contrib.auth.models import Permission
+from django.contrib.auth.models import User
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import FieldDoesNotExist
 from django.core.management import call_command
@@ -60,10 +61,11 @@ class Command(BaseCommand):
         self.manifest = None
         self.version = None
 
-    def handle(self, *args, **options):
-        logging.getLogger().handlers[0].level = logging.ERROR
-
-        self.source = Path(options["source"]).resolve()
+    def pre_check(self) -> None:
+        """
+        Runs some initial checks against the source directory, including looking for
+        common mistakes like having files still and users other than expected
+        """
 
         if not self.source.exists():
             raise CommandError("That path doesn't exist")
@@ -71,6 +73,40 @@ class Command(BaseCommand):
         if not os.access(self.source, os.R_OK):
             raise CommandError("That path doesn't appear to be readable")
 
+        for document_dir in [settings.ORIGINALS_DIR, settings.ARCHIVE_DIR]:
+            if document_dir.exists() and document_dir.is_dir():
+                for entry in document_dir.glob("**/*"):
+                    if entry.is_dir():
+                        continue
+                    self.stdout.write(
+                        self.style.WARNING(
+                            f"Found file {entry.relative_to(document_dir)}, this might indicate a non-empty installation",
+                        ),
+                    )
+                    break
+        if (
+            User.objects.exclude(username__in=["consumer", "AnonymousUser"]).count()
+            != 0
+        ):
+            self.stdout.write(
+                self.style.WARNING(
+                    "Found existing user(s), this might indicate a non-empty installation",
+                ),
+            )
+        if Document.objects.count() != 0:
+            self.stdout.write(
+                self.style.WARNING(
+                    "Found existing documents(s), this might indicate a non-empty installation",
+                ),
+            )
+
+    def handle(self, *args, **options):
+        logging.getLogger().handlers[0].level = logging.ERROR
+
+        self.source = Path(options["source"]).resolve()
+
+        self.pre_check()
+
         manifest_paths = []
 
         main_manifest_path = self.source / "manifest.json"