Cleanup tribal email accesses (#4401)

* Create clean_tribal_email_accesses.py

* Tweak language

* Cleanup commenting and proper logging

backend/support/management/commands/clean_tribal_email_accesses.py

@@ -0,0 +1,63 @@
+from django.core.management.base import BaseCommand
+from django.db.models import Count
+from django.db.models.functions import Lower
+import logging
+from users.models import UserPermission
+
+logger = logging.getLogger(__name__)
+
+
+class Command(BaseCommand):
+    """
+    Django management command for cleaning up tribal access emails.
+    This includes lowercasing all emails, and also deleting duplicates (with null user field).
+    """
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--count",
+            action="store_true",
+            help="Only logs the number of duplicates without modifying the database.",
+        )
+
+    def handle(self, *args, **options):
+
+        fixed_emails = 0
+        removed_duplicates = 0
+
+        # first, gather number of duplicate emails that exist.
+        duplicates = (
+            UserPermission.objects.values(loweremail=Lower("email"))
+            .annotate(ecount=Count("id"))
+            .filter(ecount__gt=1)
+        )
+        logger.info(
+            f"Identified {duplicates.count()} duplicate emails for tribal access."
+        )
+
+        if options.get("count"):
+            exit(0)
+
+        # then, lowercase all emails.
+        userpermissions = UserPermission.objects.all()
+        for userpermission in userpermissions:
+            if userpermission.email:
+                if userpermission.email != userpermission.email.lower():
+                    userpermission.email = userpermission.email.lower()
+                    userpermission.save()
+                    fixed_emails += 1
+        logger.info(f"Removed uppercasing on {fixed_emails} tribal access emails.")
+
+        # finally, remove duplicates (that have a null user field).
+        userpermissions = UserPermission.objects.filter(user=None)
+        for userpermission in userpermissions:
+            if (
+                UserPermission.objects.filter(email=userpermission.email)
+                .exclude(user=None)
+                .exists()
+            ):
+                userpermission.delete()
+                removed_duplicates += 1
+        logger.info(
+            f"Removed 'blank user' for {removed_duplicates} duplicate tribal access emails."
+        )