Normalize supervisor emails and add unique constraint for case-insensitive email uniqueness

generic/migrations/0028_normalize_supervisor_emails.py

@@ -0,0 +1,51 @@
+from django.db import migrations
+# no additional imports required
+
+
+def normalize_and_dedupe(apps, schema_editor):
+    Supervisor = apps.get_model('generic', 'Supervisor')
+    UserProfile = apps.get_model('generic', 'UserProfile')
+    CidUser = apps.get_model('generic', 'CidUser')
+    # Build groups by normalized email without saving changes yet to avoid unique constraint errors
+    supervisors = list(Supervisor.objects.all())
+    groups = {}
+
+    for s in supervisors:
+        norm_email = (s.email or "").strip().lower()
+        norm_name = (s.name or "").strip()
+        groups.setdefault(norm_email, []).append((s, norm_name))
+
+    # For each group, pick a keeper (smallest PK), reassign FKs from duplicates to keeper, delete duplicates,
+    # then update the keeper's normalized email/name.
+    for norm_email, entries in groups.items():
+        # pick keeper by lowest id
+        entries_sorted = sorted(entries, key=lambda e: e[0].pk)
+        keeper_obj, keeper_name = entries_sorted[0]
+
+        # reassign duplicates
+        for dup_obj, dup_name in entries_sorted[1:]:
+            UserProfile.objects.filter(supervisor_id=dup_obj.pk).update(supervisor_id=keeper_obj.pk)
+            CidUser.objects.filter(supervisor_id=dup_obj.pk).update(supervisor_id=keeper_obj.pk)
+            dup_obj.delete()
+
+        # update keeper's email and name to normalized values if needed
+        changed = False
+        if norm_email and keeper_obj.email != norm_email:
+            keeper_obj.email = norm_email
+            changed = True
+        if keeper_name and keeper_obj.name != keeper_name:
+            keeper_obj.name = keeper_name
+            changed = True
+        if changed:
+            keeper_obj.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('generic', '0027_alter_questionreview_status'),
+    ]
+
+    operations = [
+        migrations.RunPython(normalize_and_dedupe, reverse_code=migrations.RunPython.noop),
+    ]

generic/migrations/0029_add_unique_constraint_supervisor_email.py

@@ -0,0 +1,17 @@
+from django.db import migrations
+from django.db.models import UniqueConstraint
+from django.db.models.functions import Lower
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('generic', '0028_normalize_supervisor_emails'),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name='supervisor',
+            constraint=UniqueConstraint(Lower('email'), name='unique_supervisor_email_ci'),
+        ),
+    ]

generic/models.py

@@ -5,6 +5,8 @@ import os
 from typing import Optional, Self, Tuple
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.db import models
+from django.db.models import UniqueConstraint
+from django.db.models.functions import Lower
 from django.forms import ValidationError
 from django.http import Http404, HttpRequest
 from django.shortcuts import render
@@ -1859,8 +1861,16 @@ class Supervisor(models.Model):
         return reverse("generic:supervisor_detail", kwargs={"pk": self.pk})
 
     def clean(self):
-        self.email = self.email.strip()
-        self.name = self.name.strip()
+        if self.email:
+            # normalize email: strip and lowercase for consistency
+            self.email = self.email.strip().lower()
+        if self.name:
+            self.name = self.name.strip()
+
+    class Meta:
+        constraints = [
+            UniqueConstraint(Lower('email'), name='unique_supervisor_email_ci')
+        ]
 
 
 @receiver(post_save, sender=User)