Remove duplicate tag proposals

oioioi/problems/management/commands/mass_create_tool.py

@@ -191,9 +191,18 @@ def create_proposals(self, count, problems, users, tags, proposal_model, verbose
         """
         objs = []
         for i in range(count):
-            problem = random.choice(problems)
-            user = random.choice(users)
-            tag = random.choice(tags)
+            def candidate_fn():
+                return (random.choice(problems), random.choice(users), random.choice(tags))
+
+            def uniqueness_fn(candidate):
+                problem, user, tag = candidate
+                if proposal_model.__name__ == 'AlgorithmTagProposal':
+                    return not proposal_model.objects.filter(problem=problem, user=user, tag=tag).exists()
+                elif proposal_model.__name__ == 'DifficultyTagProposal':
+                    return not proposal_model.objects.filter(problem=problem, user=user).exists()
+                return True
+
+            problem, user, tag = get_unique_candidate(candidate_fn, uniqueness_fn)
             proposal = proposal_model(problem=problem, user=user, tag=tag)
             proposal.save()
             objs.append(proposal)

oioioi/problems/migrations/0039_alter_algorithmtagproposal_unique_together_and_more.py

@@ -0,0 +1,60 @@
+# Generated by Django 5.2.7 on 2025-11-17 22:44
+
+from django.conf import settings
+from django.db import migrations
+from django.db.models import Count
+
+def cleanup_duplicate_proposals(apps, schema_editor):
+    AlgorithmTagProposal = apps.get_model('problems', 'AlgorithmTagProposal')
+    DifficultyTagProposal = apps.get_model('problems', 'DifficultyTagProposal')
+
+    # Cleanup AlgorithmTagProposal
+    duplicates = (
+        AlgorithmTagProposal.objects.values('problem', 'tag', 'user')
+        .annotate(count=Count('id'))
+        .filter(count__gt=1)
+    )
+
+    for duplicate in duplicates:
+        AlgorithmTagProposal.objects.filter(
+            pk__in=AlgorithmTagProposal.objects.filter(
+                problem=duplicate["problem"],
+                tag=duplicate["tag"],
+                user=duplicate["user"]
+            ).values_list("id", flat=True)[1:]
+        ).delete()
+
+    # Cleanup DifficultyTagProposal
+    duplicates = (
+        DifficultyTagProposal.objects.values('problem', 'user')
+        .annotate(count=Count('id'))
+        .filter(count__gt=1)
+    )
+
+    for duplicate in duplicates:
+        DifficultyTagProposal.objects.filter(
+            pk__in=DifficultyTagProposal.objects.filter(
+                problem=duplicate["problem"],
+                user=duplicate["user"]
+            ).values_list("id", flat=True)[1:]
+        ).delete()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('problems', '0038_alter_algorithmtaglocalization_language_and_more'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.RunPython(cleanup_duplicate_proposals),
+        migrations.AlterUniqueTogether(
+            name='algorithmtagproposal',
+            unique_together={('problem', 'tag', 'user')},
+        ),
+        migrations.AlterUniqueTogether(
+            name='difficultytagproposal',
+            unique_together={('problem', 'user')},
+        ),
+    ]

oioioi/problems/models.py

@@ -797,6 +797,7 @@ def __str__(self):
         return str(self.problem.name) + " -- " + str(self.tag.name)
 
     class Meta:
+        unique_together = ("problem", "user")
         verbose_name = _("difficulty proposal")
         verbose_name_plural = _("difficulty proposals")
 
@@ -878,6 +879,7 @@ def __str__(self):
         return str(self.problem.name) + " -- " + str(self.tag.name)
 
     class Meta:
+        unique_together = ("problem", "tag", "user")
         verbose_name = _("algorithm tag proposal")
         verbose_name_plural = _("algorithm tag proposals")
 

oioioi/problems/tests/test_tag_proposals.py

@@ -266,3 +266,31 @@ def test_save_proposals_view(self):
         for q_data in invalid_query_data:
             response = self.client.post(self.url, q_data)
             self.assertEqual(response.status_code, 400)
+
+    def test_duplicate_difficulty_proposal_rejected(self):
+        problem = Problem.objects.get(pk=0)
+        user = User.objects.get(username="test_admin")
+
+        response = self.client.post(
+            self.url,
+            {
+                "tags[]": ["Dynamic programming"],
+                "difficulty": "Easy",
+                "user": "test_admin",
+                "problem": "0",
+            },
+        )
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(DifficultyTagProposal.objects.filter(problem=problem, user=user).count(), 1)
+
+        response = self.client.post(
+            self.url,
+            {
+                "tags[]": ["Greedy"],
+                "difficulty": "Medium",
+                "user": "test_admin",
+                "problem": "0",
+            },
+        )
+        self.assertEqual(response.status_code, 400)
+        self.assertEqual(DifficultyTagProposal.objects.filter(problem=problem, user=user).count(), 1)

oioioi/problems/views.py

@@ -1156,8 +1156,16 @@ def save_proposals_view(request):
         if not tags or not difficulty or not user or not problem:
             return HttpResponseBadRequest()
 
+        if DifficultyTagProposal.objects.filter(problem=problem, user=user).exists():
+            return HttpResponseBadRequest()
+
         for tag in tags:
             algorithm_tag = AlgorithmTagLocalization.objects.filter(full_name=tag, language=get_language()).first().algorithm_tag
+
+
+            if AlgorithmTagProposal.objects.filter(problem=problem, tag=algorithm_tag, user=user).exists():
+                return HttpResponseBadRequest()
+
             algorithm_tag_proposal = AlgorithmTagProposal(problem=problem, tag=algorithm_tag, user=user)
             algorithm_tag_proposal.save()