feat(common): add non duplicate declaration to object merger

fixes #304

scipost_django/common/migrations/0003_alter_nonduplicate_unique_together_and_more.py

+# Generated by Django 5.0.12 on 2025-03-04 16:49
+
+from django.db import migrations, models
+from django.db.models import F
+
+
+def enforce_object_id_order(apps, schema_editor):
+    Nonduplicate = apps.get_model("common", "Nonduplicate")
+
+    Nonduplicate.objects.filter(object_a_id__gt=F("object_b_id")).update(
+        object_a_id=F("object_b_id"), object_b_id=F("object_a_id")
+    )
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("common", "0002_migrate_nonduplicate_profiles"),
+        ("contenttypes", "0002_remove_content_type_name"),
+        (
+            "scipost",
+            "0041_alter_remark_contributor_alter_remark_recommendation_and_more",
+        ),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name="nonduplicate",
+            unique_together=set(),
+        ),
+        migrations.AddConstraint(
+            model_name="nonduplicate",
+            constraint=models.UniqueConstraint(
+                fields=("content_type", "object_a_id", "object_b_id"),
+                name="unique_non_duplicate",
+                violation_error_message="This non-duplicate declaration already exists",
+            ),
+        ),
+        migrations.RunPython(
+            enforce_object_id_order, reverse_code=migrations.RunPython.noop
+        ),
+        migrations.AddConstraint(
+            model_name="nonduplicate",
+            constraint=models.CheckConstraint(
+                check=models.Q(("object_a_id__lt", models.F("object_b_id"))),
+                name="object_a_lt_object_b",
+                violation_error_message="To avoid duplicate declarations, object_a_id must be less than object_b_id",
+            ),
+        ),
+    ]

scipost_django/common/models.py

@@ -8,7 +8,6 @@ from scipost.models import Contributor
 
 
 class NonDuplicate(models.Model):
-
     contributor = models.ForeignKey[Contributor](
         "scipost.Contributor",
         on_delete=models.CASCADE,
@@ -29,7 +28,18 @@ class NonDuplicate(models.Model):
     created = models.DateTimeField(auto_now_add=True)
 
     class Meta:
-        unique_together = ("content_type", "object_a_id", "object_b_id")
+        constraints = [
+            models.UniqueConstraint(
+                fields=["content_type", "object_a_id", "object_b_id"],
+                name="unique_non_duplicate",
+                violation_error_message="This non-duplicate declaration already exists",
+            ),
+            models.CheckConstraint(
+                check=models.Q(object_a_id__lt=models.F("object_b_id")),
+                name="object_a_lt_object_b",
+                violation_error_message="To avoid duplicate declarations, object_a_id must be less than object_b_id",
+            ),
+        ]
         verbose_name = "Non-duplicate"
         verbose_name_plural = "Non-duplicates"
 

scipost_django/common/templates/common/object_merger/compare.html

@@ -18,19 +18,42 @@
     <div class="col fs-4">
       <a href="{{ object_a.get_absolute_url }}">{{ object_a }}</a>
     </div>
-    <div class="col-auto d-flex flex-column justify-content-center">
-      <a class="btn btn-sm btn-primary"
-         href="{% url "common:object_merger_merge" content_type.id object_a.id object_b.id %}">
-        {% include "bi/arrow-right.html" %}
-      </a>
-      <a class="btn btn-sm btn-secondary"
-         href="{% url "common:object_merger_merge" content_type.id object_b.id object_a.id %}">
-        {% include "bi/arrow-left.html" %}
-      </a>
-    </div>
+    
+    {% if not non_duplicate_declaration %}
+      <div class="col-auto d-flex flex-column justify-content-center">
+        <div class="d-flex flex-row">
+          <a class="btn btn-sm btn-primary flex-fill"
+            href="{% url "common:object_merger_merge" content_type.id object_a.id object_b.id %}">
+            {% include "bi/arrow-right.html" %}
+          </a>
+          <a class="btn btn-sm btn-secondary flex-fill"
+            href="{% url "common:object_merger_merge" content_type.id object_b.id object_a.id %}">
+            {% include "bi/arrow-left.html" %}
+          </a>
+        </div>
+        <button class="btn btn-sm btn-warning"
+                hx-swap="afterend"
+                hx-get="{% url "common:object_merger_mark_non_duplicate" content_type.id object_b.id object_a.id %}"
+                hx-prompt="What is the reason/source for marking these as definitively not duplicates?">
+          Non Duplicate
+        </button>
+      </div>
+    {% endif %}
+
     <div class="col fs-4">
       <a href="{{ object_b.get_absolute_url }}">{{ object_b }}</a>
     </div>
+
+    {% if non_duplicate_declaration %}
+      <div class="bg-warning bg-opacity-25 p-2 mt-2">
+        <div class="d-flex justify-content-between">
+          <span class="fw-bold">Non Duplicate Declaration by {{ non_duplicate_declaration.contributor.profile.full_name }}</span>
+          <span>{{ non_duplicate_declaration.created|date:"Y-m-d" }}</span>
+        </div>
+        <p class="mb-0">{{ non_duplicate_declaration.description }}</p>
+      </div>
+    {% endif %}
+
   </div>
 
   {% for group_name, group in field_groups.items %}
@@ -67,20 +90,24 @@
 
               {% if not forloop.last %}
                 <div class="col-12 col-md-auto">
-                  <hr class="d-md-none">
+                  <hr class="d-md-none" />
                 </div>
               {% endif %}
+
             {% endfor %}
 
+
           </div>
         </details>
       {% endfor %}
 
+
     {% else %}
- 
+
       {% for field_name, objects_field_value in group.items %}
         <div class="row">
           <h3 class="fs-5 bg-light">{{ field_name|title }}</h3>
+
           {% for object_field_value in objects_field_value %}
             <div class="col-12 col-md">
 
@@ -91,10 +118,13 @@
               {% endif %}
 
             </div>
-          {% endfor %} 
+          {% endfor %}
+
+
         </div>
       {% endfor %}
 
+
     {% endif %}
 
   {% endfor %}

scipost_django/common/urls.py

@@ -43,6 +43,11 @@ urlpatterns = [
                                 merger_views.HXMergeView.as_view(),
                                 name="object_merger_merge",
                             ),
+                            path(
+                                "mark_non_duplicate",
+                                merger_views.HXNonDuplicateCreateView.as_view(),
+                                name="object_merger_mark_non_duplicate",
+                            ),
                         ]
                     ),
                 ),

scipost_django/common/views/object_merger.py

@@ -10,6 +10,9 @@ from django.db.models import Model, QuerySet, Field, ForeignObjectRel
 from django.http import Http404, HttpRequest, HttpResponse
 from django.views.generic import TemplateView
 
+from common.models import NonDuplicate
+from scipost.permissions import HTMXPermissionsDenied, HTMXResponse
+
 FieldValue = Model | list[Model] | None
 FieldOrRel = Field[Any, Any] | ForeignObjectRel
 T = TypeVar("T")
@@ -69,6 +72,28 @@ class CompareView(PermissionRequiredMixin, TemplateView):
 
         return object_a, object_b
 
+    def get_non_duplicate_declaration(self) -> NonDuplicate | None:
+        """
+        Retrieve all NonDuplicate declarations for the two objects.
+        """
+
+        if not (content_type_id := self.kwargs.get(self.content_type_kwarg)):
+            raise BadRequest("No content type ID provided.")
+        if not (object_a_id := self.kwargs.get(self.object_a_kwarg)):
+            raise BadRequest("No object A ID provided.")
+        if not (object_b_id := self.kwargs.get(self.object_b_kwarg)):
+            raise BadRequest("No object B ID provided.")
+
+        # Ensure object_a_id < object_b_id
+        if object_a_id > object_b_id:
+            object_a_id, object_b_id = object_b_id, object_a_id
+
+        return NonDuplicate.objects.filter(
+            content_type_id=content_type_id,
+            object_a_id=object_a_id,
+            object_b_id=object_b_id,
+        ).first()
+
     def get_permission_required(self) -> list[str]:
         perms = list(super().get_permission_required())
 
@@ -139,7 +164,6 @@ class CompareView(PermissionRequiredMixin, TemplateView):
 
     @staticmethod
     def group_fields(field_data: dict[FieldOrRel, T]) -> dict[str, dict[FieldOrRel, T]]:
-
         groups: dict[str, dict[FieldOrRel, T]] = {
             "fields": {},
             "related_objects_one": {},
@@ -170,12 +194,14 @@ class HXCompareView(CompareView):
 
         content_type = self.get_content_type()
         object_a, object_b = self.get_objects()
+        non_duplicate_declaration = self.get_non_duplicate_declaration()
 
         context |= {
             "content_type": content_type,
             "objects": [object_a, object_b],
             "object_a": object_a,
             "object_b": object_b,
+            "non_duplicate_declaration": non_duplicate_declaration,
         }
 
         if model := content_type.model_class():
@@ -249,12 +275,14 @@ class HXMergeView(CompareView):
 
         content_type = self.get_content_type()
         object_from, object_to = self.get_objects()
+        non_duplicate_declaration = self.get_non_duplicate_declaration()
 
         context |= {
             "content_type": content_type,
             "objects": [object_from, object_to],
             "object_from": object_from,
             "object_to": object_to,
+            "non_duplicate_declaration": non_duplicate_declaration,
         }
 
         if model := content_type.model_class():
@@ -277,3 +305,38 @@ class HXMergeView(CompareView):
 
         return context
 
+
+class HXNonDuplicateCreateView(CompareView):
+    """
+    View for creating a NonDuplicate object.
+    """
+
+    permission_required = "scipost.can_mark_non_duplicates"
+
+    def get(self, request: HttpRequest, *args: Any, **kwargs: Any) -> HttpResponse:
+        if request.headers.get("HX-Request") != "true":
+            raise BadRequest("This view is only accessible via HTMX.")
+
+        if not request.user.has_perm("scipost.can_mark_non_duplicates"):
+            return HTMXPermissionsDenied(
+                "You do not have permission to mark non-duplicates."
+            )
+
+        content_type = self.get_content_type()
+        object_a, object_b = self.get_objects()
+
+        # Ensure object_a_id < object_b_id
+        if object_a.id > object_b.id:
+            object_a, object_b = object_b, object_a
+
+        NonDuplicate.objects.create(
+            object_a=object_a,
+            object_b=object_b,
+            contributor=request.user.contributor,
+            description=request.headers.get("HX-Prompt"),
+        )
+
+        return HTMXResponse(
+            "Objects marked as non-duplicates.",
+            tag="success",
+        )