automatic submission number, student max in 1 group for every project

backend/pigeonhole/apps/groups/models.py

@@ -1,5 +1,6 @@
 from django.db import models
 from rest_framework import serializers
+from django.core.exceptions import ValidationError
 
 from backend.pigeonhole.apps.projects.models import Project
 from backend.pigeonhole.apps.users.models import Student
@@ -15,12 +16,24 @@ class Group(models.Model):
 
     objects = models.Manager()
 
+    # a student can only be in one group per project
+    def clean(self):
+        for student in self.student.all():
+            existing_groups = Group.objects.filter(
+                project_id=self.project_id, student=student).exclude(
+                group_id=self.group_id)
+            if existing_groups.exists():
+                raise ValidationError(f"Student {student} is already part of "
+                                      "another group in this project.")
+
+    # a student can only be in one group per project, group_nr is
+    # automatically assigned and unique per project
     def save(self, *args, **kwargs):
         if not self.group_id:
             if self.group_nr is None:
                 max_group_nr = Group.objects.filter(
                     project_id=self.project_id).aggregate(
-                        models.Max('group_nr'))['group_nr__max'] or 0
+                    models.Max('group_nr'))['group_nr__max'] or 0
                 self.group_nr = max_group_nr + 1
         super().save(*args, **kwargs)
 

backend/pigeonhole/apps/submissions/models.py

@@ -1,5 +1,6 @@
 from django.db import models
 from rest_framework import serializers
+from django.core.exceptions import ValidationError
 
 from backend.pigeonhole.apps.groups.models import Group
 
@@ -10,16 +11,25 @@ class Submissions(models.Model):
     group_id = models.ForeignKey(Group, on_delete=models.CASCADE, blank=False)
     submission_nr = models.IntegerField()
     file = models.FileField(upload_to='uploads/submissions/files/' +
-                            str(group_id) + '/' + str(submission_nr) + '/',
+                                      str(group_id) + '/' + str(submission_nr) + '/',
                             null=True, blank=False, max_length=255)
     timestamp = models.DateTimeField(auto_now_add=True)
     output_test = models.FileField(upload_to='uploads/submissions/outputs/' +
-                                   str(group_id) + '/' + str(submission_nr) +
-                                   '/output_test/', null=True, blank=False,
+                                             str(group_id) + '/' + str(submission_nr) +
+                                             '/output_test/', null=True, blank=False,
                                    max_length=255)
 
     objects = models.Manager()
 
+    # submission_nr is automatically assigned and unique per group, and 
+    # increments
+    def save(self, force_insert=False, force_update=False, using=None, update_fields=None):
+        if not self.submission_id:
+            max_submission_nr = Submissions.objects.filter(
+                group_id=self.group_id).aggregate(
+                models.Max('submission_nr'))['submission_nr__max'] or 0
+            self.submission_nr = max_submission_nr + 1
+        super().save(force_insert=force_insert, force_update=force_update, using=using, update_fields=update_fields)
 
 class SubmissionsSerializer(serializers.ModelSerializer):
     class Meta:

backend/pigeonhole/tests/test_models/test_submissions.py

@@ -51,7 +51,6 @@ def setUp(self):
         # Create submission
         Submissions.objects.create(
             group_id=group,
-            submission_nr=1,
         )
 
     def test_submission_student_relation(self):
@@ -66,17 +65,6 @@ def test_submission_project_relation(self):
         project = submission.group_id.project_id
         self.assertEqual(submission.group_id.project_id, project)
 
-    def test_update_and_delete_submission(self):
-        submission = Submissions.objects.get(submission_nr=1)
-        submission.submission_nr = 2
-        submission.save()
-        updated_submission = Submissions.objects.get(submission_nr=2)
-        self.assertEqual(updated_submission.submission_nr, 2)
-
-        submission.delete()
-        with self.assertRaises(Submissions.DoesNotExist):
-            Submissions.objects.get(submission_nr=2)
-
     def test_submission_file_upload_and_retrieval(self):
         submission = Submissions.objects.get(submission_nr=1)