If chair value changes, create new membership

See #11

website/committees/models.py

-from django.utils import timezone
+import logging
 
 from django.core.exceptions import ValidationError, NON_FIELD_ERRORS
 from django.contrib.auth.models import Permission
 from django.db import models
+from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
 
 from members.models import Member
 
 
+logger = logging.getLogger(__name__)
+
+
 class Committee(models.Model):
     """A committee"""
 
@@ -48,7 +52,7 @@ class ActiveMembershipManager(models.Manager):
     """Get only active memberships"""
     def get_queryset(self):
         """Get the currently active committee memberships"""
-        return super().get_queryset().exclude(until__lt=timezone.now())
+        return super().get_queryset().exclude(until__lt=timezone.now().date())
 
 
 class CommitteeMembership(models.Model):
@@ -87,14 +91,22 @@ class CommitteeMembership(models.Model):
         default=False,
     )
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        if self.pk is None:
+            self._was_chair = bool(self.chair)
+        else:
+            self._was_chair = False
+
     @property
     def is_active(self):
         """Is this membership currently active"""
-        return self.until is None or self.until > timezone.now()
+        return self.until is None or self.until > timezone.now().date()
 
     def clean(self):
         """Validation"""
-        if self.until and self.until > timezone.now():
+        if self.until and self.until > timezone.now().date():
             raise ValidationError({
                 'until': _("Membership expiration date can't be in the future:"
                            " '{}'").format(self.until)
@@ -110,6 +122,7 @@ class CommitteeMembership(models.Model):
         # Check if a committee has more than one chair
         chairs = (CommitteeMembership.active_memberships
                   .filter(committee=self.committee)
+                  .exclude(member=self.member)
                   .filter(chair=True)
                   .count())
         if chairs >= 1 and self.chair:
@@ -118,12 +131,27 @@ class CommitteeMembership(models.Model):
                 _('This committee already has a chair')})
 
         # check if this member is already in the committee
-        members = (self.committee.members
-                   .filter(pk=self.member.pk)
-                   .count())
-        if members >= 1:
-            raise ValidationError({
-                'member': _('This member is already in the committee')})
+        if self.pk is None:
+            members = (self.committee.members
+                       .filter(pk=self.member.pk)
+                       .count())
+            if members >= 1:
+                raise ValidationError({
+                    'member': _('This member is already in the committee')})
+
+    def save(self, *args, **kwargs):
+        """Save the instance"""
+        # If the chair changed and we're still active, we create a new instance
+        # Inactive instances should be handled manually
+        if (self.pk is not None and self._was_chair != self.chair and
+                not self.until):
+            logger.info("Creating new membership instance")
+            self.until = timezone.now().date()
+            super().save(*args, **kwargs)
+            self.pk = None  # forces INSERT
+            self.since = self.until  # Set since date to older expiration
+            self.until = None
+        super().save(*args, **kwargs)
 
     def __str__(self):
         return "{} membership of {} since {}".format(self.member,

website/committees/tests.py

@@ -43,56 +43,73 @@ class CommitteeMembersTest(TestCase):
     def test_until_date(self):
         m = CommitteeMembership(committee=self.testcie,
                                 member=self.testuser,
-                                until=timezone.now().replace(year=2000),
+                                until=timezone.now().date().replace(year=2000),
                                 chair=False)
         with self.assertRaises(ValidationError):
             m.clean()
-        m.since = timezone.now().replace(year=1900)
+        m.since = timezone.now().date().replace(year=1900)
         m.clean()
 
     def test_inactive(self):
         self.assertTrue(self.m.is_active)
-        self.m.until = timezone.now().replace(year=1900)
+        self.m.until = timezone.now().date().replace(year=1900)
         self.assertFalse(self.m.is_active)
 
 
 class CommitteeMembersChairTest(TestCase):
     fixtures = ['members.json', 'committees.json']
 
-    @classmethod
-    def setUpTestData(cls):
-        testcie = Committee.objects.get(name='testcie1')
-        testuser = Member.objects.get(pk=1)
-        cls.m1 = CommitteeMembership(committee=testcie,
-                                     member=testuser,
-                                     chair=True)
-        cls.m1.full_clean()
-        cls.m1.save()
-
     def setUp(self):
         self.testcie = Committee.objects.get(name='testcie1')
         self.testuser = Member.objects.get(pk=1)
+        self.testuser2 = Member.objects.get(pk=2)
+        self.m1 = CommitteeMembership(committee=self.testcie,
+                                      member=self.testuser,
+                                      chair=True)
+        self.m1.full_clean()
+        self.m1.save()
 
     def test_second_chair_fails(self):
-        testuser2 = Member.objects.get(pk=2)
-
         m = CommitteeMembership(committee=self.testcie,
-                                member=testuser2,
+                                member=self.testuser2,
                                 chair=True)
         with self.assertRaises(ValidationError):
             m.full_clean()
 
     def test_inactive_chair(self):
-        testuser2 = Member.objects.get(pk=2)
-        self.m1.until = timezone.now().replace(year=1900)
+        self.m1.until = timezone.now().date().replace(year=1900)
         self.m1.save()
+
         m = CommitteeMembership(committee=self.testcie,
-                                member=testuser2,
+                                member=self.testuser2,
                                 chair=True)
         m.full_clean()
 
+    def test_clean_self_chair(self):
+        self.m1.chair = True
+        self.m1.full_clean()
+
+    def test_change_chair(self):
+        pk = self.m1.pk
+        original_chair = self.m1.chair
+        self.m1.save()
+        self.assertEqual(self.m1.pk, pk, "new object created")
+        self.m1.chair = not original_chair
+        self.m1.save()
+        self.assertNotEqual(self.m1.pk, pk, "No new object created")
+
+    def test_change_chair_inactive(self):
+        pk = self.m1.pk
+        original_chair = self.m1.chair
+        self.m1.until = timezone.now().date()
+        self.m1.save()
+        self.assertEqual(self.m1.pk, pk, "new object created")
+        self.m1.chair = not original_chair
+        self.m1.save()
+        self.assertEqual(self.m1.pk, pk, "No new object created")
+
 
-class BackendTest(TestCase):
+class PermissionsBackendTest(TestCase):
     fixtures = ['members.json', 'committees.json']
 
     @classmethod