Implement alias models

aleksis/apps/postbuero/migrations/0005_group_address.py

+# Generated by Django 3.2.15 on 2022-08-10 16:29
+
+import aleksis.core.managers
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contenttypes', '0002_remove_content_type_name'),
+        ('sites', '0002_alter_domain_unique'),
+        ('core', '0041_update_gender_choices'),
+        ('postbuero', '0004_domain_is_public'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='MailAlias',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('extended_data', models.JSONField(default=dict, editable=False)),
+                ('local_part', models.CharField(max_length=64, verbose_name='Local part')),
+                ('domain', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='postbuero.maildomain', verbose_name='Domain')),
+                ('polymorphic_ctype', models.ForeignKey(editable=False, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='polymorphic_postbuero.mailalias_set+', to='contenttypes.contenttype')),
+                ('site', models.ForeignKey(default=1, editable=False, on_delete=django.db.models.deletion.CASCADE, to='sites.site')),
+            ],
+            options={
+                'verbose_name': 'Mail alias',
+                'verbose_name_plural': 'Mail alias',
+            },
+            managers=[
+                ('objects', aleksis.core.managers.PolymorphicCurrentSiteManager()),
+            ],
+        ),
+        migrations.CreateModel(
+            name='MailAliasForPerson',
+            fields=[
+                ('mailalias_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='postbuero.mailalias')),
+                ('person', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='local_mail_aliases', to='core.person', verbose_name='Person')),
+            ],
+            options={
+                'verbose_name': 'Mail alias for a person',
+                'verbose_name_plural': 'Mail aliases for persons',
+            },
+            bases=('postbuero.mailalias',),
+            managers=[
+                ('objects', aleksis.core.managers.PolymorphicCurrentSiteManager()),
+            ],
+        ),
+        migrations.CreateModel(
+            name='MailAliasForGroup',
+            fields=[
+                ('mailalias_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='postbuero.mailalias')),
+                ('group', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='local_mail_aliases', to='core.group', verbose_name='Group')),
+            ],
+            options={
+                'verbose_name': 'Mail alias for a group',
+                'verbose_name_plural': 'Mail aliases for groups',
+            },
+            bases=('postbuero.mailalias',),
+            managers=[
+                ('objects', aleksis.core.managers.PolymorphicCurrentSiteManager()),
+            ],
+        ),
+        migrations.AddConstraint(
+            model_name='mailalias',
+            constraint=models.UniqueConstraint(fields=('local_part', 'domain'), name='unique_alias_per_domain'),
+        ),
+    ]

aleksis/apps/postbuero/models.py

 from django.db import models
 from django.utils.translation import gettext_lazy as _
 
-from aleksis.core.mixins import ExtensibleModel
-from aleksis.core.models import Person
+from aleksis.core.mixins import ExtensibleModel, ExtensiblePolymorphicModel
+from aleksis.core.models import Group, Person
 
 
 class MailDomain(ExtensibleModel):
@@ -40,3 +40,76 @@ class MailAddress(ExtensibleModel):
                 fields=["local_part", "domain"], name="unique_local_part_per_domain"
             )
         ]
+
+
+class MailAlias(ExtensiblePolymorphicModel):
+    domain = models.ForeignKey(MailDomain, verbose_name=_("Domain"), on_delete=models.CASCADE)
+    local_part = models.CharField(verbose_name=_("Local part"), max_length=64)
+
+    def __str__(self) -> str:
+        return f"{self.local_part}@{self.domain}"
+
+    def resolve(self, **kwargs):
+        raise NotImplementedError("You must use the concrete model to resovle the alias.")
+
+    class Meta:
+        verbose_name = _("Mail alias")
+        verbose_name_plural = _("Mail alias")
+        constraints = [
+            models.UniqueConstraint(
+                fields=["local_part", "domain"], name="unique_alias_per_domain"
+            )
+        ]
+
+
+class MailAliasForPerson(MailAlias):
+    person = models.ForeignKey(
+        Person,
+        verbose_name=_("Person"),
+        null=True,
+        on_delete=models.SET_NULL,
+        related_name="local_mail_aliases",
+    )
+
+    def resolve(self, guardians: bool = False):
+        """Resolve alias to the e-mail address of this person or its guardians."""
+        if not self.person:
+            return []
+
+        if guardians:
+            return list(self.person.guardians.all().values_list("email", flat=True))
+
+        return [self.person.email]
+
+    class Meta:
+        verbose_name = _("Mail alias for a person")
+        verbose_name_plural = _("Mail aliases for persons")
+
+
+class MailAliasForGroup(MailAlias):
+    group = models.ForeignKey(
+        Group,
+        verbose_name=_("Group"),
+        null=True,
+        on_delete=models.SET_NULL,
+        related_name="local_mail_aliases",
+    )
+
+    def resolve(self, guardians: bool = False, owners: bool = False):
+        """Resolve alias to the e-mail addresses of this group's members, owners, or their guardians."""
+        if not self.group:
+            return []
+
+        if owners:
+            pq = self.group.owners.all()
+        else:
+            pq = self.group.members.all()
+
+        if guardians:
+            pq = Person.objects.filter(children__in=pq)
+
+        return list(pq.values_list("email", flat=True))
+
+    class Meta:
+        verbose_name = _("Mail alias for a group")
+        verbose_name_plural = _("Mail aliases for groups")