Add Invitation model

ref #19

src/servala/core/admin.py

@@ -9,6 +9,7 @@ from servala.core.models import (
     ControlPlane,
     ControlPlaneCRD,
     Organization,
+    OrganizationInvitation,
     OrganizationMembership,
     OrganizationOrigin,
     Service,
@@ -105,6 +106,28 @@ class OrganizationMembershipAdmin(admin.ModelAdmin):
     date_hierarchy = "date_joined"
 
 
+@admin.register(OrganizationInvitation)
+class OrganizationInvitationAdmin(admin.ModelAdmin):
+    list_display = ("email", "organization", "role", "is_accepted", "created_at")
+    list_filter = ("role", "created_at", "accepted_at", "organization")
+    search_fields = ("email", "organization__name")
+    autocomplete_fields = ("organization", "accepted_by")
+    readonly_fields = (
+        "secret",
+        "accepted_by",
+        "accepted_at",
+        "created_at",
+        "updated_at",
+    )
+    date_hierarchy = "created_at"
+
+    def is_accepted(self, obj):
+        return obj.is_accepted
+
+    is_accepted.boolean = True
+    is_accepted.short_description = _("Accepted")
+
+
 @admin.register(ServiceCategory)
 class ServiceCategoryAdmin(admin.ModelAdmin):
     list_display = ("name", "parent")

src/servala/core/migrations/0011_organizationinvitation.py

@@ -0,0 +1,107 @@
+# Generated by Django 5.2.7 on 2025-10-17 00:58
+
+import django.db.models.deletion
+import rules.contrib.models
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("core", "0010_organizationorigin_billing_entity"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="OrganizationInvitation",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                (
+                    "created_at",
+                    models.DateTimeField(auto_now_add=True, verbose_name="Created"),
+                ),
+                (
+                    "updated_at",
+                    models.DateTimeField(auto_now=True, verbose_name="Last updated"),
+                ),
+                (
+                    "email",
+                    models.EmailField(max_length=254, verbose_name="Email address"),
+                ),
+                (
+                    "role",
+                    models.CharField(
+                        choices=[
+                            ("member", "Member"),
+                            ("admin", "Administrator"),
+                            ("owner", "Owner"),
+                        ],
+                        default="member",
+                        max_length=20,
+                        verbose_name="Role",
+                    ),
+                ),
+                (
+                    "secret",
+                    models.CharField(
+                        editable=False,
+                        max_length=64,
+                        unique=True,
+                        verbose_name="Secret token",
+                    ),
+                ),
+                (
+                    "accepted_at",
+                    models.DateTimeField(
+                        blank=True, null=True, verbose_name="Accepted at"
+                    ),
+                ),
+                (
+                    "accepted_by",
+                    models.ForeignKey(
+                        blank=True,
+                        null=True,
+                        on_delete=django.db.models.deletion.SET_NULL,
+                        related_name="accepted_invitations",
+                        to=settings.AUTH_USER_MODEL,
+                        verbose_name="Accepted by",
+                    ),
+                ),
+                (
+                    "created_by",
+                    models.ForeignKey(
+                        blank=True,
+                        null=True,
+                        on_delete=django.db.models.deletion.SET_NULL,
+                        related_name="created_invitations",
+                        to=settings.AUTH_USER_MODEL,
+                        verbose_name="Created by",
+                    ),
+                ),
+                (
+                    "organization",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="invitations",
+                        to="core.organization",
+                        verbose_name="Organization",
+                    ),
+                ),
+            ],
+            options={
+                "verbose_name": "Organization invitation",
+                "verbose_name_plural": "Organization invitations",
+                "unique_together": {("organization", "email")},
+            },
+            bases=(rules.contrib.models.RulesModelMixin, models.Model),
+        ),
+    ]

src/servala/core/models/__init__.py

@@ -1,6 +1,7 @@
 from .organization import (
     BillingEntity,
     Organization,
+    OrganizationInvitation,
     OrganizationMembership,
     OrganizationOrigin,
     OrganizationRole,
@@ -23,6 +24,7 @@ __all__ = [
     "ControlPlane",
     "ControlPlaneCRD",
     "Organization",
+    "OrganizationInvitation",
     "OrganizationMembership",
     "OrganizationOrigin",
     "OrganizationRole",

src/servala/core/models/organization.py

@@ -1,3 +1,5 @@
+import secrets
+
 import rules
 import urlman
 from django.conf import settings
@@ -417,3 +419,70 @@ class OrganizationMembership(ServalaModelMixin, models.Model):
 
     def __str__(self):
         return f"{self.user} in {self.organization} as {self.role}"
+
+
+class OrganizationInvitation(ServalaModelMixin, models.Model):
+    organization = models.ForeignKey(
+        to=Organization,
+        on_delete=models.CASCADE,
+        related_name="invitations",
+        verbose_name=_("Organization"),
+    )
+    email = models.EmailField(verbose_name=_("Email address"))
+    role = models.CharField(
+        max_length=20,
+        choices=OrganizationRole.choices,
+        default=OrganizationRole.MEMBER,
+        verbose_name=_("Role"),
+    )
+    secret = models.CharField(
+        max_length=64,
+        unique=True,
+        editable=False,
+        verbose_name=_("Secret token"),
+    )
+    created_by = models.ForeignKey(
+        to="core.User",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="created_invitations",
+        verbose_name=_("Created by"),
+    )
+    accepted_by = models.ForeignKey(
+        to="core.User",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="accepted_invitations",
+        verbose_name=_("Accepted by"),
+    )
+    accepted_at = models.DateTimeField(
+        null=True, blank=True, verbose_name=_("Accepted at")
+    )
+
+    class urls(urlman.Urls):
+        accept = "/invitations/{self.secret}/accept/"
+
+    class Meta:
+        verbose_name = _("Organization invitation")
+        verbose_name_plural = _("Organization invitations")
+        unique_together = [["organization", "email"]]
+
+    def __str__(self):
+        return f"Invitation for {self.email} to {self.organization}"
+
+    def save(self, *args, **kwargs):
+        if not self.secret:
+            self.secret = secrets.token_urlsafe(48)
+        super().save(*args, **kwargs)
+
+    @property
+    def is_accepted(self):
+        # We check both accepted_by and accepted_at to avoid a deleted user
+        # freeing up an invitation
+        return self.accepted_by or self.accepted_at
+
+    @property
+    def can_be_accepted(self):
+        return not self.is_accepted