[#390] Refactor backend to use Django permissions

backend/src/openarchiefbeheer/accounts/admin.py

@@ -3,18 +3,16 @@
 from django.contrib.auth.admin import UserAdmin as _UserAdmin
 from django.core.exceptions import PermissionDenied, ValidationError
 from django.urls import reverse_lazy
-from django.utils.translation import gettext_lazy as _
 
 from .forms import PreventPrivilegeEscalationMixin, UserChangeForm
-from .models import Role, User
+from .models import User
 from .utils import validate_max_user_permissions
 
 
 @admin.register(User)
 class UserAdmin(_UserAdmin):
     hijack_success_url = reverse_lazy("root")
     form = UserChangeForm
-    list_display = _UserAdmin.list_display + ("role",)
 
     def get_form(self, request, obj=None, **kwargs):
         ModelForm = super().get_form(request, obj, **kwargs)
@@ -34,18 +32,3 @@ def user_change_password(self, request, id, form_url=""):
             raise PermissionDenied from exc
 
         return super().user_change_password(request, id, form_url)
-
-    def get_fieldsets(self, request, obj=None):
-        fieldsets = super().get_fieldsets(request, obj)
-        return tuple(fieldsets) + ((_("Role"), {"fields": ("role",)}),)
-
-
-@admin.register(Role)
-class RoleAdmin(admin.ModelAdmin):
-    list_display = (
-        "name",
-        "can_start_destruction",
-        "can_review_destruction",
-        "can_view_case_details",
-        "can_review_final_list",
-    )

backend/src/openarchiefbeheer/accounts/api/serializers.py

@@ -1,23 +1,49 @@
+from django.utils.translation import gettext_lazy as _
+
+from drf_spectacular.utils import extend_schema_field
 from rest_framework import serializers
 
-from ..models import Role, User
+from ..models import User
+
 
+class RoleSerializer(serializers.Serializer):
+    can_start_destruction = serializers.BooleanField()
+    can_review_destruction = serializers.BooleanField()
+    can_review_final_list = serializers.BooleanField()
 
-class RoleSerializer(serializers.ModelSerializer):
     class Meta:
-        model = Role
         fields = (
-            "name",
             "can_start_destruction",
             "can_review_destruction",
             "can_review_final_list",
-            "can_view_case_details",
         )
 
 
 class UserSerializer(serializers.ModelSerializer):
-    role = RoleSerializer()
+    role = serializers.SerializerMethodField(
+        help_text=_("The role of the user within the application logic."),
+        allow_null=True,
+    )
 
     class Meta:
         model = User
         fields = ("pk", "username", "first_name", "last_name", "email", "role")
+
+    @extend_schema_field(RoleSerializer)
+    def get_role(self, user: User) -> dict | None:
+        serializer = RoleSerializer(
+            data={
+                "can_review_destruction": user.has_perm(
+                    "accounts.can_review_destruction"
+                ),
+                "can_start_destruction": user.has_perm(
+                    "accounts.can_start_destruction"
+                ),
+                "can_review_final_list": user.has_perm(
+                    "accounts.can_review_final_list"
+                ),
+            }
+        )
+        serializer.is_valid()
+
+        return serializer.data

backend/src/openarchiefbeheer/accounts/fixtures/permissions.json

@@ -0,0 +1,35 @@
+[
+    {
+      "model": "auth.permission",
+      "fields": {
+        "name": "Can start destruction",
+        "content_type": [
+          "accounts",
+          "user"
+        ],
+        "codename": "can_start_destruction"
+      }
+    },
+    {
+      "model": "auth.permission",
+      "fields": {
+        "name": "Can review destruction",
+        "content_type": [
+          "accounts",
+          "user"
+        ],
+        "codename": "can_review_destruction"
+      }
+    },
+    {
+      "model": "auth.permission",
+      "fields": {
+        "name": "Can review final list",
+        "content_type": [
+          "accounts",
+          "user"
+        ],
+        "codename": "can_review_final_list"
+      }
+    }
+]

backend/src/openarchiefbeheer/accounts/managers.py

@@ -1,4 +1,10 @@
-from django.contrib.auth.models import BaseUserManager
+from typing import TYPE_CHECKING
+
+from django.contrib.auth.models import BaseUserManager, Permission
+from django.db.models import Q, QuerySet
+
+if TYPE_CHECKING:
+    from .models import User
 
 
 class UserManager(BaseUserManager):
@@ -33,8 +39,15 @@ def create_superuser(self, username, email, password, **extra_fields):
 
         return self._create_user(username, email, password, **extra_fields)
 
-    def reviewers(self):
-        return self.select_related("role").filter(role__can_review_destruction=True)
+    def _users_with_permission(self, permission: Permission) -> QuerySet["User"]:
+        return self.filter(
+            Q(groups__permissions=permission) | Q(user_permissions=permission)
+        ).distinct()
+
+    def reviewers(self) -> QuerySet["User"]:
+        permission = Permission.objects.get(codename="can_review_destruction")
+        return self._users_with_permission(permission)
 
-    def archivists(self):
-        return self.select_related("role").filter(role__can_review_final_list=True)
+    def archivists(self) -> QuerySet["User"]:
+        permission = Permission.objects.get(codename="can_review_final_list")
+        return self._users_with_permission(permission)

backend/src/openarchiefbeheer/accounts/migrations/0004_add_groups_permissions.py

@@ -0,0 +1,58 @@
+# Generated by Django 4.2.15 on 2024-09-30 11:56
+
+from django.db import migrations
+
+PERMISSIONS = {
+    "can_start_destruction": "Can start destruction",
+    "can_review_destruction": "Can review destruction",
+    "can_review_final_list": "Can review final list",
+}
+
+GROUPS = {
+    "Record Manager": [
+        "can_start_destruction",
+    ],
+    "Reviewer": [
+        "can_review_destruction",
+    ],
+    "Archivist": [
+        "can_review_final_list",
+    ],
+    "Administrator": [
+        "can_start_destruction",
+        "can_review_destruction",
+        "can_review_final_list",
+    ],
+}
+
+
+def create_groups_permissions(apps, schema_editor):
+    User = apps.get_model("accounts", "User")
+    Group = apps.get_model("auth", "Group")
+    Permission = apps.get_model("auth", "Permission")
+    ContentType = apps.get_model("contenttypes", "ContentType")
+
+    content_type = ContentType.objects.get_for_model(User)
+    for code_name, name in PERMISSIONS.items():
+        Permission.objects.get_or_create(
+            codename=code_name, name=name, content_type=content_type
+        )
+
+    for group_name, permission_codenames in GROUPS.items():
+        group, _ = Group.objects.get_or_create(name=group_name)
+
+        for codename in permission_codenames:
+            permission = Permission.objects.get(codename=codename)
+            group.permissions.add(permission)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("accounts", "0003_role_can_review_final_list"),
+        ("auth", "0012_alter_user_first_name_max_length"),
+    ]
+
+    operations = [
+        migrations.RunPython(create_groups_permissions, migrations.RunPython.noop),
+    ]

backend/src/openarchiefbeheer/accounts/migrations/0005_add_users_to_groups.py

@@ -0,0 +1,101 @@
+# Generated by Django 4.2.15 on 2024-09-30 12:10
+
+from django.db import migrations
+
+
+def add_users_to_groups(apps, schema_editor):
+    User = apps.get_model("accounts", "User")
+    Group = apps.get_model("auth", "Group")
+
+    administrators = User.objects.filter(
+        role__can_start_destruction=True,
+        role__can_review_destruction=True,
+        role__can_review_final_list=True,
+    )
+    admin_group = Group.objects.get(name="Administrator")
+    for user in administrators:
+        user.groups.add(admin_group)
+
+    record_managers = User.objects.filter(
+        role__can_start_destruction=True,
+        role__can_review_destruction=False,
+        role__can_review_final_list=False,
+    )
+    record_manager_group = Group.objects.get(name="Record Manager")
+    for user in record_managers:
+        user.groups.add(record_manager_group)
+
+    reviewers = User.objects.filter(
+        role__can_start_destruction=False,
+        role__can_review_destruction=True,
+        role__can_review_final_list=False,
+    )
+    reviewer_group = Group.objects.get(name="Reviewer")
+    for user in reviewers:
+        user.groups.add(reviewer_group)
+
+    archivists = User.objects.filter(
+        role__can_start_destruction=False,
+        role__can_review_destruction=False,
+        role__can_review_final_list=True,
+    )
+    archivist_group = Group.objects.get(name="Archivist")
+    for user in archivists:
+        user.groups.add(archivist_group)
+
+
+def add_role_to_users(apps, schema_editor):
+    User = apps.get_model("accounts", "User")
+    Role = apps.get_model("accounts", "Role")
+
+    administrator, _ = Role.objects.get_or_create(
+        name="Administrator",
+        can_start_destruction=True,
+        can_review_destruction=True,
+        can_review_final_list=True,
+    )
+    record_manager, _ = Role.objects.get_or_create(
+        name="Record Manager",
+        can_start_destruction=True,
+        can_review_destruction=False,
+        can_review_final_list=False,
+    )
+    reviewer, _ = Role.objects.get_or_create(
+        name="Reviewer",
+        can_start_destruction=False,
+        can_review_destruction=True,
+        can_review_final_list=False,
+    )
+    archivist, _ = Role.objects.get_or_create(
+        name="Archivist",
+        can_start_destruction=False,
+        can_review_destruction=False,
+        can_review_final_list=True,
+    )
+
+    users = User.objects.all()
+
+    for user in users:
+        if user.groups.filter(name="Administrator").exists():
+            user.role = administrator
+        elif user.groups.filter(name="Record Manager").exists():
+            user.role = record_manager
+        elif user.groups.filter(name="Reviewer").exists():
+            user.role = reviewer
+        elif user.groups.filter(name="Archivist").exists():
+            user.role = archivist
+        else:
+            continue
+
+        user.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("accounts", "0004_add_groups_permissions"),
+    ]
+
+    operations = [
+        migrations.RunPython(add_users_to_groups, add_role_to_users),
+    ]

backend/src/openarchiefbeheer/accounts/migrations/0006_remove_user_role_delete_role.py

@@ -0,0 +1,20 @@
+# Generated by Django 4.2.15 on 2024-09-30 12:55
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("accounts", "0005_add_users_to_groups"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="user",
+            name="role",
+        ),
+        migrations.DeleteModel(
+            name="Role",
+        ),
+    ]