feat: Contributor backend 21 (#144)

* avoid importing models

* fix issues

* fix type imports

* fix: type as vars

* fix: type imports

* fix: imports

* fix: imports

* base request

* fix: types

* ignore duplicate code

* disable duplicate code

* split request objects

* session param

* disable duplicate code

* fix: abstract api request factory

* import base api request factory

* split model list serializer

* abstract model view and serializer

* abstract model list

* import BaseModelListSerializer

* disable missing-function-docstring

* init request

* fix: init request

* abstract model serializer test case

* fix types

* fix linting issues

* split code

* fix: abstract api test case and client

* # pylint: disable-next=too-many-ancestors

* split code

* abstract user and session

* fix: type hints

* fix types

* fix types

* disable too-many-ancestors

* fix linting

* abstract model view set test case and client

* import base classes

* fix: session def

* mypy ignore

* remove id field

* abstract is authenticated

* fix: comment out check

* delete unnecessary code

* fix pre setup

* disable no-member

* model serializer type arg

* AnyBaseModelViewSet

* AnyBaseModelViewSet

* fix type hints

* base login view and form

* fix: import

* get arg helper

* delete unused var

* migrate on app startup

* feedback

codeforlife/app.py

@@ -6,6 +6,7 @@
 import multiprocessing
 import typing as t
 
+from django.core.management import call_command
 from gunicorn.app.base import BaseApplication  # type: ignore[import-untyped]
 
 
@@ -19,6 +20,8 @@ class StandaloneApplication(BaseApplication):
     """
 
     def __init__(self, app: t.Callable):
+        call_command("migrate", interactive=False)
+
         self.options = {
             "bind": "0.0.0.0:8080",
             # https://docs.gunicorn.org/en/stable/design.html#how-many-workers

codeforlife/forms.py

@@ -0,0 +1,81 @@
+"""
+© Ocado Group
+Created on 07/11/2024 at 15:08:33(+00:00).
+"""
+
+import typing as t
+
+from django import forms
+from django.contrib.auth import authenticate
+from django.core.exceptions import ValidationError
+from django.core.handlers.wsgi import WSGIRequest
+
+from .models import AbstractBaseUser
+from .types import get_arg
+
+AnyAbstractBaseUser = t.TypeVar("AnyAbstractBaseUser", bound=AbstractBaseUser)
+
+
+class BaseLoginForm(forms.Form, t.Generic[AnyAbstractBaseUser]):
+    """Base login form that all other login forms must inherit."""
+
+    user: AnyAbstractBaseUser
+
+    @classmethod
+    def get_user_class(cls) -> t.Type[AnyAbstractBaseUser]:
+        """Get the user class."""
+        return get_arg(cls, 0)
+
+    def __init__(self, request: WSGIRequest, *args, **kwargs):
+        self.request = request
+        super().__init__(*args, **kwargs)
+
+    def clean(self):
+        """Authenticates a user.
+
+        Raises:
+            ValidationError: If there are form errors.
+            ValidationError: If the user's credentials were incorrect.
+            ValidationError: If the user's account is deactivated.
+
+        Returns:
+            The cleaned form data.
+        """
+
+        if self.errors:
+            raise ValidationError(
+                "Found form errors. Skipping authentication.",
+                code="form_errors",
+            )
+
+        user = authenticate(
+            self.request,
+            **{key: self.cleaned_data[key] for key in self.fields.keys()}
+        )
+        if user is None:
+            raise ValidationError(
+                self.get_invalid_login_error_message(),
+                code="invalid_login",
+            )
+        if not isinstance(user, self.get_user_class()):
+            raise ValidationError(
+                "Incorrect user class.",
+                code="incorrect_user_class",
+            )
+        if not user.is_active:
+            raise ValidationError(
+                "User is not active",
+                code="user_not_active",
+            )
+
+        self.user = user
+
+        return self.cleaned_data
+
+    def get_invalid_login_error_message(self) -> str:
+        """Returns the error message if the user failed to login.
+
+        Raises:
+            NotImplementedError: If message is not set.
+        """
+        raise NotImplementedError()

codeforlife/models/__init__.py

@@ -3,4 +3,7 @@
 Created on 19/01/2024 at 15:20:45(+00:00).
 """
 
+from .abstract_base_session import AbstractBaseSession
+from .abstract_base_user import AbstractBaseUser
 from .base import *
+from .base_session_store import BaseSessionStore

codeforlife/models/abstract_base_session.py

@@ -0,0 +1,78 @@
+"""
+© Ocado Group
+Created on 06/11/2024 at 16:44:56(+00:00).
+"""
+
+import typing as t
+
+from django.contrib.sessions.base_session import (
+    AbstractBaseSession as _AbstractBaseSession,
+)
+from django.db import models
+from django.utils import timezone
+from django.utils.translation import gettext_lazy as _
+
+from .abstract_base_user import AbstractBaseUser
+
+# pylint: disable=duplicate-code
+if t.TYPE_CHECKING:
+    from django_stubs_ext.db.models import TypedModelMeta
+
+    from .base_session_store import BaseSessionStore
+else:
+    TypedModelMeta = object
+
+AnyAbstractBaseUser = t.TypeVar("AnyAbstractBaseUser", bound=AbstractBaseUser)
+# pylint: enable=duplicate-code
+
+
+class AbstractBaseSession(_AbstractBaseSession):
+    """
+    Base session class to be inherited by all session classes.
+    https://docs.djangoproject.com/en/3.2/topics/http/sessions/#example
+    """
+
+    pk: str  # type: ignore[assignment]
+
+    user_id: int
+
+    # pylint: disable-next=missing-class-docstring,too-few-public-methods
+    class Meta(TypedModelMeta):
+        abstract = True
+        verbose_name = _("session")
+        verbose_name_plural = _("sessions")
+
+    @property
+    def is_expired(self):
+        """Whether or not this session has expired."""
+        return self.expire_date < timezone.now()
+
+    @property
+    def store(self):
+        """A store instance for this session."""
+        return self.get_session_store_class()(self.session_key)
+
+    @classmethod
+    def get_session_store_class(cls) -> t.Type["BaseSessionStore"]:
+        raise NotImplementedError
+
+    @staticmethod
+    def init_user_field(user_class: t.Type[AnyAbstractBaseUser]):
+        """Initializes the user field that relates a session to a user.
+
+        Example:
+            class Session(AbstractBaseSession):
+                user = AbstractBaseSession.init_user_field(User)
+
+        Args:
+            user_class: The user model to associate sessions to.
+
+        Returns:
+            A one-to-one field that relates to the provided user model.
+        """
+        return models.OneToOneField(
+            user_class,
+            null=True,
+            blank=True,
+            on_delete=models.CASCADE,
+        )

codeforlife/models/abstract_base_user.py

@@ -0,0 +1,58 @@
+"""
+© Ocado Group
+Created on 06/11/2024 at 16:38:15(+00:00).
+"""
+
+import typing as t
+from functools import cached_property
+
+from django.apps import apps
+from django.conf import settings
+from django.contrib.auth.models import AbstractBaseUser as _AbstractBaseUser
+from django.utils.translation import gettext_lazy as _
+
+if t.TYPE_CHECKING:
+    from django_stubs_ext.db.models import TypedModelMeta
+
+    from .abstract_base_session import AbstractBaseSession
+else:
+    TypedModelMeta = object
+
+
+class AbstractBaseUser(_AbstractBaseUser):
+    """
+    Base user class to be inherited by all user classes.
+    https://docs.djangoproject.com/en/3.2/topics/auth/customizing/#using-a-custom-user-model-when-starting-a-project
+    """
+
+    pk: int
+    session: "AbstractBaseSession"
+
+    # pylint: disable-next=missing-class-docstring,too-few-public-methods
+    class Meta(TypedModelMeta):
+        abstract = True
+        verbose_name = _("user")
+        verbose_name_plural = _("users")
+
+    @cached_property
+    def _session_class(self):
+        return t.cast(
+            t.Type["AbstractBaseSession"],
+            apps.get_model(
+                app_label=(
+                    t.cast(str, settings.SESSION_ENGINE)
+                    .lower()
+                    .removesuffix(".models.session")
+                    .split(".")[-1]
+                ),
+                model_name="session",
+            ),
+        )
+
+    @property
+    def is_authenticated(self):
+        """A flag designating if this contributor has authenticated."""
+        try:
+            return self.is_active and not self.session.is_expired
+        except self._session_class.DoesNotExist:
+            return False

codeforlife/models/base.py

@@ -7,23 +7,20 @@
 
 import typing as t
 
+from django.db.models import Manager
 from django.db.models import Model as _Model
 
 if t.TYPE_CHECKING:
     from django_stubs_ext.db.models import TypedModelMeta
 else:
     TypedModelMeta = object
 
-Id = t.TypeVar("Id")
 
+class Model(_Model):
+    """Base for all models."""
 
-class Model(_Model, t.Generic[Id]):
-    """A base class for all Django models."""
+    objects: Manager[t.Self]
 
-    id: Id
-    pk: Id
-
-    # pylint: disable-next=missing-class-docstring,too-few-public-methods
     class Meta(TypedModelMeta):
         abstract = True
 

codeforlife/models/base_session_store.py

@@ -0,0 +1,91 @@
+"""
+© Ocado Group
+Created on 06/11/2024 at 17:31:32(+00:00).
+"""
+
+import typing as t
+
+from django.contrib.auth import SESSION_KEY
+from django.contrib.sessions.backends.db import SessionStore
+from django.utils import timezone
+
+from ..types import get_arg
+
+if t.TYPE_CHECKING:
+    from .abstract_base_session import AbstractBaseSession
+    from .abstract_base_user import AbstractBaseUser
+
+    AnyAbstractBaseSession = t.TypeVar(
+        "AnyAbstractBaseSession", bound=AbstractBaseSession
+    )
+    AnyAbstractBaseUser = t.TypeVar(
+        "AnyAbstractBaseUser", bound=AbstractBaseUser
+    )
+else:
+    AnyAbstractBaseSession = t.TypeVar("AnyAbstractBaseSession")
+    AnyAbstractBaseUser = t.TypeVar("AnyAbstractBaseUser")
+
+
+class BaseSessionStore(
+    SessionStore,
+    t.Generic[AnyAbstractBaseSession, AnyAbstractBaseUser],
+):
+    """
+    Base session store class to be inherited by all session store classes.
+    https://docs.djangoproject.com/en/3.2/topics/http/sessions/#example
+    """
+
+    @classmethod
+    def get_model_class(cls) -> t.Type[AnyAbstractBaseSession]:
+        return get_arg(cls, 0)
+
+    @classmethod
+    def get_user_class(cls) -> t.Type[AnyAbstractBaseUser]:
+        """Get the user class."""
+        return get_arg(cls, 1)
+
+    def associate_session_to_user(
+        self, session: AnyAbstractBaseSession, user_id: int
+    ):
+        """Associate an anon session to a user.
+
+        Args:
+            session: The anon session.
+            user_id: The user to associate.
+        """
+        objects = self.get_user_class().objects  # type: ignore[attr-defined]
+        session.user = objects.get(id=user_id)  # type: ignore[attr-defined]
+
+    def create_model_instance(self, data):
+        try:
+            user_id = int(data.get(SESSION_KEY))
+        except (ValueError, TypeError):
+            # Create an anon session.
+            return super().create_model_instance(data)
+
+        model_class = self.get_model_class()
+
+        try:
+            session = model_class.objects.get(
+                user_id=user_id,  # type: ignore[misc]
+            )
+        except model_class.DoesNotExist:
+            session = model_class.objects.get(session_key=self.session_key)
+            self.associate_session_to_user(
+                t.cast(AnyAbstractBaseSession, session), user_id
+            )
+
+        session.session_data = self.encode(data)
+
+        return session
+
+    @classmethod
+    def clear_expired(cls, user_id=None):
+        session_query = cls.get_model_class().objects.filter(
+            expire_date__lt=timezone.now()
+        )
+
+        if user_id is not None:
+            session_query = session_query.filter(user_id=user_id)
+
+        session_query.delete()

codeforlife/request/__init__.py

@@ -0,0 +1,8 @@
+"""
+© Ocado Group
+Created on 05/11/2024 at 14:40:32(+00:00).
+"""
+
+from .drf import BaseRequest, Request
+from .http import BaseHttpRequest, HttpRequest
+from .wsgi import BaseWSGIRequest, WSGIRequest