"""User API Views"""

from datetime import timedelta
from json import loads
from typing import Any

from django.contrib.auth import update_session_auth_hash
from django.contrib.auth.models import AnonymousUser, Permission
from django.db.models import Exists, OuterRef, Prefetch, Q
from django.db.transaction import atomic
from django.db.utils import IntegrityError
from django.urls import reverse_lazy
from django.utils.http import urlencode
from django.utils.text import slugify
from django.utils.timezone import now
from django.utils.translation import gettext as _
from django.utils.translation import gettext_lazy
from django_filters.filters import (
    BooleanFilter,
    CharFilter,
    IsoDateTimeFilter,
    ModelMultipleChoiceFilter,
    MultipleChoiceFilter,
    UUIDFilter,
)
from django_filters.filterset import FilterSet
from djangoql.schema import BoolField, StrField
from drf_spectacular.types import OpenApiTypes
from drf_spectacular.utils import (
    OpenApiParameter,
    OpenApiResponse,
    extend_schema,
    extend_schema_field,
    inline_serializer,
)
from rest_framework.authentication import SessionAuthentication
from rest_framework.decorators import action
from rest_framework.exceptions import ValidationError
from rest_framework.fields import (
    BooleanField,
    CharField,
    ChoiceField,
    DateTimeField,
    IntegerField,
    ListField,
    SerializerMethodField,
    UUIDField,
)
from rest_framework.permissions import IsAuthenticated
from rest_framework.request import Request
from rest_framework.response import Response
from rest_framework.serializers import (
    ListSerializer,
    PrimaryKeyRelatedField,
)
from rest_framework.validators import UniqueValidator
from rest_framework.viewsets import ModelViewSet
from structlog.stdlib import get_logger

from authentik.api.authentication import TokenAuthentication
from authentik.api.search.fields import (
    ChoiceSearchField,
    JSONSearchField,
)
from authentik.api.validation import validate
from authentik.blueprints.v1.importer import SERIALIZER_CONTEXT_BLUEPRINT
from authentik.brands.models import Brand
from authentik.core.api.used_by import UsedByMixin
from authentik.core.api.utils import (
    JSONDictField,
    LinkSerializer,
    ModelSerializer,
    PassiveSerializer,
)
from authentik.core.middleware import (
    SESSION_KEY_IMPERSONATE_ORIGINAL_USER,
    SESSION_KEY_IMPERSONATE_USER,
)
from authentik.core.models import (
    USER_ATTRIBUTE_TOKEN_EXPIRING,
    USER_PATH_SERVICE_ACCOUNT,
    USERNAME_MAX_LENGTH,
    Group,
    Session,
    Token,
    TokenIntents,
    User,
    UserTypes,
    default_token_duration,
)
from authentik.endpoints.connectors.agent.auth import AgentAuth
from authentik.events.models import Event, EventAction
from authentik.flows.exceptions import FlowNonApplicableException
from authentik.flows.models import FlowToken
from authentik.flows.planner import PLAN_CONTEXT_PENDING_USER, FlowPlanner
from authentik.flows.views.executor import QS_KEY_TOKEN
from authentik.lib.avatars import get_avatar
from authentik.lib.utils.reflection import ConditionalInheritance
from authentik.lib.utils.time import timedelta_from_string, timedelta_string_validator
from authentik.rbac.api.roles import RoleSerializer
from authentik.rbac.decorators import permission_required
from authentik.rbac.models import Role, get_permission_choices
from authentik.stages.email.flow import pickle_flow_token_for_email
from authentik.stages.email.models import EmailStage
from authentik.stages.email.tasks import send_mails
from authentik.stages.email.utils import TemplateEmailMessage

LOGGER = get_logger()

INVALID_PASSWORD_HASH_MESSAGE = gettext_lazy(
    "Invalid password hash format. Must be a valid Django password hash."
)


class ParamUserSerializer(PassiveSerializer):
    """Partial serializer for query parameters to select a user"""

    user = PrimaryKeyRelatedField(queryset=User.objects.all().exclude_anonymous(), required=False)


class PartialGroupSerializer(ModelSerializer):
    """Partial Group Serializer, does not include child relations."""

    attributes = JSONDictField(required=False)

    class Meta:
        model = Group
        fields = [
            "pk",
            "num_pk",
            "name",
            "is_superuser",
            "attributes",
        ]


class UserSerializer(ModelSerializer):
    """User Serializer"""

    is_superuser = SerializerMethodField()
    avatar = SerializerMethodField()
    attributes = JSONDictField(required=False)
    groups = PrimaryKeyRelatedField(
        allow_empty=True,
        many=True,
        queryset=Group.objects.all().order_by("name"),
        default=list,
    )
    groups_obj = SerializerMethodField(allow_null=True)
    roles = PrimaryKeyRelatedField(
        allow_empty=True,
        many=True,
        queryset=Role.objects.all().order_by("name"),
        default=list,
    )
    roles_obj = SerializerMethodField(allow_null=True)
    uid = CharField(read_only=True)
    username = CharField(
        max_length=USERNAME_MAX_LENGTH,
        validators=[UniqueValidator(queryset=User.objects.all().order_by("username"))],
    )

    @property
    def _should_include_groups(self) -> bool:
        request: Request = self.context.get("request", None)
        if not request:
            return True
        return str(request.query_params.get("include_groups", "true")).lower() == "true"

    @property
    def _should_include_roles(self) -> bool:
        request: Request = self.context.get("request", None)
        if not request:
            return True
        return str(request.query_params.get("include_roles", "true")).lower() == "true"

    @extend_schema_field(BooleanField)
    def get_is_superuser(self, instance: User) -> bool:
        """Use annotation if available to avoid N+1 query"""
        ann = getattr(instance, "_annotated_is_superuser", None)
        if ann is not None:
            return ann
        return instance.is_superuser

    @extend_schema_field(PartialGroupSerializer(many=True))
    def get_groups_obj(self, instance: User) -> list[PartialGroupSerializer] | None:
        if not self._should_include_groups:
            return None
        return PartialGroupSerializer(instance.groups, many=True).data

    @extend_schema_field(RoleSerializer(many=True))
    def get_roles_obj(self, instance: User) -> list[RoleSerializer] | None:
        if not self._should_include_roles:
            return None
        return RoleSerializer(instance.roles, many=True).data

    def __init__(self, *args, **kwargs):
        """Setting password and permissions directly is allowed only in blueprints."""
        super().__init__(*args, **kwargs)
        if SERIALIZER_CONTEXT_BLUEPRINT in self.context:
            self.fields["password"] = CharField(required=False, allow_null=True)
            self.fields["password_hash"] = CharField(required=False, allow_null=True)
            self.fields["permissions"] = ListField(
                required=False,
                child=ChoiceField(choices=get_permission_choices()),
            )

    def create(self, validated_data: dict) -> User:
        """Create a user, with blueprint-only password and permission writes."""
        is_blueprint = SERIALIZER_CONTEXT_BLUEPRINT in self.context
        if is_blueprint:
            password = validated_data.pop("password", None)
            password_hash = validated_data.pop("password_hash", None)
            permissions = validated_data.pop("permissions", [])
            self._validate_password_inputs(password, password_hash)

        instance: User = super().create(validated_data)
        if is_blueprint:
            self._set_password(instance, password, password_hash)
            perms_qs = Permission.objects.filter(
                codename__in=[permission.split(".")[1] for permission in permissions]
            ).values_list("content_type__app_label", "codename")
            perms_list = [f"{ct}.{name}" for ct, name in perms_qs]
            instance.assign_perms_to_managed_role(perms_list)
        self._ensure_password_not_empty(instance)
        return instance

    def update(self, instance: User, validated_data: dict) -> User:
        """Update a user, with blueprint-only password and permission writes."""
        is_blueprint = SERIALIZER_CONTEXT_BLUEPRINT in self.context
        if is_blueprint:
            password = validated_data.pop("password", None)
            password_hash = validated_data.pop("password_hash", None)
            permissions = validated_data.pop("permissions", [])
            self._validate_password_inputs(password, password_hash)

        instance = super().update(instance, validated_data)
        if is_blueprint:
            self._set_password(instance, password, password_hash)
            perms_qs = Permission.objects.filter(
                codename__in=[permission.split(".")[1] for permission in permissions]
            ).values_list("content_type__app_label", "codename")
            perms_list = [f"{ct}.{name}" for ct, name in perms_qs]
            instance.assign_perms_to_managed_role(perms_list)
        self._ensure_password_not_empty(instance)
        return instance

    def _validate_password_inputs(self, password: str | None, password_hash: str | None):
        """Validate mutually-exclusive password inputs before any model mutation."""
        if password is not None and password_hash is not None:
            raise ValidationError(_("Cannot set both password and password_hash. Use only one."))
        if password_hash is None:
            return
        try:
            User.validate_password_hash(password_hash)
        except ValueError as exc:
            LOGGER.warning("Failed to identify password hash format", exc_info=exc)
            raise ValidationError(INVALID_PASSWORD_HASH_MESSAGE) from exc

    def _set_password(self, instance: User, password: str | None, password_hash: str | None = None):
        """Set password from plain text or hash."""
        if password_hash is not None:
            instance.set_password_from_hash(password_hash)
            instance.save()
        elif password:
            instance.set_password(password)
            instance.save()

    def _ensure_password_not_empty(self, instance: User):
        """Store an explicit unusable password instead of an empty password field."""
        if len(instance.password) == 0:
            instance.set_unusable_password()
            instance.save()

    def get_avatar(self, user: User) -> str:
        """User's avatar, either a http/https URL or a data URI"""
        return get_avatar(user, self.context.get("request"))

    def validate_path(self, path: str) -> str:
        """Validate path"""
        if path[:1] == "/" or path[-1] == "/":
            raise ValidationError(_("No leading or trailing slashes allowed."))
        for segment in path.split("/"):
            if segment == "":
                raise ValidationError(_("No empty segments in user path allowed."))
        return path

    def validate_type(self, user_type: str) -> str:
        """Validate user type, internal_service_account is an internal value"""
        if (
            self.instance
            and self.instance.type == UserTypes.INTERNAL_SERVICE_ACCOUNT
            and user_type != UserTypes.INTERNAL_SERVICE_ACCOUNT.value
        ):
            raise ValidationError(_("Can't change internal service account to other user type."))
        if not self.instance and user_type == UserTypes.INTERNAL_SERVICE_ACCOUNT.value:
            raise ValidationError(_("Setting a user to internal service account is not allowed."))
        return user_type

    def validate_groups(self, groups: list) -> list:
        """Require enable_group_superuser permission when adding a user to a superuser group."""
        request: Request = self.context.get("request", None)
        if not request:
            return groups
        current_groups = set(self.instance.groups.all()) if self.instance else set()
        for group in groups:
            if not group.is_superuser:
                continue
            if group in current_groups:
                continue
            if not request.user.has_perm("authentik_core.enable_group_superuser"):
                raise ValidationError(
                    _("User does not have permission to add members to a superuser group.")
                )
        return groups

    def validate_roles(self, roles: list) -> list:
        """Require change_role permission when assigning new roles to a user."""
        request: Request = self.context.get("request", None)
        if not request:
            return roles
        current_roles = set(self.instance.roles.all()) if self.instance else set()
        new_roles = [r for r in roles if r not in current_roles]
        if not new_roles:
            return roles
        if not request.user.has_perm("authentik_rbac.change_role"):
            raise ValidationError(_("User does not have permission to assign roles."))
        return roles

    def validate(self, attrs: dict) -> dict:
        if self.instance and self.instance.type == UserTypes.INTERNAL_SERVICE_ACCOUNT:
            raise ValidationError(_("Can't modify internal service account users"))
        return super().validate(attrs)

    class Meta:
        model = User
        fields = [
            "pk",
            "username",
            "name",
            "is_active",
            "last_login",
            "date_joined",
            "is_superuser",
            "groups",
            "groups_obj",
            "roles",
            "roles_obj",
            "email",
            "avatar",
            "attributes",
            "uid",
            "path",
            "type",
            "uuid",
            "password_change_date",
            "last_updated",
        ]
        extra_kwargs = {
            "name": {"allow_blank": True},
            "date_joined": {"read_only": True},
            "password_change_date": {"read_only": True},
        }


class UserSelfSerializer(ModelSerializer):
    """User Serializer for information a user can retrieve about themselves"""

    is_superuser = BooleanField(read_only=True)
    avatar = SerializerMethodField()
    groups = SerializerMethodField()
    roles = SerializerMethodField()
    uid = CharField(read_only=True)
    settings = SerializerMethodField()
    system_permissions = SerializerMethodField()

    def get_avatar(self, user: User) -> str:
        """User's avatar, either a http/https URL or a data URI"""
        return get_avatar(user, self.context.get("request"))

    @extend_schema_field(
        ListSerializer(
            child=inline_serializer(
                "UserSelfGroups",
                {
                    "name": CharField(read_only=True),
                    "pk": CharField(read_only=True),
                },
            )
        )
    )
    def get_groups(self, _: User):
        """Return only the group names a user is member of"""
        for group in self.instance.all_groups().order_by("name"):
            yield {
                "name": group.name,
                "pk": group.pk,
            }

    @extend_schema_field(
        ListSerializer(
            child=inline_serializer(
                "UserSelfRoles",
                {
                    "name": CharField(read_only=True),
                    "pk": CharField(read_only=True),
                },
            )
        )
    )
    def get_roles(self, _: User):
        """Return only the roles a user is member of"""
        for role in self.instance.all_roles().order_by("name"):
            yield {
                "name": role.name,
                "pk": role.pk,
            }

    def get_settings(self, user: User) -> dict[str, Any]:
        """Get user settings with brand and group settings applied"""
        return user.group_attributes(self._context["request"]).get("settings", {})

    def get_system_permissions(self, user: User) -> list[str]:
        """Get all system permissions assigned to the user"""
        return list(
            x.split(".", maxsplit=1)[1]
            for x in user.get_all_permissions()
            if x.startswith("authentik_rbac")
        )

    class Meta:
        model = User
        fields = [
            "pk",
            "username",
            "name",
            "is_active",
            "is_superuser",
            "groups",
            "roles",
            "email",
            "avatar",
            "uid",
            "settings",
            "type",
            "system_permissions",
        ]
        extra_kwargs = {
            "is_active": {"read_only": True},
            "name": {"allow_blank": True},
        }


class SessionUserSerializer(PassiveSerializer):
    """Response for the /user/me endpoint, returns the currently active user (as `user` property)
    and, if this user is being impersonated, the original user in the `original` property.
    """

    user = UserSelfSerializer()
    original = UserSelfSerializer(required=False)


class UserPasswordSetSerializer(PassiveSerializer):
    """Payload to set a users' password directly"""

    password = CharField(required=True)


class UserPasswordHashSetSerializer(PassiveSerializer):
    """Payload to set a users' password hash directly"""

    password = CharField(required=True)


class UserServiceAccountSerializer(PassiveSerializer):
    """Payload to create a service account"""

    name = CharField(
        required=True,
        validators=[UniqueValidator(queryset=User.objects.all().order_by("username"))],
    )
    create_group = BooleanField(default=False)
    expiring = BooleanField(default=True)
    expires = DateTimeField(
        required=False,
        help_text="If not provided, valid for 360 days",
    )


class UserRecoveryLinkSerializer(PassiveSerializer):
    """Payload to create a recovery link"""

    token_duration = CharField(required=False)


class UserRecoveryEmailSerializer(UserRecoveryLinkSerializer):
    """Payload to create and email a recovery link"""

    email_stage = UUIDField()


class UsersFilter(FilterSet):
    """Filter for users"""

    attributes = CharFilter(
        field_name="attributes",
        lookup_expr="",
        label="Attributes",
        method="filter_attributes",
    )

    date_joined__lt = IsoDateTimeFilter(field_name="date_joined", lookup_expr="lt")
    date_joined = IsoDateTimeFilter(field_name="date_joined")
    date_joined__gt = IsoDateTimeFilter(field_name="date_joined", lookup_expr="gt")

    last_updated__lt = IsoDateTimeFilter(field_name="last_updated", lookup_expr="lt")
    last_updated = IsoDateTimeFilter(field_name="last_updated")
    last_updated__gt = IsoDateTimeFilter(field_name="last_updated", lookup_expr="gt")

    last_login__lt = IsoDateTimeFilter(field_name="last_login", lookup_expr="lt")
    last_login = IsoDateTimeFilter(field_name="last_login")
    last_login__gt = IsoDateTimeFilter(field_name="last_login", lookup_expr="gt")
    last_login__isnull = BooleanFilter(field_name="last_login", lookup_expr="isnull")

    is_superuser = BooleanFilter(field_name="groups", method="filter_is_superuser")
    uuid = UUIDFilter(field_name="uuid")

    path = CharFilter(field_name="path")
    path_startswith = CharFilter(field_name="path", lookup_expr="startswith")

    type = MultipleChoiceFilter(choices=UserTypes.choices, field_name="type")

    groups_by_name = ModelMultipleChoiceFilter(
        field_name="groups__name",
        to_field_name="name",
        queryset=Group.objects.all().order_by("name"),
    )
    groups_by_pk = ModelMultipleChoiceFilter(
        field_name="groups",
        queryset=Group.objects.all().order_by("name"),
    )

    roles_by_name = ModelMultipleChoiceFilter(
        field_name="roles__name",
        to_field_name="name",
        queryset=Role.objects.all().order_by("name"),
    )
    roles_by_pk = ModelMultipleChoiceFilter(
        field_name="roles",
        queryset=Role.objects.all().order_by("name"),
    )

    def filter_is_superuser(self, queryset, name, value):
        if value:
            return queryset.filter(groups__is_superuser=True).distinct()
        return queryset.exclude(groups__is_superuser=True).distinct()

    def filter_attributes(self, queryset, name, value):
        """Filter attributes by query args"""
        try:
            value = loads(value)
        except ValueError:
            raise ValidationError(_("filter: failed to parse JSON")) from None
        if not isinstance(value, dict):
            raise ValidationError(_("filter: value must be key:value mapping"))
        qs = {}
        for key, _value in value.items():
            qs[f"attributes__{key}"] = _value
        try:
            __ = len(queryset.filter(**qs))
            return queryset.filter(**qs)
        except ValueError:
            return queryset

    class Meta:
        model = User
        fields = [
            "username",
            "email",
            "date_joined",
            "last_updated",
            "last_login",
            "name",
            "is_active",
            "is_superuser",
            "attributes",
            "groups_by_name",
            "groups_by_pk",
            "roles_by_name",
            "roles_by_pk",
            "type",
        ]


class UserViewSet(
    ConditionalInheritance(
        "authentik.enterprise.stages.account_lockdown.api.UserAccountLockdownMixin"
    ),
    ConditionalInheritance("authentik.enterprise.reports.api.reports.ExportMixin"),
    UsedByMixin,
    ModelViewSet,
):
    """User Viewset"""

    queryset = User.objects.none()
    ordering = ["username", "date_joined", "last_updated", "last_login"]
    serializer_class = UserSerializer
    filterset_class = UsersFilter
    search_fields = ["email", "name", "uuid", "username"]
    authentication_classes = [
        TokenAuthentication,
        SessionAuthentication,
        AgentAuth,
    ]

    def get_ql_fields(self):
        return [
            StrField(User, "username"),
            StrField(User, "name"),
            StrField(User, "email"),
            StrField(User, "path"),
            BoolField(User, "is_active", nullable=True),
            ChoiceSearchField(User, "type"),
            JSONSearchField(User, "attributes"),
        ]

    def get_queryset(self):
        base_qs = User.objects.all().exclude_anonymous()
        # Always prefetch groups since group PKs are always serialized.
        # Use full prefetch when include_groups=true (for groups_obj), ID-only otherwise.
        if self.serializer_class(context={"request": self.request})._should_include_groups:
            base_qs = base_qs.prefetch_related("groups")
        else:
            base_qs = base_qs.prefetch_related(
                Prefetch("groups", queryset=Group.objects.all().only("group_uuid"))
            )
        if self.serializer_class(context={"request": self.request})._should_include_roles:
            base_qs = base_qs.prefetch_related("roles")
        else:
            base_qs = base_qs.prefetch_related(
                Prefetch("roles", queryset=Role.objects.all().only("uuid"))
            )
        # Annotate is_superuser to avoid N+1 query per user
        base_qs = base_qs.annotate(
            _annotated_is_superuser=Exists(
                Group.objects.filter(
                    is_superuser=True,
                ).filter(
                    Q(users=OuterRef("pk")) | Q(descendant_nodes__descendant__users=OuterRef("pk"))
                )
            )
        )
        return base_qs

    @extend_schema(
        parameters=[
            OpenApiParameter("include_groups", bool, default=True),
            OpenApiParameter("include_roles", bool, default=True),
        ]
    )
    def list(self, request, *args, **kwargs):
        return super().list(request, *args, **kwargs)

    def _create_recovery_link(
        self, token_duration: str | None, for_email=False
    ) -> tuple[str, Token]:
        """Create a recovery link (when the current brand has a recovery flow set),
        that can either be shown to an admin or sent to the user directly"""
        brand: Brand = self.request.brand
        # Check that there is a recovery flow, if not return an error
        flow = brand.flow_recovery
        if not flow:
            raise ValidationError({"non_field_errors": _("No recovery flow set.")})
        user: User = self.get_object()
        planner = FlowPlanner(flow)
        planner.allow_empty_flows = True
        self.request._request.user = AnonymousUser()
        try:
            plan = planner.plan(
                self.request._request,
                {
                    PLAN_CONTEXT_PENDING_USER: user,
                },
            )
        except FlowNonApplicableException:
            raise ValidationError(
                {"non_field_errors": _("Recovery flow not applicable to user")}
            ) from None
        _plan = FlowToken.pickle(plan)
        if for_email:
            _plan = pickle_flow_token_for_email(plan)
        expires = default_token_duration()
        if token_duration:
            timedelta_string_validator(token_duration)
            expires = now() + timedelta_from_string(token_duration)
        token, __ = FlowToken.objects.update_or_create(
            identifier=f"{user.uid}-password-reset",
            defaults={
                "user": user,
                "flow": flow,
                "_plan": _plan,
                "revoke_on_execution": not for_email,
                "expires": expires,
            },
        )
        querystring = urlencode({QS_KEY_TOKEN: token.key})
        link = self.request.build_absolute_uri(
            reverse_lazy("authentik_core:if-flow", kwargs={"flow_slug": flow.slug})
            + f"?{querystring}"
        )
        return link, token

    @permission_required(None, ["authentik_core.add_user", "authentik_core.add_token"])
    @extend_schema(
        request=UserServiceAccountSerializer,
        responses={
            200: inline_serializer(
                "UserServiceAccountResponse",
                {
                    "username": CharField(required=True),
                    "token": CharField(required=True),
                    "user_uid": CharField(required=True),
                    "user_pk": IntegerField(required=True),
                    "group_pk": CharField(required=False),
                },
            )
        },
    )
    @action(
        detail=False,
        methods=["POST"],
        pagination_class=None,
        filter_backends=[],
    )
    @validate(UserServiceAccountSerializer)
    def service_account(self, request: Request, body: UserServiceAccountSerializer) -> Response:
        """Create a new user account that is marked as a service account"""
        expires = body.validated_data.get("expires", now() + timedelta(days=360))

        username = body.validated_data["name"]
        expiring = body.validated_data["expiring"]
        with atomic():
            try:
                user: User = User.objects.create(
                    username=username,
                    name=username,
                    type=UserTypes.SERVICE_ACCOUNT,
                    attributes={USER_ATTRIBUTE_TOKEN_EXPIRING: expiring},
                    path=USER_PATH_SERVICE_ACCOUNT,
                )
                user.set_unusable_password()
                user.save()

                response = {
                    "username": user.username,
                    "user_uid": user.uid,
                    "user_pk": user.pk,
                }
                if body.validated_data["create_group"] and self.request.user.has_perm(
                    "authentik_core.add_group"
                ):
                    group = Group.objects.create(name=username)
                    group.users.add(user)
                    response["group_pk"] = str(group.pk)
                token = Token.objects.create(
                    identifier=slugify(f"service-account-{username}-password"),
                    intent=TokenIntents.INTENT_APP_PASSWORD,
                    user=user,
                    expires=expires,
                    expiring=expiring,
                )
                response["token"] = token.key
                return Response(response)
            except IntegrityError as exc:
                error_msg = str(exc).lower()

                if "unique" in error_msg:
                    return Response(
                        data={
                            "non_field_errors": [
                                _("A user/group with these details already exists")
                            ]
                        },
                        status=400,
                    )
                else:
                    LOGGER.warning("Service account creation failed", exc=exc)
                    return Response(
                        data={"non_field_errors": [_("Unable to create user")]},
                        status=400,
                    )
            except (ValueError, TypeError) as exc:
                LOGGER.error("Unexpected error during service account creation", exc=exc)
                return Response(
                    data={"non_field_errors": [_("Unknown error occurred")]},
                    status=500,
                )

    @extend_schema(responses={200: SessionUserSerializer(many=False)})
    @action(
        url_path="me",
        url_name="me",
        detail=False,
        pagination_class=None,
        filter_backends=[],
    )
    def user_me(self, request: Request) -> Response:
        """Get information about current user"""
        context = {"request": request}
        serializer = SessionUserSerializer(
            data={"user": UserSelfSerializer(instance=request.user, context=context).data}
        )
        if SESSION_KEY_IMPERSONATE_USER in request._request.session:
            serializer.initial_data["original"] = UserSelfSerializer(
                instance=request._request.session[SESSION_KEY_IMPERSONATE_ORIGINAL_USER],
                context=context,
            ).data
        self.request.session.modified = True
        return Response(serializer.initial_data)

    def _update_session_hash_after_password_change(self, request: Request, user: User):
        if user.pk == request.user.pk and SESSION_KEY_IMPERSONATE_USER not in self.request.session:
            LOGGER.debug("Updating session hash after password change")
            update_session_auth_hash(self.request, user)

    @permission_required("authentik_core.reset_user_password")
    @extend_schema(
        request=UserPasswordSetSerializer,
        responses={
            204: OpenApiResponse(description="Successfully changed password"),
            400: OpenApiResponse(description="Bad request"),
        },
    )
    @action(
        detail=True,
        methods=["POST"],
        permission_classes=[IsAuthenticated],
    )
    @validate(UserPasswordSetSerializer)
    def set_password(self, request: Request, pk: int, body: UserPasswordSetSerializer) -> Response:
        """Set password for user"""
        user: User = self.get_object()
        try:
            user.set_password(body.validated_data["password"], request=request)
            user.save()
        except (ValidationError, IntegrityError) as exc:
            LOGGER.debug("Failed to set password", exc=exc)
            return Response(status=400)
        self._update_session_hash_after_password_change(request, user)
        return Response(status=204)

    @permission_required("authentik_core.reset_user_password")
    @extend_schema(
        request=UserPasswordHashSetSerializer,
        responses={
            204: OpenApiResponse(description="Successfully changed password"),
            400: OpenApiResponse(description="Bad request"),
        },
    )
    @action(
        detail=True,
        methods=["POST"],
        permission_classes=[IsAuthenticated],
    )
    @validate(UserPasswordHashSetSerializer)
    def set_password_hash(
        self, request: Request, pk: int, body: UserPasswordHashSetSerializer
    ) -> Response:
        """Set a user's password from a pre-hashed Django password value.

        Submit the Django password hash in the shared ``password`` request field.

        This updates authentik's local password verifier only. It does not attempt
        to propagate the password change to LDAP or Kerberos because no raw password
        is available from the request payload.
        """
        user: User = self.get_object()
        try:
            user.set_password_from_hash(body.validated_data["password"], request=request)
            user.save()
        except ValueError as exc:
            LOGGER.debug("Failed to set password hash", exc=exc)
            return Response(data={"password": [INVALID_PASSWORD_HASH_MESSAGE]}, status=400)
        except (ValidationError, IntegrityError) as exc:
            LOGGER.debug("Failed to set password hash", exc=exc)
            return Response(status=400)
        self._update_session_hash_after_password_change(request, user)
        return Response(status=204)

    @permission_required("authentik_core.reset_user_password")
    @extend_schema(
        request=UserRecoveryLinkSerializer,
        responses={
            "200": LinkSerializer(many=False),
        },
    )
    @action(detail=True, pagination_class=None, filter_backends=[], methods=["POST"])
    @validate(UserRecoveryLinkSerializer)
    def recovery(self, request: Request, pk: int, body: UserRecoveryLinkSerializer) -> Response:
        """Create a temporary link that a user can use to recover their account"""
        link, _ = self._create_recovery_link(
            token_duration=body.validated_data.get("token_duration")
        )
        return Response({"link": link})

    @permission_required("authentik_core.reset_user_password")
    @extend_schema(
        request=UserRecoveryEmailSerializer,
        responses={
            "204": OpenApiResponse(description="Successfully sent recover email"),
        },
    )
    @action(detail=True, pagination_class=None, filter_backends=[], methods=["POST"])
    @validate(UserRecoveryEmailSerializer)
    def recovery_email(
        self, request: Request, pk: int, body: UserRecoveryEmailSerializer
    ) -> Response:
        """Send an email with a temporary link that a user can use to recover their account"""
        email_error_message = _("User does not have an email address set.")
        stage_error_message = _("Email stage not found.")
        user: User = self.get_object()
        if not user.email:
            LOGGER.debug("User doesn't have an email address")
            raise ValidationError({"non_field_errors": email_error_message})
        if not (stage := EmailStage.objects.filter(pk=body.validated_data["email_stage"]).first()):
            LOGGER.debug("Email stage does not exist")
            raise ValidationError({"non_field_errors": stage_error_message})
        if not request.user.has_perm("authentik_stages_email.view_emailstage", stage):
            LOGGER.debug("User has no view access to email stage")
            raise ValidationError({"non_field_errors": stage_error_message})
        link, token = self._create_recovery_link(
            token_duration=body.validated_data.get("token_duration"), for_email=True
        )
        message = TemplateEmailMessage(
            subject=_(stage.subject),
            to=[(user.name, user.email)],
            template_name=stage.template,
            language=user.locale(request),
            template_context={
                "url": link,
                "user": user,
                "expires": token.expires,
            },
        )
        send_mails(stage, message)
        return Response(status=204)

    @permission_required("authentik_core.impersonate")
    @extend_schema(
        request=inline_serializer(
            "ImpersonationSerializer",
            {
                "reason": CharField(required=True),
            },
        ),
        responses={
            204: OpenApiResponse(description="Successfully started impersonation"),
        },
    )
    @action(detail=True, methods=["POST"], permission_classes=[IsAuthenticated])
    def impersonate(self, request: Request, pk: int) -> Response:
        """Impersonate a user"""
        if not request.tenant.impersonation:
            LOGGER.debug("User attempted to impersonate", user=request.user)
            return Response(status=401)
        user_to_be = self.get_object()
        reason = request.data.get("reason", "")
        # Check both object-level perms and global perms
        if not request.user.has_perm(
            "authentik_core.impersonate", user_to_be
        ) and not request.user.has_perm("authentik_core.impersonate"):
            LOGGER.debug(
                "User attempted to impersonate without permissions",
                user=request.user,
            )
            return Response(status=403)
        if user_to_be.pk == self.request.user.pk:
            LOGGER.debug("User attempted to impersonate themselves", user=request.user)
            return Response(status=401)
        if not reason and request.tenant.impersonation_require_reason:
            LOGGER.debug(
                "User attempted to impersonate without providing a reason",
                user=request.user,
            )
            raise ValidationError({"reason": _("This field is required.")})

        request.session[SESSION_KEY_IMPERSONATE_ORIGINAL_USER] = request.user
        request.session[SESSION_KEY_IMPERSONATE_USER] = user_to_be

        Event.new(EventAction.IMPERSONATION_STARTED, reason=reason).from_http(request, user_to_be)

        return Response(status=204)

    @extend_schema(
        request=None,
        responses={
            "204": OpenApiResponse(description="Successfully ended impersonation"),
        },
    )
    @action(detail=False, methods=["GET"])
    def impersonate_end(self, request: Request) -> Response:
        """End Impersonation a user"""
        if (
            SESSION_KEY_IMPERSONATE_USER not in request.session
            or SESSION_KEY_IMPERSONATE_ORIGINAL_USER not in request.session
        ):
            LOGGER.debug("Can't end impersonation", user=request.user)
            return Response(status=204)

        original_user = request.session[SESSION_KEY_IMPERSONATE_ORIGINAL_USER]

        del request.session[SESSION_KEY_IMPERSONATE_USER]
        del request.session[SESSION_KEY_IMPERSONATE_ORIGINAL_USER]

        Event.new(EventAction.IMPERSONATION_ENDED).from_http(request, original_user)

        return Response(status=204)

    @extend_schema(
        responses={
            200: inline_serializer(
                "UserPathSerializer",
                {"paths": ListField(child=CharField(), read_only=True)},
            )
        },
        parameters=[
            OpenApiParameter(
                name="search",
                location=OpenApiParameter.QUERY,
                type=OpenApiTypes.STR,
            )
        ],
    )
    @action(detail=False, pagination_class=None)
    def paths(self, request: Request) -> Response:
        """Get all user paths"""
        return Response(
            data={
                "paths": list(
                    self.filter_queryset(self.get_queryset())
                    .values("path")
                    .distinct()
                    .order_by("path")
                    .values_list("path", flat=True)
                )
            }
        )

    def partial_update(self, request: Request, *args, **kwargs) -> Response:
        response = super().partial_update(request, *args, **kwargs)
        instance: User = self.get_object()
        if not instance.is_active:
            Session.objects.filter(authenticatedsession__user=instance).delete()
            LOGGER.debug("Deleted user's sessions", user=instance.username)
        return response
