Sith/core/views/__init__.py

#
# Copyright 2016,2017
# - Skia <skia@libskia.so>
# - Sli <antoine@bartuccio.fr>
#
# Ce fichier fait partie du site de l'Association des Étudiants de l'UTBM,
# http://ae.utbm.fr.
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License a published by the Free Software
# Foundation; either version 3 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Sofware Foundation, Inc., 59 Temple
# Place - Suite 330, Boston, MA 02111-1307, USA.
#
#

import types

from django.core.exceptions import (
    ImproperlyConfigured,
    PermissionDenied,
)
from django.http import (
    HttpResponseForbidden,
    HttpResponseNotFound,
    HttpResponseServerError,
)
from django.utils.functional import cached_property
from django.views.generic.base import View
from django.views.generic.detail import SingleObjectMixin
from django.views.generic.edit import FormView
from sentry_sdk import last_event_id

from core.views.forms import LoginForm


def forbidden(request, exception):
    context = {"next": request.path, "form": LoginForm()}
    if popup := request.resolver_match.kwargs.get("popup"):
        context["popup"] = popup
    return HttpResponseForbidden(render(request, "core/403.jinja", context=context))


def not_found(request, exception):
    return HttpResponseNotFound(
        render(request, "core/404.jinja", context={"exception": exception})
    )


def internal_servor_error(request):
    request.sentry_last_event_id = last_event_id
    return HttpResponseServerError(render(request, "core/500.jinja"))


def can_edit_prop(obj, user):
    """
    :param obj: Object to test for permission
    :param user: core.models.User to test permissions against
    :return: if user is authorized to edit object properties
    :rtype: bool

    :Example:

    .. code-block:: python

        if not can_edit_prop(self.object ,request.user):
            raise PermissionDenied

    """
    if obj is None or user.is_owner(obj):
        return True
    return False


def can_edit(obj, user):
    """
    :param obj: Object to test for permission
    :param user: core.models.User to test permissions against
    :return: if user is authorized to edit object
    :rtype: bool

    :Example:

    .. code-block:: python

        if not can_edit(self.object ,request.user):
            raise PermissionDenied

    """
    if obj is None or user.can_edit(obj):
        return True
    return can_edit_prop(obj, user)


def can_view(obj, user):
    """
    :param obj: Object to test for permission
    :param user: core.models.User to test permissions against
    :return: if user is authorized to see object
    :rtype: bool

    :Example:

    .. code-block:: python

        if not can_view(self.object ,request.user):
            raise PermissionDenied

    """
    if obj is None or user.can_view(obj):
        return True
    return can_edit(obj, user)


class GenericContentPermissionMixinBuilder(View):
    """
    Used to build permission mixins
    This view protect any child view that would be showing an object that is restricted based
      on two properties

    :prop permission_function: function to test permission with, takes an object and an user an return a bool
    :prop raised_error: permission to be raised

    :raises: raised_error
    """

    permission_function = lambda obj, user: False
    raised_error = PermissionDenied

    @classmethod
    def get_permission_function(cls, obj, user):
        return cls.permission_function(obj, user)

    def dispatch(self, request, *arg, **kwargs):
        if hasattr(self, "get_object") and callable(self.get_object):
            self.object = self.get_object()
            if not self.get_permission_function(self.object, request.user):
                raise self.raised_error
            return super().dispatch(request, *arg, **kwargs)

        # If we get here, it's a ListView

        queryset = self.get_queryset()
        l_id = [o.id for o in queryset if self.get_permission_function(o, request.user)]
        if not l_id and queryset.count() != 0:
            raise self.raised_error
        self._get_queryset = self.get_queryset

        def get_qs(self2):
            return self2._get_queryset().filter(id__in=l_id)

        self.get_queryset = types.MethodType(get_qs, self)
        return super().dispatch(request, *arg, **kwargs)


class CanCreateMixin(View):
    """
    This view is made to protect any child view that would create an object, and thus, that can not be protected by any
    of the following mixin

    :raises: PermissionDenied
    """

    def dispatch(self, request, *arg, **kwargs):
        res = super().dispatch(request, *arg, **kwargs)
        if not request.user.is_authenticated:
            raise PermissionDenied
        return res

    def form_valid(self, form):
        obj = form.instance
        if can_edit_prop(obj, self.request.user):
            return super().form_valid(form)
        raise PermissionDenied


class CanEditPropMixin(GenericContentPermissionMixinBuilder):
    """
    This view is made to protect any child view that would be showing some properties of an object that are restricted
    to only the owner group of the given object.
    In other word, you can make a view with this view as parent, and it would be retricted to the users that are in the
    object's owner_group

    :raises: PermissionDenied
    """

    permission_function = can_edit_prop


class CanEditMixin(GenericContentPermissionMixinBuilder):
    """
    This view makes exactly the same thing as its direct parent, but checks the group on the edit_groups field of the
    object

    :raises: PermissionDenied
    """

    permission_function = can_edit


class CanViewMixin(GenericContentPermissionMixinBuilder):
    """
    This view still makes exactly the same thing as its direct parent, but checks the group on the view_groups field of
    the object

    :raises: PermissionDenied
    """

    permission_function = can_view


class UserIsRootMixin(GenericContentPermissionMixinBuilder):
    """
    This view check if the user is root

    :raises: PermissionDenied
    """

    permission_function = lambda obj, user: user.is_root


class FormerSubscriberMixin(View):
    """
    This view check if the user was at least an old subscriber

    :raises: PermissionDenied
    """

    def dispatch(self, request, *args, **kwargs):
        if not request.user.was_subscribed:
            raise PermissionDenied
        return super().dispatch(request, *args, **kwargs)


class UserIsLoggedMixin(View):
    """
    This view check if the user is logged

    :raises: PermissionDenied
    """

    def dispatch(self, request, *args, **kwargs):
        if request.user.is_anonymous:
            raise PermissionDenied
        return super().dispatch(request, *args, **kwargs)


class TabedViewMixin(View):
    """
    This view provide the basic functions for displaying tabs in the template
    """

    def get_tabs_title(self):
        if hasattr(self, "tabs_title"):
            return self.tabs_title
        raise ImproperlyConfigured("tabs_title is required")

    def get_current_tab(self):
        if hasattr(self, "current_tab"):
            return self.current_tab
        raise ImproperlyConfigured("current_tab is required")

    def get_list_of_tabs(self):
        if hasattr(self, "list_of_tabs"):
            return self.list_of_tabs
        raise ImproperlyConfigured("list_of_tabs is required")

    def get_context_data(self, **kwargs):
        kwargs = super().get_context_data(**kwargs)
        kwargs["tabs_title"] = self.get_tabs_title()
        kwargs["current_tab"] = self.get_current_tab()
        kwargs["list_of_tabs"] = self.get_list_of_tabs()
        return kwargs


class QuickNotifMixin:
    quick_notif_list = []

    def dispatch(self, request, *arg, **kwargs):
        # In some cases, the class can stay instanciated, so we need to reset the list
        self.quick_notif_list = []
        return super().dispatch(request, *arg, **kwargs)

    def get_success_url(self):
        ret = super().get_success_url()
        if hasattr(self, "quick_notif_url_arg"):
            if "?" in ret:
                ret += "&" + self.quick_notif_url_arg
            else:
                ret += "?" + self.quick_notif_url_arg
        return ret

    def get_context_data(self, **kwargs):
        """Add quick notifications to context"""
        kwargs = super().get_context_data(**kwargs)
        kwargs["quick_notifs"] = []
        for n in self.quick_notif_list:
            kwargs["quick_notifs"].append(settings.SITH_QUICK_NOTIF[n])
        for k, v in settings.SITH_QUICK_NOTIF.items():
            for gk in self.request.GET.keys():
                if k == gk:
                    kwargs["quick_notifs"].append(v)
        return kwargs


class DetailFormView(SingleObjectMixin, FormView):
    """
    Class that allow both a detail view and a form view
    """

    def get_object(self):
        """
        Get current group from id in url
        """
        return self.cached_object

    @cached_property
    def cached_object(self):
        """
        Optimisation on group retrieval
        """
        return super().get_object()


from .files import *
from .group import *
from .page import *
from .site import *
from .user import *