re2o/re2o/acl.py

# -*- mode: python; coding: utf-8 -*-
# Re2o est un logiciel d'administration développé initiallement au rezometz. Il
# se veut agnostique au réseau considéré, de manière à être installable en
# quelques clics.
#
# Copyright © 2017  Gabriel Détraz
# Copyright © 2017  Goulven Kermarec
# Copyright © 2017  Augustin Lemesle
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 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 Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

"""Handles ACL for re2o.

Here are defined some decorators that can be used in views to handle ACL.
"""
from __future__ import unicode_literals

import sys

from django.contrib import messages
from django.shortcuts import redirect
from django.urls import reverse

import cotisations
import logs
import machines
import preferences
import search
import topologie
import users


def can_create(model):
    """Decorator to check if an user can create a model.
    It assumes that a valid user exists in the request and that the model has a
    method can_create(user) which returns true if the user can create this kind
    of models.
    """
    def decorator(view):
        def wrapper(request, *args, **kwargs):
            can, msg = model.can_create(request.user, *args, **kwargs)
            if not can:
                messages.error(
                    request, msg or "Vous ne pouvez pas accéder à ce menu")
                return redirect(reverse('index'))
            return view(request, *args, **kwargs)
        return wrapper
    return decorator


def can_edit(model, *field_list):
    """Decorator to check if an user can edit a model.
    It tries to get an instance of the model, using
    `model.get_instance(*args, **kwargs)` and assumes that the model has a
    method `can_edit(user)` which returns `true` if the user can edit this
    kind of models.
    """
    def decorator(view):
        def wrapper(request, *args, **kwargs):
            try:
                instance = model.get_instance(*args, **kwargs)
            except model.DoesNotExist:
                messages.error(request, u"Entrée inexistante")
                return redirect(reverse('users:profil',
                                        kwargs={'userid': str(request.user.id)}
                                        ))
            can, msg = instance.can_edit(request.user)
            if not can:
                messages.error(
                    request, msg or "Vous ne pouvez pas accéder à ce menu")
                return redirect(reverse('users:profil',
                                        kwargs={'userid': str(request.user.id)}
                                        ))
            for field in field_list:
                can_change = getattr(instance, 'can_change_' + field)
                can, msg = can_change(request.user, *args, **kwargs)
                if not can:
                    messages.error(
                        request, msg or "Vous ne pouvez pas accéder à ce menu")
                    return redirect(reverse('users:profil',
                                            kwargs={'userid': str(
                                                request.user.id)}
                                            ))
            return view(request, instance, *args, **kwargs)
        return wrapper
    return decorator


def can_change(model, *field_list):
    """Decorator to check if an user can edit a field of a model class.
    Difference with can_edit : take a class and not an instance
    """
    def decorator(view):
        def wrapper(request, *args, **kwargs):
            for field in field_list:
                can_change = getattr(model, 'can_change_' + field)
                can, msg = can_change(request.user, *args, **kwargs)
                if not can:
                    messages.error(
                        request, msg or "Vous ne pouvez pas accéder à ce menu")
                    return redirect(reverse('users:profil',
                                            kwargs={'userid': str(
                                                request.user.id)}
                                            ))
            return view(request, *args, **kwargs)
        return wrapper
    return decorator


def can_delete(model):
    """Decorator to check if an user can delete a model.
    It tries to get an instance of the model, using
    `model.get_instance(*args, **kwargs)` and assumes that the model has a
    method `can_delete(user)` which returns `true` if the user can delete this
    kind of models.
    """
    def decorator(view):
        def wrapper(request, *args, **kwargs):
            try:
                instance = model.get_instance(*args, **kwargs)
            except model.DoesNotExist:
                messages.error(request, u"Entrée inexistante")
                return redirect(reverse('users:profil',
                                        kwargs={'userid': str(request.user.id)}
                                        ))
            can, msg = instance.can_delete(request.user)
            if not can:
                messages.error(
                    request, msg or "Vous ne pouvez pas accéder à ce menu")
                return redirect(reverse('users:profil',
                                        kwargs={'userid': str(request.user.id)}
                                        ))
            return view(request, instance, *args, **kwargs)
        return wrapper
    return decorator


def can_delete_set(model):
    """Decorator which returns a list of detable models by request user.
    If none of them, return an error"""
    def decorator(view):
        def wrapper(request, *args, **kwargs):
            all_objects = model.objects.all()
            instances_id = []
            for instance in all_objects:
                can, msg = instance.can_delete(request.user)
                if can:
                    instances_id.append(instance.id)
            instances = model.objects.filter(id__in=instances_id)
            if not instances:
                messages.error(request, "Vous ne pouvez pas accéder à ce menu")
                return redirect(reverse('users:profil',
                                        kwargs={'userid': str(request.user.id)}
                                        ))
            return view(request, instances, *args, **kwargs)
        return wrapper
    return decorator


def can_view(model):
    """Decorator to check if an user can view a model.
    It tries to get an instance of the model, using
    `model.get_instance(*args, **kwargs)` and assumes that the model has a
    method `can_view(user)` which returns `true` if the user can view this
    kind of models.
    """
    def decorator(view):
        def wrapper(request, *args, **kwargs):
            try:
                instance = model.get_instance(*args, **kwargs)
            except model.DoesNotExist:
                messages.error(request, u"Entrée inexistante")
                return redirect(reverse('users:profil',
                                        kwargs={'userid': str(request.user.id)}
                                        ))
            can, msg = instance.can_view(request.user)
            if not can:
                messages.error(
                    request, msg or "Vous ne pouvez pas accéder à ce menu")
                return redirect(reverse('users:profil',
                                        kwargs={'userid': str(request.user.id)}
                                        ))
            return view(request, instance, *args, **kwargs)
        return wrapper
    return decorator


def can_view_all(model):
    """Decorator to check if an user can view a class of model.
    """
    def decorator(view):
        def wrapper(request, *args, **kwargs):
            can, msg = model.can_view_all(request.user)
            if not can:
                messages.error(
                    request, msg or "Vous ne pouvez pas accéder à ce menu")
                return redirect(reverse('users:profil',
                                        kwargs={'userid': str(request.user.id)}
                                        ))
            return view(request, *args, **kwargs)
        return wrapper
    return decorator


def can_view_app(app_name):
    """Decorator to check if an user can view an application.
    """
    assert app_name in sys.modules.keys()

    def decorator(view):
        def wrapper(request, *args, **kwargs):
            app = sys.modules[app_name]
            can, msg = app.can_view(request.user)
            if can:
                return view(request, *args, **kwargs)
            messages.error(request, msg)
            return redirect(reverse('users:profil',
                                    kwargs={'userid': str(request.user.id)}
                                    ))
        return wrapper
    return decorator


def can_edit_history(view):
    """Decorator to check if an user can edit history."""
    def wrapper(request, *args, **kwargs):
        if request.user.has_perm('admin.change_logentry'):
            return view(request, *args, **kwargs)
        messages.error(
            request,
            "Vous ne pouvez pas éditer l'historique."
        )
        return redirect(reverse('users:profil',
                                kwargs={'userid': str(request.user.id)}
                                ))
    return wrapper