ScoDoc/app/decorators.py

# -*- coding: UTF-8 -*
"""Decorators for permissions, roles and ScoDoc7 Zope compatibility
"""
from functools import wraps
import inspect


import werkzeug
import flask
from flask import g, current_app, request
from flask import abort, url_for, redirect
from flask_login import current_user
from flask_login import login_required
import flask_login

import app
from app.auth.models import User
import app.scodoc.sco_utils as scu
from app.scodoc.sco_exceptions import ScoValueError


class ZUser(object):
    "Emulating Zope User"

    def __init__(self):
        "create, based on `flask_login.current_user`"
        self.username = current_user.user_name

    def __str__(self):
        return self.username

    def has_permission(self, perm, dept=None):
        """check if this user as the permission `perm`
        in departement given by `g.scodoc_dept`.
        """
        raise NotImplementedError()


def scodoc(func):
    """Décorateur pour toutes les fonctions ScoDoc
    Affecte le département à g
    et ouvre la connexion à la base

    Set `g.scodoc_dept` and `g.scodoc_dept_id` if `scodoc_dept` is present
    in the argument (for routes like
    `/<scodoc_dept>/Scolarite/sco_exemple`).
    Else set scodoc_dept=None, scodoc_dept_id=-1.
    """

    @wraps(func)
    def scodoc_function(*args, **kwargs):
        # print("@scodoc")
        # interdit les POST si pas loggué
        if (
            request.method == "POST"
            and not current_user.is_authenticated
            and not request.form.get(
                "__ac_password"
            )  # exception pour compat API ScoDoc7
        ):
            current_app.logger.info(
                "POST by non authenticated user (request.form=%s)",
                str(request.form)[:2048],
            )
            return redirect(
                url_for(
                    "auth.login",
                    message="La page a expiré. Identifiez-vous et recommencez l'opération",
                )
            )
        if "scodoc_dept" in kwargs:
            dept_acronym = kwargs["scodoc_dept"]
            # current_app.logger.info("setting dept to " + dept_acronym)
            app.set_sco_dept(dept_acronym)
            del kwargs["scodoc_dept"]
        elif not hasattr(g, "scodoc_dept"):
            # current_app.logger.info("setting dept to None")
            g.scodoc_dept = None
            g.scodoc_dept_id = -1  # invalide

        return func(*args, **kwargs)

    return scodoc_function


def permission_required(permission):
    """Vérifie les permissions"""

    # Attention: l'API utilise api_permission_required
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            scodoc_dept = getattr(g, "scodoc_dept", None)
            if not current_user.has_permission(permission, scodoc_dept):
                return current_app.login_manager.unauthorized()
            return f(*args, **kwargs)

        return decorated_function

    return decorator


def permission_required_compat_scodoc7(permission):  # XXX TODO A SUPPRIMER
    """Décorateur pour les fonctions utilisées comme API dans ScoDoc 7
    Comme @permission_required mais autorise de passer directement
    les informations d'auth en paramètres:
        __ac_name, __ac_password
    """

    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            # cherche les paramètre d'auth:
            # print("@permission_required_compat_scodoc7")
            auth_ok = False
            if request.method == "GET":
                user_name = request.args.get("__ac_name")
                user_password = request.args.get("__ac_password")
            elif request.method == "POST":
                user_name = request.form.get("__ac_name")
                user_password = request.form.get("__ac_password")
            else:
                abort(405)  # method not allowed
            if user_name and user_password:
                # Ancienne API: va être supprimée courant mars 2023
                current_app.logger.warning(
                    "using DEPRECATED ScoDoc7 authentication method !"
                )
                u = User.query.filter_by(user_name=user_name).first()
                if u and u.check_password(user_password):
                    auth_ok = True
                    flask_login.login_user(u)
            # reprend le chemin classique:
            scodoc_dept = getattr(g, "scodoc_dept", None)

            if not current_user.has_permission(permission, scodoc_dept):
                abort(403)
            if auth_ok:
                return f(*args, **kwargs)
            else:
                return login_required(f)(*args, **kwargs)

        return decorated_function

    return decorator


def admin_required(f):
    from app.auth.models import Permission

    return permission_required(Permission.ScoSuperAdmin)(f)


def scodoc7func(func):
    """Décorateur pour intégrer les fonctions Zope 2 de ScoDoc 7.
    Les paramètres de la query string deviennent des (keywords) paramètres de la fonction.
    """

    @wraps(func)
    def scodoc7func_decorator(*args, **kwargs):
        """Decorator allowing legacy Zope published methods to be called via Flask
        routes without modification.

        There are two cases: the function can be called
        1. via a Flask route ("top level call")
        2.  or be called directly from Python.

        """
        # print("@scodoc7func")
        # Détermine si on est appelé via une route ("toplevel")
        # ou par un appel de fonction python normal.
        top_level = not hasattr(g, "scodoc7_decorated")
        if not top_level:
            # ne "redécore" pas
            return func(*args, **kwargs)
        g.scodoc7_decorated = True
        # --- Emulate Zope's REQUEST
        # REQUEST = ZRequest()
        # g.zrequest = REQUEST
        # args from query string (get) or form (post)
        req_args = scu.get_request_args()
        ## --- Add positional arguments
        pos_arg_values = []
        argspec = inspect.getfullargspec(func)
        # current_app.logger.info("argspec=%s" % str(argspec))
        nb_default_args = len(argspec.defaults) if argspec.defaults else 0
        if nb_default_args:
            arg_names = argspec.args[:-nb_default_args]
        else:
            arg_names = argspec.args
        for arg_name in arg_names:  # pour chaque arg de la fonction vue
            # peut produire une KeyError s'il manque un argument attendu:
            try:
                v = req_args[arg_name]
            except KeyError as exc:
                raise ScoValueError(f"argument {arg_name} manquant") from exc
            # try to convert all arguments to INTEGERS
            # necessary for db ids and boolean values
            try:
                v = int(v) if v else v
            except (ValueError, TypeError) as exc:
                if arg_name in {
                    "etudid",
                    "formation_id",
                    "formsemestre_id",
                    "module_id",
                    "moduleimpl_id",
                    "partition_id",
                    "ue_id",
                }:
                    raise ScoValueError("page introuvable (id invalide)") from exc
            pos_arg_values.append(v)
        # current_app.logger.info("pos_arg_values=%s" % pos_arg_values)
        # current_app.logger.info("req_args=%s" % req_args)
        # Add keyword arguments
        if nb_default_args:
            for arg_name in argspec.args[-nb_default_args:]:
                # if arg_name == "REQUEST":  # special case
                #    kwargs[arg_name] = REQUEST
                if arg_name in req_args:
                    # set argument kw optionnel
                    v = req_args[arg_name]
                    # try to convert all arguments to INTEGERS
                    # necessary for db ids and boolean values
                    try:
                        v = int(v)
                    except (ValueError, TypeError):
                        pass
                    kwargs[arg_name] = v
        # current_app.logger.info(
        #    "scodoc7func_decorator: top_level=%s, pos_arg_values=%s, kwargs=%s"
        #    % (top_level, pos_arg_values, kwargs)
        # )
        value = func(*pos_arg_values, **kwargs)

        if not top_level:
            return value
        else:
            if isinstance(value, werkzeug.wrappers.response.Response):
                return value  # redirected
            # Build response, adding collected http headers:
            headers = []
            kw = {"response": value, "status": 200}
            # if g.zrequest:
            #     headers = g.zrequest.RESPONSE.headers
            #     if not headers:
            #         # no customized header, speedup:
            #         return value
            #     if "content-type" in headers:
            #         kw["mimetype"] = headers["content-type"]
            r = flask.Response(**kw)
            for h in headers:
                r.headers[h] = headers[h]
            return r

    return scodoc7func_decorator