ScoDoc/app/decorators.py

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

import werkzeug
from werkzeug.exceptions import BadRequest
import flask
from flask import g
from flask import abort, current_app
from flask import request
from flask_login import current_user
from flask_login import login_required
from flask import current_app

import app


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()


class ZRequest(object):
    "Emulating Zope 2 REQUEST"

    def __init__(self):
        self.URL = request.base_url

        self.URL0 = self.URL
        self.BASE0 = request.url_root
        self.QUERY_STRING = request.query_string.decode(
            "utf-8"
        )  # query_string is bytes
        self.REQUEST_METHOD = request.method
        self.AUTHENTICATED_USER = current_user
        self.REMOTE_ADDR = request.remote_addr
        if request.method == "POST":
            # request.form is a werkzeug.datastructures.ImmutableMultiDict
            # must copy to get a mutable version (needed by TrivialFormulator)
            self.form = request.form.copy()
            if request.files:
                # Add files in form:
                self.form.update(request.files)
            for k in request.form:
                if k.endswith(":list"):
                    self.form[k[:-5]] = request.form.getlist(k)
        elif request.method == "GET":
            self.form = {}
            for k in request.args:
                current_app.logger.debug("%s\t%s" % (k, request.args.getlist(k)))
                if k.endswith(":list"):
                    self.form[k[:-5]] = request.args.getlist(k)
                else:
                    self.form[k] = request.args[k]
            current_app.logger.info("ZRequest.form=%s" % str(self.form))
        self.RESPONSE = ZResponse()

    def __str__(self):
        return """REQUEST
        URL={r.URL}
        QUERY_STRING={r.QUERY_STRING}
        REQUEST_METHOD={r.REQUEST_METHOD}
        AUTHENTICATED_USER={r.AUTHENTICATED_USER}
        form={r.form}
        """.format(
            r=self
        )


class ZResponse(object):
    "Emulating Zope 2 RESPONSE"

    def __init__(self):
        self.headers = {}

    def redirect(self, url):
        current_app.logger.debug("ZResponse redirect to:" + str(url))
        return flask.redirect(url)  # http 302

    def setHeader(self, header, value):
        self.headers[header.lower()] = value


def permission_required(permission):
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            if "scodoc_dept" in kwargs:
                g.scodoc_dept = kwargs["scodoc_dept"]
                del kwargs["scodoc_dept"]
            # current_app.logger.info(
            #    "permission_required: %s in %s" % (permission, g.scodoc_dept)
            # )
            if not current_user.has_permission(permission, g.scodoc_dept):
                abort(403)
            return 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(context):
    """Décorateur pour intégrer les fonctions Zope 2 de ScoDoc 7.
    Si on a un kwarg `scodoc_dept`(venant de la route), le stocke dans `g.scodoc_dept`.
    Ajoute l'argument REQUEST s'il est dans la signature de la fonction.
    Les paramètres de la query string deviennent des (keywords) paramètres de la fonction.
    """

    def s7_decorator(func):
        @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.

            If called via a route, this decorator setups a REQUEST object (emulating Zope2 REQUEST)
            and `g.scodoc_dept` if present in the argument (for routes like `/<scodoc_dept>/Scolarite/sco_exemple`).
            """
            # Détermine si on est appelé via une route ("toplevel")
            # ou par un appel de fonction python normal.
            top_level = not hasattr(g, "zrequest")
            if not top_level:
                # ne "redécore" pas
                return func(*args, **kwargs)
            #
            if "scodoc_dept" in kwargs:
                g.scodoc_dept = kwargs["scodoc_dept"]
                del kwargs["scodoc_dept"]
            elif not hasattr(g, "scodoc_dept"):
                g.scodoc_dept = None
            # --- Open DB connection
            app.open_dept_db_connection()
            # --- Emulate Zope's REQUEST
            REQUEST = ZRequest()
            g.zrequest = REQUEST
            req_args = REQUEST.form  # args from query string (get) or form (post)
            # --- Add positional arguments
            pos_arg_values = []
            # PY3 à remplacer par inspect.getfullargspec en py3: TODO
            argspec = inspect.getargspec(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:
                if arg_name == "REQUEST":  # special case
                    pos_arg_values.append(REQUEST)
                elif arg_name == "context":
                    pos_arg_values.append(context)
                else:
                    pos_arg_values.append(req_args[arg_name])
            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
                    elif arg_name in req_args:
                        # set argument kw optionnel
                        kwargs[arg_name] = req_args[arg_name]
            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

    return s7_decorator


# Le "context" de ScoDoc7
class ScoDoc7Context(object):
    """Context object for legacy Zope methods.
    Mainly used to call published methods, as context.function(...)
    """

    def __init__(self, name=""):
        self.name = name
        logging.getLogger(__name__).info("created %s" % self)

    def populate(self, globals_dict):
        logging.getLogger(__name__).info("populating context %s" % self)
        for k in globals_dict:
            if (not k.startswith("_")) and (
                isinstance(globals_dict[k], types.FunctionType)
            ):
                setattr(self, k, globals_dict[k].__get__(self))

    def __repr__(self):
        return "ScoDoc7Context('%s')" % self.name