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 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`).
    """

    @wraps(func)
    def scodoc_function(*args, **kwargs):
        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):
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            # current_app.logger.info("PERMISSION; kwargs=%s" % str(kwargs))
            scodoc_dept = getattr(g, "scodoc_dept", None)
            if not current_user.has_permission(permission, scodoc_dept):
                abort(403)
            return f(*args, **kwargs)

        return login_required(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.
    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.
    """

    @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)
        """
        # 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)
        # --- 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 = []
        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:
            if arg_name == "REQUEST":  # special case
                pos_arg_values.append(REQUEST)
            else:
                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:
                    pass
                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
                elif 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