"""user authentication component

:organization: Logilab

:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

from logilab.common.decorators import clear_cache

from cubicweb import AuthenticationError, BadConnectionId

from cubicweb.view import Component

from cubicweb.dbapi import repo_connect, ConnectionProperties

from cubicweb.web.application import AbstractAuthenticationManager

class NoAuthInfo(Exception): pass

class WebAuthInfoRetreiver(Component):

    __registry__ = 'webauth'

    order = None

    def authentication_information(self, req):

        """retreive authentication information from the given request, raise

        NoAuthInfo if expected information is not found.

        """

        raise NotImplementedError()

        """callback when return authentication information have opened a

        """

        pass

class LoginPasswordRetreiver(WebAuthInfoRetreiver):

    __regid__ = 'loginpwdauth'

    order = 10

    def authentication_information(self, req):

        """retreive authentication information from the given request, raise

        NoAuthInfo if expected information is not found.

        """

        login, password = req.get_authorization()

        if not login:

            raise NoAuthInfo()

        return login, {'password': password}

class RepositoryAuthenticationManager(AbstractAuthenticationManager):

    """authenticate user associated to a request and check session validity"""

    def __init__(self, vreg):

        super(RepositoryAuthenticationManager, self).__init__(vreg)

        self.repo = vreg.config.repository(vreg)

        self.log_queries = vreg.config['query-log-file']

        self.authinforetreivers = sorted(vreg['webauth'].possible_objects(vreg),

                                    key=lambda x: x.order)

        assert self.authinforetreivers

        self.anoninfo = vreg.config.anonymous_user()

    def validate_session(self, req, session):

        """

        # with this authentication manager, session is actually a dbapi

        # connection

        login = req.get_authorization()[0]

        try:

            # calling cnx.user() check connection validity, raise

            # BadConnectionId on failure

            user = cnx.user(req)

        except BadConnectionId:

            # check if a connection should be automatically restablished

                user = cnx.user(req)

            else:

                raise InvalidSession('bad connection id')

    def authenticate(self, req):

        """

        for retreiver in self.authinforetreivers:

            try:

                login, authinfo = retreiver.authentication_information(req)

            except NoAuthInfo:

                continue

            try:

                continue # the next one may succeed

            for retreiver_ in self.authinforetreivers:

        cnxprops = ConnectionProperties(self.vreg.config.repo_method,

                                        close=False, log=self.log_queries)

        return cnx