"""web session component: by dfault the session is actually the db connection

object :/

:organization: Logilab

:copyright: 2001-2009 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 cubicweb.web import InvalidSession

from cubicweb.web.application import AbstractSessionManager

class InMemoryRepositorySessionManager(AbstractSessionManager):

    """manage session data associated to a session identifier"""

    def __init__(self):

        AbstractSessionManager.__init__(self)

        # XXX require a RepositoryAuthenticationManager which violates

        #     authenticate interface by returning a session instead of a user

        #assert isinstance(self.authmanager, RepositoryAuthenticationManager)

        self._sessions = {}

    def current_sessions(self):

        return self._sessions.values()

    def get_session(self, req, sessionid):

        """return existing session for the given session identifier"""

        if not sessionid in self._sessions:

            raise InvalidSession()

        session = self._sessions[sessionid]

        if self.has_expired(session):

            self.close_session(session)

            raise InvalidSession()

        # give an opportunity to auth manager to hijack the session

        # (necessary with the RepositoryAuthenticationManager in case

        #  the connection to the repository has expired)

        try:

            session = self.authmanager.validate_session(req, session)

            # necessary in case session has been hijacked

            self._sessions[session.sessionid] = session

        except InvalidSession:

            # invalid session

            del self._sessions[sessionid]

            raise

        return session

    def open_session(self, req):

        """open and return a new session for the given request

        :raise ExplicitLogin: if authentication is required

        """

        session = self.authmanager.authenticate(req)

        self._sessions[session.sessionid] = session

        return session

    def close_session(self, session):

        """close session on logout or on invalid session detected (expired out,

        corrupted...)

        """

        self.info('closing http session %s' % session)

        del self._sessions[session.sessionid]

        try:

            session.close()

        except:

            # already closed, may occurs if the repository session expired but

            # not the web session

            pass