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

:organization: Logilab
:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
"""
__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