# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

#

# This file is part of CubicWeb.

#

# CubicWeb is free software: you can redistribute it and/or modify it under the

# terms of the GNU Lesser General Public License as published by the Free

# Software Foundation, either version 2.1 of the License, or (at your option)

# any later version.

#

# CubicWeb is distributed in the hope that it will be useful, but WITHOUT

# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more

# details.

#

# You should have received a copy of the GNU Lesser General Public License along

# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.

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

object :/

"""

__docformat__ = "restructuredtext en"

from cubicweb import (RepositoryError, Unauthorized, AuthenticationError,

                      BadConnectionId)

from cubicweb.web import InvalidSession, Redirect

from cubicweb.web.application import AbstractSessionManager

from cubicweb.dbapi import ProgrammingError, DBAPISession

class InMemoryRepositorySessionManager(AbstractSessionManager):

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

    def __init__(self, *args, **kwargs):

        AbstractSessionManager.__init__(self, *args, **kwargs)

        # XXX require a RepositoryAuthenticationManager which violates

        #     authenticate interface by returning a session instead of a user

        #assert isinstance(self.authmanager, RepositoryAuthenticationManager)

        self._sessions = {}

    # dump_data / restore_data to avoid loosing open sessions on registry

    # reloading

    def dump_data(self):

        return self._sessions

    def restore_data(self, data):

        self._sessions = data

    def current_sessions(self):

        return self._sessions.values()

    def get_session(self, req, sessionid):

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

        if sessionid not in self._sessions:

            raise InvalidSession()

        session = self._sessions[sessionid]

        if session.cnx:

            try:

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

            except InvalidSession:

                # invalid session

                self.close_session(session)

                raise

            # associate the connection to the current request

            req.set_session(session, user)

        return session

    def open_session(self, req, allow_no_cnx=True):

        """open and return a new session for the given request. The session is

        also bound to the request.

        raise :exc:`cubicweb.AuthenticationError` if authentication failed

        (no authentication info found or wrong user/password)

        """

        try:

            cnx, login = self.authmanager.authenticate(req)

        except AuthenticationError:

            if allow_no_cnx:

                session = DBAPISession(None)

            else:

                raise

        else:

            session = DBAPISession(cnx, login)

        self._sessions[session.sessionid] = session

        # associate the connection to the current request

        req.set_session(session)

        return session

    def postlogin(self, req):

        """postlogin: the user has been authenticated, redirect to the original

        page (index by default) with a welcome message

        """

        # Update last connection date

        # XXX: this should be in a post login hook in the repository, but there

        #      we can't differentiate actual login of automatic session

        #      reopening. Is it actually a problem?

        if 'last_login_time' in req.vreg.schema:

            self._update_last_login_time(req)

    def _update_last_login_time(self, req):

        # XXX should properly detect missing permission / non writeable source

        # and avoid "except (RepositoryError, Unauthorized)" below

        try:

            req.execute('SET X last_login_time NOW WHERE X eid %(x)s',

                        {'x' : req.user.eid})

            req.cnx.commit()

        except (RepositoryError, Unauthorized):

            req.cnx.rollback()

        except Exception:

            req.cnx.rollback()

            raise

    def close_session(self, session):

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

        corrupted...)

        """

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

        del self._sessions[session.sessionid]

        if session.cnx:

            try:

                session.cnx.close()

            except (ProgrammingError, BadConnectionId): # expired on the repository side

                pass

            session.cnx = None