# 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/>.

"""Source to query another RQL repository using pyro"""

__docformat__ = "restructuredtext en"

_ = unicode

import threading

from Pyro.errors import PyroError, ConnectionClosedError

from logilab.common.configuration import REQUIRED

from cubicweb import dbapi

from cubicweb import ConnectionError

from cubicweb.server.sources import ConnectionWrapper

from cubicweb.server.sources.remoterql import RemoteSource

class PyroRQLSource(RemoteSource):

    """External repository source, using Pyro connection"""

    CNX_TYPE = 'pyro'

    options = RemoteSource.options + (

        # XXX pyro-ns host/port

        ('pyro-ns-id',

         {'type' : 'string',

          'default': REQUIRED,

          'help': 'identifier of the repository in the pyro name server',

          'group': 'remote-source', 'level': 0,

          }),

        ('pyro-ns-host',

         {'type' : 'string',

          'default': None,

          'help': 'Pyro name server\'s host. If not set, default to the value \

from all_in_one.conf. It may contains port information using <host>:<port> notation.',

          'group': 'remote-source', 'level': 1,

          }),

        ('pyro-ns-group',

         {'type' : 'string',

          'default': None,

          'help': 'Pyro name server\'s group where the repository will be \

registered. If not set, default to the value from all_in_one.conf.',

          'group': 'remote-source', 'level': 2,

          }),

    )

    def _get_connection(self):

        """open and return a connection to the source"""

        nshost = self.config.get('pyro-ns-host') or self.repo.config['pyro-ns-host']

        nsgroup = self.config.get('pyro-ns-group') or self.repo.config['pyro-ns-group']

        self.info('connecting to instance :%s.%s for user %s',

                  nsgroup, self.config['pyro-ns-id'], self.config['cubicweb-user'])

        return dbapi.connect(database=self.config['pyro-ns-id'],

                             login=self.config['cubicweb-user'],

                             password=self.config['cubicweb-password'],

                             host=nshost, group=nsgroup,

                             setvreg=False)

    def get_connection(self):

        try:

            return self._get_connection()

        except (ConnectionError, PyroError), ex:

            self.critical("can't get connection to source %s: %s", self.uri, ex)

            return ConnectionWrapper()

    def check_connection(self, cnx):

        """check connection validity, return None if the connection is still valid

        else a new connection

        """

        # we have to transfer manually thread ownership. This can be done safely

        # since the connections set holding the connection is affected to one

        # session/thread and can't be called simultaneously

        try:

            cnx._repo._transferThread(threading.currentThread())

        except AttributeError:

            # inmemory connection

            pass

        try:

            return super(PyroRQLSource, self).check_connection(cnx)

        except ConnectionClosedError:

            # try to reconnect

            return self.get_connection()