# copyright 2003-2013 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/>.

"""CubicWeb server connections set : the repository has a limited number of

:class:`ConnectionsSet` (defined in configuration, default to 4). Each of them

hold a connection to the system source.

"""

__docformat__ = "restructuredtext en"

import sys

from logilab.common.deprecation import deprecated

class ConnectionsSet(object):

    """handle connection to the system source, at some point associated to a

    :class:`Session`

    """

    # since 3.19, we only have to manage the system source connection

    def __init__(self, system_source):

        # dictionary of (source, connection), indexed by sources'uri

        self._source = system_source

        self.cnx = system_source.get_connection()

        self.cu = self.cnx.cursor()

    def commit(self):

        """commit the current transaction for this user"""

        # let exception propagates

        self.cnx.commit()

    def rollback(self):

        """rollback the current transaction for this user"""

        # catch exceptions, rollback other sources anyway

        try:

            self.cnx.rollback()

        except Exception:

            self._source.critical('rollback error', exc_info=sys.exc_info())

            # error on rollback, the connection is much probably in a really

            # bad state. Replace it by a new one.

            self.reconnect()

    def close(self, i_know_what_i_do=False):

        """close all connections in the set"""

        if i_know_what_i_do is not True: # unexpected closing safety belt

            raise RuntimeError('connections set shouldn\'t be closed')

        try:

            self.cu.close()

            self.cu = None

        except Exception:

            pass

        try:

            self.cnx.close()

        except Exception:

            pass

    # internals ###############################################################

    def cnxset_set(self):

        """connections set is being set on a session"""

        self.check_connections()

    def cnxset_freed(self):

        """connections set is being freed from a session"""

        self._source.cnxset_freed(self.cnx)

    def reconnect(self):

        """reopen a connection for this source or all sources if none specified

        """

        try:

            # properly close existing connection if any

            self.cnx.close()

        except Exception:

            pass

        self._source.info('trying to reconnect')

        self.cnx = self._source.get_connection()

        self.cu = self.cnx.cursor()

    def check_connections(self):

        newcnx = self._source.check_connection(self.cnx)

        if newcnx is not None:

            self.cnx = newcnx

            self.cu = self.cnx.cursor()

    @deprecated('[3.19] use .cu instead')

    def __getitem__(self, uri):

        assert uri == 'system'

        return self.cu

    @deprecated('[3.19] use repo.system_source instead')

    def source(self, uid):

        assert uid == 'system'

        return self._source

    @deprecated('[3.19] use .cnx instead')

    def connection(self, uid):

        assert uid == 'system'

        return self.cnx

from cubicweb.server.hook import Operation, LateOperation, SingleLastOperation

from logilab.common.deprecation import class_moved, class_renamed

Operation = class_moved(Operation)

PreCommitOperation = class_renamed('PreCommitOperation', Operation)

LateOperation = class_moved(LateOperation)

SingleLastOperation = class_moved(SingleLastOperation)