# copyright 2003-2016 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/>.

"""Core hooks: synchronize living session on persistent data changes"""

from cubicweb import _

from cubicweb import UnknownProperty, validation_error

from cubicweb.predicates import is_instance

from cubicweb.server import hook

class SyncSessionHook(hook.Hook):

    __abstract__ = True

    category = 'syncsession'

class _ChangeSiteWideCWPropertyOp(hook.Operation):

    """Synchronize site wide properties when one has been added/updated"""

    cwprop = None  # make pylint happy

    def postcommit_event(self):

        cwprop = self.cwprop

        if not cwprop.for_user:

            self.cnx.vreg['propertyvalues'][cwprop.pkey] = \

                self.cnx.vreg.typed_value(cwprop.pkey, cwprop.value)

        # if for_user is set, update is handled by a ChangeUserCWPropertyOp operation

class _DelSiteWideCWPropertyOp(hook.Operation):

    """Synchronize site wide properties when one has been deleted"""

    key = None  # make pylint happy

    def postcommit_event(self):

        self.cnx.vreg['propertyvalues'].pop(self.key, None)

class AddCWPropertyHook(SyncSessionHook):

    __regid__ = 'addcwprop'

    __select__ = SyncSessionHook.__select__ & is_instance('CWProperty')

    events = ('after_add_entity',)

    def __call__(self):

        key, value = self.entity.pkey, self.entity.value

        if key.startswith('sources.'):

            return

        cnx = self._cw

        try:

            value = cnx.vreg.typed_value(key, value)

        except UnknownProperty:

            msg = _('unknown property key %s')

            raise validation_error(self.entity, {('pkey', 'subject'): msg}, (key,))

        except ValueError as ex:

            raise validation_error(self.entity, {('value', 'subject'): str(ex)})

        if cnx.user.matching_groups('managers'):

            _ChangeSiteWideCWPropertyOp(cnx, cwprop=self.entity)

        else:

            cnx.add_relation(self.entity.eid, 'for_user', cnx.user.eid)

class UpdateCWPropertyHook(AddCWPropertyHook):

    __regid__ = 'updatecwprop'

    events = ('after_update_entity',)

    def __call__(self):

        entity = self.entity

        if not ('pkey' in entity.cw_edited or

                'value' in entity.cw_edited):

            return

        key, value = entity.pkey, entity.value

        if key.startswith('sources.'):

            return

        cnx = self._cw

        try:

            value = cnx.vreg.typed_value(key, value)

        except UnknownProperty:

            return

        except ValueError as ex:

            raise validation_error(entity, {('value', 'subject'): str(ex)})

        if not entity.for_user:

            _ChangeSiteWideCWPropertyOp(cnx, cwprop=self.entity)

class DeleteCWPropertyHook(AddCWPropertyHook):

    __regid__ = 'delcwprop'

    events = ('before_delete_entity',)

    def __call__(self):

        cnx = self._cw

        for eidfrom, rtype, eidto in cnx.transaction_data.get('pendingrelations', ()):

            if rtype == 'for_user' and eidfrom == self.entity.eid:

                # not need to sync user specific properties

                break

        else:

            _DelSiteWideCWPropertyOp(cnx, key=self.entity.pkey)

class AddForUserRelationHook(SyncSessionHook):

    __regid__ = 'addcwpropforuser'

    __select__ = SyncSessionHook.__select__ & hook.match_rtype('for_user')

    events = ('after_add_relation',)

    def __call__(self):

        cnx = self._cw

        eidfrom = self.eidfrom

        if not cnx.entity_type(eidfrom) == 'CWProperty':

            return

        key, value = cnx.execute('Any K,V WHERE P eid %(x)s,P pkey K,P value V',

                                 {'x': eidfrom})[0]

        if cnx.vreg.property_info(key)['sitewide']:

            msg = _("site-wide property can't be set for user")

            raise validation_error(eidfrom, {('for_user', 'subject'): msg})

class DelForUserRelationHook(AddForUserRelationHook):

    __regid__ = 'delcwpropforuser'

    events = ('after_delete_relation',)

    def __call__(self):

        cnx = self._cw

        cnx.transaction_data.setdefault('pendingrelations', []).append(

            (self.eidfrom, self.rtype, self.eidto))