# copyright 2003-2010 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: set generic metadata"""

__docformat__ = "restructuredtext en"

from datetime import datetime

from cubicweb.selectors import is_instance

from cubicweb.server import hook

from cubicweb.server.utils import eschema_eid

class MetaDataHook(hook.Hook):

    __abstract__ = True

    category = 'metadata'

class InitMetaAttrsHook(MetaDataHook):

    """before create a new entity -> set creation and modification date

    this is a conveniency hook, you shouldn't have to disable it

    """

    __regid__ = 'metaattrsinit'

    events = ('before_add_entity',)

    def __call__(self):

        timestamp = datetime.now()

        self.entity.setdefault('creation_date', timestamp)

        self.entity.setdefault('modification_date', timestamp)

        if not self._cw.get_shared_data('do-not-insert-cwuri'):

            cwuri = u'%seid/%s' % (self._cw.base_url(), self.entity.eid)

            self.entity.setdefault('cwuri', cwuri)

class UpdateMetaAttrsHook(MetaDataHook):

    """update an entity -> set modification date"""

    __regid__ = 'metaattrsupdate'

    events = ('before_update_entity',)

    def __call__(self):

        # repairing is true during c-c upgrade/shell and similar commands. We

        # usually don't want to update modification date in such cases.

        #

        # XXX to be really clean, we should turn off modification_date update

        # explicitly on each command where we do not want that behaviour.

        if not self._cw.vreg.config.repairing:

            self.entity.setdefault('modification_date', datetime.now())

class _SetCreatorOp(hook.Operation):

    def precommit_event(self):

        session = self.session

        for eid in session.transaction_data.pop('set_creator_op'):

            if session.deleted_in_transaction(eid):

                # entity have been created and deleted in the same transaction

                continue

            entity = session.entity_from_eid(eid)

            if not entity.created_by:

                session.add_relation(eid, 'created_by', session.user.eid)

class SetIsHook(MetaDataHook):

    """create a new entity -> set is and is_instance_of relations

    those relations are inserted using sql so they are not hookable.

    """

    __regid__ = 'setis'

    events = ('after_add_entity',)

    def __call__(self):

        if hasattr(self.entity, '_cw_recreating'):

            return

        session = self._cw

        entity = self.entity

        try:

            session.system_sql('INSERT INTO is_relation(eid_from,eid_to) VALUES (%s,%s)'

                           % (entity.eid, eschema_eid(session, entity.e_schema)))

        except IndexError:

            # during schema serialization, skip

            return

        for eschema in entity.e_schema.ancestors() + [entity.e_schema]:

            session.system_sql('INSERT INTO is_instance_of_relation(eid_from,eid_to) VALUES (%s,%s)'

                               % (entity.eid, eschema_eid(session, eschema)))

class SetOwnershipHook(MetaDataHook):

    """create a new entity -> set owner and creator metadata"""

    __regid__ = 'setowner'

    events = ('after_add_entity',)

    def __call__(self):

        if not self._cw.is_internal_session:

            self._cw.add_relation(self.entity.eid, 'owned_by', self._cw.user.eid)

            hook.set_operation(self._cw, 'set_creator_op', self.entity.eid, _SetCreatorOp)

class _SyncOwnersOp(hook.Operation):

    def precommit_event(self):

        for compositeeid, composedeid in self.session.transaction_data.pop('sync_owners_op'):

            self.session.execute('SET X owned_by U WHERE C owned_by U, C eid %(c)s,'

                                 'NOT EXISTS(X owned_by U, X eid %(x)s)',

                                 {'c': compositeeid, 'x': composedeid})

class SyncCompositeOwner(MetaDataHook):

    """when adding composite relation, the composed should have the same owners

    has the composite

    """

    __regid__ = 'synccompositeowner'

    events = ('after_add_relation',)

    def __call__(self):

        if self.rtype == 'wf_info_for':

            # skip this special composite relation # XXX (syt) why?

            return

        eidfrom, eidto = self.eidfrom, self.eidto

        composite = self._cw.schema_rproperty(self.rtype, eidfrom, eidto, 'composite')

        if composite == 'subject':

            hook.set_operation(self._cw, 'sync_owners_op', (eidfrom, eidto), _SyncOwnersOp)

        elif composite == 'object':

            hook.set_operation(self._cw, 'sync_owners_op', (eidto, eidfrom), _SyncOwnersOp)

class FixUserOwnershipHook(MetaDataHook):

    """when a user has been created, add owned_by relation on itself"""

    __regid__ = 'fixuserowner'

    __select__ = MetaDataHook.__select__ & is_instance('CWUser')

    events = ('after_add_entity',)

    def __call__(self):

        self._cw.add_relation(self.entity.eid, 'owned_by', self.entity.eid)

class UpdateFTIHook(MetaDataHook):

    """sync fulltext index text index container when a relation with

    fulltext_container set is added / removed

    """

    __regid__ = 'updateftirel'

    events = ('after_add_relation', 'after_delete_relation')

    def __call__(self):

        rtype = self.rtype

        session = self._cw

        ftcontainer = session.vreg.schema.rschema(rtype).fulltext_container

        if ftcontainer == 'subject':

            session.repo.system_source.index_entity(

                session, session.entity_from_eid(self.eidfrom))

        elif ftcontainer == 'object':

            session.repo.system_source.index_entity(

                session, session.entity_from_eid(self.eidto))