"""hooks to ensure use_email / primary_email relations consistency

:organization: Logilab

:copyright: 2001-2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

"""

__docformat__ = "restructuredtext en"

from cubicweb.server.hooksmanager import Hook

from cubicweb.server.pool import PreCommitOperation

class SetUseEmailRelationOp(PreCommitOperation):

    """delay this operation to commit to avoid conflict with a late rql query

    already setting the relation

    """

    rtype = 'use_email'

    fromeid = toeid = None # make pylint happy

    def condition(self):

        """check entity has use_email set for the email address"""

        return not self.session.unsafe_execute(

            'Any X WHERE X eid %(x)s, X use_email Y, Y eid %(y)s',

            {'x': self.fromeid, 'y': self.toeid}, 'x')

    def precommit_event(self):

        session = self.session

        if self.condition():

            session.unsafe_execute(

                'SET X %s Y WHERE X eid %%(x)s, Y eid %%(y)s' % self.rtype,

                {'x': self.fromeid, 'y': self.toeid}, 'x')

class SetPrimaryEmailRelationOp(SetUseEmailRelationOp):

    rtype = 'primary_email'

    def condition(self):

        """check entity has no primary_email set"""

        return not self.session.unsafe_execute(

            'Any X WHERE X eid %(x)s, X primary_email Y',

            {'x': self.fromeid}, 'x')

class SetPrimaryEmailHook(Hook):

    """notify when a bug or story or version has its state modified"""

    events = ('after_add_relation',)

    accepts = ('use_email',)

    def call(self, session, fromeid, rtype, toeid):

        subjtype = session.describe(fromeid)[0]

        eschema = self.vreg.schema[subjtype]

        if 'primary_email' in eschema.subject_relations():

            SetPrimaryEmailRelationOp(session, vreg=self.vreg, 

                                      fromeid=fromeid, toeid=toeid)

class SetUseEmailHook(Hook):

    """notify when a bug or story or version has its state modified"""

    events = ('after_add_relation',)

    accepts = ('primary_email',)

    def call(self, session, fromeid, rtype, toeid):

        subjtype = session.describe(fromeid)[0]

        eschema = self.vreg.schema[subjtype]

        if 'use_email' in eschema.subject_relations():

            SetUseEmailRelationOp(session, vreg=self.vreg, 

                                  fromeid=fromeid, toeid=toeid)