# 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/>.

"""cubicweb on google appengine

"""

__docformat__ = "restructuredtext en"

try:

    # WARNING: do not import the google's db module here since it will take

    #          precedence over our own db submodule

    from google.appengine.api.datastore import Key, Get, Query

    from google.appengine.api.datastore_errors import BadKeyError

except ImportError:

    # not in google app environment

    pass

else:

    import os

    _SS = os.environ.get('SERVER_SOFTWARE')

    if _SS is None:

        MODE = 'test'

    elif _SS.startswith('Dev'):

        MODE = 'dev'

    else:

        MODE = 'prod'

    from cubicweb.server import SOURCE_TYPES

    from cubicweb.goa.gaesource import GAESource

    SOURCE_TYPES['gae'] = GAESource

    def do_monkey_patch():

        # monkey patch yams Bytes validator since it should take a bytes string with gae

        # and not a StringIO

        def check_bytes(eschema, value):

            """check value is a bytes string"""

            return isinstance(value, str)

        from yams import constraints

        constraints.BASE_CHECKERS['Bytes'] = check_bytes

        def rql_for_eid(eid):

            return 'Any X WHERE X eid "%s"' % eid

        from cubicweb import uilib

        uilib.rql_for_eid = rql_for_eid

        def typed_eid(eid):

            try:

                return str(Key(eid))

            except BadKeyError:

                raise ValueError(eid)

        import cubicweb

        cubicweb.typed_eid = typed_eid

        # XXX monkey patch cubicweb.schema.CubicWebSchema to have string eid with

        #     optional cardinality (since eid is set after the validation)

        import re

        from yams import buildobjs as ybo

        def add_entity_type(self, edef):

            edef.name = edef.name.encode()

            assert re.match(r'[A-Z][A-Za-z0-9]*[a-z]+[0-9]*$', edef.name), repr(edef.name)

            eschema = super(CubicWebSchema, self).add_entity_type(edef)

            if not eschema.final:

                # automatically add the eid relation to non final entity types

                rdef = ybo.RelationDefinition(eschema.type, 'eid', 'Bytes',

                                              cardinality='?1', uid=True)

                self.add_relation_def(rdef)

                rdef = ybo.RelationDefinition(eschema.type, 'identity', eschema.type)

                self.add_relation_def(rdef)

            self._eid_index[eschema.eid] = eschema

            return eschema

        from cubicweb.schema import CubicWebSchema

        CubicWebSchema.add_entity_type = add_entity_type

        # don't reset vreg on repository set_schema

        from cubicweb.server import repository

        orig_set_schema = repository.Repository.set_schema

        def set_schema(self, schema, resetvreg=True):

            orig_set_schema(self, schema, False)

        repository.Repository.set_schema = set_schema

        # deactivate function ensuring relation cardinality consistency

        repository.del_existing_rel_if_needed = lambda *args: None

        def get_cubes(self):

            """return the list of top level cubes used by this instance"""

            config = self.config

            cubes = config['included-cubes'] + config['included-yams-cubes']

            return config.expand_cubes(cubes)

        repository.Repository.get_cubes = get_cubes

        from rql import RQLHelper

        RQLHelper.simplify = lambda x, r: None

        # activate entity caching on the server side

        def set_entity_cache(self, entity):

            self.transaction_data.setdefault('_eid_cache', {})[entity.eid] = entity

        def entity_cache(self, eid):

            return self.transaction_data['_eid_cache'][eid]

        def drop_entity_cache(self, eid=None):

            if eid is None:

                self.transaction_data['_eid_cache'] = {}

            elif '_eid_cache' in self.transaction_data:

                self.transaction_data['_eid_cache'].pop(eid, None)

        def datastore_get(self, key):

            if isinstance(key, basestring):

                key = Key(key)

            try:

                gentity = self.transaction_data['_key_cache'][key]

                #self.critical('cached %s', gentity)

            except KeyError:

                gentity = Get(key)

                #self.critical('Get %s', gentity)

                self.transaction_data.setdefault('_key_cache', {})[key] = gentity

            return gentity

        def clear_datastore_cache(self, key=None):

            if key is None:

                self.transaction_data['_key_cache'] = {}

            else:

                if isinstance(key, basestring):

                    key = Key(key)

                self.transaction_data['_key_cache'].pop(key, None)

        from cubicweb.server.session import Session

        Session.set_entity_cache = set_entity_cache

        Session.entity_cache = entity_cache

        Session.drop_entity_cache = drop_entity_cache

        Session.datastore_get = datastore_get

        Session.clear_datastore_cache = clear_datastore_cache

        from docutils.frontend import OptionParser

        # avoid a call to expanduser which is not available under gae

        def get_standard_config_files(self):

            return self.standard_config_files

        OptionParser.get_standard_config_files = get_standard_config_files