for rtype in ('cw_support', 'cw_dont_cross', 'cw_may_cross'):

    drop_relation_type(rtype)

add_entity_type('CWSourceSchemaConfig')

try:

    from cubicweb.server.sources.pyrorql import PyroRQLSource

except ImportError:

    pass

else:

    from os.path import join

    # function to read old python mapping file

    def load_mapping_file(source):

        mappingfile = source.config['mapping-file']

        mappingfile = join(source.repo.config.apphome, mappingfile)

        mapping = {}

        execfile(mappingfile, mapping)

        for junk in ('__builtins__', '__doc__'):

            mapping.pop(junk, None)

        mapping.setdefault('support_relations', {})

        mapping.setdefault('dont_cross_relations', set())

        mapping.setdefault('cross_relations', set())

        # do some basic checks of the mapping content

        assert 'support_entities' in mapping, \

               'mapping file should at least define support_entities'

        assert isinstance(mapping['support_entities'], dict)

        assert isinstance(mapping['support_relations'], dict)

        assert isinstance(mapping['dont_cross_relations'], set)

        assert isinstance(mapping['cross_relations'], set)

        unknown = set(mapping) - set( ('support_entities', 'support_relations',

                                       'dont_cross_relations', 'cross_relations') )

        assert not unknown, 'unknown mapping attribute(s): %s' % unknown

        # relations that are necessarily not crossed

        for rtype in ('is', 'is_instance_of', 'cw_source'):

            assert rtype not in mapping['dont_cross_relations'], \

                   '%s relation should not be in dont_cross_relations' % rtype

            assert rtype not in mapping['support_relations'], \

                   '%s relation should not be in support_relations' % rtype

        return mapping

    # for now, only pyrorql sources have a mapping

    for source in repo.sources_by_uri.values():

        if not isinstance(source, PyroRQLSource):

            continue

        sourceentity = session.entity_from_eid(source.eid)

        mapping = load_mapping_file(source)

        # write mapping as entities

        print 'migrating map for', source

        for etype, write in mapping['support_entities'].items():

            create_entity('CWSourceSchemaConfig',

                          cw_for_source=sourceentity,

                          cw_schema=session.entity_from_eid(schema[etype].eid),

                          options=write and u'write' or None,

                          ask_confirm=False)

        for rtype, write in mapping['support_relations'].items():

            options = []

            if write:

                options.append(u'write')

            if rtype in mapping['cross_relations']:

                options.append(u'maycross')

            create_entity('CWSourceSchemaConfig',

                          cw_for_source=sourceentity,

                          cw_schema=session.entity_from_eid(schema[rtype].eid),

                          options=u':'.join(options) or None,

                          ask_confirm=False)

        for rtype in mapping['dont_cross_relations']:

            create_entity('CWSourceSchemaConfig',

                          cw_for_source=source,

                          cw_schema=session.entity_from_eid(schema[etype].eid),

                          options=u'dontcross')