"""extends yams to be able to load google appengine's schemas

MISSING FEATURES:

 - ListProperty, StringList, EmailProperty, etc. (XXX)

 - ReferenceProperty.verbose_name, collection_name, etc. (XXX)

XXX proprify this knowing we'll use goa.db

"""

from os.path import join

from datetime import datetime, date, time

from google.appengine.ext import db

from google.appengine.api import datastore_types

from yams.buildobjs import (String, Int, Float, Boolean, Date, Time, Datetime,

                            Bytes, SubjectRelation)

from yams.buildobjs import metadefinition, EntityType

from cubicweb.schema import CubicWebSchemaLoader

from cubicweb.goa import db as goadb

# db.Model -> yams ############################################################

DBM2Y_TYPESMAP = {

    basestring: String,

    datastore_types.Text: String,

    int: Int,

    float: Float,

    bool: Boolean,

    time: Time,

    date: Date,

    datetime: Datetime,

    datastore_types.Blob: Bytes,

    }

def dbm2y_default_factory(prop, **kwargs):

    """just wraps the default types map to set

    basic constraints like `required`, `default`, etc.

    """

    yamstype = DBM2Y_TYPESMAP[prop.data_type]

    if 'default' not in kwargs:

        default = prop.default_value()

        if default is not None:

            kwargs['default'] = default

    if prop.required:

        kwargs['required'] = True

    return yamstype(**kwargs)

def dbm2y_string_factory(prop):

    """like dbm2y_default_factory but also deals with `maxsize` and `vocabulary`"""

    kwargs = {}

    if prop.data_type is basestring:

        kwargs['maxsize'] = 500

    if prop.choices is not None:

        kwargs['vocabulary'] = prop.choices

    return dbm2y_default_factory(prop, **kwargs)

def dbm2y_date_factory(prop):

    """like dbm2y_default_factory but also deals with today / now definition"""

    kwargs = {}

    if prop.auto_now_add:

        if prop.data_type is datetime:

            kwargs['default'] = 'now'

        else:

            kwargs['default'] = 'today'

    # XXX no equivalent to Django's `auto_now`

    return dbm2y_default_factory(prop, **kwargs)

def dbm2y_relation_factory(etype, prop, multiple=False):

    """called if `prop` is a `db.ReferenceProperty`"""

    if multiple:

        cardinality = '**'

    elif prop.required:

        cardinality = '1*'

    else:

        cardinality = '?*'

    # XXX deal with potential kwargs of ReferenceProperty.__init__()

    try:

        return SubjectRelation(prop.data_type.kind(), cardinality=cardinality)

    except AttributeError, ex:

        # hack, data_type is still _SELF_REFERENCE_MARKER

        return SubjectRelation(etype, cardinality=cardinality)

DBM2Y_FACTORY = {

    basestring: dbm2y_string_factory,

    datastore_types.Text: dbm2y_string_factory,

    int: dbm2y_default_factory,

    float: dbm2y_default_factory,

    bool: dbm2y_default_factory,

    time: dbm2y_date_factory,

    date: dbm2y_date_factory,

    datetime: dbm2y_date_factory,

    datastore_types.Blob: dbm2y_default_factory,

    }

class GaeSchemaLoader(CubicWebSchemaLoader):

    """Google appengine schema loader class"""

    def __init__(self, *args, **kwargs):

        self.use_gauthservice = kwargs.pop('use_gauthservice', False)

        super(GaeSchemaLoader, self).__init__(*args, **kwargs)

        self.defined = {}

        self.created = []

        self.loaded_files = []

        self._instantiate_handlers()

    def finalize(self, register_base_types=False):

        return self._build_schema('google-appengine', register_base_types)

    def load_dbmodel(self, name, props):

        clsdict = {}

        ordered_props = sorted(props.items(),

                               key=lambda x: x[1].creation_counter)

        for pname, prop in ordered_props:

            if isinstance(prop, db.ListProperty):

                if not issubclass(prop.item_type, db.Model):

                    self.error('ignoring list property with %s item type'

                               % prop.item_type)

                    continue

                rdef = dbm2y_relation_factory(name, prop, multiple=True)

            else:

                try:

                    if isinstance(prop, (db.ReferenceProperty,

                                         goadb.ReferencePropertyStub)):

                        rdef = dbm2y_relation_factory(name, prop)

                    else:

                        rdef = DBM2Y_FACTORY[prop.data_type](prop)

                except KeyError, ex:

                    import traceback

                    traceback.print_exc()

                    self.error('ignoring property %s (keyerror on %s)' % (pname, ex))

                    continue

            rdef.creation_rank = prop.creation_counter

            clsdict[pname] = rdef

        edef = metadefinition(name, (EntityType,), clsdict)

        self.add_definition(self, edef())

    def error(self, msg):

        print 'ERROR:', msg

    def import_yams_schema(self, ertype, schemamod):

        erdef = self.pyreader.import_erschema(ertype, schemamod)

    def import_yams_cube_schema(self, templpath):

        for filepath in self.get_schema_files(templpath):

            self.handle_file(filepath)

    @property

    def pyreader(self):

        return self._live_handlers['.py']

import os

from cubicweb import CW_SOFTWARE_ROOT

if os.environ.get('APYCOT_ROOT'):

    SCHEMAS_LIB_DIRECTORY = join(os.environ['APYCOT_ROOT'],

                                 'local', 'share', 'cubicweb', 'schemas')

else:

    SCHEMAS_LIB_DIRECTORY = join(CW_SOFTWARE_ROOT, 'schemas')

def load_schema(config, schemaclasses=None, extrahook=None):

    """high level method to load all the schema for a lax application"""

    # IMPORTANT NOTE: dbmodel schemas must be imported **BEFORE**

    # the loader is instantiated because this is where the dbmodels

    # are registered in the yams schema

    for compname in config['included-cubes']:

        __import__('%s.schema' % compname)

    loader = GaeSchemaLoader(use_gauthservice=config['use-google-auth'], db=db)

    loader.lib_directory = SCHEMAS_LIB_DIRECTORY

    if schemaclasses is not None:

        for cls in schemaclasses:

            loader.load_dbmodel(cls.__name__, goadb.extract_dbmodel(cls))

    elif config['schema-type'] == 'dbmodel':

        import schema as appschema

        for obj in vars(appschema).values():

            if isinstance(obj, type) and issubclass(obj, goadb.Model) and obj.__module__ == appschema.__name__:

                loader.load_dbmodel(obj.__name__, goadb.extract_dbmodel(obj))

    for erschema in ('EGroup', 'EEType', 'ERType', 'RQLExpression',

                     'is_', 'is_instance_of',

                     'read_permission', 'add_permission',

                     'delete_permission', 'update_permission'):

        loader.import_yams_schema(erschema, 'bootstrap')  

    loader.handle_file(join(SCHEMAS_LIB_DIRECTORY, 'base.py'))

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

    for cube in reversed(config.expand_cubes(cubes)):

        config.info('loading cube %s', cube)

        loader.import_yams_cube_schema(config.cube_dir(cube))

    if config['schema-type'] == 'yams':

        loader.import_yams_cube_schema('.')

    if extrahook is not None:

        extrahook(loader)

    if config['use-google-auth']:

        loader.defined['EUser'].remove_relation('upassword')

        loader.defined['EUser'].permissions['add'] = ()

        loader.defined['EUser'].permissions['delete'] = ()

    for etype in ('EGroup', 'RQLExpression'):

        read_perm_rel = loader.defined[etype].get_relations('read_permission').next()

        read_perm_rel.cardinality = '**'

    # XXX not yet ready for EUser workflow

    loader.defined['EUser'].remove_relation('in_state')

    loader.defined['EUser'].remove_relation('wf_info_for')

    # remove RQLConstraint('NOT O name "owners"') on EUser in_group EGroup

    # since "owners" group is not persistent with gae

    loader.defined['EUser'].get_relations('in_group').next().constraints = []

    # return the full schema including the cubes' schema

    for ertype in loader.defined.values():

        if getattr(ertype, 'inlined', False):

            ertype.inlined = False

    return loader.finalize()