"""extend the generic VRegistry with some cubicweb specific stuff

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

"""

__docformat__ = "restructuredtext en"

from warnings import warn

from logilab.common.decorators import cached, clear_cache

from logilab.common.interface import extend

from rql import RQLHelper

from cubicweb import Binary, UnknownProperty

from cubicweb.vregistry import VRegistry, ObjectNotFound, NoSelectableObject

_ = unicode

def use_interfaces(obj):

    from cubicweb.selectors import implements

    try:

        # XXX deprecated

        return sorted(obj.accepts_interfaces) 

    except AttributeError:

        try:

            impl = obj.__select__.search_selector(implements)

            if impl:

                return sorted(impl.expected_ifaces)

        except AttributeError:

            pass # old-style vobject classes with no accepts_interfaces

        return ()

def expand_parent_classes(iface):

    res = [iface]

    for parent in iface.__bases__:

        res += expand_parent_classes(parent)

    return res

class CubicWebRegistry(VRegistry):

    """extend the generic VRegistry with some cubicweb specific stuff"""

    def __init__(self, config, debug=None, initlog=True):

        if initlog:

            # first init log service

            config.init_log(debug=debug)

        super(CubicWebRegistry, self).__init__(config)

        self.schema = None

        self.reset()

        self.initialized = False

    def items(self):

        return [item for item in self._registries.items()

                if not item[0] in ('propertydefs', 'propertyvalues')]

    def values(self):

        return [value for key,value in self._registries.items()

                if not key in ('propertydefs', 'propertyvalues')]

    def reset(self):

        self._registries = {}

        self._lastmodifs = {}

        self._needs_iface = {}

        # two special registries, propertydefs which care all the property

        # definitions, and propertyvals which contains values for those

        # properties

        self._registries['propertydefs'] = {}

        self._registries['propertyvalues'] = self.eprop_values = {}

        for key, propdef in self.config.eproperty_definitions():

            self.register_property(key, **propdef)

    def set_schema(self, schema):

        """set application'schema and load application objects"""

        self.schema = schema

        clear_cache(self, 'rqlhelper')

        # now we can load application's web objects

        self.register_objects(self.config.vregistry_path())

    def update_schema(self, schema):

        """update .schema attribute on registered objects, necessary for some

        tests

        """

        self.schema = schema

        for registry, regcontent in self._registries.items():

            if registry in ('propertydefs', 'propertyvalues'):

                continue

            for objects in regcontent.values():

                for obj in objects:

                    obj.schema = schema

    def register_if_interface_found(self, obj, ifaces, **kwargs):

        """register an object but remove it if no entity class implements one of

        the given interfaces

        """

        self.register(obj, **kwargs)

        if not isinstance(ifaces,  (tuple, list)):

            self._needs_iface[obj] = (ifaces,)

        else:

            self._needs_iface[obj] = ifaces

    def register(self, obj, **kwargs):

        if kwargs.get('registryname', obj.__registry__) == 'etypes':

            if obj.id != 'Any' and not obj.id in self.schema:

                self.error('don\'t register %s, %s type not defined in the schema',

                           obj, obj.id)

                return

            kwargs['clear'] = True

        super(CubicWebRegistry, self).register(obj, **kwargs)

        # XXX bw compat

        ifaces = use_interfaces(obj)

        if ifaces:

            self._needs_iface[obj] = ifaces

    def register_objects(self, path, force_reload=None):

        """overriden to remove objects requiring a missing interface"""

        if super(CubicWebRegistry, self).register_objects(path, force_reload):

            # clear etype cache if you don't want to run into deep weirdness

            clear_cache(self, 'etype_class')

            # we may want to keep interface dependent objects (e.g.for i18n

            # catalog generation)

            if not self.config.cleanup_interface_sobjects:

                return

            # remove vobjects that don't support any available interface

            interfaces = set()

            for classes in self.get('etypes', {}).values():

                for cls in classes:

                    for iface in cls.__implements__:

                        interfaces.update(expand_parent_classes(iface))

                    interfaces.update(expand_parent_classes(cls))

            for obj, ifaces in self._needs_iface.items():

                ifaces = frozenset(isinstance(iface, basestring) and iface in self.schema and self.etype_class(iface) or iface

                                   for iface in ifaces)

                if not ifaces & interfaces:

                    self.debug('kicking vobject %s (unsupported interface)', obj)

                    self.unregister(obj)

    def eid_rset(self, cursor, eid, etype=None):

        """return a result set for the given eid without doing actual query

        (we have the eid, we can suppose it exists and user has access to the

        entity)

        """

        msg = '.eid_rset is deprecated, use req.eid_rset'

        warn(msg, DeprecationWarning, stacklevel=2)

        try:

            return cursor.req.eid_rset(eid, etype)

        except AttributeError:

            # cursor is a session

            return cursor.eid_rset(eid, etype)

    @cached

    def etype_class(self, etype):

        """return an entity class for the given entity type.

        Try to find out a specific class for this kind of entity or

        default to a dump of the class registered for 'Any'

        """

        etype = str(etype)

        if etype == 'Any':

            return self.select(self.registry_objects('etypes', 'Any'), 'Any')

        eschema = self.schema.eschema(etype)

        baseschemas = [eschema] + eschema.ancestors()

        # browse ancestors from most specific to most generic and

        # try to find an associated custom entity class

        for baseschema in baseschemas:

            btype = str(baseschema)

            try:

                cls = self.select(self.registry_objects('etypes', btype), etype)

                break

            except ObjectNotFound:

                pass

        else:

            # no entity class for any of the ancestors, fallback to the default

            # one

            cls = self.select(self.registry_objects('etypes', 'Any'), etype)

        # add class itself to the list of implemented interfaces, as well as the

        # Any entity class so we can select according to class using the

        # `implements` selector

        extend(cls, cls)

        extend(cls, self.etype_class('Any'))

        return cls

    def render(self, registry, oid, req, **context):

        """select an object in a given registry and render it

        - registry: the registry's name

        - oid : the view to call

        - req : the HTTP request         

        """

        objclss = self.registry_objects(registry, oid)

        try:

            rset = context.pop('rset')

        except KeyError:

            rset = None

        selected = self.select(objclss, req, rset, **context)

        return selected.dispatch(**context)

    def main_template(self, req, oid='main-template', **context):

        """display query by calling the given template (default to main),

        and returning the output as a string instead of requiring the [w]rite

        method as argument

        """

        res = self.render('views', oid, req, **context)

        if isinstance(res, unicode):

            return res.encode(req.encoding)

        assert isinstance(res, str)

        return res

    def possible_vobjects(self, registry, *args, **kwargs):

        """return an ordered list of possible app objects in a given registry,

        supposing they support the 'visible' and 'order' properties (as most

        visualizable objects)

        """

        return [x for x in sorted(self.possible_objects(registry, *args, **kwargs),

                                  key=lambda x: x.propval('order'))

                if x.propval('visible')]

    def possible_actions(self, req, rset, **kwargs):

        if rset is None:

            actions = self.possible_vobjects('actions', req, rset)

        else:

            actions = rset.possible_actions() # cached implementation

        result = {}

        for action in actions:

            result.setdefault(action.category, []).append(action)

        return result

    def possible_views(self, req, rset, **kwargs):

        """return an iterator on possible views for this result set

        views returned are classes, not instances

        """

        for vid, views in self.registry('views').items():

            if vid[0] == '_':

                continue

            try:

                view = self.select(views, req, rset, **kwargs)

                if view.linkable():

                    yield view

            except NoSelectableObject:

                continue

            except Exception:

                self.exception('error while trying to list possible %s views for %s',

                               vid, rset)

    def select_box(self, oid, *args, **kwargs):

        """return the most specific view according to the result set"""

        try:

            return self.select_object('boxes', oid, *args, **kwargs)

        except NoSelectableObject:

            return

    def select_action(self, oid, *args, **kwargs):

        """return the most specific view according to the result set"""

        try:

            return self.select_object('actions', oid, *args, **kwargs)

        except NoSelectableObject:

            return

    def select_component(self, cid, *args, **kwargs):

        """return the most specific component according to the result set"""

        try:

            return self.select_object('components', cid, *args, **kwargs)

        except (NoSelectableObject, ObjectNotFound):

            return

    def select_view(self, __vid, req, rset, **kwargs):

        """return the most specific view according to the result set"""

        views = self.registry_objects('views', __vid)

        return self.select(views, req, rset, **kwargs)

    # properties handling #####################################################

    def user_property_keys(self, withsitewide=False):

        if withsitewide:

            return sorted(self['propertydefs'])

        return sorted(k for k, kd in self['propertydefs'].iteritems()

                      if not kd['sitewide'])

    def register_property(self, key, type, help, default=None, vocabulary=None,

                          sitewide=False):

        """register a given property"""

        properties = self._registries['propertydefs']

        assert type in YAMS_TO_PY

        properties[key] = {'type': type, 'vocabulary': vocabulary, 

                           'default': default, 'help': help,

                           'sitewide': sitewide}

    def property_info(self, key):

        """return dictionary containing description associated to the given

        property key (including type, defaut value, help and a site wide

        boolean)

        """

        try:

            return self._registries['propertydefs'][key]

        except KeyError:

            if key.startswith('system.version.'):

                soft = key.split('.')[-1]

                return {'type': 'String', 'sitewide': True,

                        'default': None, 'vocabulary': None,

                        'help': _('%s software version of the database') % soft}

            raise UnknownProperty('unregistered property %r' % key)

    def property_value(self, key):

        try:

            return self._registries['propertyvalues'][key]

        except KeyError:

            return self._registries['propertydefs'][key]['default']

    def typed_value(self, key, value):

        """value is an unicode string, return it correctly typed. Let potential

        type error propagates.

        """

        pdef = self.property_info(key)

        try:

            value = YAMS_TO_PY[pdef['type']](value)

        except (TypeError, ValueError):

            raise ValueError(_('bad value'))

        vocab = pdef['vocabulary']

        if vocab is not None:

            if callable(vocab):

                vocab = vocab(key, None) # XXX need a req object

            if not value in vocab:

                raise ValueError(_('unauthorized value'))

        return value

    def init_properties(self, propvalues):

        """init the property values registry using the given set of couple (key, value)

        """

        self.initialized = True

        values = self._registries['propertyvalues']

        for key, val in propvalues:

            try:

                values[key] = self.typed_value(key, val)

            except ValueError:

                self.warning('%s (you should probably delete that property '

                             'from the database)', ex)

            except UnknownProperty, ex:

                self.warning('%s (you should probably delete that property '

                             'from the database)', ex)

    def property_value_widget(self, propkey, req=None, **attrs):

        """return widget according to key's type / vocab"""

        from cubicweb.web.widgets import StaticComboBoxWidget, widget_factory

        if req is None:

            tr = unicode

        else:

            tr = req._

        try:

            pdef = self.property_info(propkey)

        except UnknownProperty, ex:

            self.warning('%s (you should probably delete that property '

                         'from the database)', ex)

            return widget_factory(self, 'EProperty', self.schema['value'], 'String',

                                  description=u'', **attrs)

        req.form['value'] = pdef['default'] # XXX hack to pass the default value

        vocab = pdef['vocabulary']

        if vocab is not None:

            if callable(vocab):

                # list() just in case its a generator function

                vocabfunc = lambda e: list(vocab(propkey, req))

            else:

                vocabfunc = lambda e: vocab

            w = StaticComboBoxWidget(self, 'EProperty', self.schema['value'], 'String',

                                     vocabfunc=vocabfunc, description=tr(pdef['help']),

                                     **attrs)

        else:

            w = widget_factory(self, 'EProperty', self.schema['value'], pdef['type'],

                               description=tr(pdef['help']), **attrs)

        return w

    def parse(self, session, rql, args=None):

        rqlst = self.rqlhelper.parse(rql)

        def type_from_eid(eid, session=session):

            return session.describe(eid)[0]

        self.rqlhelper.compute_solutions(rqlst, {'eid': type_from_eid}, args)

        return rqlst