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

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

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

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

_ = unicode

from logilab.common.decorators import cached, clear_cache

from logilab.common.deprecation import  deprecated

from rql import RQLHelper

from cubicweb import ETYPE_NAME_MAP, Binary, UnknownProperty, UnknownEid

from cubicweb.vregistry import VRegistry, ObjectNotFound, NoSelectableObject

from cubicweb.rtags import RTAGS

def use_interfaces(obj):

    """return interfaces used by the given object by searchinf for implements

    selectors, with a bw compat fallback to accepts_interfaces attribute

    """

    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

        except:

            print 'bad selector %s on %s' % (obj.__select__, obj)

            raise

        return ()

class CubicWebRegistry(VRegistry):

    """Central registry for the cubicweb instance, extending the generic

    VRegistry with some cubicweb specific stuff.

    This is one of the central object in cubicweb instance, coupling

    dynamically loaded objects with the schema and the configuration objects.

    It specializes the VRegistry by adding some convenience methods to access to

    stored objects. Currently we have the following registries of objects known

    by the web instance (library may use some others additional registries):

    * etypes

    * views

    * components

    * actions

    * forms

    * formrenderers

    * controllers, which are directly plugged into the application

      object to handle request publishing XXX to merge with views

    * contentnavigation XXX to merge with components? to kill?

    """

    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 instance'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())

        # map lowered entity type names to their actual name

        self.case_insensitive_etypes = {}

        for etype in self.schema.entities():

            etype = str(etype)

            self.case_insensitive_etypes[etype.lower()] = etype

    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"""

        extrapath = {}

        for cubesdir in self.config.cubes_search_path():

            if cubesdir != self.config.CUBES_DIR:

                extrapath[cubesdir] = 'cubes'

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

                                                          extrapath):

            self.initialization_completed()

            # call vreg_initialization_completed on appobjects and print

            # registry content

            for registry, objects in self.items():

                self.debug('available in registry %s: %s', registry,

                           sorted(objects))

                for appobjects in objects.itervalues():

                    for appobject in appobjects:

                        appobject.vreg_initialization_completed()

            # don't check rtags if we don't want to cleanup_interface_sobjects

            for rtag in RTAGS:

                rtag.init(self.schema,

                          check=self.config.cleanup_interface_sobjects)

    def initialization_completed(self):

        # 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 self.config.cleanup_interface_sobjects:

            # remove vobjects that don't support any available interface

            implemented_interfaces = set()

            if 'Any' in self.get('etypes', ()):

                for etype in self.schema.entities():

                    cls = self.etype_class(etype)

                    for iface in cls.__implements__:

                        implemented_interfaces.update(iface.__mro__)

                    implemented_interfaces.update(cls.__mro__)

            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 ('Any' in ifaces or ifaces & implemented_interfaces):

                    self.debug('kicking vobject %s (no implemented '

                               'interface among %s)', obj, ifaces)

                    self.unregister(obj)

        # clear needs_iface so we don't try to remove some not-anymore-in

        # objects on automatic reloading

        self._needs_iface.clear()

    @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('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:

            try:

                btype = ETYPE_NAME_MAP[baseschema]

            except KeyError:

                btype = str(baseschema)

            try:

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

                break

            except ObjectNotFound:

                pass

        else:

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

            # one

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

        return cls

    def render(self, __oid, req, __fallback_oid=None, __registry='views',

               rset=None, **kwargs):

        """select object, or fallback object if specified and the first one

        isn't selectable, then render it

        """

        try:

            obj = self.select(__registry, __oid, req, rset=rset, **kwargs)

        except NoSelectableObject:

            if __fallback_oid is None:

                raise

            obj = self.select(__registry, __fallback_oid, req, rset=rset,

                              **kwargs)

        return obj.render(**kwargs)

    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(oid, req, **context)

        if isinstance(res, unicode):

            return res.encode(req.encoding)

        assert isinstance(res, str)

        return res

    def select_vobject(self, registry, oid, *args, **kwargs):

        selected = self.select_object(registry, oid, *args, **kwargs)

        if selected and selected.propval('visible'):

            return selected

        return None

    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=None, **kwargs):

        if rset is None:

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

        else:

            actions = rset.possible_actions(**kwargs) # cached implementation

        result = {}

        for action in actions:

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

        return result

    def possible_views(self, req, rset=None, **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_best(views, req, rset=rset, **kwargs)

                if view.linkable():

                    yield view

            except NoSelectableObject:

                continue

            except Exception:

                self.exception('error while trying to select %s view for %s',

                               vid, rset)

    @deprecated("use .select_object('boxes', ...)")

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

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

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

    @deprecated("use .select_object('components', ...)")

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

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

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

    @deprecated("use .select_object('actions', ...)")

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

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

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

    @deprecated("use .select('views', ...)")

    def select_view(self, __vid, req, rset=None, **kwargs):

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

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

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

    def user_property_keys(self, withsitewide=False):

        if withsitewide:

            return sorted(k for k in self['propertydefs']

                          if not k.startswith('sources.'))

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

                      if not kd['sitewide'] and not k.startswith('sources.'))

    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)