"""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, monkeypatch

from logilab.common.deprecation import  deprecated

from logilab.common.modutils import cleanup_sys_modules

from rql import RQLHelper

from cubicweb import (ETYPE_NAME_MAP, Binary, UnknownProperty, UnknownEid,

                      ObjectNotFound, NoSelectableObject, RegistryNotFound,

                      RegistryOutOfDate, CW_EVENT_MANAGER)

from cubicweb.utils import dump_class

from cubicweb.vregistry import VRegistry, Registry

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 appobject classes with no accepts_interfaces

        except:

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

            raise

        return ()

class CWRegistry(Registry):

    def __init__(self, vreg):

        super(CWRegistry, self).__init__(vreg.config)

        self.vreg = vreg

        self.schema = vreg.schema

    def initialization_completed(self):

        # call vreg_initialization_completed on appobjects and print

        # registry content

        for appobjects in self.itervalues():

            for appobject in appobjects:

                appobject.vreg_initialization_completed()

    def render(self, __oid, req, __fallback_oid=None, rset=None, **kwargs):

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

        isn't selectable, then render it

        """

        try:

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

        except NoSelectableObject:

            if __fallback_oid is None:

                raise

            obj = self.select(__fallback_oid, req, **kwargs)

        return obj.render(**kwargs)

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

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

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

            return selected

        return None

    def possible_vobjects(self, *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 sorted([x for x in self.possible_objects(*args, **kwargs)

                       if x.propval('visible')],

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

VRegistry.REGISTRY_FACTORY[None] = CWRegistry

class ETypeRegistry(CWRegistry):

    def initialization_completed(self):

        """on registration completed, clear etype_class internal cache

        """

        super(ETypeRegistry, self).initialization_completed()

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

        clear_cache(self, 'etype_class')

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

        oid = kwargs.get('oid') or obj.id

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

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

                       'schema', obj, obj.id)

            return

        kwargs['clear'] = True

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

    @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 nearest parent class (in yams inheritance) registered.

        Fall back to 'Any' if not yams parent class found.

        """

        etype = str(etype)

        if etype == 'Any':

            return self.select('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:

                objects = self[btype]

                assert len(objects) == 1, objects

                cls = objects[0]

                break

            except ObjectNotFound:

                pass

        else:

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

            # one

            objects = self['Any']

            assert len(objects) == 1, objects

            cls = objects[0]

        if cls.id == etype:

            cls.__initialize__()

            return cls

        cls = dump_class(cls, etype)

        cls.id = etype

        cls.__initialize__()

        return cls

VRegistry.REGISTRY_FACTORY['etypes'] = ETypeRegistry

class ViewsRegistry(CWRegistry):

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

        """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, **kwargs)

        if isinstance(res, unicode):

            return res.encode(req.encoding)

        assert isinstance(res, str)

        return res

    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.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)

VRegistry.REGISTRY_FACTORY['views'] = ViewsRegistry

class ActionsRegistry(CWRegistry):

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

        if rset is None:

            actions = self.possible_vobjects(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

VRegistry.REGISTRY_FACTORY['actions'] = ActionsRegistry

class CubicWebVRegistry(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(CubicWebVRegistry, self).__init__(config)

        self.schema = None

        self.reset()

    def setdefault(self, regid):

        try:

            return self[regid]

        except RegistryNotFound:

            self[regid] = self.registry_class(regid)(self)

            return self[regid]

    def items(self):

        return [item for item in super(CubicWebVRegistry, self).items()

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

    def iteritems(self):

        return (item for item in super(CubicWebVRegistry, self).iteritems()

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

    def values(self):

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

    def itervalues(self):

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

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

        super(CubicWebVRegistry, self).reset(path, force_reload)

        self._needs_iface = {}

        # two special registries, propertydefs which care all the property

        # definitions, and propertyvals which contains values for those

        # properties

        if path is not None and force_reload:

            cleanup_sys_modules(path)

            cubes = self.config.cubes()

            # if the fs code use some cubes not yet registered into the instance

            # we should cleanup sys.modules for those as well to avoid potential

            # bad class reference pb after reloading

            cfg = self.config

            for cube in cfg.expand_cubes(cubes, with_recommends=True):

                if not cube in cubes:

                    cpath = cfg.build_vregistry_cube_path([cfg.cube_dir(cube)])

                    cleanup_sys_modules(cpath)

    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

        searchpath = self.config.vregistry_path()

        self.reset(searchpath, force_reload=False)

        self.register_objects(searchpath, force_reload=False)

        # 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.items():

            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):

        super(CubicWebVRegistry, 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 force_reload is None:

            force_reload = self.config.mode == 'dev'

        try:

            self._register_objects(path, force_reload)

        except RegistryOutOfDate:

            CW_EVENT_MANAGER.emit('before-registry-reload')

            # modification detected, reset and reload

            self.reset(path, force_reload)

            self._register_objects(path, force_reload)

            CW_EVENT_MANAGER.emit('after-registry-reload')

    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(CubicWebVRegistry, self).register_objects(path, force_reload,

                                                          extrapath):

            self.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):

        for regname, reg in self.items():

            self.debug('available in registry %s: %s', regname, sorted(reg))

            reg.initialization_completed()

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

        # catalog generation)

        if self.config.cleanup_interface_sobjects:

            # remove appobjects that don't support any available interface

            implemented_interfaces = set()

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

                for etype in self.schema.entities():

                    cls = self['etypes'].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['etypes'].etype_class(iface)

                                   or iface

                                   for iface in ifaces)

                if not ('Any' in ifaces or ifaces & implemented_interfaces):

                    self.debug('kicking appobject %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()

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

        rqlst = self.rqlhelper.parse(rql)

        def type_from_eid(eid, session=session):

            return session.describe(eid)[0]