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

:organization: Logilab

:copyright: 2001-2010 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, onevent)

from cubicweb.utils import dump_class

from cubicweb.vregistry import VRegistry, Registry, class_regid

from cubicweb.rtags import RTAGS

@onevent('before-registry-reload')

def clear_rtag_objects():

    for rtag in RTAGS:

        rtag.clear()

def use_interfaces(obj):

    """return interfaces used by the given object by searching 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

    @property

    def schema(self):

        return self.vreg.schema

    def initialization_completed(self):

        pass

    @deprecated('[3.6] select object, then use obj.render()')

    def render(self, __oid, req, __fallback_oid=None, rset=None, initargs=None,

               **kwargs):

        """Select object with the given id (`__oid`) then render it.  If the

        object isn't selectable, try to select fallback object if

        `__fallback_oid` is specified.

        If specified `initargs` is expected to be a dictionnary containing

        arguments that should be given to selection (hence to object's __init__

        as well), but not to render(). Other arbitrary keyword arguments will be

        given to selection *and* to render(), and so should be handled by

        object's call or cell_call method..

        """

        if initargs is None:

            initargs = kwargs

        else:

            initargs.update(kwargs)

        try:

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

        except NoSelectableObject:

            if __fallback_oid is None:

                raise

            obj = self.select(__fallback_oid, req, rset=rset, **initargs)

        return obj.render(**kwargs)

    @deprecated('[3.6] use select_or_none and test for obj.cw_propval("visible")')

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

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

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

            return selected

        return None

    def poss_visible_objects(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.cw_propval('visible')],

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

    possible_vobjects = deprecated('[3.6] use poss_visible_objects()')(poss_visible_objects)

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')

        clear_cache(self, 'parent_classes')

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

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

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

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

                       'schema', obj, oid)

            return

        kwargs['clear'] = True

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

    @cached

    def parent_classes(self, etype):

        if etype == 'Any':

            return [self.etype_class('Any')]

        eschema = self.schema.eschema(etype)

        parents = [self.etype_class(e.type) for e in eschema.ancestors()]

        parents.append(self.etype_class('Any'))

        return parents

    @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':

            objects = self['Any']

            assert len(objects) == 1, objects

            return objects[0]

        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

                if btype == etype:

                    cls = objects[0]

                else:

                    # recurse to ensure issubclass(etype_class('Child'),

                    #                              etype_class('Parent'))

                    cls = self.etype_class(btype)

                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]

        # make a copy event if cls.__regid__ == etype, else we may have pb for

        # client application using multiple connections to different

        # repositories (eg shingouz)

        cls = dump_class(cls, etype)

        cls.__regid__ = etype

        cls.__initialize__(self.schema)

        return cls

VRegistry.REGISTRY_FACTORY['etypes'] = ETypeRegistry

class ViewsRegistry(CWRegistry):

    def main_template(self, req, oid='main-template', rset=None, **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

        """

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

        res = obj.render(**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.poss_visible_objects(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.initialized = False

        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 not self.initialized:

            self['propertydefs'] = {}

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

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

                self.register_property(key, **propdef)

        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._set_schema(schema)

        # 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 eschema in self.schema.entities():

            etype = str(eschema)

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

            clear_cache(eschema, 'ordered_relations')

            clear_cache(eschema, 'meta_attributes')

    def _set_schema(self, schema):

        """set instance'schema"""

        self.schema = schema

        clear_cache(self, 'rqlhelper')

    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

        """

        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, *args, **kwargs):

        super(CubicWebVRegistry, self).register(obj, *args, **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.debugmode

        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"""

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

                                                          self.config.extrapath):

            self.initialization_completed()