"""base application's entities class implementation: `AnyEntity`

: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.deprecation import deprecated_function

from logilab.common.decorators import cached

from cubicweb import Unauthorized, typed_eid

from cubicweb.entity import Entity

from cubicweb.utils import dump_class

from cubicweb.schema import FormatConstraint

from cubicweb.interfaces import IBreadCrumbs, IFeed

class AnyEntity(Entity):

    """an entity instance has e_schema automagically set on the class and

    instances have access to their issuing cursor

    """

    id = 'Any'   

    __rtags__ = {

        'is' : ('generated', 'link'),

        'is_instance_of' : ('generated', 'link'),

        'identity' : ('generated', 'link'),

        # use primary and not generated for eid since it has to be an hidden

        # field in edition

        ('eid',                '*', 'subject'): 'primary',

        ('creation_date',      '*', 'subject'): 'generated',

        ('modification_date',  '*', 'subject'): 'generated',

        ('has_text',           '*', 'subject'): 'generated',

        ('require_permission', '*', 'subject') : ('generated', 'link'),

        ('owned_by',           '*', 'subject') : ('generated', 'link'),

        ('created_by',         '*', 'subject') : ('generated', 'link'),

        ('wf_info_for',        '*', 'subject') : ('generated', 'link'),

        ('wf_info_for',        '*', 'object')  : ('generated', 'link'),

        ('description',        '*', 'subject'): 'secondary',

        # XXX should be moved in their respective cubes

        ('filed_under',        '*', 'subject') : ('generic', 'link'),

        ('filed_under',        '*', 'object')  : ('generic', 'create'),

        # generated since there is a componant to handle comments

        ('comments',           '*', 'subject') : ('generated', 'link'),

        ('comments',           '*', 'object')  : ('generated', 'link'),

        }

    __implements__ = (IBreadCrumbs, IFeed)

    @classmethod

    def selected(cls, etype):

        """the special Any entity is used as the default factory, so

        the actual class has to be constructed at selection time once we

        have an actual entity'type

        """

        if cls.id == etype:

            return cls

        usercls = dump_class(cls, etype)

        usercls.id = etype

        usercls.__initialize__()

        return usercls

    fetch_attrs = ('modification_date',)

    @classmethod

    def fetch_order(cls, attr, var):

        """class method used to control sort order when multiple entities of

        this type are fetched

        """

        return cls.fetch_unrelated_order(attr, var)

    @classmethod

    def fetch_unrelated_order(cls, attr, var):

        """class method used to control sort order when multiple entities of

        this type are fetched to use in edition (eg propose them to create a

        new relation on an edited entity).

        """

        if attr == 'modification_date':

            return '%s DESC' % var

        return None

    @classmethod

    def __initialize__(cls): 

        super(ANYENTITY, cls).__initialize__() # XXX

        eschema = cls.e_schema

    # meta data api ###########################################################

    def dc_title(self):

        """return a suitable *unicode* title for this entity"""

        for rschema, attrschema in self.e_schema.attribute_definitions():

            if rschema.meta:

                continue

            value = self.get_value(rschema.type)

            if value:

                # make the value printable (dates, floats, bytes, etc.)

                return self.printable_value(rschema.type, value, attrschema.type,

                                            format='text/plain')

        return u'%s #%s' % (self.dc_type(), self.eid)

    def dc_long_title(self):

        """return a more detailled title for this entity"""

        return self.dc_title()

    def dc_description(self, format='text/plain'):

        """return a suitable description for this entity"""

        if self.e_schema.has_subject_relation('description'):

            return self.printable_value('description', format=format)

        return u''

    def dc_authors(self):

        """return a suitable description for the author(s) of the entity"""

        try:

            return ', '.join(u.name() for u in self.owned_by)

        except Unauthorized:

            return u''

    def dc_creator(self):

        """return a suitable description for the creator of the entity"""

        if self.creator:

            return self.creator.name()

        return u''

    def dc_date(self, date_format=None):# XXX default to ISO 8601 ?

        """return latest modification date of this entity"""

        return self.format_date(self.modification_date, date_format=date_format)

    def dc_type(self, form=''):

        """return the display name for the type of this entity (translated)"""

        return self.e_schema.display_name(self.req, form)

    display_name = deprecated_function(dc_type) # require agueol > 0.8.1, asteretud > 0.10.0 for removal

    def dc_language(self):

        """return language used by this entity (translated)"""

        # check if entities has internationalizable attributes

        # XXX one is enough or check if all String attributes are internationalizable?

        for rschema, attrschema in self.e_schema.attribute_definitions():

            if rschema.rproperty(self.e_schema, attrschema,

                                 'internationalizable'):

                return self.req._(self.req.user.property_value('ui.language'))

        return self.req._(self.vreg.property_value('ui.language'))

    @property

    def creator(self):

        """return the EUser entity which has created this entity, or None if

        unknown or if the curent user doesn't has access to this euser

        """

        try:

            return self.created_by[0]

        except (Unauthorized, IndexError):

            return None

    def breadcrumbs(self, view=None, recurs=False):

        path = [self]

        if hasattr(self, 'parent'):

            parent = self.parent()

            if parent is not None:

                try:

                    path = parent.breadcrumbs(view, True) + [self]

                except TypeError:

                    warn("breadcrumbs method's now takes two arguments "

                         "(view=None, recurs=False), please update",

                         DeprecationWarning)

                    path = parent.breadcrumbs(view) + [self]

        if not recurs:

            if view is None:

                if 'vtitle' in self.req.form:

                    # embeding for instance

                    path.append( self.req.form['vtitle'] )

            elif view.id != 'primary' and hasattr(view, 'title'):

                path.append( self.req._(view.title) )

        return path

    ## IFeed interface ########################################################

    def rss_feed_url(self):

        return self.absolute_url(vid='rss')

    # abstractions making the whole things (well, some at least) working ######

    def sortvalue(self, rtype=None):

        """return a value which can be used to sort this entity or given

        entity's attribute

        """

        if rtype is None:

            return self.dc_title().lower()

        value = self.get_value(rtype)

        # do not restrict to `unicode` because Bytes will return a `str` value

        if isinstance(value, basestring):

            return self.printable_value(rtype, format='text/plain').lower()

        return value

    def add_related_schemas(self):

        """this is actually used ui method to generate 'addrelated' actions from

        the schema.

        If you're using explicit 'addrelated' actions for an entity types, you

        should probably overrides this method to return an empty list else you

        may get some unexpected actions.

        """

        req = self.req

        eschema = self.e_schema

        for role, rschemas in (('subject', eschema.subject_relations()),

                               ('object', eschema.object_relations())):

            for rschema in rschemas:

                if rschema.is_final():

                    continue

                # check the relation can be added as well

                if role == 'subject'and not rschema.has_perm(req, 'add', fromeid=self.eid):

                    continue

                if role == 'object'and not rschema.has_perm(req, 'add', toeid=self.eid):

                    continue

                # check the target types can be added as well

                for teschema in rschema.targets(eschema, role):

                    if not self.relation_mode(rschema, teschema, role) == 'create':

                        continue

                    if teschema.has_local_role('add') or teschema.has_perm(req, 'add'):

                        yield rschema, teschema, role

    def relation_mode(self, rtype, targettype, role='subject'):

        """return a string telling if the given relation is usually created

        to a new entity ('create' mode) or to an existant entity ('link' mode)

        """

        return self.rtags.get_mode(rtype, targettype, role)

    # edition helper functions ################################################    

    def linked_to(self, rtype, target, remove=True):

        """if entity should be linked to another using __linkto form param for

        the given relation/target, return eids of related entities

        This method is consuming matching link-to information from form params

        if `remove` is True (by default).

        """

        try:

            return self.__linkto[(rtype, target)]

        except AttributeError:

            self.__linkto = {}

        except KeyError:

            pass

        linktos = list(self.req.list_form_param('__linkto'))

        linkedto = []

        for linkto in linktos[:]:

            ltrtype, eid, lttarget = linkto.split(':')

            if rtype == ltrtype and target == lttarget:

                # delete __linkto from form param to avoid it being added as

                # hidden input

                if remove:

                    linktos.remove(linkto)

                    self.req.form['__linkto'] = linktos

                linkedto.append(typed_eid(eid))

        self.__linkto[(rtype, target)] = linkedto

        return linkedto

    # edit controller callbacks ###############################################

    def after_deletion_path(self):

        """return (path, parameters) which should be used as redirect

        information when this entity is being deleted

        """

        return str(self.e_schema).lower(), {}

    def pre_web_edit(self):

        """callback called by the web editcontroller when an entity will be

        created/modified, to let a chance to do some entity specific stuff.

        Do nothing by default.

        """

        pass

    # server side helpers #####################################################

    def notification_references(self, view):

        """used to control References field of email send on notification

        for this entity. `view` is the notification view.

        Should return a list of eids which can be used to generate message ids

        of previously sent email

        """

        return ()

    # XXX deprecates, may be killed once old widgets system is gone ###########

    @classmethod

    def get_widget(cls, rschema, x='subject'):

        """return a widget to view or edit a relation

        notice that when the relation support multiple target types, the widget

        is necessarily the same for all those types

        """

        # let ImportError propage if web par isn't available

        from cubicweb.web.widgets import widget

        if isinstance(rschema, basestring):

            rschema = cls.schema.rschema(rschema)

        if x == 'subject':

            tschema = rschema.objects(cls.e_schema)[0]

            wdg = widget(cls.vreg, cls, rschema, tschema, 'subject')

        else:

            tschema = rschema.subjects(cls.e_schema)[0]

            wdg = widget(cls.vreg, tschema, rschema, cls, 'object')

        return wdg

    def relations_by_category(self, categories=None, permission=None):

        if categories is not None:

            if not isinstance(categories, (list, tuple, set, frozenset)):

                categories = (categories,)

            if not isinstance(categories, (set, frozenset)):

                categories = frozenset(categories)

        eschema, rtags  = self.e_schema, self.rtags

        if self.has_eid():

            eid = self.eid

        else:

            eid = None

        for rschema, targetschemas, role in eschema.relation_definitions(True):

            if rschema in ('identity', 'has_text'):

                continue

            # check category first, potentially lower cost than checking

            # permission which may imply rql queries

            if categories is not None:

                targetschemas = [tschema for tschema in targetschemas

                                 if rtags.get_tags(rschema.type, tschema.type, role).intersection(categories)]

                if not targetschemas:

                    continue

            tags = rtags.get_tags(rschema.type, role=role)

            if permission is not None:

                # tag allowing to hijack the permission machinery when

                # permission is not verifiable until the entity is actually

                # created...

                if eid is None and ('%s_on_new' % permission) in tags:

                    yield (rschema, targetschemas, role)

                    continue

                if rschema.is_final():

                    if not rschema.has_perm(self.req, permission, eid):

                        continue

                elif role == 'subject':

                    if not ((eid is None and rschema.has_local_role(permission)) or

                            rschema.has_perm(self.req, permission, fromeid=eid)):

                        continue

                    # on relation with cardinality 1 or ?, we need delete perm as well

                    # if the relation is already set

                    if (permission == 'add'

                        and rschema.cardinality(eschema, targetschemas[0], role) in '1?'

                        and self.has_eid() and self.related(rschema.type, role)

                        and not rschema.has_perm(self.req, 'delete', fromeid=eid,

                                                 toeid=self.related(rschema.type, role)[0][0])):

                        continue

                elif role == 'object':

                    if not ((eid is None and rschema.has_local_role(permission)) or

                            rschema.has_perm(self.req, permission, toeid=eid)):

                        continue

                    # on relation with cardinality 1 or ?, we need delete perm as well

                    # if the relation is already set

                    if (permission == 'add'

                        and rschema.cardinality(targetschemas[0], eschema, role) in '1?'

                        and self.has_eid() and self.related(rschema.type, role)

                        and not rschema.has_perm(self.req, 'delete', toeid=eid,

                                                 fromeid=self.related(rschema.type, role)[0][0])):

                        continue

            yield (rschema, targetschemas, role)

    def srelations_by_category(self, categories=None, permission=None):

        result = []

        for rschema, ttypes, target in self.relations_by_category(categories,

                                                                  permission):

            if rschema.is_final():

                continue

            result.append( (rschema.display_name(self.req, target), rschema, target) )

        return sorted(result)

    def _default_format(self):

        return self.req.property_value('ui.default-text-format')

    def attribute_values(self, attrname):

        if self.has_eid() or attrname in self:

            try:

                values = self[attrname]

            except KeyError:

                values = getattr(self, attrname)

            # actual relation return a list of entities