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

: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"

from warnings import warn

from logilab.common.deprecation import deprecated

from logilab.common.decorators import cached

from cubicweb import Unauthorized, typed_eid

from cubicweb.entity import Entity

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

    """

    __implements__ = (IBreadCrumbs, IFeed)

    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

    # 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)

    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 CWUser 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

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

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

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

        the given relation/role, 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, role)]

        except AttributeError:

            self.__linkto = {}

        except KeyError:

            pass

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

        linkedto = []

        for linkto in linktos[:]:

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

            if rtype == ltrtype and role == ltrole:

                # 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, role)] = 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:  store a reference to the AnyEntity class since it is hijacked in goa

#       configuration and we need the actual reference to avoid infinite loops

#       in mro

ANYENTITY = AnyEntity

def fetch_config(fetchattrs, mainattr=None, pclass=AnyEntity, order='ASC'):

    if pclass is ANYENTITY:

        pclass = AnyEntity # AnyEntity and ANYENTITY may be different classes

    if pclass is not None:

        fetchattrs += pclass.fetch_attrs

    if mainattr is None:

        mainattr = fetchattrs[0]

    @classmethod

    def fetch_order(cls, attr, var):

        if attr == mainattr:

            return '%s %s' % (var, order)

        return None

    return fetchattrs, fetch_order