"""Set of views allowing edition of entities/relations using ajax

:organization: Logilab

:copyright: 2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

"""

__docformat__ = "restructuredtext en"

from cubicweb.common.selectors import (chainfirst, match_form_params,

                                    match_kwargs)

from cubicweb.web.box import EditRelationBoxTemplate

class AddRelationView(EditRelationBoxTemplate):

    """base class for view which let add entities linked

    by a given relation

    subclasses should define at least id, rtype and target

    class attributes.

    """

    __registry__ = 'views'

    __selectors__ = (chainfirst(match_form_params, match_kwargs),)

    property_defs = {} # don't want to inherit this from Box

    id = 'xaddrelation'

    expected_kwargs = form_params = ('rtype', 'target')

    build_js = EditRelationBoxTemplate.build_reload_js_call

    def cell_call(self, row, col, rtype=None, target=None, etype=None):

        self.rtype = rtype or self.req.form['rtype']

        self.target = target or self.req.form['target']

        self.etype = etype or self.req.form.get('etype')

        entity = self.entity(row, col)

        rschema = self.schema.rschema(self.rtype)

        if not self.etype:

            if self.target == 'object':

                etypes = rschema.objects(entity.e_schema)

            else:

                etypes = rschema.subjects(entity.e_schema)

            if len(etypes) == 1:

                self.etype = etypes[0]

        fakebox = []

        self.w(u'<div id="%s">' % self.id)

        self.w(u'<h1>%s</h1>' % self.req._('relation %(relname)s of %(ent)s')

               % {'relname': rschema.display_name(self.req, self.xtarget()[0]),

                  'ent': entity.view('incontext')})

        self.w(u'<ul>')

        self.w_unrelated(fakebox, entity)

        for boxitem in fakebox:

            boxitem.render(self.w)

        self.w(u'</ul></div>')

    def unrelated_entities(self, entity):

        """returns the list of unrelated entities

        if etype is not defined on the Box's class, the default

        behaviour is to use the entity's appropraite vocabulary function

        """

        x, target = self.xtarget()

        # use entity.unrelated if we've been asked for a particular etype

        if getattr(self, 'etype', None):

            rset = entity.unrelated(self.rtype, self.etype, x, ordermethod='fetch_order')

            self.pagination(self.req, rset, w=self.w)

            return rset.entities()

        # in other cases, use vocabulary functions

        entities = []

        for _, eid in entity.vocabulary(self.rtype, x):

            if eid is not None:

                rset = self.req.eid_rset(eid)

                entities.append(rset.get_entity(0, 0))

        return entities