"""abstract box classes for CubicWeb web client

: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.mtconverter import xml_escape

from cubicweb import Unauthorized, role as get_role, target as get_target
from cubicweb.schema import display_name
from cubicweb.selectors import (one_line_rset,  primary_view,
                                match_context_prop, partial_has_related_entities)
from cubicweb.view import View, ReloadableMixIn

from cubicweb.web import INTERNAL_FIELD_VALUE
from cubicweb.web.htmlwidgets import (BoxLink, BoxWidget, SideBoxWidget,
                                      RawBoxItem, BoxSeparator)
from cubicweb.web.action import UnregisteredAction


class BoxTemplate(View):
    """base template for boxes, usually a (contextual) list of possible

    actions. Various classes attributes may be used to control the box
    rendering.

    You may override on of the formatting callbacks is this is not necessary
    for your custom box.

    Classes inheriting from this class usually only have to override call
    to fetch desired actions, and then to do something like  ::

        box.render(self.w)
    """
    __registry__ = 'boxes'
    __select__ = match_context_prop()

    categories_in_order = ()
    cw_property_defs = {
        _('visible'): dict(type='Boolean', default=True,
                           help=_('display the box or not')),
        _('order'):   dict(type='Int', default=99,
                           help=_('display order of the box')),
        # XXX 'incontext' boxes are handled by the default primary view
        _('context'): dict(type='String', default='left',
                           vocabulary=(_('left'), _('incontext'), _('right')),
                           help=_('context where this box should be displayed')),
        }
    context = 'left'
    htmlitemclass = 'boxItem'

    def sort_actions(self, actions):
        """return a list of (category, actions_sorted_by_title)"""
        result = []
        actions_by_cat = {}
        for action in actions:
            actions_by_cat.setdefault(action.category, []).append(
                (action.title, action) )
        for key, values in actions_by_cat.items():
            actions_by_cat[key] = [act for title, act in sorted(values)]
        for cat in self.categories_in_order:
            if cat in actions_by_cat:
                result.append( (cat, actions_by_cat[cat]) )
        for item in sorted(actions_by_cat.items()):
            result.append(item)
        return result

    def mk_action(self, title, path, escape=True, **kwargs):
        """factory function to create dummy actions compatible with the
        .format_actions method
        """
        if escape:
            title = xml_escape(title)
        return self.box_action(self._action(title, path, **kwargs))

    def _action(self, title, path, **kwargs):
        return UnregisteredAction(self._cw, self.cw_rset, title, path, **kwargs)

    # formating callbacks

    def boxitem_link_tooltip(self, action):
        if action.__regid__:
            return u'keyword: %s' % action.__regid__
        return u''

    def box_action(self, action):
        cls = getattr(action, 'html_class', lambda: None)() or self.htmlitemclass
        return BoxLink(action.url(), self._cw._(action.title),
                       cls, self.boxitem_link_tooltip(action))


class RQLBoxTemplate(BoxTemplate):
    """abstract box for boxes displaying the content of a rql query not
    related to the current result set.

    It rely on etype, rtype (both optional, usable to control registration
    according to application schema and display according to connected
    user's rights) and rql attributes
    """
#XXX    __selectors__ = BoxTemplate.__selectors__ + (etype_rtype_selector,)

    rql  = None

    def to_display_rql(self):
        assert self.rql is not None, self.__regid__
        return (self.rql,)

    def call(self, **kwargs):
        try:
            rset = self._cw.execute(*self.to_display_rql())
        except Unauthorized:
            # can't access to something in the query, forget this box
            return
        if len(rset) == 0:
            return
        box = BoxWidget(self._cw._(self.title), self.__regid__)
        for i, (teid, tname) in enumerate(rset):
            entity = rset.get_entity(i, 0)
            box.append(self.mk_action(tname, entity.absolute_url()))
        box.render(w=self.w)


class UserRQLBoxTemplate(RQLBoxTemplate):
    """same as rql box template but the rql is build using the eid of the
    request's user
    """

    def to_display_rql(self):
        assert self.rql is not None, self.__regid__
        return (self.rql, {'x': self._cw.user.eid}, 'x')


class EntityBoxTemplate(BoxTemplate):
    """base class for boxes related to a single entity"""
    __select__ = BoxTemplate.__select__ & one_line_rset() & primary_view()
    context = 'incontext'

    def call(self, row=0, col=0, **kwargs):
        """classes inheriting from EntityBoxTemplate should define cell_call"""
        self.cell_call(row, col, **kwargs)


class RelatedEntityBoxTemplate(EntityBoxTemplate):
    __select__ = EntityBoxTemplate.__select__ & partial_has_related_entities()

    def cell_call(self, row, col, **kwargs):
        entity = self.cw_rset.get_entity(row, col)
        limit = self._cw.property_value('navigation.related-limit') + 1
        role = get_role(self)
        self.w(u'<div class="sideBox">')
        self.wview('sidebox', entity.related(self.rtype, role, limit=limit),
                   title=display_name(self._cw, self.rtype, role))
        self.w(u'</div>')


class EditRelationBoxTemplate(ReloadableMixIn, EntityBoxTemplate):
    """base class for boxes which let add or remove entities linked
    by a given relation

    subclasses should define at least id, rtype and target
    class attributes.
    """

    def cell_call(self, row, col, view=None, **kwargs):
        self._cw.add_js('cubicweb.ajax.js')
        entity = self.cw_rset.get_entity(row, col)
        box = SideBoxWidget(display_name(self._cw, self.rtype), self.__regid__)
        related = self.related_boxitems(entity)
        unrelated = self.unrelated_boxitems(entity)
        box.extend(related)
        if related and unrelated:
            box.append(BoxSeparator())
        box.extend(unrelated)
        box.render(self.w)

    def div_id(self):
        return self.__regid__

    def box_item(self, entity, etarget, rql, label):
        """builds HTML link to edit relation between `entity` and `etarget`
        """
        role, target = get_role(self), get_target(self)
        args = {role[0] : entity.eid, target[0] : etarget.eid}
        url = self.user_rql_callback((rql, args))
        # for each target, provide a link to edit the relation
        label = u'[<a href="%s">%s</a>] %s' % (xml_escape(url), label,
                                               etarget.view('incontext'))
        return RawBoxItem(label, liclass=u'invisible')

    def related_boxitems(self, entity):
        rql = 'DELETE S %s O WHERE S eid %%(s)s, O eid %%(o)s' % self.rtype
        related = []
        for etarget in self.related_entities(entity):
            related.append(self.box_item(entity, etarget, rql, u'-'))
        return related

    def unrelated_boxitems(self, entity):
        rql = 'SET S %s O WHERE S eid %%(s)s, O eid %%(o)s' % self.rtype
        unrelated = []
        for etarget in self.unrelated_entities(entity):
            unrelated.append(self.box_item(entity, etarget, rql, u'+'))
        return unrelated

    def related_entities(self, entity):
        return entity.related(self.rtype, get_role(self), entities=True)

    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
        """
        # use entity.unrelated if we've been asked for a particular etype
        if hasattr(self, 'etype'):
            return entity.unrelated(self.rtype, self.etype, get_role(self)).entities()
        # in other cases, use vocabulary functions
        entities = []
        form = self.vreg['forms'].select('edition', self._cw, rset=self.cw_rset,
                                         row=self.cw_row or 0)
        field = form.field_by_name(self.rtype, get_role(self), entity.e_schema)
        for _, eid in field.choices(form):
            if eid is not None and eid != INTERNAL_FIELD_VALUE:
                rset = self._cw.eid_rset(eid)
                entities.append(rset.get_entity(0, 0))
        return entities