# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

#

# This file is part of CubicWeb.

#

# CubicWeb is free software: you can redistribute it and/or modify it under the

# terms of the GNU Lesser General Public License as published by the Free

# Software Foundation, either version 2.1 of the License, or (at your option)

# any later version.

#

# CubicWeb is distributed in the hope that it will be useful, but WITHOUT

# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more

# details.

#

# You should have received a copy of the GNU Lesser General Public License along

# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.

"""the facets box and some basic facets"""

__docformat__ = "restructuredtext en"

_ = unicode

from warnings import warn

from logilab.mtconverter import xml_escape

from logilab.common.decorators import cachedproperty

from logilab.common.registry import objectify_predicate, yes

from cubicweb import tags

from cubicweb.predicates import (non_final_entity, multi_lines_rset,

                                 match_context_prop, relation_possible)

from cubicweb.utils import json_dumps

from cubicweb.uilib import css_em_num_value

from cubicweb.view import AnyRsetView

from cubicweb.web import component, facet as facetbase

from cubicweb.web.views.ajaxcontroller import ajaxfunc

def facets(req, rset, context, mainvar=None, **kwargs):

    """return the base rql and a list of widgets for facets applying to the

    given rset/context (cached version of :func:`_facet`)

    :param req: A :class:`~cubicweb.req.RequestSessionBase` object

    :param rset: A :class:`~cubicweb.rset.ResultSet`

    :param context: A string that match the ``__regid__`` of a ``FacetFilter``

    :param mainvar: A string that match a select var from the rset

    """

    try:

        cache = req.__rset_facets

    except AttributeError:

        cache = req.__rset_facets = {}

    try:

        return cache[(rset, context, mainvar)]

    except KeyError:

        facets = _facets(req, rset, context, mainvar, **kwargs)

        cache[(rset, context, mainvar)] = facets

        return facets

def _facets(req, rset, context, mainvar, **kwargs):

    """return the base rql and a list of widgets for facets applying to the

    given rset/context

    :param req: A :class:`~cubicweb.req.RequestSessionBase` object

    :param rset: A :class:`~cubicweb.rset.ResultSet`

    :param context: A string that match the ``__regid__`` of a ``FacetFilter``

    :param mainvar: A string that match a select var from the rset

    """

    ### initialisation

    # XXX done by selectors, though maybe necessary when rset has been hijacked

    # (e.g. contextview_selector matched)

    origqlst = rset.syntax_tree()

    # union not yet supported

    if len(origqlst.children) != 1:

        req.debug('facette disabled on union request %s', origqlst)

        return None, ()

    rqlst = origqlst.copy()

    select = rqlst.children[0]

    filtered_variable, baserql = facetbase.init_facets(rset, select, mainvar)

    ### Selection

    possible_facets = req.vreg['facets'].poss_visible_objects(

        req, rset=rset, rqlst=origqlst, select=select,

        context=context, filtered_variable=filtered_variable, **kwargs)

    wdgs = [(facet, facet.get_widget()) for facet in possible_facets]

    return baserql, [wdg for facet, wdg in wdgs if wdg is not None]

@objectify_predicate

def contextview_selector(cls, req, rset=None, row=None, col=None, view=None,

                         **kwargs):

    if view:

        try:

            getcontext = getattr(view, 'filter_box_context_info')

        except AttributeError:

            return 0

        rset = getcontext()[0]

        if rset is None or rset.rowcount < 2:

            return 0

        wdgs = facets(req, rset, cls.__regid__, view=view)[1]

        return len(wdgs)

    return 0

@objectify_predicate

def has_facets(cls, req, rset=None, **kwargs):

    if rset is None or rset.rowcount < 2:

        return 0

    wdgs = facets(req, rset, cls.__regid__, **kwargs)[1]

    return len(wdgs)

def filter_hiddens(w, baserql, wdgs, **kwargs):

    kwargs['facets'] = ','.join(wdg.facet.__regid__ for wdg in wdgs)

    kwargs['baserql'] = baserql

    for key, val in kwargs.items():

        w(u'<input type="hidden" name="%s" value="%s" />' % (

            key, xml_escape(val)))

class FacetFilterMixIn(object):

    """Mixin Class to generate Facet Filter Form

    To generate the form, you need to explicitly call the following method:

    .. automethod:: generate_form

    The most useful function to override is:

    .. automethod:: layout_widgets

    """

    needs_js = ['cubicweb.ajax.js', 'cubicweb.facets.js']

    needs_css = ['cubicweb.facets.css']

    def generate_form(self, w, rset, divid, vid, vidargs=None, mainvar=None,

                      paginate=False, cssclass='', hiddens=None, **kwargs):

        """display a form to filter some view's content

        :param w:        Write function

        :param rset:     ResultSet to be filtered

        :param divid:    Dom ID of the div where the rendering of the view is done.

        :type divid:     string

        :param vid:      ID of the view display in the div

        :type vid:       string

        :param paginate: Is the view paginated?

        :type paginate:  boolean

        :param cssclass: Additional css classes to put on the form.

        :type cssclass:  string

        :param hiddens:  other hidden parametters to include in the forms.

        :type hiddens:   dict from extra keyword argument

        """

        # XXX Facet.context property hijacks an otherwise well-behaved

        #     vocabulary with its own notions

        #     Hence we whack here to avoid a clash

        kwargs.pop('context', None)

        baserql, wdgs = facets(self._cw, rset, context=self.__regid__,

                               mainvar=mainvar, **kwargs)

        assert wdgs

        self._cw.add_js(self.needs_js)

        self._cw.add_css(self.needs_css)

        self._cw.html_headers.define_var('facetLoadingMsg',

                                         self._cw._('facet-loading-msg'))

        if vidargs is not None:

            warn("[3.14] vidargs is deprecated. Maybe you're using some TableView?",

                 DeprecationWarning, stacklevel=2)

        else:

            vidargs = {}

        vidargs = dict((k, v) for k, v in vidargs.iteritems() if v)

        facetargs = xml_escape(json_dumps([divid, vid, paginate, vidargs]))

        w(u'<form id="%sForm" class="%s" method="post" action="" '

          'cubicweb:facetargs="%s" >' % (divid, cssclass, facetargs))

        w(u'<fieldset>')

        if hiddens is None:

            hiddens = {}

        if mainvar:

            hiddens['mainvar'] = mainvar

        filter_hiddens(w, baserql, wdgs, **hiddens)

        self.layout_widgets(w, self.sorted_widgets(wdgs))

        # <Enter> is supposed to submit the form only if there is a single

        # input:text field. However most browsers will submit the form

        # on <Enter> anyway if there is an input:submit field.

        #

        # see: http://www.w3.org/MarkUp/html-spec/html-spec_8.html#SEC8.2

        #

        # Firefox 7.0.1 does not submit form on <Enter> if there is more than a

        # input:text field and not input:submit but does it if there is an

        # input:submit.

        #

        # IE 6 or Firefox 2 behave the same way.

        w(u'<input type="submit" class="hidden" />')

        #

        w(u'</fieldset>\n')

        w(u'</form>\n')

    def sorted_widgets(self, wdgs):

        """sort widgets: by default sort by widget height, then according to

        widget.order (the original widgets order)

        """

        return sorted(wdgs, key=lambda x: 99 * (not x.facet.start_unfolded) or x.height )

    def layout_widgets(self, w, wdgs):

        """layout widgets: by default simply render each of them

        (i.e. succession of <div>)

        """

        for wdg in wdgs:

            wdg.render(w=w)

class FilterBox(FacetFilterMixIn, component.CtxComponent):

    """filter results of a query"""

    __regid__ = 'facet.filterbox'

    __select__ = ((non_final_entity() & has_facets())

                  | contextview_selector()) # can't use has_facets because of

                                            # contextview mecanism

    context = 'left' # XXX doesn't support 'incontext', only 'left' or 'right'

    title = _('facet.filters')

    visible = True # functionality provided by the search box by default

    order = 1

    bk_linkbox_template = u'<div class="facetTitle">%s</div>'

    def render_body(self, w, **kwargs):

        req = self._cw

        rset, vid, divid, paginate = self._get_context()

        assert len(rset) > 1

        if vid is None:

            vid = req.form.get('vid')

        if self.bk_linkbox_template and req.vreg.schema['Bookmark'].has_perm(req, 'add'):

            w(self.bookmark_link(rset))

        w(self.focus_link(rset))

        hiddens = {}

        for param in ('subvid', 'vtitle'):

            if param in req.form:

                hiddens[param] = req.form[param]

        self.generate_form(w, rset, divid, vid, paginate=paginate,

                           hiddens=hiddens, **self.cw_extra_kwargs)

    def _get_context(self):

        view = self.cw_extra_kwargs.get('view')

        context = getattr(view, 'filter_box_context_info', lambda: None)()

        if context:

            rset, vid, divid, paginate = context

        else:

            rset = self.cw_rset

            vid, divid = None, 'pageContent'

            paginate = view and view.paginable

        return rset, vid, divid, paginate

    def bookmark_link(self, rset):

        req = self._cw

        bk_path = u'rql=%s' % req.url_quote(rset.printable_rql())

        if req.form.get('vid'):

            bk_path += u'&vid=%s' % req.url_quote(req.form['vid'])

        bk_path = u'view?' + bk_path

        bk_title = req._('my custom search')

        linkto = u'bookmarked_by:%s:subject' % req.user.eid

        bkcls = req.vreg['etypes'].etype_class('Bookmark')

        bk_add_url = bkcls.cw_create_url(req, path=bk_path, title=bk_title,

                                         __linkto=linkto)

        bk_base_url = bkcls.cw_create_url(req, title=bk_title, __linkto=linkto)

        bk_link = u'<a cubicweb:target="%s" id="facetBkLink" href="%s">%s</a>' % (

                xml_escape(bk_base_url), xml_escape(bk_add_url),

                req._('bookmark this search'))

        return self.bk_linkbox_template % bk_link

    def focus_link(self, rset):

        return self.bk_linkbox_template % tags.a(self._cw._('focus on this selection'),

                                                 href=self._cw.url(), id='focusLink')

class FilterTable(FacetFilterMixIn, AnyRsetView):

    __regid__ = 'facet.filtertable'

    __select__ = has_facets()

    average_perfacet_uncomputable_overhead = .3

    def call(self, vid, divid, vidargs=None, cssclass=''):

        hiddens = self.cw_extra_kwargs.setdefault('hiddens', {})

        hiddens['fromformfilter'] = '1'

        self.generate_form(self.w, self.cw_rset, divid, vid, vidargs=vidargs,

                           cssclass=cssclass, **self.cw_extra_kwargs)

    @cachedproperty

    def per_facet_height_overhead(self):

        return (css_em_num_value(self._cw.vreg, 'facet_MarginBottom', .2) +

                css_em_num_value(self._cw.vreg, 'facet_Padding', .2) +

                self.average_perfacet_uncomputable_overhead)

    def layout_widgets(self, w, wdgs):

        """layout widgets: put them in a table where each column should have

        sum(wdg.height) < wdg_stack_size.

        """

        w(u'<div class="filter">\n')

        widget_queue = []

        queue_height = 0

        wdg_stack_size = facetbase._DEFAULT_FACET_GROUP_HEIGHT

        for wdg in wdgs:

            height = wdg.height + self.per_facet_height_overhead

            if queue_height + height <= wdg_stack_size:

                widget_queue.append(wdg)

                queue_height += height

                continue

            w(u'<div class="facetGroup">')

            for queued in widget_queue:

                queued.render(w=w)

            w(u'</div>')

            widget_queue = [wdg]

            queue_height = height

        if widget_queue:

            w(u'<div class="facetGroup">')

            for queued in widget_queue:

                queued.render(w=w)

            w(u'</div>')

        w(u'</div>\n')

# python-ajax remote functions used by facet widgets #########################

@ajaxfunc(output_type='json')

def filter_build_rql(self, names, values):

    form = self._rebuild_posted_form(names, values)

    self._cw.form = form

    builder = facetbase.FilterRQLBuilder(self._cw)

    return builder.build_rql()

@ajaxfunc(output_type='json')

def filter_select_content(self, facetids, rql, mainvar):

    # Union unsupported yet

    select = self._cw.vreg.parse(self._cw, rql).children[0]

    filtered_variable = facetbase.get_filtered_variable(select, mainvar)

    facetbase.prepare_select(select, filtered_variable)

    update_map = {}

    for fid in facetids:

        fobj = facetbase.get_facet(self._cw, fid, select, filtered_variable)

        update_map[fid] = fobj.possible_values()

    return update_map

# facets ######################################################################

class CWSourceFacet(facetbase.RelationFacet):

    __regid__ = 'cw_source-facet'

    rtype = 'cw_source'

    target_attr = 'name'

class CreatedByFacet(facetbase.RelationFacet):

    __regid__ = 'created_by-facet'

    rtype = 'created_by'

    target_attr = 'login'

class InGroupFacet(facetbase.RelationFacet):

    __regid__ = 'in_group-facet'

    rtype = 'in_group'

    target_attr = 'name'

class InStateFacet(facetbase.RelationAttributeFacet):

    __regid__ = 'in_state-facet'

    rtype = 'in_state'

    target_attr = 'name'

# inherit from RelationFacet to benefit from its possible_values implementation

class ETypeFacet(facetbase.RelationFacet):

    __regid__ = 'etype-facet'

    __select__ = yes()

    order = 1

    rtype = 'is'

    target_attr = 'name'

    @property

    def title(self):

        return self._cw._('entity type')