"""base xml and rss views

: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"

_ = unicode

from time import timezone

from logilab.mtconverter import xml_escape

from cubicweb.selectors import non_final_entity, one_line_rset, appobject_selectable

from cubicweb.view import EntityView, AnyRsetView

from cubicweb.web.httpcache import MaxAgeHTTPCacheManager

from cubicweb.web.component import Component

from cubicweb.web.box import BoxTemplate

from cubicweb.common.uilib import simple_sgml_tag

# base xml views ##############################################################

class XMLView(EntityView):

    """xml view for entities"""

    id = 'xml'

    title = _('xml')

    templatable = False

    content_type = 'text/xml'

    xml_root = 'rset'

    item_vid = 'xmlitem'

    def cell_call(self, row, col):

        self.wview(self.item_vid, self.rset, row=row, col=col)

    def call(self):

        """display a list of entities by calling their <item_vid> view"""

        self.w(u'<?xml version="1.0" encoding="%s"?>\n' % self.req.encoding)

        self.w(u'<%s size="%s">\n' % (self.xml_root, len(self.rset)))

        for i in xrange(self.rset.rowcount):

            self.cell_call(i, 0)

        self.w(u'</%s>\n' % self.xml_root)

class XMLItemView(EntityView):

    id = 'xmlitem'

    def cell_call(self, row, col):

        """ element as an item for an xml feed """

        entity = self.complete_entity(row, col)

        self.w(u'<%s>\n' % (entity.e_schema))

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

            attr = rschema.type

            try:

                value = entity[attr]

            except KeyError:

                # Bytes

                continue

            if value is not None:

                if attrschema == 'Bytes':

                    from base64 import b64encode

                    value = '<![CDATA[%s]]>' % b64encode(value.getvalue())

                elif isinstance(value, basestring):

                    value = xml_escape(value)

                self.w(u'  <%s>%s</%s>\n' % (attr, value, attr))

        self.w(u'</%s>\n' % (entity.e_schema))

class XMLRsetView(AnyRsetView):

    """dumps raw rset as xml"""

    id = 'rsetxml'

    title = _('xml export')

    templatable = False

    content_type = 'text/xml'

    xml_root = 'rset'

    def call(self):

        w = self.w

        rset, descr = self.rset, self.rset.description

        eschema = self.schema.eschema

        labels = self.columns_labels(False)

        w(u'<?xml version="1.0" encoding="%s"?>\n' % self.req.encoding)

        w(u'<%s query="%s">\n' % (self.xml_root, xml_escape(rset.printable_rql())))

        for rowindex, row in enumerate(self.rset):

            w(u' <row>\n')

            for colindex, val in enumerate(row):

                etype = descr[rowindex][colindex]

                tag = labels[colindex]

                attrs = {}

                if '(' in tag:

                    attrs['expr'] = tag

                    tag = 'funccall'

                if val is not None and not eschema(etype).is_final():

                    attrs['eid'] = val

                    # csvrow.append(val) # val is eid in that case

                    val = self.view('textincontext', rset,

                                    row=rowindex, col=colindex)

                else:

                    val = self.view('final', rset, displaytime=True,

                                    row=rowindex, col=colindex, format='text/plain')

                w(simple_sgml_tag(tag, val, **attrs))

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

        w(u'</%s>\n' % self.xml_root)

# RSS stuff ###################################################################

class RSSFeedURL(Component):

    id = 'rss_feed_url'

    __select__ = non_final_entity()

    def feed_url(self):

        return self.build_url(rql=self.limited_rql(), vid='rss')

class RSSEntityFeedURL(Component):

    id = 'rss_feed_url'

    __select__ = non_final_entity() & one_line_rset()

    def feed_url(self):

        return self.entity(0, 0).rss_feed_url()

class RSSIconBox(BoxTemplate):

    """just display the RSS icon on uniform result set"""

    id = 'rss'

    __select__ = (BoxTemplate.__select__

                  & appobject_selectable('components', 'rss_feed_url'))

    visible = False

    order = 999

    def call(self, **kwargs):

        try:

            rss = self.req.external_resource('RSS_LOGO')

        except KeyError:

            self.error('missing RSS_LOGO external resource')

            return

        urlgetter = self.vreg.select_component('rss_feed_url', self.req, self.rset)

        url = urlgetter.feed_url()

        self.w(u'<a href="%s"><img src="%s" alt="rss"/></a>\n' % (xml_escape(url), rss))

class RSSView(XMLView):

    id = 'rss'

    title = _('rss')

    templatable = False

    content_type = 'text/xml'

    http_cache_manager = MaxAgeHTTPCacheManager

    cache_max_age = 60*60*2 # stay in http cache for 2 hours by default

    def _open(self):

        req = self.req

        self.w(u'<?xml version="1.0" encoding="%s"?>\n' % req.encoding)

        self.w(u'<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">\n')

        self.w(u'  <channel>\n')

        self.w(u'    <title>%s RSS Feed</title>\n'

               % xml_escape(self.page_title()))

        self.w(u'    <description>%s</description>\n'

               % xml_escape(req.form.get('vtitle', '')))

        params = req.form.copy()

        params.pop('vid', None)

        self.w(u'    <link>%s</link>\n' % xml_escape(self.build_url(**params)))

    def _close(self):

        self.w(u'  </channel>\n')

        self.w(u'</rss>')

    def call(self):

        """display a list of entities by calling their <item_vid> view"""

        self._open()

        for i in xrange(self.rset.rowcount):

            self.cell_call(i, 0)

        self._close()

    def cell_call(self, row, col):

        self.wview('rssitem', self.rset, row=row, col=col)

class RSSItemView(EntityView):

    id = 'rssitem'

    date_format = '%%Y-%%m-%%dT%%H:%%M%+03i:00' % (timezone / 3600)

    add_div_section = False

    def cell_call(self, row, col):

        entity = self.complete_entity(row, col)

        self.w(u'<item>\n')

        self.w(u'<guid isPermaLink="true">%s</guid>\n'

               % xml_escape(entity.absolute_url()))

        self.render_title_link(entity)

        self._marker('description', entity.dc_description(format='text/html'))

        self._marker('dc:date', entity.dc_date(self.date_format))

        self.render_entity_creator(entity)

        self.w(u'</item>\n')

    def render_title_link(self, entity):

        self._marker('title', entity.dc_long_title())

        self._marker('link', entity.absolute_url())

    def render_entity_creator(self, entity):

        if entity.creator:

            self._marker('dc:creator', entity.dc_creator())

    def _marker(self, marker, value):

        if value:

            self.w(u'  <%s>%s</%s>\n' % (marker, xml_escape(value), marker))