# copyright 2003-2011 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/>.

"""base xml and rss views"""

__docformat__ = "restructuredtext en"

_ = unicode

from base64 import b64encode

from time import timezone

from logilab.mtconverter import xml_escape

from cubicweb.selectors import (is_instance, non_final_entity, one_line_rset,

                                appobject_selectable, adaptable)

from cubicweb.view import EntityView, EntityAdapter, AnyRsetView, Component

from cubicweb.view import implements_adapter_compat

from cubicweb.uilib import simple_sgml_tag

from cubicweb.web import httpcache, component

def encode_bytes(value):

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

# see cubicweb.sobjects.parser.DEFAULT_CONVERTERS

SERIALIZERS = {

    'String': xml_escape,

    'Bytes': encode_bytes,

    'Date': lambda x: x.strftime('%Y-%m-%d'),

    'Datetime': lambda x: x.strftime('%Y-%m-%d %H:%M:%S'),

    'Time': lambda x: x.strftime('%H:%M:%S'),

    'Interval': lambda x: x.days * 60*60*24 + x.seconds,

    }

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

class XMLView(EntityView):

    """xml view for entities"""

    __regid__ = '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.cw_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._cw.encoding)

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

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

            self.cell_call(i, 0)

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

class XMLItemView(EntityView):

    __regid__ = 'xmlitem'

    def cell_call(self, row, col):

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

        entity = self.cw_rset.complete_entity(row, col)

        self.w(u'<%s eid="%s" cwuri="%s">\n'

               % (entity.e_schema, entity.eid, xml_escape(entity.cwuri)))

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

            attr = rschema.type

            if attr in ('eid', 'cwuri'):

                continue

            else:

                try:

                    value = entity.cw_attr_cache[attr]

                except KeyError:

                    # Bytes

                    continue

            if value is None:

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

            else:

                try:

                    value = SERIALIZERS[attrschema](value)

                except KeyError:

                    pass

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

        for relstr in self._cw.list_form_param('relation'):

            try:

                rtype, role = relstr.split('-')

            except ValueError:

                self.error('badly formated relation name %r', relstr)

                continue

            if role == 'subject':

                getrschema = entity.e_schema.subjrels

            elif role == 'object':

                getrschema = entity.e_schema.objrels

            else:

                self.error('badly formated relation name %r', relstr)

                continue

            if not rtype in getrschema:

                self.error('unexisting relation %r', relstr)

                continue

            self.w(u'  <%s role="%s">\n' % (rtype, role))

            for related in entity.related(rtype, role, entities=True):

                # XXX put unique attributes as xml attribute, they are much

                # probably used to search existing entities in client data feed,

                # and putting it here may avoid an extra request to get those

                # attributes values

                self.w(u'    <%s eid="%s" cwuri="%s"/>\n'

                       % (related.e_schema, related.eid,

                          xml_escape(related.cwuri)))

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

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

class XMLRsetView(AnyRsetView):

    """dumps raw rset as xml"""

    __regid__ = 'rsetxml'

    title = _('xml export')

    templatable = False

    content_type = 'text/xml'

    xml_root = 'rset'

    def call(self):

        w = self.w

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

        eschema = self._cw.vreg.schema.eschema

        labels = self.columns_labels(tr=False)

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

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

        for rowindex, row in enumerate(self.cw_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).final:

                    attrs['eid'] = val

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

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

                                        row=rowindex, col=colindex)

                else:

                    val = self._cw.view('final', rset, 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 IFeedAdapter(EntityAdapter):

    __needs_bw_compat__ = True

    __regid__ = 'IFeed'

    __select__ = is_instance('Any')

    @implements_adapter_compat('IFeed')

    def rss_feed_url(self):

        """return an url to the rss feed for this entity"""

        return self.entity.absolute_url(vid='rss')

class RSSFeedURL(Component):

    __regid__ = 'rss_feed_url'

    __select__ = non_final_entity()

    def feed_url(self):

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

class RSSEntityFeedURL(Component):

    __regid__ = 'rss_feed_url'

    __select__ = one_line_rset() & adaptable('IFeed')

    def feed_url(self):

        entity = self.cw_rset.get_entity(self.cw_row or 0, self.cw_col or 0)

        return entity.cw_adapt_to('IFeed').rss_feed_url()

class RSSIconBox(component.CtxComponent):

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

    __regid__ = 'rss'

    __select__ = (component.CtxComponent.__select__

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

    visible = False

    order = 999

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

        try:

            rss = self._cw.uiprops['RSS_LOGO']

        except KeyError:

            self.error('missing RSS_LOGO external resource')

            return

        urlgetter = self._cw.vreg['components'].select('rss_feed_url', self._cw,

                                                       rset=self.cw_rset)

        url = urlgetter.feed_url()

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

class RSSView(XMLView):

    __regid__ = 'rss'

    title = _('rss')

    templatable = False

    content_type = 'text/xml'

    http_cache_manager = httpcache.MaxAgeHTTPCacheManager

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

    item_vid = 'rssitem'

    def _open(self):

        req = self._cw

        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._cw.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.cw_rset.rowcount):

            self.cell_call(i, 0)

        self._close()

    def cell_call(self, row, col):

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

class RSSItemView(EntityView):

    __regid__ = 'rssitem'

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

    add_div_section = False

    def cell_call(self, row, col):

        entity = self.cw_rset.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.render_description(entity)

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

        self.render_entity_creator(entity)

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

    def render_description(self, entity):

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

    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))