# -*- coding: utf-8 -*-
# copyright 2016 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr -- mailto:contact@logilab.fr
#
# This program 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.
#
# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.

"""elasticsearch search views"""
from elasticsearch import Elasticsearch
from elasticsearch.exceptions import NotFoundError
from elasticsearch_dsl import Search
from elasticsearch_dsl.connections import connections
from elasticsearch_dsl import FacetedSearch, TermsFacet, DateHistogramFacet
from bs4 import BeautifulSoup

from logilab.mtconverter import xml_escape

from cubicweb.view import StartupView

from cubes.elasticsearch.es import indexable_types

def get_connection(config):
    try:
        connections.get_connection()
    except KeyError:
        locations = config['elasticsearch-locations']
        index_name = config['index-name']
        # TODO sanitize locations
        connections.create_connection(hosts=locations.split(','),
                                      index=index_name,
                                      timeout=20)

class CWFacetedSearch(FacetedSearch):
    #doc_types = ['NewsContent', 'CommemorationItem', 'Circular',]
    # fields that should be searched
    fields = ["title^3", "name^3", "content^2", 'content', '_all',]

    facets = {
        # use bucket aggregations to define facets
        'cw_etype': TermsFacet(field='cw_etype'),
        'creation_date': DateHistogramFacet(field='creation_date', interval='month'),
        'commemoration_year': DateHistogramFacet(field='commemoration_year', interval='year'),
        'year': DateHistogramFacet(field='year', interval='year'),
    }
    def __init__(self, query=None, filters={}, doc_types=None):
        if doc_types:
            self.doc_types = doc_types
        super(CWFacetedSearch, self).__init__(query, filters)

    def highlight(self, search):
        """
        Add custom highlighting
        """
        return search.highlight(*self.fields) \
                 .highlight_options(pre_tags="",
                                    post_tags="",
                                    fragment_size=150)

class ElasticSearchView(StartupView):
    __regid__ = "esearch"

    def call(self, **kwargs):
        # TODO if no ES configuration, redirect or display warning
        search_comp = self._cw.vreg['components'].select_or_none('search-comp',
                                                                 self._cw)
        if search_comp:
            search_comp.render(w=self.w)

        self.w(u'<h1>%s</h1>' % self._cw._('Recherche'))
        query_string = xml_escape(self._cw.form.get('search', ''))
        self.w(u'<h2>Résultats pour : <em>%s</em></h2>' % query_string)
        get_connection(self._cw.vreg.config)
        facet_selections = {}
        start, stop = 0, 10
        for key, value in self._cw.form.items():
            if key.startswith('es_'):
                facet_selections[key.replace('es_', '')] = value
            if key == 'page':
                start = (max(int(value) - 1, 0)) * 10
                stop = start + 10
        indexable = indexable_types(self._cw.vreg.schema)
        search = CWFacetedSearch(query_string,
                                 facet_selections,
                                 doc_types=indexable)[start:stop]
        try:
            response = search.execute()
        except NotFoundError:
            self.w(u'index not found in elasticsearch')
            return
        self.w(u'Résultats: %s' % response.hits.total)
        if response.facets:
            self.display_facets(response)
        self.display_results(response)

    def display_results(self, response):
        self.w(u'<div id="main-center" class="col-xs-10" role="main">')
        self.w(u'<ul>')
        for result in response:
            self.w(u'<li>')
            infos = result.to_dict()
            infos['_score'] = result.meta.score
            infos['keys'] = result.to_dict().keys()
            infos.setdefault('title', infos.get('name', infos.get('reference', u'n/a')))
            try:
                self.w(u'<a href="%(cwuri)s">%(title)s</a> (%(_score).2f)<br/>' % (infos))
                if self._cw.form.get('debug-es'):
                    self.w(u' [%(keys)s] <br/>' % infos)
            except KeyError:
                self.w(u'Missing key in : %s' % infos.keys())
            try:
                for fragment in result.meta.highlight.content:
                    self.w(u'... %s' % BeautifulSoup(fragment, 'lxml').get_text())
                    self.w(u' ... <br/>')
            except AttributeError:
                pass
            self.w(u'</li>')
        self.w(u'</ul>')
        self.w(u'</div>')


    def display_facets(self, response):
        self.w(u'''<aside id="aside-main-left" class="col-xs-2 cwjs-aside">
                   <div class="panel panel-default contextFreeBox facet_filterbox">
                      <div class="panel-heading">
                         <div class="panel-title">Facettes</div>
                      </div>
        ''')
        for attribute in ('cw_etype', 'creation_date'):
            url_params = self._cw.form.copy()
            self.w(u'<div class="facetBody vocabularyFacet">')
            self.w(u'<div class="facetTitle">{}</div>'.format(attribute))
            for (tag, count, selected) in response.facets[attribute]:
                # facetValueSelected / facetValueDisabled in class
                facet_item = u'<div class="facetValue facetCheckBox">' \
                             '    <span>' \
                             '      <a href="{}">{} {}</a>' \
                             '    </span>' \
                             '</div>'
                if url_params.get('es_{}'.format(attribute)) != tag:
                    url_params['es_{}'.format(attribute)] = str(tag)
                else:
                    del url_params['es_{}'.format(attribute)]
                url = self._cw.build_url(**url_params)
                self.w(facet_item.format(url,
                                         '<b>{}</b>'.format(tag) if selected else tag,
                                         count))
            self.w(u'</div>')
        self.w(u'</div></aside>')