from __future__ import unicode_literals
import datetime
from django.template.loader import render_to_string
from django.utils import six
from django.utils.translation import ugettext_lazy as _
from haystack import connections
from debug_toolbar.panels import DebugPanel


class HaystackDebugPanel(DebugPanel):
    """
    Panel that displays information about the Haystack queries run while
    processing the request.
    """
    name = 'Haystack'
    has_content = True

    def __init__(self, *args, **kwargs):
        super(self.__class__, self).__init__(*args, **kwargs)
        self._offset = dict((alias, len(connections[alias].queries)) for alias in connections.connections_info.keys())
        self._search_time = 0
        self._queries = []
        self._backends = {}

    def nav_title(self):
        return _('Haystack')

    def nav_subtitle(self):
        self._queries = []
        self._backends = {}

        for alias in connections.connections_info.keys():
            search_queries = connections[alias].queries[self._offset[alias]:]
            self._backends[alias] = {
                'time_spent': sum(float(q['time']) for q in search_queries),
                'queries': len(search_queries),
            }
            self._queries.extend([(alias, q) for q in search_queries])

        self._queries.sort(key=lambda x: x[1]['start'])
        self._search_time = sum([d['time_spent'] for d in self._backends.itervalues()])
        num_queries = len(self._queries)
        return "%d %s in %.2fms" % (
            num_queries,
            (num_queries == 1) and 'query' or 'queries',
            self._search_time
        )

    def title(self):
        return _('Search Queries')

    def url(self):
        return ''

    def content(self):
        width_ratio_tally = 0

        for alias, query in self._queries:
            query['alias'] = alias
            query['query'] = query['query_string']

            if query.get('additional_kwargs'):
                if query['additional_kwargs'].get('result_class'):
                    query['additional_kwargs']['result_class'] = six.text_type(query['additional_kwargs']['result_class'])

            try:
                query['width_ratio'] = (float(query['time']) / self._search_time) * 100
            except ZeroDivisionError:
                query['width_ratio'] = 0

            query['start_offset'] = width_ratio_tally
            width_ratio_tally += query['width_ratio']

        context = self.context.copy()
        context.update({
            'backends': sorted(self._backends.items(), key=lambda x: -x[1]['time_spent']),
            'queries': [q for a, q in self._queries],
            'sql_time': self._search_time,
        })

        return render_to_string('panels/haystack.html', context)
