"""Present karma data."""

import logging

from django.shortcuts import get_object_or_404, render, reverse
from django.views.generic import TemplateView
from django_datatables_view.base_datatable_view import BaseDatatableView
from rest_framework import viewsets

from karma.models import KarmaKey
from karma.serializers import KarmaKeySerializer

log = logging.getLogger('karma.views')


class IndexView(TemplateView):
    """ Routes to the index template using the generic view """
    template_name = 'karma/index.html'


def key_detail(request, karma_key):
    """Display the requested karma key."""
    entry = get_object_or_404(KarmaKey, key=karma_key.lower())

    return render(request, 'karma/karma_key.html', {'entry': entry, 'entry_history': entry.history(mode='date')})


class KarmaKeyViewSet(viewsets.ReadOnlyModelViewSet):
    """Provide list and detail actions for karma keys."""

    queryset = KarmaKey.objects.all()
    serializer_class = KarmaKeySerializer


class KarmaKeyListJson(BaseDatatableView):
    """ Provide list of KarmaKeys in snazzy JSON format that DataTables enjoys """

    model = KarmaKey
    max_display_length = 500
    columns = ['key', 'current_score']

    # maintain order from columns
    order_columns = ['key', 'current_score']

    def get_initial_queryset(self):
        """ Add another column that operates like score() """
        return KarmaKey.objects.extra(select={
            'current_score':
                'SELECT SUM(kle.delta) FROM karma_karmalogentry kle WHERE kle.key_id = karma_karmakey.id'
        })

    def prepare_results(self, qs):
        # prepare list with output column data
        # queryset is already paginated here
        json_data = []
        for kk in qs:
            json_data.append([
                '<a href="{}">{}</a>'.format(reverse('karma_key_detail', args=[kk.key]), kk.key),
                kk.current_score,
            ])
        return json_data