"""passbook administration overview"""
import time
from collections import Counter
from datetime import timedelta
from typing import Dict, List

from django.db.models import Count, ExpressionWrapper, F
from django.db.models.fields import DurationField
from django.db.models.functions import ExtractHour
from django.http import response
from django.utils.timezone import now
from drf_yasg.utils import swagger_auto_schema
from rest_framework.fields import SerializerMethodField
from rest_framework.permissions import IsAdminUser
from rest_framework.request import Request
from rest_framework.response import Response
from rest_framework.serializers import Serializer
from rest_framework.viewsets import ViewSet

from passbook.audit.models import Event, EventAction


class AdministrationMetricsSerializer(Serializer):
    """Overview View"""

    logins_per_1h = SerializerMethodField()
    logins_failed_per_1h = SerializerMethodField()

    def get_events_per_1h(self, action: str) -> List[Dict[str, int]]:
        """Get event count by hour in the last day, fill with zeros"""
        date_from = now() - timedelta(days=1)
        result = (
            Event.objects.filter(action=action, created__gte=date_from)
            .annotate(
                age=ExpressionWrapper(
                    now() - F("created"), output_field=DurationField()
                )
            )
            .annotate(age_hours=ExtractHour("age"))
            .values("age_hours")
            .annotate(count=Count("pk"))
            .order_by("age_hours")
        )
        data = Counter({d["age_hours"]: d["count"] for d in result})
        results = []
        _now = now()
        for hour in range(0, -24, -1):
            results.append(
                {
                    "x": time.mktime((_now + timedelta(hours=hour)).timetuple()) * 1000,
                    "y": data[hour * -1],
                }
            )
        return results

    def get_logins_per_1h(self, _):
        """Get successful logins per hour for the last 24 hours"""
        return self.get_events_per_1h(EventAction.LOGIN)

    def get_logins_failed_per_1h(self, _):
        """Get failed logins per hour for the last 24 hours"""
        return self.get_events_per_1h(EventAction.LOGIN_FAILED)

    def create(self, request: Request) -> response:
        raise NotImplementedError

    def update(self, request: Request) -> Response:
        raise NotImplementedError


class AdministrationMetricsViewSet(ViewSet):
    """Return single instance of AdministrationMetricsSerializer"""

    permission_classes = [IsAdminUser]

    @swagger_auto_schema(responses={200: AdministrationMetricsSerializer(many=True)})
    def list(self, request: Request) -> Response:
        """Return single instance of AdministrationMetricsSerializer"""
        serializer = AdministrationMetricsSerializer(True)
        return Response(serializer.data)