"""
web_admin analytics view file
"""
# python imports
import datetime

# third party imports
from rest_framework.viewsets import GenericViewSet
from rest_framework.decorators import action
from rest_framework.permissions import IsAuthenticated

# django imports
from django.contrib.auth import get_user_model
from django.db.models import Q
from django.db.models import Count, OuterRef, Subquery, Sum
from django.db.models.functions import TruncDate
from django.db.models import F, Window
from django.db.models.functions.window import Rank

# local imports
from account.utils import custom_response
from base.constants import PENDING, IN_PROGRESS, REJECTED, REQUESTED, COMPLETED, EXPIRED
from guardian.models import JuniorTask
from junior.models import JuniorPoints
from web_admin.pagination import CustomPageNumberPagination
from web_admin.permission import AdminPermission
from web_admin.serializers.analytics_serializer import LeaderboardSerializer

USER = get_user_model()


class AnalyticsViewSet(GenericViewSet):
    """
    analytics api view
    """
    serializer_class = None
    permission_classes = [IsAuthenticated, AdminPermission]

    def get_queryset(self):
        user_qs = USER.objects.filter(
            (Q(junior_profile__is_verified=True) | Q(guardian_profile__is_verified=True)),
            is_superuser=False
                    ).prefetch_related('guardian_profile',
                                       'junior_profile'
                                       ).exclude(junior_profile__isnull=True,
                                                 guardian_profile__isnull=True).order_by('date_joined')
        return user_qs

    @action(methods=['get'], url_name='users-count', url_path='users-count', detail=False)
    def total_users_count(self, request, *args, **kwargs):
        """
        api method to get total users, guardians and juniors
        :param request: query params {start_date and end_date}, date format (yyyy-mm-dd)
        :return:
        """

        end_date = datetime.date.today()
        start_date = end_date - datetime.timedelta(days=6)

        if request.query_params.get('start_date') and request.query_params.get('end_date'):
            start_date = datetime.datetime.strptime(request.query_params.get('start_date'), '%Y-%m-%d')
            end_date = datetime.datetime.strptime(request.query_params.get('end_date'), '%Y-%m-%d')

        user_qs = self.get_queryset()
        queryset = user_qs.filter(date_joined__range=(start_date, (end_date + datetime.timedelta(days=1))))

        data = {'total_users': queryset.count(),
                'total_guardians': queryset.filter(junior_profile__isnull=True).count(),
                'total_juniors': queryset.filter(guardian_profile__isnull=True).count()}

        return custom_response(None, data)

    @action(methods=['get'], url_name='new-signups', url_path='new-signups', detail=False)
    def new_signups(self, request, *args, **kwargs):
        """
        api method to get new signups
        :param request: query params {start_date and end_date}, date format (yyyy-mm-dd)
        :return:
        """
        end_date = datetime.date.today()
        start_date = end_date - datetime.timedelta(days=6)

        if request.query_params.get('start_date') and request.query_params.get('end_date'):
            start_date = datetime.datetime.strptime(request.query_params.get('start_date'), '%Y-%m-%d')
            end_date = datetime.datetime.strptime(request.query_params.get('end_date'), '%Y-%m-%d')

        user_qs = self.get_queryset()
        signup_data = user_qs.filter(date_joined__range=[start_date, (end_date + datetime.timedelta(days=1))]
                                     ).annotate(date=TruncDate('date_joined')
                                                ).values('date').annotate(signups=Count('id')).order_by('date')

        return custom_response(None, signup_data)

    @action(methods=['get'], url_name='assign-tasks', url_path='assign-tasks', detail=False)
    def assign_tasks_report(self, request, *args, **kwargs):
        """
        api method to get assign tasks
        :param request: query params {start_date and end_date}, date format (yyyy-mm-dd)
        :return:
        """
        end_date = datetime.date.today()
        start_date = end_date - datetime.timedelta(days=6)

        if request.query_params.get('start_date') and request.query_params.get('end_date'):
            start_date = datetime.datetime.strptime(request.query_params.get('start_date'), '%Y-%m-%d')
            end_date = datetime.datetime.strptime(request.query_params.get('end_date'), '%Y-%m-%d')

        assign_tasks = JuniorTask.objects.filter(
                                created_at__range=[start_date, (end_date + datetime.timedelta(days=1))]
                                        ).exclude(task_status__in=[PENDING, EXPIRED])

        data = {
            'task_completed': assign_tasks.filter(task_status=COMPLETED).count(),
            'task_in_progress': assign_tasks.filter(task_status=IN_PROGRESS).count(),
            'task_requested': assign_tasks.filter(task_status=REQUESTED).count(),
            'task_rejected': assign_tasks.filter(task_status=REJECTED).count(),
        }

        return custom_response(None, data)

    @action(methods=['get'], url_name='junior-leaderboard', url_path='junior-leaderboard', detail=False,
            serializer_class=LeaderboardSerializer)
    def junior_leaderboard(self, request):
        """

        :param request:
        :return:
        """
        # queryset = JuniorPoints.objects.all().order_by('-total_points', 'junior__created_at')
        queryset = JuniorPoints.objects.prefetch_related('junior', 'junior__auth').annotate(rank=Window(
            expression=Rank(),
            order_by=[F('total_points').desc(), 'junior__created_at']
        )).order_by('-total_points', 'junior__created_at')
        paginator = CustomPageNumberPagination()
        paginated_queryset = paginator.paginate_queryset(queryset, request)
        serializer = self.serializer_class(paginated_queryset, many=True)
        return custom_response(None, serializer.data)