"""
web_admin analytics view file
"""
# python imports
import datetime
import io
import pandas as pd
import xlsxwriter

# 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
from django.db.models.functions import TruncDate
from django.db.models import F, Window
from django.db.models.functions.window import Rank
from django.http import HttpResponse

# local imports
from account.utils import custom_response, get_user_full_name
from base.constants import PENDING, IN_PROGRESS, REJECTED, REQUESTED, COMPLETED, EXPIRED, DATE_FORMAT, TASK_STATUS
from guardian.models import JuniorTask
from guardian.utils import upload_excel_file_to_alibaba
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, UserCSVReportSerializer
from web_admin.utils import get_dates

USER = get_user_model()


class AnalyticsViewSet(GenericViewSet):
    """
    analytics api view
    to get user report (active users, guardians and juniors counts)
    to get new user sign up report
    to get task report (completed, in-progress, requested and rejected tasks count)
    to get junior leaderboard and ranking
    """
    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: start_date: date format (yyyy-mm-dd)
        :param request: end_date: date format (yyyy-mm-dd)
        :return:
        """
        start_date, end_date = get_dates(request.query_params.get('start_date'),
                                         request.query_params.get('end_date'))

        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: start_date: date format (yyyy-mm-dd)
        :param request: end_date: date format (yyyy-mm-dd)
        :return:
        """
        start_date, end_date = get_dates(request.query_params.get('start_date'),
                                         request.query_params.get('end_date'))

        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 count for (completed, in-progress, requested and rejected) task
        :param request: start_date: date format (yyyy-mm-dd)
        :param request: end_date: date format (yyyy-mm-dd)
        :return:
        """
        start_date, end_date = get_dates(request.query_params.get('start_date'),
                                         request.query_params.get('end_date'))

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

        data = {
            'task_completed': assign_tasks.filter(task_status=COMPLETED).count(),
            'task_pending': assign_tasks.filter(task_status=PENDING).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(),
            'task_expired': assign_tasks.filter(task_status=EXPIRED).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):
        """
        to get junior leaderboard and rank
        :param request:
        :return:
        """
        queryset = JuniorPoints.objects.filter(
                                    junior__is_verified=True
                                    ).select_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)

    @action(methods=['get'], url_name='export-excel', url_path='export-excel', detail=False)
    def export_excel(self, request):
        """
        to export users count, task details and top juniors in csv/excel file
        :param request: start_date: date format (yyyy-mm-dd)
        :param request: end_date: date format (yyyy-mm-dd)
        :return:
        """

        response = HttpResponse(content_type='application/vnd.openxmlformats-officedocument.spreadsheetml.sheet')
        response['Content-Disposition'] = 'attachment; filename="ZOD_Bank_Analytics.xlsx"'

        start_date, end_date = get_dates(request.query_params.get('start_date'),
                                         request.query_params.get('end_date'))

        # Use BytesIO for binary data
        buffer = io.BytesIO()

        # Create an XlsxWriter Workbook object
        workbook = xlsxwriter.Workbook(buffer)

        # Add sheets
        sheets = ['Users', 'Assign Tasks', 'Juniors Leaderboard']

        for sheet_name in sheets:
            worksheet = workbook.add_worksheet(name=sheet_name)

            # sheet 1 for Total Users
            if sheet_name == 'Users':
                user_qs = self.get_queryset()
                queryset = user_qs.filter(date_joined__range=(start_date, (end_date + datetime.timedelta(days=1))))
                serializer = UserCSVReportSerializer(queryset, many=True)

                df_users = pd.DataFrame([
                    {'Name': user['name'], 'Email': user['email'],
                     'Phone Number': user['phone_number'], 'User Type': user['user_type'],
                     'Status': user['is_active'], 'Date Joined': user['date_joined']}
                    for user in serializer.data
                ])
                write_excel_worksheet(worksheet, df_users)

            # sheet 2 for Assign Task
            elif sheet_name == 'Assign Tasks':
                assign_tasks = JuniorTask.objects.filter(
                    created_at__range=[start_date, (end_date + datetime.timedelta(days=1))]
                ).select_related('junior__auth', 'guardian__user').only('task_name', 'task_status',
                                                                        'junior__auth__first_name',
                                                                        'junior__auth__last_name',
                                                                        'guardian__user__first_name',
                                                                        'guardian__user__last_name',)

                df_tasks = pd.DataFrame([
                    {'Task Name': task.task_name, 'Assign To': get_user_full_name(task.junior.auth),
                     'Assign By': get_user_full_name(task.guardian.user),
                     'Task Status': dict(TASK_STATUS).get(task.task_status).capitalize()}
                    for task in assign_tasks
                ])

                write_excel_worksheet(worksheet, df_tasks)

            # sheet 3 for Juniors Leaderboard and rank
            elif sheet_name == 'Juniors Leaderboard':
                queryset = JuniorPoints.objects.filter(
                                    junior__is_verified=True
                                    ).select_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')[:15]
                df_leaderboard = pd.DataFrame([
                    {
                        'Name': get_user_full_name(junior.junior.auth),
                        'Points': junior.total_points,
                        'Rank': junior.rank
                    }
                    for junior in queryset
                ])

                write_excel_worksheet(worksheet, df_leaderboard)

        # Close the workbook to save the content
        workbook.close()

        # Reset the buffer position and write the content to the response
        buffer.seek(0)
        response.write(buffer.getvalue())
        buffer.close()

        filename = f"{'analytics'}/{'ZOD_Bank_Analytics.xlsx'}"
        file_link = upload_excel_file_to_alibaba(response, filename)
        return custom_response(None, file_link)


def write_excel_worksheet(worksheet, dataframe):
    """
    to perform write action on worksheets
    :param worksheet:
    :param dataframe:
    :return: worksheet
    """
    for idx, col in enumerate(dataframe.columns):
        # Write header
        worksheet.write(0, idx, col)
    for row_num, row in enumerate(dataframe.values, start=1):
        for col_num, value in enumerate(row):
            worksheet.write(row_num, col_num, value)
    return worksheet