import logging, os
from rest_framework import viewsets, status
from rest_framework.response import Response
from rest_framework.views import APIView
from rest_framework.permissions import IsAuthenticated
from rest_framework.decorators import action
from drf_yasg.utils import swagger_auto_schema
from drf_yasg import openapi
from django.utils import timezone
from datetime import timedelta
from .models import EPGSource, ProgramData, EPGData  # Added ProgramData
from .serializers import ProgramDataSerializer, EPGSourceSerializer, EPGDataSerializer # Updated serializer
from .tasks import refresh_epg_data

logger = logging.getLogger(__name__)

# ─────────────────────────────
# 1) EPG Source API (CRUD)
# ─────────────────────────────
class EPGSourceViewSet(viewsets.ModelViewSet):
    """Handles CRUD operations for EPG sources"""
    queryset = EPGSource.objects.all()
    serializer_class = EPGSourceSerializer
    permission_classes = [IsAuthenticated]

    def list(self, request, *args, **kwargs):
        logger.debug("Listing all EPG sources.")
        return super().list(request, *args, **kwargs)

    @action(detail=False, methods=['post'])
    def upload(self, request):
        if 'file' not in request.FILES:
            return Response({'error': 'No file uploaded'}, status=status.HTTP_400_BAD_REQUEST)

        file = request.FILES['file']
        file_name = file.name
        file_path = os.path.join('/data/uploads/epgs', file_name)

        os.makedirs(os.path.dirname(file_path), exist_ok=True)
        with open(file_path, 'wb+') as destination:
            for chunk in file.chunks():
                destination.write(chunk)

        new_obj_data = request.data.copy()
        new_obj_data['file_path'] = file_path

        serializer = self.get_serializer(data=new_obj_data)
        serializer.is_valid(raise_exception=True)
        self.perform_create(serializer)

        return Response(serializer.data, status=status.HTTP_201_CREATED)

# ─────────────────────────────
# 2) Program API (CRUD)
# ─────────────────────────────
class ProgramViewSet(viewsets.ModelViewSet):
    """Handles CRUD operations for EPG programs"""
    queryset = ProgramData.objects.all()
    serializer_class = ProgramDataSerializer
    permission_classes = [IsAuthenticated]

    def list(self, request, *args, **kwargs):
        logger.debug("Listing all EPG programs.")
        return super().list(request, *args, **kwargs)

# ─────────────────────────────
# 3) EPG Grid View
# ─────────────────────────────
class EPGGridAPIView(APIView):
    """Returns all programs airing in the next 24 hours including currently running ones and recent ones"""

    @swagger_auto_schema(
        operation_description="Retrieve programs from the previous hour, currently running and upcoming for the next 24 hours",
        responses={200: ProgramDataSerializer(many=True)}
    )
    def get(self, request, format=None):
        # Use current time instead of midnight
        now = timezone.now()
        one_hour_ago = now - timedelta(hours=1)
        twenty_four_hours_later = now + timedelta(hours=24)
        logger.debug(f"EPGGridAPIView: Querying programs between {one_hour_ago} and {twenty_four_hours_later}.")

        # Use select_related to prefetch EPGData and include programs from the last hour
        programs = ProgramData.objects.select_related('epg').filter(
            # Programs that end after one hour ago (includes recently ended programs)
            end_time__gt=one_hour_ago,
            # AND start before the end time window
            start_time__lt=twenty_four_hours_later
        )
        count = programs.count()
        logger.debug(f"EPGGridAPIView: Found {count} program(s), including recently ended, currently running, and upcoming shows.")
        serializer = ProgramDataSerializer(programs, many=True)
        return Response({'data': serializer.data}, status=status.HTTP_200_OK)

# ─────────────────────────────
# 4) EPG Import View
# ─────────────────────────────
class EPGImportAPIView(APIView):
    """Triggers an EPG data refresh"""

    @swagger_auto_schema(
        operation_description="Triggers an EPG data import",
        responses={202: "EPG data import initiated"}
    )
    def post(self, request, format=None):
        logger.info("EPGImportAPIView: Received request to import EPG data.")
        refresh_epg_data.delay(request.data.get('id', None))  # Trigger Celery task
        logger.info("EPGImportAPIView: Task dispatched to refresh EPG data.")
        return Response({'success': True, 'message': 'EPG data import initiated.'}, status=status.HTTP_202_ACCEPTED)


# ─────────────────────────────
# 5) EPG Data View
# ─────────────────────────────
class EPGDataViewSet(viewsets.ReadOnlyModelViewSet):
    """
    API endpoint that allows EPGData objects to be viewed.
    """
    queryset = EPGData.objects.all()
    serializer_class = EPGDataSerializer
    permission_classes = [IsAuthenticated]