import logging
from decimal import Decimal
from django.db.models import Q, F
from django.shortcuts import get_object_or_404
from django.utils.translation import gettext_lazy as _
from rest_framework import status
from rest_framework.views import APIView
from rest_framework.generics import GenericAPIView
from rest_framework.permissions import AllowAny, IsAuthenticated
from rest_framework.response import Response
from drf_spectacular.utils import extend_schema, OpenApiResponse, OpenApiParameter

from apps.donations.models import DonationCampaign, DonationTransaction, PaymentStatus
from apps.donations.serializers import (
    DonationCampaignListSerializer,
    DonationCampaignDetailSerializer,
    DonationTransactionSerializer,
    DonationContributeRequestSerializer,
)

logger = logging.getLogger(__name__)


def get_campaign_by_pk_or_slug(pk_or_slug, queryset=None):
    if queryset is None:
        queryset = DonationCampaign.objects.all()
    if str(pk_or_slug).isdigit():
        return get_object_or_404(queryset, pk=int(pk_or_slug))
    return get_object_or_404(queryset, slug=pk_or_slug)


class DonationCampaignListView(GenericAPIView):
    permission_classes = [AllowAny]
    serializer_class = DonationCampaignListSerializer
    queryset = DonationCampaign.objects.filter(is_active=True)

    @extend_schema(
        summary="List active donation appeals & campaigns",
        description="Retrieves charitable campaigns with target, raised amounts, progress percentages, and filters.",
        parameters=[
            OpenApiParameter('category', str, description="Filter by campaign category"),
            OpenApiParameter('priority', str, description="Filter by priority (urgent, high, medium)"),
            OpenApiParameter('search', str, description="Search in campaign title or description"),
            OpenApiParameter('featured', bool, description="Filter featured campaigns"),
        ],
        responses={200: DonationCampaignListSerializer(many=True)},
        tags=["Donations & Financial Campaigns"],
    )
    def get(self, request, *args, **kwargs):
        qs = DonationCampaign.objects.all()
        if not (request.user and request.user.is_authenticated and request.user.is_staff):
            qs = qs.filter(is_active=True)

        category = request.query_params.get('category')
        if category:
            qs = qs.filter(category=category)

        priority = request.query_params.get('priority')
        if priority:
            qs = qs.filter(priority=priority)

        featured = request.query_params.get('featured')
        if featured is not None:
            qs = qs.filter(is_featured=featured.lower() in ('true', '1'))

        search = request.query_params.get('search')
        if search:
            qs = qs.filter(Q(title__icontains=search) | Q(description__icontains=search))

        serializer = self.get_serializer(qs, many=True)
        return Response(serializer.data, status=status.HTTP_200_OK)


class DonationCampaignDetailView(GenericAPIView):
    permission_classes = [AllowAny]
    serializer_class = DonationCampaignDetailSerializer
    queryset = DonationCampaign.objects.all()

    @extend_schema(
        summary="Retrieve campaign details & recent contributions",
        description="Returns detailed campaign goal, beneficiary center, progress rate, and recent donors.",
        responses={
            200: DonationCampaignDetailSerializer,
            404: OpenApiResponse(description="Campaign not found"),
        },
        tags=["Donations & Financial Campaigns"],
    )
    def get(self, request, pk_or_slug, *args, **kwargs):
        campaign = get_campaign_by_pk_or_slug(pk_or_slug, self.get_queryset())
        serializer = self.get_serializer(campaign)
        return Response(serializer.data, status=status.HTTP_200_OK)


class DonationContributeView(GenericAPIView):
    permission_classes = [AllowAny]
    serializer_class = DonationContributeRequestSerializer
    queryset = DonationCampaign.objects.all()

    @extend_schema(
        summary="Make a charitable contribution to campaign",
        description="Processes a donation contribution, persists transaction, and increments campaign accumulated funds.",
        request=DonationContributeRequestSerializer,
        responses={
            201: DonationTransactionSerializer,
            400: OpenApiResponse(description="Validation error"),
            404: OpenApiResponse(description="Campaign not found"),
        },
        tags=["Donations & Financial Campaigns"],
    )
    def post(self, request, pk_or_slug, *args, **kwargs):
        campaign = get_campaign_by_pk_or_slug(pk_or_slug, self.get_queryset())

        if not campaign.is_active:
            return Response({'error': _("This campaign is currently inactive or closed.")}, status=status.HTTP_400_BAD_REQUEST)

        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)

        amount = serializer.validated_data['amount']
        donor_name = serializer.validated_data.get('donor_name') or 'Anonymous Donor'
        donor_email = serializer.validated_data.get('donor_email')

        user = request.user if (request.user and request.user.is_authenticated) else None
        if user and not serializer.validated_data.get('donor_name'):
            donor_name = user.get_full_name() or user.email

        transaction = DonationTransaction.objects.create(
            campaign=campaign,
            donor_user=user,
            donor_name=donor_name,
            donor_email=donor_email or (user.email if user else None),
            amount=amount,
            currency=campaign.currency,
            payment_status=PaymentStatus.COMPLETED,
        )

        # Increment campaign raised amount
        campaign.raised_amount = (campaign.raised_amount or Decimal('0.00')) + amount
        campaign.save()

        return Response(DonationTransactionSerializer(transaction).data, status=status.HTTP_201_CREATED)