from django.shortcuts import render
from rest_framework import viewsets, permissions, status
from rest_framework.response import Response

from .models import Bill, Payment
from .serializers import BillSerializer, PaymentSerializer
from datetime import datetime


# to be implemented
class BalanceViewSet(viewsets.ViewSet):
    # here we return a number
    # number = sum(payments) - sum(bills)

    #bills = Bill.objects.filter(owner=self.request.user)
    #payments = Payment.objects.filter(owner=self.request.user)

    # sum_paid = sum([ amount for amount payments..,.  ]) # you get the picture
    # sum_to_be_paid = sum([ amount for amount bills..,.  ]) # you get the picture
    pass


class BillViewSet(viewsets.ModelViewSet):
    serializer_class = BillSerializer
    permission_classes = [permissions.IsAuthenticated]
    http_method_names = ['get']

    def get_queryset(self):
        return Bill.objects.filter(owner=self.request.user)

    def unpaid(self, request):
        return Bill.objects.filter(owner=self.request.user, paid=False)

class PaymentViewSet(viewsets.ModelViewSet):
    serializer_class = PaymentSerializer
    permission_classes = [permissions.IsAuthenticated]
    http_method_names = ['get', 'post']

    def get_queryset(self):
        return Payment.objects.filter(owner=self.request.user)

    def create(self, request):
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        serializer.save(owner=request.user,timestamp=datetime.now())

        headers = self.get_success_headers(serializer.data)
        return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)