from itertools import chain

from django.shortcuts import render

from .models import Service, Cost, Good, CostUse, GoodUse


def index(request):
    return render(request, 'costs/index.html')


def list_services(request):
    context = {
        'services': Service.objects.all(),
    }
    return render(request, 'costs/services_list.html', context)


def list_resources(request):
    context = {
        'goods': Good.objects.all(),
        'costs': Cost.objects.all(),
    }
    return render(request, 'costs/resources_list.html', context)


def detail_service(request, pk):
    service = Service.objects.get(pk=pk)

    costs_uses = CostUse.objects.filter(service=service)
    goods_uses = GoodUse.objects.filter(service=service)

    total_costs_price = sum(chain(
        (i.monthly_provision_share() for i in goods_uses),
        (i.cost_share() for i in costs_uses),
    ))

    total_goods_value_share = sum(i.value_share() for i in goods_uses)

    if service.subscriptions_count == 0:
        unit_costs_price = 0
        unit_goods_value_share = 0
    else:
        unit_costs_price = total_costs_price/service.subscriptions_count
        unit_goods_value_share = total_goods_value_share/service.subscriptions_count

    if unit_costs_price > 0:
        months_fas_equivalent = unit_goods_value_share/unit_costs_price
    else:
        months_fas_equivalent = 0

    context = {
        'service': service,
        'costs_uses': costs_uses,
        'goods_uses': goods_uses,
        'total_costs_price': total_costs_price,
        'unit_costs_price': unit_costs_price,

        'total_goods_value_share': total_goods_value_share,
        'unit_goods_value_share': unit_goods_value_share,
        'months_fas_equivalent': months_fas_equivalent,
    }
    return render(request, 'costs/service_detail.html', context)