import sys

from registrasion import forms

from registrasion import util

from registrasion.models import commerce

from registrasion.models import inventory

from registrasion.models import people

from registrasion.controllers.cart import CartController

from registrasion.controllers.credit_note import CreditNoteController

from registrasion.controllers.invoice import InvoiceController

from registrasion.controllers.product import ProductController

from registrasion.exceptions import CartValidationError

from collections import namedtuple

from django.conf import settings

from django.contrib.auth.decorators import login_required

from django.contrib.auth.decorators import user_passes_test

from django.contrib import messages

from django.core.exceptions import ObjectDoesNotExist

from django.core.exceptions import ValidationError

from django.http import Http404

from django.shortcuts import redirect

from django.shortcuts import render

_GuidedRegistrationSection = namedtuple(

    "GuidedRegistrationSection",

    (

        "title",

        "discounts",

        "description",

        "form",

            cats = cats.filter(id__in=_cats)

        else:

            cats = cats.exclude(

                id__in=attendee.guided_categories_complete.all(),

            )

        cats = cats.order_by("order")

        request.session[SESSION_KEY] = []

        if starting:

            # Only display the first Category

            title = "Select ticket type"

            current_step = 2

            cats = [cats[0]]

        else:

            # Set title appropriately for remaining categories

            current_step = 3

            title = "Additional items"

        all_products = inventory.Product.objects.filter(

            category__in=cats,

        ).select_related("category")

            for category in cats:

                products = [

                    i for i in available_products

                    if i.category == category

                ]

                prefix = "category_" + str(category.id)

                p = _handle_products(request, category, products, prefix)

                products_form, discounts, products_handled = p

                section = GuidedRegistrationSection(

                    title=category.name,

                    description=category.description,

                    discounts=discounts,

                    form=products_form,

                )

                if products:

                    # This product category has items to show.

                    sections.append(section)

                    # Add this to the list of things to show if the form

                    # errors.

                    request.session[SESSION_KEY].append(category.id)

                {

                    "category": category,         # An inventory.Category for

                                                  # category_id

                    "discounts": discounts,       # A list of

                                                  # DiscountAndQuantity

                    "form": products_form,        # A form for selecting

                                                  # products

                    "voucher_form": voucher_form, # A form for entering a

                                                  # voucher code

                }

    '''

    PRODUCTS_FORM_PREFIX = "products"

    VOUCHERS_FORM_PREFIX = "vouchers"

    # Handle the voucher form *before* listing products.

    # Products can change as vouchers are entered.

    v = _handle_voucher(request, VOUCHERS_FORM_PREFIX)

    voucher_form, voucher_handled = v

    category_id = int(category_id)  # Routing is [0-9]+

    category = inventory.Category.objects.get(pk=category_id)

        )

    if request.POST and not voucher_handled and not products_form.errors:

        # Only return to the dashboard if we didn't add a voucher code

        # and if there's no errors in the products form

        messages.success(

            request,

            "Your reservations have been updated.",

        )

        return redirect("dashboard")

    data = {

        "category": category,

        "discounts": discounts,

        "form": products_form,

        "voucher_form": voucher_form,

    }

    return render(request, "registrasion/product_category.html", data)

def _handle_products(request, category, products, prefix):

    ''' Handles a products list form in the given request. Returns the

    form instance, the discounts applicable to this form, and whether the

    contents were handled. '''