import datetime

import itertools

from django.core.exceptions import ValidationError

from django.core.exceptions import ObjectDoesNotExist

from django.contrib.auth.models import User

from django.db import models

from django.db.models import F, Q

from django.utils import timezone

from django.utils.encoding import python_2_unicode_compatible

from django.utils.translation import ugettext_lazy as _

from model_utils.managers import InheritanceManager

# User models

@python_2_unicode_compatible

class Attendee(models.Model):

    ''' Miscellaneous user-related data. '''

    def __str__(self):

        return "%s" % self.user

    @staticmethod

    def get_instance(user):

        ''' Returns the instance of attendee for the given user, or creates

        a new one. '''

        attendees = Attendee.objects.filter(user=user)

        if len(attendees) > 0:

            return attendees[0]

        else:

            attendee = Attendee(user=user)

            attendee.save()

            return attendee

    user = models.OneToOneField(User, on_delete=models.CASCADE)

    # Badge/profile is linked

    completed_registration = models.BooleanField(default=False)

    highest_complete_category = models.IntegerField(default=0)

class AttendeeProfileBase(models.Model):

    ''' Information for an attendee's badge and related preferences.

    Subclass this in your Django site to ask for attendee information in your

    registration progess.

     '''

    attendee = models.OneToOneField(Attendee, on_delete=models.CASCADE)

# Inventory Models

@python_2_unicode_compatible

class Category(models.Model):

    ''' Registration product categories '''

    class Meta:

        verbose_name_plural = _("categories")

    def __str__(self):

        return self.name

    RENDER_TYPE_RADIO = 1

    RENDER_TYPE_QUANTITY = 2

    CATEGORY_RENDER_TYPES = [

        (RENDER_TYPE_RADIO, _("Radio button")),

        (RENDER_TYPE_QUANTITY, _("Quantity boxes")),

    ]

    name = models.CharField(

        max_length=65,

        verbose_name=_("Name"),

    )

    description = models.CharField(

        max_length=255,

        verbose_name=_("Description"),

    )

    limit_per_user = models.PositiveIntegerField(

        null=True,

        blank=True,

        verbose_name=_("Limit per user"),

        help_text=_("The total number of items from this category one "

                    "attendee may purchase."),

    )

    required = models.BooleanField(

        blank=True,

        help_text=_("If enabled, a user must select an "

                    "item from this category."),

    )

    order = models.PositiveIntegerField(

        verbose_name=("Display order"),

    )

    render_type = models.IntegerField(

        choices=CATEGORY_RENDER_TYPES,

import sys

from registrasion import forms

from registrasion import models as rego

from registrasion.controllers import discount

from registrasion.controllers.cart import CartController

from registrasion.controllers.invoice import InvoiceController

from registrasion.controllers.product import ProductController

from collections import namedtuple

from django.conf import settings

from django.contrib.auth.decorators import login_required

from django.contrib import messages

from django.core.exceptions import ObjectDoesNotExist

from django.core.exceptions import ValidationError

from django.db import transaction

from django.http import Http404

from django.shortcuts import redirect

from django.shortcuts import render

GuidedRegistrationSection = namedtuple(

    "GuidedRegistrationSection",

    (

        "title",

        "discounts",

        "description",

        "form",

    )

)

GuidedRegistrationSection.__new__.__defaults__ = (

    (None,) * len(GuidedRegistrationSection._fields)

)

def get_form(name):

    dot = name.rindex(".")

    mod_name, form_name = name[:dot], name[dot + 1:]

    __import__(mod_name)

    return getattr(sys.modules[mod_name], form_name)

@login_required

def guided_registration(request, page_id=0):

    ''' Goes through the registration process in order,

    making sure user sees all valid categories.

    WORK IN PROGRESS: the finalised version of this view will allow

    grouping of categories into a specific page. Currently, it just goes

                discounts=discounts,

                form=products_form,

            )

            sections.append(section)

            if request.method == "POST" and not products_form.errors:

                if category.id > attendee.highest_complete_category:

                    # This is only saved if we pass each form with no errors.

                    attendee.highest_complete_category = category.id

    if sections and request.method == "POST":

        for section in sections:

            if section.form.errors:

                break

        else:

            attendee.save()

            # We've successfully processed everything

            return next_step

    data = {

        "current_step": current_step,

        "sections": sections,

        "title" : title,

        "total_steps": 3,

    }

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

@login_required

def edit_profile(request):

    form, handled = handle_profile(request, "profile")

    data = {

        "form": form,

    }

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

def handle_profile(request, prefix):

    ''' Returns a profile form instance, and a boolean which is true if the

    form was handled. '''

    attendee = rego.Attendee.get_instance(request.user)

    try:

        profile = attendee.attendeeprofilebase

    except ObjectDoesNotExist:

        profile = None

    ProfileForm = get_form(settings.ATTENDEE_PROFILE_FORM)

    form = ProfileForm(

        request.POST or None,

        instance=profile,

        prefix=prefix

    )

    handled = True if request.POST else False

    if request.POST and form.is_valid():

        form.instance.attendee = attendee

        form.save()

    return form, handled

@login_required

def product_category(request, category_id):

    ''' Registration selections form for a specific category of items.

    '''

    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 = rego.Category.objects.get(pk=category_id)

    products = ProductController.available_products(

        request.user,

        category=category,

    )

    p = handle_products(request, category, products, PRODUCTS_FORM_PREFIX)

    products_form, discounts, products_handled = p

    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

        return redirect("dashboard")

    data = {

        "category": category,

        "discounts": discounts,

        "form": products_form,

        "voucher_form": voucher_form,

    }