from __future__ import unicode_literals

import datetime

import itertools

from django.core.exceptions import ValidationError

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.

     '''

    @classmethod

    def name_field(cls):

        ''' This is used to pre-fill the attendee's name from the

        speaker profile. If it's None, that functionality is disabled. '''

        return None

    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."),

            section = GuidedRegistrationSection(

                title=category.name,

                description=category.description,

                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)

    # Load a pre-entered name from the speaker's profile,

    # if they have one.

    try:

        speaker_profile = request.user.speaker_profile

        speaker_name = speaker_profile.name

    except ObjectDoesNotExist:

        speaker_name = None

    name_field = ProfileForm.Meta.model.name_field()

    initial = {}

        initial[name_field] = speaker_name

    form = ProfileForm(

        request.POST or None,

        initial=initial,

        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 = {