from decimal import Decimal

from django.http import HttpResponseRedirect
from django.shortcuts import get_object_or_404, render
from django.contrib.auth.decorators import login_required
from django.contrib.auth.models import User
from django.contrib.auth.forms import UserCreationForm
from django.db import transaction
from webshop.models import (Article,
                            Category,
                            ArticleStatus,
                            Person,
                            City,
                            Picture,
                            CartPosition,
                            ShoppingCart)
from webshop.forms import (RegistrationForm,
                           AddToCartForm,
                           CartForm,
                           CheckoutForm)
from webshop.utils import (get_categories,
                           get_hidden_status_id,
                           process_article_prices)

from currencies.models import ExchangeRate, ExchangeRate_name
from currencies.forms import CurrenciesForm

def index(request):
    category_list = get_categories()
    currencies_form = CurrenciesForm
    article_view = True

    articles = Article.objects.all().exclude(status=get_hidden_status_id())
    return_values = process_article_prices(request, articles)
    articles_list = return_values['articles_list']
    currency_name = return_values['currency_name']

    return render(request,
                  'webshop/index.html',
                  {'category_list': category_list,
                   'articles_list': articles_list,
                   'currencies_form': currencies_form,
                   'article_view': article_view,
                   'currency_name': currency_name})


def articles_in_category(request, category_id):
    category_list = get_categories()
    selected_category = Category.objects.get(id=category_id)

    currencies_form = CurrenciesForm
    article_view = True

    articles = Article.objects.filter(
        category=selected_category.id).exclude(status=get_hidden_status_id())
    return_values = process_article_prices(request, articles)
    articles_list = return_values['articles_list']
    currency_name = return_values['currency_name']

    return render(request, 'webshop/category.html',
                  {'articles_list': articles_list,
                   'category_list': category_list,
                   'currencies_form': currencies_form,
                   'article_view': article_view,
                   'currency_name': currency_name,
                   'category': selected_category})


def article_details(request, article_id):
    category_list = get_categories()
    currencies_form = CurrenciesForm
    amount = AddToCartForm
    rate = ExchangeRate
    article_view = True
    currency_name = "CHF"

    if not 'currency' in request.session:
        request.session['currency'] = None

    article = get_object_or_404(Article, pk=article_id)
    picture_list = Picture.objects.filter(article=article_id)

    if request.method == 'POST':
        # hier wird das Currency dropdown bearbeitet:
        if 'currencies' in request.POST:
            currencies_form = CurrenciesForm(request.POST)
            if currencies_form.is_valid():
                cf = currencies_form.cleaned_data
                if cf['currencies']:
                    selection = cf['currencies']
                    request.session['currency'] = selection.id
                    currency_name = ExchangeRate_name.objects.get(
                        id=selection.id)
                else:
                    request.session['currency'] = None

        # hier wird der Artikel in den Wahrenkorb transferiert:
        if 'amount' in request.POST:
            amount = AddToCartForm(request.POST)
            if amount.is_valid():
                amount = amount.cleaned_data['amount']
                currency_id = request.session['currency']
                article = Article.objects.get(id=article_id)
                try:
                    # lookup if cart_id is already existent:
                    cart_id = ShoppingCart.objects.get(user=request.user)
                except:
                    # if cart_id is not existent create a cart:
                    cart_id = ShoppingCart.objects.create(user=request.user)
                    cart_id.save()
                if cart_id:
                    # check if the article is existent in cart already:
                    try:
                        article_amount = CartPosition.objects.get(
                            article=article_id)
                        new_amount = article_amount.amount + amount
                        # if article is in cart already update amount:
                        cart_position = CartPosition.objects.filter(
                            id=article_id).update(
                            amount=new_amount
                            )
                    except Exception as e:
                        # if the article is not in cart yet add full item:
                        cart_position = CartPosition.objects.create(
                            article=article,
                            amount=amount,
                            position_price=article.price_in_chf,
                            cart=ShoppingCart.objects.get(user=request.user)
                            )
                        cart_position.save()
                # write default value (1) to form field:
                amount = AddToCartForm()
        else:
            amount = AddToCartForm()

    if request.session['currency']:
        currency = request.session['currency']
        article.price_in_chf = rate.exchange(currency, article.price_in_chf)
        currency_name = ExchangeRate_name.objects.get(id=currency)

    return render(request, 'webshop/article_details.html',
                  {'article': article,
                   'category_list': category_list,
                   'currencies_form': currencies_form,
                   'article_view': article_view,
                   'currency_name': currency_name,
                   'picture_list': picture_list,
                   'amount': amount
                   })


@login_required
def profile(request):
    category_list = get_categories()
    person = Person.objects.get(user=request.user)
    return render(request, 'registration/profile.html',
                  {'person': person,
                   'category_list': category_list})


def registration(request):
    category_list = get_categories()
    if request.method == 'POST':
            profile_form = RegistrationForm(request.POST)
            user_form = UserCreationForm(request.POST)
            if (profile_form.is_valid() and user_form.is_valid()):
                with transaction.atomic():
                    pf = profile_form.cleaned_data
                    uf = user_form.cleaned_data
                    user = User.objects.create_user(uf['username'],
                                                    pf['email'],
                                                    uf['password2'])
                    user.last_name = pf['last_name']
                    user.first_name = pf['first_name']
                    user.save()
                    person = Person.objects.create(
                        salutation=pf['salutation'],
                        city=City.objects.get(zip_code=pf['zip_code'],
                                            name=pf['city']),
                        street_name=pf['street_name'],
                        street_number=pf['street_number'],
                        user=user)
                return HttpResponseRedirect('/login/')
    else:
        profile_form = RegistrationForm
        user_form = UserCreationForm
    return render(request, 'registration/register.html',
                  {'profile_form': profile_form,
                   'category_list': category_list,
                   'user_form': user_form})


def cart(request):
    category_list = get_categories()
    currencies_form = CurrenciesForm
    cart_form = CartForm
    rate = ExchangeRate
    article_view = True
    currency_name = "CHF"
    message = ""
    articles_list = ""
    prices_in_cart = []
    totalprice_list = []
    total = 0

    if not 'currency' in request.session:
        request.session['currency'] = None
    else:
        currency = request.session['currency']

    if request.method == 'POST':
        print(request.POST)
        # here we react to a currency dropdown change:
        if 'currencies' in request.POST:
            print('currencies')
            currencies_form = CurrenciesForm(request.POST)
            if currencies_form.is_valid():
                cf = currencies_form.cleaned_data
                if cf['currencies']:
                    selection = cf['currencies']
                    request.session['currency'] = selection.id
                    currency_name = ExchangeRate_name.objects.get(
                        id=selection.id)
                else:
                    request.session['currency'] = None
        # here we react to a change of amount per item in the Cart:
        if 'amountfield' in request.POST:
            print('yes amount post')

            if amount.is_valid():
                amount = amount.cleaned_data['amount']
                article = Article.objects.get(id=article_id)
                try:
                    cart_id = ShoppingCart.objects.get(user=request.user)
                except:
                    cart_id = ShoppingCart.objects.create(user=request.user)
                    cart_id.save()
                if cart_id:
                    cart_position = CartPosition.objects.create(
                        article=article,
                        amount=amount,
                        cart=ShoppingCart.objects.get(user=request.user)
                        )
                    cart_position.save()
                amount = CartForm.ChangeAmount()

        if 'checkout' in request.POST:
            print('checkout')
            checkout_form = CheckoutForm(request.POST)
            if checkout_form.is_valid():
                checkout_form = checkout_form.cleaned_data['checkout']
                print('views checkout checkout_form', checkout_form)
                if checkout_form is True:
                    # add to order
                    order = ''

    checkout_form = CheckoutForm()
    # if the cart_id is set the user has already added items to cart.
    try:
        cart_id = ShoppingCart.objects.get(user=request.user.id)
    except Exception as e:
        message = "You have no items in the Basket"
        print('try cart_id exception as: ', e)
        cart_id = False
    if cart_id:
        print('cart_id', cart_id)
        articles = CartPosition.objects.filter(cart=cart_id)
        cart_position_list = list(articles)
        # scrap out the details to calculate Total of item and Summ of All:
        for idx, cart_position in enumerate(cart_position_list):
            cart_position.calculate_position_price()
            if currency:
                cart_position.price_in_chf = rate.exchange(
                    currency, cart_position.article.price_in_chf)
                # get currencyname to display:
                currency_name = ExchangeRate_name.objects.get(id=currency)
                # get exchange_rate multiplyed:
                cart_position.article.price_in_chf = rate.exchange(
                                                    currency,
                                                    cart_position.article.price_in_chf)
            amount = cart_form.change_amount(request.POST,
                                            cart_position.article)
            totalprice_list.append(cart_position.position_price)
            cart_position_list[idx] = cart_position

    total = sum(totalprice_list)

    return render(request, 'webshop/cart.html',
                  {'cart_position_list': cart_position_list,
                   'totalprice_list': totalprice_list,
                   'total': total,
                   'cart_form': cart_form,
                   'currencies_form': currencies_form,
                   'checkout_form': checkout_form,
                   'article_view': article_view,
                   'currency_name': currency_name,
                   'category_list': category_list,
                   'message': message,
                   })