# -*- coding: utf-8 -*-
from django.shortcuts import get_object_or_404
from django.utils.decorators import method_decorator
from django.views.decorators.csrf import csrf_protect
from django.forms.models import model_to_dict

from ..models import Invoice, InvoiceItem
from ..forms import InvoiceForm, InvoiceItemForm


class AddByInvoiceMethodMixin(object):
    """Mixin: добавляет метод add_by_invoice."""

    @method_decorator(csrf_protect)
    def add_by_invoice(self, *args, **kwargs):
        """Добавить документ по Счёту."""
        invoice_id = (kwargs['invoice_id'])
        invoice = get_object_or_404(Invoice, pk=invoice_id, user=self.request.user)
        invoice_items = InvoiceItem.objects.filter(parent=invoice).select_related()

        kwargs['initial'] = model_to_dict(
            invoice,
            fields=getattr(InvoiceForm.Meta, 'fields', None),
            exclude=getattr(InvoiceItemForm.Meta, 'exclude', None)
        )
        kwargs['initial'].update(self.init_form())
        kwargs['initial']['invoice'] = invoice

        if invoice_items:
            kwargs['initial_items'] = []
            for item in invoice_items:
                kwargs['initial_items'].append(
                    model_to_dict(
                        item,
                        fields=getattr(InvoiceItemForm.Meta, 'fields', None),
                        exclude=getattr(InvoiceItemForm.Meta, 'exclude', None)
                    ))

        return self.add(self.request, *args, **kwargs)