# -*- coding: utf-8 -*-
from django.db import models
from django.db.models import Sum

from django.conf import settings
from pytils.numeral import choose_plural
from docs.models.base_models import BaseInvoiceModel, BaseItemInvoiceModel
from docs.models.linked_docs_mixin import LinkedDocsMixin
from docs import consts


class Invoice(BaseInvoiceModel, LinkedDocsMixin):
    """Счет."""
    UNPAID = 1
    PARTLY_PAID = 2
    PAID = 3

    PAID_CHOICES = (
        (UNPAID, 'Нет'),
        (PARTLY_PAID, 'Частично'),
        (PAID, 'Да'),
    )

    paid_status = models.PositiveSmallIntegerField(
        'Оплачен?',
        choices=PAID_CHOICES,
        default=UNPAID
    )
    closed_status = models.BooleanField('Закрыт?', choices=consts.BOOL_CHOICES, default=False)

    class Meta(BaseInvoiceModel.Meta):
        verbose_name = 'Счёт'
        verbose_name_plural = 'Счета'

    def to_string_for_json(self):
        # Счёт №Х от ХХ.ХХ.ХХ, Х позиций, на сумму ХХ.
        # import ipdb;ipdb.set_trace()
        date_format = settings.DATE_INPUT_FORMATS[0]
        count = self.invoice_items.count()
        str_date = self.doc_date.strftime(format=date_format)

        return '{name} № {number} от {date}, {count} {count_name}, на сумму {sum}'.format(
            name=self._meta.verbose_name or '',
            number=self.doc_num,
            date=str_date,
            count=count or '',
            count_name=choose_plural(count, (u"позиция", u"позиции", u"позиций")),
            sum=self.invoice_items.aggregate(Sum('total_price'))['total_price__sum']
        )

    def __str__(self):
        return self.to_string_for_json()


class InvoiceItem(BaseItemInvoiceModel):
    """Табличная часть счета."""
    parent = models.ForeignKey(Invoice, related_name='invoice_items')

    class Meta(BaseItemInvoiceModel.Meta):
        verbose_name = 'Табл. часть счета'
        verbose_name_plural = 'Табл. части счетов'