from django.conf import settings
from django.urls import reverse_lazy
from django.utils.translation import ugettext_lazy as _
from django.db import models

from mptt import (
    models as mptt_models,
    managers as mptt_managers,
)

# Create your models here.
STATUS_NEW = 0
STATUS_ACTIVE = 25
STATUS_DELETED = 50

STATUS_DEFAULT = STATUS_NEW

STATUS_CHOICES = (
    (STATUS_NEW, _('Новый')),
    (STATUS_ACTIVE, _('Активный')),
    (STATUS_DELETED, _('Удаленный')),
)


class CaseInsensitiveQuerySet(models.QuerySet):
    CASE_INSENSITIVE_FIELDS = ('email',)

    def _filter_or_exclude(self, negate, *args, **kwargs):
        for field in self.CASE_INSENSITIVE_FIELDS:
            if field in kwargs:
                kwargs[field + '__iexact'] = kwargs[field]
                del kwargs[field]
        return super()._filter_or_exclude(negate, *args, **kwargs)


class ActualOnlyManager(models.Manager):
    def get_queryset(self):
        queryset = super().get_queryset()
        if not settings.DEBUG:
            queryset = queryset.exclude(status=STATUS_DELETED)
        return queryset


class ActiveOnlyManager(models.Manager):
    def get_queryset(self):
        return super().get_queryset().filter(status=STATUS_ACTIVE)


class DeletedManager(models.Manager):
    def get_queryset(self):
        return super().get_queryset().filter(status=STATUS_DELETED)


class ActualOnlyTreeManager(mptt_managers.TreeManager, ActualOnlyManager):
    _base_manager = None


class ActiveOnlyTreeManager(mptt_managers.TreeManager, ActiveOnlyManager):
    _base_manager = None


class DeletedTreeManager(mptt_managers.TreeManager, DeletedManager):
    _base_manager = None


class AbstractDateTimeModel(models.Model):
    create_at = models.DateTimeField(_('создан в'), auto_now_add=True)
    updated_at = models.DateTimeField(_('обновлен'), auto_now=True)

    class Meta:
        abstract = True


# @TODO: translate into english and use translation
class AbstractStatusModel(AbstractDateTimeModel):
    status = models.SmallIntegerField(_('статус'), default=STATUS_DEFAULT, choices=STATUS_CHOICES)

    objects = ActualOnlyManager()
    deleted = DeletedManager()
    active = ActiveOnlyManager()

    @property
    def is_active(self):
        return self.status == STATUS_ACTIVE

    @is_active.setter
    def is_active(self, value):
        if value:
            self.status = STATUS_ACTIVE
        else:
            self.status = STATUS_DEFAULT

    def delete(self, using=None, keep_parents=False):
        self.status = STATUS_DELETED
        self.save(using=using)

    def delete_from_base(self, using=None, keep_parents=False):
        return super().delete(using, keep_parents)

    class Meta:
        abstract = True


class AbstractStatusMPTTModel(mptt_models.MPTTModel, AbstractStatusModel):
    objects = ActualOnlyTreeManager()
    deleted = DeletedTreeManager()
    active = ActiveOnlyTreeManager()

    @property
    def viewname(self):
        raise NotImplementedError

    @property
    def viewname_kwargs(self):
        raise NotImplementedError

    def get_absolute_url(self):
        return reverse_lazy(self.viewname, kwargs=self.viewname_kwargs)

    class Meta:
        abstract = True


class Currency(AbstractDateTimeModel):
    name = models.CharField(_('название'), max_length=255)
    code = models.CharField(_('код валюты'), max_length=64)
    sign = models.CharField(_('символ валюты'), max_length=10, blank=True, null=True)
    value = models.DecimalField(_('Курс'), max_digits=6, decimal_places=2, help_text=_('Указывается в рублях'))

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = _('Валюта')
        verbose_name_plural = _('Валюта')


class City(AbstractDateTimeModel):
    name = models.CharField(_('Город'), max_length=255)

    class Meta:
        verbose_name = _('Город')
        verbose_name_plural = _('Города')


class Certificate(AbstractStatusModel):
    def upload_file_to(self, filename):
        return "certificates/{filename}".format(**{
            'category': self.name,
            'filename': filename
        })

    name = models.CharField(_('Название'), max_length=255)
    image = models.FileField(_('Изображение'), upload_to=upload_file_to, blank=True, null=True)
    preview = models.FileField(_('Миниатюрка'), upload_to=upload_file_to)

    class Meta:
        verbose_name = _('Сертификат')
        verbose_name_plural = _('Сертификаты')