"""Product app models."""
from django.db import models
from django.contrib.contenttypes import fields as generic
from django.core.exceptions import ValidationError
from django.contrib.postgres.fields import JSONField
from django.utils.translation import gettext_lazy as _
from utils.models import (BaseAttributes, ProjectBaseMixin,
                          TranslatedFieldsMixin, TJSONField)


class ProductType(TranslatedFieldsMixin, ProjectBaseMixin):
    """ProductType model."""

    STR_FIELD_NAME = 'name'

    # INDEX NAME CHOICES
    FOOD = 'food'
    WINE = 'wine'
    LIQUOR = 'liquor'

    INDEX_NAME_TYPES = (
        (FOOD, _('Food')),
        (WINE, _('Wine')),
        (LIQUOR, _('Liquor')),
    )

    name = TJSONField(blank=True, null=True, default=None,
                      verbose_name=_('Name'), help_text='{"en-GB":"some text"}')
    index_name = models.CharField(max_length=50, choices=INDEX_NAME_TYPES,
                                  unique=True, db_index=True,
                                  verbose_name=_('Index name'))
    use_subtypes = models.BooleanField(_('Use subtypes'), default=True)

    class Meta:
        """Meta class."""

        verbose_name = _('Product type')
        verbose_name_plural = _('Product types')


class ProductSubType(TranslatedFieldsMixin, ProjectBaseMixin):
    """ProductSubtype model."""

    STR_FIELD_NAME = 'name'

    # INDEX NAME CHOICES
    RUM = 'rum'
    OTHER = 'other'

    INDEX_NAME_TYPES = (
        (RUM, _('Rum')),
        (OTHER, _('Other')),
    )

    product_type = models.ForeignKey(ProductType, on_delete=models.CASCADE,
                                     related_name='subtypes',
                                     verbose_name=_('Product type'))
    name = TJSONField(blank=True, null=True, default=None,
                      verbose_name=_('Name'), help_text='{"en-GB":"some text"}')
    index_name = models.CharField(max_length=50, choices=INDEX_NAME_TYPES,
                                  unique=True, db_index=True,
                                  verbose_name=_('Index name'))

    class Meta:
        """Meta class."""

        verbose_name = _('Product subtype')
        verbose_name_plural = _('Product subtypes')

    def clean_fields(self, exclude=None):
        if not self.product_type.use_subtypes:
            raise ValidationError(_('Product type is not use subtypes.'))


class ProductManager(models.Manager):
    """Extended manager for Product model."""


class ProductQuerySet(models.QuerySet):
    """Product queryset."""

    def with_base_related(self):
        return self.select_related('product_type', 'establishment') \
                   .prefetch_related('product_type__subtypes', 'country')

    def common(self):
        return self.filter(category=self.model.COMMON)

    def online(self):
        return self.filter(category=self.model.ONLINE)

    def wines(self):
        return self.filter(type__index_name=ProductType.WINE)

    def by_product_type(self, product_type: str):
        """Filter by type."""
        return self.filter(product_type__index_name=product_type)

    def by_product_subtype(self, product_subtype: str):
        """Filter by subtype."""
        return self.filter(subtypes__index_name=product_subtype)


class Product(TranslatedFieldsMixin, BaseAttributes):
    """Product models."""

    STR_FIELD_NAME = 'name'

    COMMON = 0
    ONLINE = 1

    CATEGORY_CHOICES = (
        (COMMON, _('Common')),
        (ONLINE, _('Online')),
    )

    category = models.PositiveIntegerField(choices=CATEGORY_CHOICES,
                                           default=COMMON)
    name = TJSONField(_('Name'), null=True, blank=True, default=None,
                      help_text='{"en-GB":"some text"}')
    description = TJSONField(_('Description'), null=True, blank=True,
                             default=None, help_text='{"en-GB":"some text"}')
    characteristics = JSONField(_('Characteristics'))
    country = models.ManyToManyField('location.Country',
                                     verbose_name=_('Country'))
    available = models.BooleanField(_('Available'), default=True)
    product_type = models.ForeignKey(ProductType, on_delete=models.PROTECT,
                                     related_name='products', verbose_name=_('Type'))
    subtypes = models.ManyToManyField(ProductSubType, blank=True,
                                      related_name='products',
                                      verbose_name=_('Subtypes'))
    establishment = models.ForeignKey('establishment.Establishment',
                                      on_delete=models.PROTECT,
                                      related_name='products',
                                      verbose_name=_('establishment'))
    public_mark = models.PositiveIntegerField(blank=True, null=True, default=None,
                                              verbose_name=_('public mark'),)
    wine_region = models.ForeignKey('location.WineRegion', on_delete=models.PROTECT,
                                    related_name='wines',
                                    blank=True, null=True,
                                    verbose_name=_('wine region'))
    wine_appellation = models.ForeignKey('location.WineAppellation', on_delete=models.PROTECT,
                                         blank=True, null=True,
                                         verbose_name=_('wine appellation'))
    slug = models.SlugField(unique=True, max_length=255, null=True,
                            verbose_name=_('Establishment slug'))
    favorites = generic.GenericRelation(to='favorites.Favorites')

    objects = ProductManager.from_queryset(ProductQuerySet)()

    class Meta:
        """Meta class."""

        verbose_name = _('Product')
        verbose_name_plural = _('Products')

    def clean_fields(self, exclude=None):
        super().clean_fields(exclude=exclude)
        if self.product_type.index_name == ProductType.WINE and not self.wine_region:
            raise ValidationError(_('wine_region field must be specified.'))
        if not self.product_type.index_name == ProductType.WINE and self.wine_region:
            raise ValidationError(_('wine_region field must not be specified.'))
        if (self.wine_region and self.wine_appellation) and \
           self.wine_appellation not in self.wine_region.appellations.all():
            raise ValidationError(_('Wine appellation not exists in wine region.'))


class OnlineProductManager(ProductManager):
    """Extended manger for OnlineProduct model."""

    def get_queryset(self):
        """Overridden get_queryset method."""
        return super().get_queryset().online()


class OnlineProduct(Product):
    """Online product."""

    objects = OnlineProductManager.from_queryset(ProductQuerySet)()

    class Meta:
        """Meta class."""

        proxy = True
        verbose_name = _('Online product')
        verbose_name_plural = _('Online products')