"""News app models."""
from django.db import models
from django.contrib.contenttypes import fields as generic
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from rest_framework.reverse import reverse
from utils.models import BaseAttributes, TJSONField, TranslatedFieldsMixin


class NewsType(models.Model):
    """NewsType model."""

    name = models.CharField(_('name'), max_length=250)

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

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

    def __str__(self):
        """Overrided __str__ method."""
        return self.name


class NewsQuerySet(models.QuerySet):
    """QuerySet for model News"""

    def with_base_related(self):
        """Return qs with related objects."""
        return self.select_related('news_type', 'country').prefetch_related('tags')

    def with_extended_related(self):
        """Return qs with related objects."""
        return self.select_related('created_by')

    def by_type(self, news_type):
        """Filter News by type"""
        return self.filter(news_type__name=news_type)

    def by_tags(self, tags):
        return self.filter(tags__in=tags)

    def by_country_code(self, code):
        """Filter collection by country code."""
        return self.filter(country__code=code)

    def published(self):
        """Return only published news"""
        now = timezone.now()
        return self.filter(models.Q(models.Q(end__gte=now) |
                                    models.Q(end__isnull=True)),
                           state__in=self.model.PUBLISHED_STATES, start__lte=now)

    # todo: filter by best score
    # todo: filter by country?
    def should_read(self, news):
        return self.model.objects.exclude(pk=news.pk).published().\
            with_base_related().by_type(news.news_type).distinct().order_by('?')

    def same_theme(self, news):
        return self.model.objects.exclude(pk=news.pk).published().\
            with_base_related().by_type(news.news_type).\
            by_tags(news.tags.all()).distinct().order_by('-start')


class News(BaseAttributes, TranslatedFieldsMixin):
    """News model."""

    STR_FIELD_NAME = 'title'

    # TEMPLATE CHOICES
    NEWSPAPER = 0
    MAIN_PDF_ERB = 1
    MAIN = 2

    TEMPLATE_CHOICES = (
        (NEWSPAPER, 'newspaper'),
        (MAIN_PDF_ERB, 'main.pdf.erb'),
        (MAIN, 'main'),
    )

    # STATE CHOICES
    WAITING = 0
    HIDDEN = 1
    PUBLISHED = 2
    PUBLISHED_EXCLUSIVE = 3

    PUBLISHED_STATES = [PUBLISHED, PUBLISHED_EXCLUSIVE]

    STATE_CHOICES = (
        (WAITING, _('Waiting')),
        (HIDDEN, _('Hidden')),
        (PUBLISHED, _('Published')),
        (PUBLISHED_EXCLUSIVE, _('Published exclusive')),
    )

    news_type = models.ForeignKey(NewsType, on_delete=models.PROTECT,
                                  verbose_name=_('news type'))
    title = TJSONField(blank=True, null=True, default=None,
                       verbose_name=_('title'),
                       help_text='{"en-GB":"some text"}')
    subtitle = TJSONField(blank=True, null=True, default=None,
                          verbose_name=_('subtitle'),
                          help_text='{"en-GB":"some text"}')
    description = TJSONField(blank=True, null=True, default=None,
                             verbose_name=_('description'),
                             help_text='{"en-GB":"some text"}')
    start = models.DateTimeField(verbose_name=_('Start'))
    end = models.DateTimeField(blank=True, null=True, default=None,
                               verbose_name=_('End'))
    slug = models.SlugField(unique=True, max_length=50,
                            verbose_name=_('News slug'))
    playlist = models.IntegerField(_('playlist'))
    state = models.PositiveSmallIntegerField(default=WAITING, choices=STATE_CHOICES,
                                             verbose_name=_('State'))
    is_highlighted = models.BooleanField(default=False,
                                         verbose_name=_('Is highlighted'))
    # TODO: metadata_keys - описание ключей для динамического построения полей метаданных
    # TODO: metadata_values - Описание значений для динамических полей из MetadataKeys
    image_url = models.URLField(blank=True, null=True, default=None,
                                verbose_name=_('Image URL path'))
    preview_image_url = models.URLField(blank=True, null=True, default=None,
                                        verbose_name=_('Preview image URL path'))
    template = models.PositiveIntegerField(choices=TEMPLATE_CHOICES, default=NEWSPAPER)
    address = models.ForeignKey('location.Address', blank=True, null=True,
                                default=None, verbose_name=_('address'),
                                on_delete=models.SET_NULL)
    country = models.ForeignKey('location.Country', blank=True, null=True,
                                on_delete=models.SET_NULL,
                                verbose_name=_('country'))
    tags = generic.GenericRelation(to='main.MetaDataContent')

    objects = NewsQuerySet.as_manager()

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

        verbose_name = _('news')
        verbose_name_plural = _('news')

    def __str__(self):
        return f'news: {self.slug}'

    @property
    def is_publish(self):
        return self.state in self.PUBLISHED_STATES

    @property
    def web_url(self):
        return reverse('web:news:rud', kwargs={'slug': self.slug})

    @property
    def should_read(self):
        return self.__class__.objects.should_read(self)[:3]

    @property
    def same_theme(self):
        return self.__class__.objects.same_theme(self)[:3]