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

from rating.models import Rating, ViewCount
from utils.models import (BaseAttributes, TJSONField, TranslatedFieldsMixin, HasTagsMixin,
                          ProjectBaseMixin, GalleryModelMixin, IntermediateGalleryModelMixin,
                          FavoritesMixin)
from utils.querysets import TranslationQuerysetMixin
from django.conf import settings


class Agenda(ProjectBaseMixin, TranslatedFieldsMixin):
    """News agenda model"""

    event_datetime = models.DateTimeField(default=timezone.now, editable=False,
                                          verbose_name=_('Event datetime'))
    address = models.ForeignKey('location.Address', blank=True, null=True,
                                default=None, verbose_name=_('address'),
                                on_delete=models.SET_NULL)
    content = TJSONField(blank=True, null=True, default=None,
                         verbose_name=_('content'),
                         help_text='{"en-GB":"some text"}')


class NewsBanner(ProjectBaseMixin, TranslatedFieldsMixin):
    """News banner model"""
    title = TJSONField(blank=True, null=True, default=None,
                       verbose_name=_('title'),
                       help_text='{"en-GB":"some text"}')
    image_url = models.URLField(verbose_name=_('Image URL path'),
                                blank=True, null=True, default=None)
    content_url = models.URLField(verbose_name=_('Content URL path'),
                                  blank=True, null=True, default=None)


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

    name = models.CharField(_('name'), max_length=250)
    tag_categories = models.ManyToManyField('tag.TagCategory',
                                            related_name='news_types')

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

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

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


class NewsQuerySet(TranslationQuerysetMixin):
    """QuerySet for model News"""

    def sort_by_start(self):
        """Return qs sorted by start DESC"""
        return self.order_by('-start')

    def rating_value(self):
        return self.annotate(rating=models.Count('ratings__ip', distinct=True))

    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', 'agenda', 'banner')

    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 recipe_news(self):
        """Returns news with tag 'cook' qs."""
        return self.filter(tags__value=News.RECIPES_TAG_VALUE)

    def international_news(self):
        """Returns only international news qs."""
        return self.filter(tags__value=News.INTERNATIONAL_TAG_VALUE)

    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, user):
        return self.model.objects.exclude(pk=news.pk).published(). \
            annotate_in_favorites(user). \
            with_base_related().by_type(news.news_type).distinct().order_by('?')

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

    def annotate_in_favorites(self, user):
        """Annotate flag in_favorites"""
        favorite_news_ids = []
        if user.is_authenticated:
            favorite_news_ids = user.favorite_news_ids
        return self.annotate(
            in_favorites=Case(
                When(id__in=favorite_news_ids, then=True),
                default=False,
                output_field=models.BooleanField(default=False)
            )
        )


class News(GalleryModelMixin, BaseAttributes, TranslatedFieldsMixin, HasTagsMixin,
           FavoritesMixin):
    """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')),
    )

    INTERNATIONAL_TAG_VALUE = 'international'
    RECIPES_TAG_VALUE = 'cook'

    old_id = models.PositiveIntegerField(_('old id'), blank=True, null=True, default=None)
    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=255,
                            verbose_name=_('News slug'))
    state = models.PositiveSmallIntegerField(default=WAITING, choices=STATE_CHOICES,
                                             verbose_name=_('State'))
    is_highlighted = models.BooleanField(default=False,
                                         verbose_name=_('Is highlighted'))
    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 = models.ManyToManyField('tag.Tag', related_name='news',
                                  verbose_name=_('Tags'))
    gallery = models.ManyToManyField('gallery.Image', through='news.NewsGallery')
    views_count = models.OneToOneField('rating.ViewCount', blank=True, null=True, on_delete=models.SET_NULL)
    ratings = generic.GenericRelation(Rating)
    favorites = generic.GenericRelation(to='favorites.Favorites')
    agenda = models.ForeignKey('news.Agenda', blank=True, null=True,
                               on_delete=models.SET_NULL,
                               verbose_name=_('agenda'))

    banner = models.ForeignKey('news.NewsBanner', blank=True, null=True,
                               on_delete=models.SET_NULL,
                               verbose_name=_('banner'))

    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})

    def should_read(self, user):
        return self.__class__.objects.should_read(self, user)[:3]

    def same_theme(self, user):
        return self.__class__.objects.same_theme(self, user)[:3]

    @property
    def main_image(self):
        qs = self.news_gallery.main_image()
        if qs.exists():
            return qs.first().image

    @property
    def image_url(self):
        return self.main_image.image.url if self.main_image else None

    @property
    def preview_image_url(self):
        if self.main_image:
            return self.main_image.get_image_url(thumbnail_key='news_preview')

    @property
    def view_counter(self):
        count_value = 0
        if self.views_count:
            count_value = self.views_count.count
        return count_value

    # todo: remove in future
    @property
    def crop_gallery(self):
        if hasattr(self, 'gallery'):
            gallery = []
            images = self.gallery.all()
            model_name = self._meta.model_name.lower()
            crop_parameters = [p for p in settings.SORL_THUMBNAIL_ALIASES
                               if p.startswith(model_name)]
            for image in images:
                d = {
                    'id': image.id,
                    'title': image.title,
                    'original_url': image.image.url,
                    'orientation_display': image.get_orientation_display(),
                    'auto_crop_images': {},
                }
                for crop in crop_parameters:
                    d['auto_crop_images'].update(
                        {f'{crop[len(f"{model_name}_"):]}_url': image.get_image_url(crop)})
                gallery.append(d)
            return gallery

    @property
    def crop_main_image(self):
        if hasattr(self, 'main_image') and self.main_image:
            image = self.main_image
            model_name = self._meta.model_name.lower()
            image_property = {
                'id': image.id,
                'title': image.title,
                'original_url': image.image.url,
                'orientation_display': image.get_orientation_display(),
                'auto_crop_images': {},
            }
            crop_parameters = [p for p in settings.SORL_THUMBNAIL_ALIASES
                               if p.startswith(self._meta.model_name.lower())]
            for crop in crop_parameters:
                image_property['auto_crop_images'].update(
                    {f'{crop[len(f"{model_name}_"):]}_url': image.get_image_url(crop)})
            return image_property


class NewsGallery(IntermediateGalleryModelMixin):

    news = models.ForeignKey(News, null=True,
                             related_name='news_gallery',
                             on_delete=models.CASCADE,
                             verbose_name=_('news'))
    image = models.ForeignKey('gallery.Image', null=True,
                              related_name='news_gallery',
                              on_delete=models.CASCADE,
                              verbose_name=_('gallery'))

    class Meta:
        """NewsGallery meta class."""
        verbose_name = _('news gallery')
        verbose_name_plural = _('news galleries')
        unique_together = (('news', 'is_main'), ('news', 'image'))