''' make a list of books!! '''
from django.apps import apps
from django.db import models

from bookwyrm import activitypub
from bookwyrm.settings import DOMAIN
from .activitypub_mixin import CollectionItemMixin, OrderedCollectionMixin
from .base_model import BookWyrmModel
from . import fields


CurationType = models.TextChoices('Curation', [
    'closed',
    'open',
    'curated',
])

class List(OrderedCollectionMixin, BookWyrmModel):
    ''' a list of books '''
    name = fields.CharField(max_length=100)
    user = fields.ForeignKey(
        'User', on_delete=models.PROTECT, activitypub_field='owner')
    description = fields.TextField(
        blank=True, null=True, activitypub_field='summary')
    privacy = fields.PrivacyField()
    curation = fields.CharField(
        max_length=255,
        default='closed',
        choices=CurationType.choices
    )
    books = models.ManyToManyField(
        'Edition',
        symmetrical=False,
        through='ListItem',
        through_fields=('book_list', 'book'),
    )
    activity_serializer = activitypub.BookList

    def get_remote_id(self):
        ''' don't want the user to be in there in this case '''
        return 'https://%s/list/%d' % (DOMAIN, self.id)

    @property
    def collection_queryset(self):
        ''' list of books for this shelf, overrides OrderedCollectionMixin  '''
        return self.books.filter(
            listitem__approved=True
        ).all().order_by('listitem')

    class Meta:
        ''' default sorting '''
        ordering = ('-updated_date',)


class ListItem(CollectionItemMixin, BookWyrmModel):
    ''' ok '''
    book = fields.ForeignKey(
        'Edition', on_delete=models.PROTECT, activitypub_field='object')
    book_list = fields.ForeignKey(
        'List', on_delete=models.CASCADE, activitypub_field='target')
    user = fields.ForeignKey(
        'User',
        on_delete=models.PROTECT,
        activitypub_field='actor'
    )
    notes = fields.TextField(blank=True, null=True)
    approved = models.BooleanField(default=True)
    order = fields.IntegerField(blank=True, null=True)
    endorsement = models.ManyToManyField('User', related_name='endorsers')

    activity_serializer = activitypub.AddListItem
    object_field = 'book'
    collection_field = 'book_list'

    def save(self, *args, **kwargs):
        ''' create a notification too '''
        created = not bool(self.id)
        super().save(*args, **kwargs)
        list_owner = self.book_list.user
        # create a notification if somoene ELSE added to a local user's list
        if created and list_owner.local and list_owner != self.user:
            model = apps.get_model('bookwyrm.Notification', require_ready=True)
            model.objects.create(
                user=list_owner,
                related_user=self.user,
                related_list_item=self,
                notification_type='ADD',
            )


    class Meta:
        ''' an opinionated constraint! you can't put a book on a list twice '''
        unique_together = ('book', 'book_list')
        ordering = ('-created_date',)