''' database schema for user data '''
from urllib.parse import urlparse

from django.contrib.auth.models import AbstractUser
from django.db import models
from django.dispatch import receiver

from bookwyrm import activitypub
from bookwyrm.connectors import get_data
from bookwyrm.models.shelf import Shelf
from bookwyrm.models.status import Status, Review
from bookwyrm.settings import DOMAIN
from bookwyrm.signatures import create_key_pair
from bookwyrm.tasks import app
from .base_model import OrderedCollectionPageMixin
from .base_model import ActivitypubMixin, BookWyrmModel
from .federated_server import FederatedServer
from . import fields


class User(OrderedCollectionPageMixin, AbstractUser):
    ''' a user who wants to read books '''
    username = fields.UsernameField()

    key_pair = fields.OneToOneField(
        'KeyPair',
        on_delete=models.CASCADE,
        blank=True, null=True,
        activitypub_field='publicKey',
        related_name='owner'
    )
    inbox = fields.RemoteIdField(unique=True)
    shared_inbox = fields.RemoteIdField(
        activitypub_field='sharedInbox',
        activitypub_wrapper='endpoints', null=True)
    federated_server = models.ForeignKey(
        'FederatedServer',
        on_delete=models.PROTECT,
        null=True,
        blank=True,
    )
    outbox = fields.RemoteIdField(unique=True)
    summary = fields.TextField(default='')
    local = models.BooleanField(default=False)
    bookwyrm_user = fields.BooleanField(default=True)
    localname = models.CharField(
        max_length=255,
        null=True,
        unique=True
    )
    # name is your display name, which you can change at will
    name = fields.CharField(max_length=100, default='')
    avatar = fields.ImageField(
        upload_to='avatars/', blank=True, null=True, activitypub_field='icon')
    followers = fields.ManyToManyField(
        'self',
        link_only=True,
        symmetrical=False,
        through='UserFollows',
        through_fields=('user_object', 'user_subject'),
        related_name='following'
    )
    follow_requests = models.ManyToManyField(
        'self',
        symmetrical=False,
        through='UserFollowRequest',
        through_fields=('user_subject', 'user_object'),
        related_name='follower_requests'
    )
    blocks = models.ManyToManyField(
        'self',
        symmetrical=False,
        through='UserBlocks',
        through_fields=('user_subject', 'user_object'),
        related_name='blocked_by'
    )
    favorites = models.ManyToManyField(
        'Status',
        symmetrical=False,
        through='Favorite',
        through_fields=('user', 'status'),
        related_name='favorite_statuses'
    )
    remote_id = fields.RemoteIdField(
        null=True, unique=True, activitypub_field='id')
    created_date = models.DateTimeField(auto_now_add=True)
    updated_date = models.DateTimeField(auto_now=True)
    last_active_date = models.DateTimeField(auto_now=True)
    manually_approves_followers = fields.BooleanField(default=False)

    @property
    def display_name(self):
        ''' show the cleanest version of the user's name possible '''
        if self.name != '':
            return self.name
        return self.localname or self.username

    activity_serializer = activitypub.Person

    def to_outbox(self, **kwargs):
        ''' an ordered collection of statuses '''
        queryset = Status.objects.filter(
            user=self,
            deleted=False,
        ).select_subclasses()
        return self.to_ordered_collection(queryset, \
                remote_id=self.outbox, **kwargs)

    def to_following_activity(self, **kwargs):
        ''' activitypub following list '''
        remote_id = '%s/following' % self.remote_id
        return self.to_ordered_collection(self.following.all(), \
                remote_id=remote_id, id_only=True, **kwargs)

    def to_followers_activity(self, **kwargs):
        ''' activitypub followers list '''
        remote_id = '%s/followers' % self.remote_id
        return self.to_ordered_collection(self.followers.all(), \
                remote_id=remote_id, id_only=True, **kwargs)

    def to_activity(self):
        ''' override default AP serializer to add context object
            idk if this is the best way to go about this '''
        activity_object = super().to_activity()
        activity_object['@context'] = [
            'https://www.w3.org/ns/activitystreams',
            'https://w3id.org/security/v1',
            {
                'manuallyApprovesFollowers': 'as:manuallyApprovesFollowers',
                'schema': 'http://schema.org#',
                'PropertyValue': 'schema:PropertyValue',
                'value': 'schema:value',
            }
        ]
        return activity_object


    def save(self, *args, **kwargs):
        ''' populate fields for new local users '''
        # this user already exists, no need to populate fields
        if self.id:
            return super().save(*args, **kwargs)

        if not self.local:
            # generate a username that uses the domain (webfinger format)
            actor_parts = urlparse(self.remote_id)
            self.username = '%s@%s' % (self.username, actor_parts.netloc)
            return super().save(*args, **kwargs)

        # populate fields for local users
        self.remote_id = 'https://%s/user/%s' % (DOMAIN, self.username)
        self.localname = self.username
        self.username = '%s@%s' % (self.username, DOMAIN)
        self.actor = self.remote_id
        self.inbox = '%s/inbox' % self.remote_id
        self.shared_inbox = 'https://%s/inbox' % DOMAIN
        self.outbox = '%s/outbox' % self.remote_id

        return super().save(*args, **kwargs)


class KeyPair(ActivitypubMixin, BookWyrmModel):
    ''' public and private keys for a user '''
    private_key = models.TextField(blank=True, null=True)
    public_key = fields.TextField(
        blank=True, null=True, activitypub_field='publicKeyPem')

    activity_serializer = activitypub.PublicKey
    serialize_reverse_fields = ['owner']

    def get_remote_id(self):
        # self.owner is set by the OneToOneField on User
        return '%s/#main-key' % self.owner.remote_id

    def save(self, *args, **kwargs):
        ''' create a key pair '''
        self.private_key, self.public_key = create_key_pair()
        return super().save(*args, **kwargs)

    def to_activity(self):
        ''' override default AP serializer to add context object
            idk if this is the best way to go about this '''
        activity_object = super().to_activity()
        del activity_object['@context']
        del activity_object['type']
        return activity_object


@receiver(models.signals.post_save, sender=User)
def execute_after_save(sender, instance, created, *args, **kwargs):
    ''' create shelves for new users '''
    if not created:
        return

    if not instance.local:
        set_remote_server.delay(instance.id)

    instance.key_pair = KeyPair.objects.create(
        remote_id='%s/#main-key' % instance.remote_id)

    shelves = [{
        'name': 'To Read',
        'identifier': 'to-read',
    }, {
        'name': 'Currently Reading',
        'identifier': 'reading',
    }, {
        'name': 'Read',
        'identifier': 'read',
    }]

    for shelf in shelves:
        Shelf(
            name=shelf['name'],
            identifier=shelf['identifier'],
            user=instance,
            editable=False
        ).save()


@app.task
def set_remote_server(user_id):
    ''' figure out the user's remote server in the background '''
    user = User.objects.get(id=user_id)
    actor_parts = urlparse(user.remote_id)
    user.federated_server = \
        get_or_create_remote_server(actor_parts.netloc)
    user.save()
    if user.bookwyrm_user:
        get_remote_reviews.delay(user.outbox)


def get_or_create_remote_server(domain):
    ''' get info on a remote server '''
    try:
        return FederatedServer.objects.get(
            server_name=domain
        )
    except FederatedServer.DoesNotExist:
        pass

    data = get_data('https://%s/.well-known/nodeinfo' % domain)

    try:
        nodeinfo_url = data.get('links')[0].get('href')
    except (TypeError, KeyError):
        return None

    data = get_data(nodeinfo_url)

    server = FederatedServer.objects.create(
        server_name=domain,
        application_type=data['software']['name'],
        application_version=data['software']['version'],
    )
    return server


@app.task
def get_remote_reviews(outbox):
    ''' ingest reviews by a new remote bookwyrm user '''
    outbox_page = outbox + '?page=true'
    data = get_data(outbox_page)

    # TODO: pagination?
    for activity in data['orderedItems']:
        if not activity['type'] == 'Review':
            continue
        activitypub.Review(**activity).to_model(Review)