''' manage remote users '''
from urllib.parse import urlparse
from uuid import uuid4
import requests

from django.core.files.base import ContentFile
from django.db import transaction

from bookwyrm import activitypub, models
from bookwyrm import status as status_builder
from bookwyrm.tasks import app


def get_or_create_remote_user(actor):
    ''' look up a remote user or add them '''
    try:
        return models.User.objects.get(remote_id=actor)
    except models.User.DoesNotExist:
        pass

    data = fetch_user_data(actor)

    actor_parts = urlparse(actor)
    with transaction.atomic():
        user = create_remote_user(data)
        user.federated_server = get_or_create_remote_server(actor_parts.netloc)
        user.save()

    avatar = get_avatar(data)
    if avatar:
        user.avatar.save(*avatar)

    if user.bookwyrm_user:
        get_remote_reviews.delay(user.id)
    return user


def fetch_user_data(actor):
    ''' load the user's info from the actor url '''
    response = requests.get(
        actor,
        headers={'Accept': 'application/activity+json'}
    )
    if not response.ok:
        response.raise_for_status()
    data = response.json()

    # make sure our actor is who they say they are
    if actor != data['id']:
        raise ValueError("Remote actor id must match url.")
    return data


def create_remote_user(data):
    ''' parse the activitypub actor data into a user '''
    actor = activitypub.Person(**data)
    return actor.to_model(models.User)


def refresh_remote_user(user):
    ''' get updated user data from its home instance '''
    data = fetch_user_data(user.remote_id)

    activity = activitypub.Person(**data)
    activity.to_model(models.User, instance=user)


def get_avatar(data):
    ''' find the icon attachment and load the image from the remote sever '''
    icon_blob = data.get('icon')
    if not icon_blob or not icon_blob.get('url'):
        return None

    response = requests.get(icon_blob['url'])
    if not response.ok:
        return None

    image_name = str(uuid4()) + '.' + icon_blob['url'].split('.')[-1]
    image_content = ContentFile(response.content)
    return [image_name, image_content]


@app.task
def get_remote_reviews(user_id):
    ''' ingest reviews by a new remote bookwyrm user '''
    user = models.User.objects.get(id=user_id)
    outbox_page = user.outbox + '?page=true'
    response = requests.get(
        outbox_page,
        headers={'Accept': 'application/activity+json'}
    )
    data = response.json()
    # TODO: pagination?
    for activity in data['orderedItems']:
        status_builder.create_status(activity)


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

    response = requests.get(
        'https://%s/.well-known/nodeinfo' % domain,
        headers={'Accept': 'application/activity+json'}
    )

    if response.status_code != 200:
        return None

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

    response = requests.get(
        nodeinfo_url,
        headers={'Accept': 'application/activity+json'}
    )
    data = response.json()

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