''' 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


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(user)
    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]


def get_remote_reviews(user):
    ''' ingest reviews by a new remote bookwyrm user '''
    outbox_page = user.outbox + '?page=true'
    response = requests.get(
        outbox_page,
        headers={'Accept': 'application/activity+json'}
    )
    data = response.json()
    # TODO: pagination?
    for status in data['orderedItems']:
        if status.get('bookwyrmType') == 'Review':
            activitypub.Review(**status).to_model(models.Review)


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