import json
import requests

from django.conf import settings

from funkwhale_api.common import session

from . import actors
from . import models
from . import serializers
from . import signing
from . import webfinger


def scan_from_account_name(account_name):
    """
    Given an account name such as library@test.library, will:

    1. Perform the webfinger lookup
    2. Perform the actor lookup
    3. Perform the library's collection lookup

    and return corresponding data in a dictionary.
    """
    data = {}
    try:
        username, domain = webfinger.clean_acct(account_name, ensure_local=False)
    except serializers.ValidationError:
        return {"webfinger": {"errors": ["Invalid account string"]}}
    system_library = actors.SYSTEM_ACTORS["library"].get_actor_instance()
    library = (
        models.Library.objects.filter(
            actor__domain=domain, actor__preferred_username=username
        )
        .select_related("actor")
        .first()
    )
    data["local"] = {"following": False, "awaiting_approval": False}
    try:
        follow = models.Follow.objects.get(
            target__preferred_username=username,
            target__domain=username,
            actor=system_library,
        )
        data["local"]["awaiting_approval"] = not bool(follow.approved)
        data["local"]["following"] = True
    except models.Follow.DoesNotExist:
        pass

    try:
        data["webfinger"] = webfinger.get_resource("acct:{}".format(account_name))
    except requests.ConnectionError:
        return {"webfinger": {"errors": ["This webfinger resource is not reachable"]}}
    except requests.HTTPError as e:
        return {
            "webfinger": {
                "errors": [
                    "Error {} during webfinger request".format(e.response.status_code)
                ]
            }
        }
    except json.JSONDecodeError as e:
        return {"webfinger": {"errors": ["Could not process webfinger response"]}}

    try:
        data["actor"] = actors.get_actor_data(data["webfinger"]["actor_url"])
    except requests.ConnectionError:
        data["actor"] = {"errors": ["This actor is not reachable"]}
        return data
    except requests.HTTPError as e:
        data["actor"] = {
            "errors": ["Error {} during actor request".format(e.response.status_code)]
        }
        return data

    serializer = serializers.LibraryActorSerializer(data=data["actor"])
    if not serializer.is_valid():
        data["actor"] = {"errors": ["Invalid ActivityPub actor"]}
        return data
    data["library"] = get_library_data(serializer.validated_data["library_url"])

    return data


def get_library_data(library_url):
    actor = actors.SYSTEM_ACTORS["library"].get_actor_instance()
    auth = signing.get_auth(actor.private_key, actor.private_key_id)
    try:
        response = session.get_session().get(
            library_url,
            auth=auth,
            timeout=5,
            verify=settings.EXTERNAL_REQUESTS_VERIFY_SSL,
            headers={"Content-Type": "application/activity+json"},
        )
    except requests.ConnectionError:
        return {"errors": ["This library is not reachable"]}
    scode = response.status_code
    if scode == 401:
        return {"errors": ["This library requires authentication"]}
    elif scode == 403:
        return {"errors": ["Permission denied while scanning library"]}
    elif scode >= 400:
        return {"errors": ["Error {} while fetching the library".format(scode)]}
    serializer = serializers.PaginatedCollectionSerializer(data=response.json())
    if not serializer.is_valid():
        return {"errors": ["Invalid ActivityPub response from remote library"]}

    return serializer.validated_data


def get_library_page(library, page_url):
    actor = actors.SYSTEM_ACTORS["library"].get_actor_instance()
    auth = signing.get_auth(actor.private_key, actor.private_key_id)
    response = session.get_session().get(
        page_url,
        auth=auth,
        timeout=5,
        verify=settings.EXTERNAL_REQUESTS_VERIFY_SSL,
        headers={"Content-Type": "application/activity+json"},
    )
    serializer = serializers.CollectionPageSerializer(
        data=response.json(),
        context={"library": library, "item_serializer": serializers.AudioSerializer},
    )
    serializer.is_valid(raise_exception=True)
    return serializer.validated_data