from typing import Any, Dict, Optional, Text, Union, cast

from django.http import HttpRequest, HttpResponse
from django.utils import timezone
from django.utils.translation import ugettext as _

from zerver.lib.exceptions import JsonableError
from zerver.lib.push_notifications import send_android_push_notification, \
    send_apple_push_notification
from zerver.lib.request import REQ, has_request_variables
from zerver.lib.response import json_error, json_success
from zerver.lib.validator import check_int
from zerver.models import UserProfile
from zerver.views.push_notifications import validate_token
from zilencer.models import RemotePushDeviceToken, RemoteZulipServer

def validate_entity(entity: Union[UserProfile, RemoteZulipServer]) -> None:
    if not isinstance(entity, RemoteZulipServer):
        raise JsonableError(_("Must validate with valid Zulip server API key"))

def validate_bouncer_token_request(entity: Union[UserProfile, RemoteZulipServer],
                                   token: bytes, kind: int) -> None:
    if kind not in [RemotePushDeviceToken.APNS, RemotePushDeviceToken.GCM]:
        raise JsonableError(_("Invalid token type"))
    validate_entity(entity)
    validate_token(token, kind)

@has_request_variables
def remote_server_register_push(request: HttpRequest, entity: Union[UserProfile, RemoteZulipServer],
                                user_id: int=REQ(), token: bytes=REQ(),
                                token_kind: int=REQ(validator=check_int),
                                ios_app_id: Optional[Text]=None) -> HttpResponse:
    validate_bouncer_token_request(entity, token, token_kind)
    server = cast(RemoteZulipServer, entity)

    # If a user logged out on a device and failed to unregister,
    # we should delete any other user associations for this token
    # & RemoteServer pair
    RemotePushDeviceToken.objects.filter(
        token=token, kind=token_kind, server=server).exclude(user_id=user_id).delete()

    # Save or update
    remote_token, created = RemotePushDeviceToken.objects.update_or_create(
        user_id=user_id,
        server=server,
        kind=token_kind,
        token=token,
        defaults=dict(
            ios_app_id=ios_app_id,
            last_updated=timezone.now()))

    return json_success()

@has_request_variables
def remote_server_unregister_push(request: HttpRequest, entity: Union[UserProfile, RemoteZulipServer],
                                  token: bytes=REQ(),
                                  token_kind: int=REQ(validator=check_int),
                                  ios_app_id: Optional[Text]=None) -> HttpResponse:
    validate_bouncer_token_request(entity, token, token_kind)
    server = cast(RemoteZulipServer, entity)
    deleted = RemotePushDeviceToken.objects.filter(token=token,
                                                   kind=token_kind,
                                                   server=server).delete()
    if deleted[0] == 0:
        return json_error(_("Token does not exist"))

    return json_success()

@has_request_variables
def remote_server_notify_push(request: HttpRequest, entity: Union[UserProfile, RemoteZulipServer],
                              payload: Dict[str, Any]=REQ(argument_type='body')) -> HttpResponse:
    validate_entity(entity)
    server = cast(RemoteZulipServer, entity)

    user_id = payload['user_id']
    gcm_payload = payload['gcm_payload']
    apns_payload = payload['apns_payload']

    android_devices = list(RemotePushDeviceToken.objects.filter(
        user_id=user_id,
        kind=RemotePushDeviceToken.GCM,
        server=server
    ))

    apple_devices = list(RemotePushDeviceToken.objects.filter(
        user_id=user_id,
        kind=RemotePushDeviceToken.APNS,
        server=server
    ))

    if android_devices:
        send_android_push_notification(android_devices, gcm_payload, remote=True)

    if apple_devices:
        send_apple_push_notification(user_id, apple_devices, apns_payload)

    return json_success()