# -*- coding: utf-8 -*-

import base64
import binascii
import logging
import lxml.html
import re
import time

from typing import Any, Dict, List, Optional, Tuple, Union, cast

from django.conf import settings
from django.db import IntegrityError, transaction
from django.db.models import F
from django.utils.timezone import now as timezone_now
from django.utils.translation import ugettext as _
import gcm
import requests
import ujson

from zerver.decorator import statsd_increment
from zerver.lib.avatar import absolute_avatar_url
from zerver.lib.exceptions import JsonableError
from zerver.lib.message import access_message, \
    bulk_access_messages_expect_usermessage, huddle_users
from zerver.lib.queue import retry_event
from zerver.lib.remote_server import send_to_push_bouncer, send_json_to_push_bouncer
from zerver.lib.timestamp import datetime_to_timestamp
from zerver.models import PushDeviceToken, Message, Realm, Recipient, \
    UserMessage, UserProfile, \
    get_display_recipient, receives_offline_push_notifications, \
    receives_online_notifications, get_user_profile_by_id, \
    ArchivedMessage

logger = logging.getLogger(__name__)

if settings.ZILENCER_ENABLED:
    from zilencer.models import RemotePushDeviceToken
else:  # nocoverage  -- Not convenient to add test for this.
    from mock import Mock
    RemotePushDeviceToken = Mock()  # type: ignore # https://github.com/JukkaL/mypy/issues/1188

DeviceToken = Union[PushDeviceToken, RemotePushDeviceToken]

# We store the token as b64, but apns-client wants hex strings
def b64_to_hex(data: bytes) -> str:
    return binascii.hexlify(base64.b64decode(data)).decode('utf-8')

def hex_to_b64(data: str) -> bytes:
    return base64.b64encode(binascii.unhexlify(data.encode('utf-8')))

#
# Sending to APNs, for iOS
#

_apns_client = None  # type: Optional[Any]
_apns_client_initialized = False

def get_apns_client() -> Any:
    # We lazily do this import as part of optimizing Zulip's base
    # import time.
    from apns2.client import APNsClient
    global _apns_client, _apns_client_initialized
    if not _apns_client_initialized:
        # NB if called concurrently, this will make excess connections.
        # That's a little sloppy, but harmless unless a server gets
        # hammered with a ton of these all at once after startup.
        if settings.APNS_CERT_FILE is not None:
            _apns_client = APNsClient(credentials=settings.APNS_CERT_FILE,
                                      use_sandbox=settings.APNS_SANDBOX)
        _apns_client_initialized = True
    return _apns_client

def apns_enabled() -> bool:
    client = get_apns_client()
    return client is not None

def modernize_apns_payload(data: Dict[str, Any]) -> Dict[str, Any]:
    '''Take a payload in an unknown Zulip version's format, and return in current format.'''
    # TODO this isn't super robust as is -- if a buggy remote server
    # sends a malformed payload, we are likely to raise an exception.
    if 'message_ids' in data:
        # The format sent by 1.6.0, from the earliest pre-1.6.0
        # version with bouncer support up until 613d093d7 pre-1.7.0:
        #   'alert': str,              # just sender, and text about PM/group-PM/mention
        #   'message_ids': List[int],  # always just one
        return {
            'alert': data['alert'],
            'badge': 0,
            'custom': {
                'zulip': {
                    'message_ids': data['message_ids'],
                },
            },
        }
    else:
        # Something already compatible with the current format.
        # `alert` may be a string, or a dict with `title` and `body`.
        # In 1.7.0 and 1.7.1, before 0912b5ba8 pre-1.8.0, the only
        # item in `custom.zulip` is `message_ids`.
        return data

APNS_MAX_RETRIES = 3

@statsd_increment("apple_push_notification")
def send_apple_push_notification(user_id: int, devices: List[DeviceToken],
                                 payload_data: Dict[str, Any], remote: bool=False) -> None:
    # We lazily do the APNS imports as part of optimizing Zulip's base
    # import time; since these are only needed in the push
    # notification queue worker, it's best to only import them in the
    # code that needs them.
    from apns2.payload import Payload as APNsPayload
    from apns2.client import APNsClient
    from hyper.http20.exceptions import HTTP20Error

    client = get_apns_client()  # type: APNsClient
    if client is None:
        logger.debug("APNs: Dropping a notification because nothing configured.  "
                     "Set PUSH_NOTIFICATION_BOUNCER_URL (or APNS_CERT_FILE).")
        return

    if remote:
        DeviceTokenClass = RemotePushDeviceToken
    else:
        DeviceTokenClass = PushDeviceToken

    logger.info("APNs: Sending notification for user %d to %d devices",
                user_id, len(devices))
    payload = APNsPayload(**modernize_apns_payload(payload_data))
    expiration = int(time.time() + 24 * 3600)
    retries_left = APNS_MAX_RETRIES
    for device in devices:
        # TODO obviously this should be made to actually use the async

        def attempt_send() -> Optional[str]:
            try:
                stream_id = client.send_notification_async(
                    device.token, payload, topic='org.zulip.Zulip',
                    expiration=expiration)
                return client.get_notification_result(stream_id)
            except HTTP20Error as e:
                logger.warning("APNs: HTTP error sending for user %d to device %s: %s",
                               user_id, device.token, e.__class__.__name__)
                return None
            except BrokenPipeError as e:
                logger.warning("APNs: BrokenPipeError sending for user %d to device %s: %s",
                               user_id, device.token, e.__class__.__name__)
                return None
            except ConnectionError as e:  # nocoverage
                logger.warning("APNs: ConnectionError sending for user %d to device %s: %s",
                               user_id, device.token, e.__class__.__name__)
                return None

        result = attempt_send()
        while result is None and retries_left > 0:
            retries_left -= 1
            result = attempt_send()
        if result is None:
            result = "HTTP error, retries exhausted"

        if result[0] == "Unregistered":
            # For some reason, "Unregistered" result values have a
            # different format, as a tuple of the pair ("Unregistered", 12345132131).
            result = result[0]  # type: ignore # APNS API is inconsistent
        if result == 'Success':
            logger.info("APNs: Success sending for user %d to device %s",
                        user_id, device.token)
        elif result in ["Unregistered", "BadDeviceToken", "DeviceTokenNotForTopic"]:
            logger.info("APNs: Removing invalid/expired token %s (%s)" % (device.token, result))
            # We remove all entries for this token (There
            # could be multiple for different Zulip servers).
            DeviceTokenClass.objects.filter(token=device.token, kind=DeviceTokenClass.APNS).delete()
        else:
            logger.warning("APNs: Failed to send for user %d to device %s: %s",
                           user_id, device.token, result)

#
# Sending to GCM, for Android
#

def make_gcm_client() -> gcm.GCM:  # nocoverage
    # From GCM upstream's doc for migrating to FCM:
    #
    #   FCM supports HTTP and XMPP protocols that are virtually
    #   identical to the GCM server protocols, so you don't need to
    #   update your sending logic for the migration.
    #
    #   https://developers.google.com/cloud-messaging/android/android-migrate-fcm
    #
    # The one thing we're required to change on the server is the URL of
    # the endpoint.  So we get to keep using the GCM client library we've
    # been using (as long as we're happy with it) -- just monkey-patch in
    # that one change, because the library's API doesn't anticipate that
    # as a customization point.
    gcm.gcm.GCM_URL = 'https://fcm.googleapis.com/fcm/send'
    return gcm.GCM(settings.ANDROID_GCM_API_KEY)

if settings.ANDROID_GCM_API_KEY:  # nocoverage
    gcm_client = make_gcm_client()
else:
    gcm_client = None

def gcm_enabled() -> bool:  # nocoverage
    return gcm_client is not None

def send_android_push_notification_to_user(user_profile: UserProfile, data: Dict[str, Any],
                                           options: Dict[str, Any]) -> None:
    devices = list(PushDeviceToken.objects.filter(user=user_profile,
                                                  kind=PushDeviceToken.GCM))
    send_android_push_notification(devices, data, options)

def parse_gcm_options(options: Dict[str, Any], data: Dict[str, Any]) -> str:
    """
    Parse GCM options, supplying defaults, and raising an error if invalid.

    The options permitted here form part of the Zulip notification
    bouncer's API.  They are:

    `priority`: Passed through to GCM; see upstream doc linked below.
        Zulip servers should always set this; when unset, we guess a value
        based on the behavior of old server versions.

    Including unrecognized options is an error.

    For details on options' semantics, see this GCM upstream doc:
      https://developers.google.com/cloud-messaging/http-server-ref

    Returns `priority`.
    """
    priority = options.pop('priority', None)
    if priority is None:
        # An older server.  Identify if this seems to be an actual notification.
        if data.get('event') == 'message':
            priority = 'high'
        else:  # `'event': 'remove'`, presumably
            priority = 'normal'
    if priority not in ('normal', 'high'):
        raise JsonableError(_("Invalid GCM option to bouncer: priority %r")
                            % (priority,))

    if options:
        # We're strict about the API; there is no use case for a newer Zulip
        # server talking to an older bouncer, so we only need to provide
        # one-way compatibility.
        raise JsonableError(_("Invalid GCM options to bouncer: %s")
                            % (ujson.dumps(options),))

    return priority  # when this grows a second option, can make it a tuple

@statsd_increment("android_push_notification")
def send_android_push_notification(devices: List[DeviceToken], data: Dict[str, Any],
                                   options: Dict[str, Any], remote: bool=False) -> None:
    """
    Send a GCM message to the given devices.

    See https://developers.google.com/cloud-messaging/http-server-ref
    for the GCM upstream API which this talks to.

    data: The JSON object (decoded) to send as the 'data' parameter of
        the GCM message.
    options: Additional options to control the GCM message sent.
        For details, see `parse_gcm_options`.
    """
    if not gcm_client:
        logger.debug("Skipping sending a GCM push notification since "
                     "PUSH_NOTIFICATION_BOUNCER_URL and ANDROID_GCM_API_KEY are both unset")
        return

    reg_ids = [device.token for device in devices]
    priority = parse_gcm_options(options, data)
    try:
        # See https://developers.google.com/cloud-messaging/http-server-ref .
        # Two kwargs `retries` and `session` get eaten by `json_request`;
        # the rest pass through to the GCM server.
        res = gcm_client.json_request(registration_ids=reg_ids,
                                      priority=priority,
                                      data=data,
                                      retries=10)
    except IOError as e:
        logger.warning(str(e))
        return

    if res and 'success' in res:
        for reg_id, msg_id in res['success'].items():
            logger.info("GCM: Sent %s as %s" % (reg_id, msg_id))

    if remote:
        DeviceTokenClass = RemotePushDeviceToken
    else:
        DeviceTokenClass = PushDeviceToken

    # res.canonical will contain results when there are duplicate registrations for the same
    # device. The "canonical" registration is the latest registration made by the device.
    # Ref: http://developer.android.com/google/gcm/adv.html#canonical
    if 'canonical' in res:
        for reg_id, new_reg_id in res['canonical'].items():
            if reg_id == new_reg_id:
                # I'm not sure if this should happen. In any case, not really actionable.
                logger.warning("GCM: Got canonical ref but it already matches our ID %s!" % (reg_id,))
            elif not DeviceTokenClass.objects.filter(token=new_reg_id,
                                                     kind=DeviceTokenClass.GCM).count():
                # This case shouldn't happen; any time we get a canonical ref it should have been
                # previously registered in our system.
                #
                # That said, recovery is easy: just update the current PDT object to use the new ID.
                logger.warning(
                    "GCM: Got canonical ref %s replacing %s but new ID not registered! Updating." %
                    (new_reg_id, reg_id))
                DeviceTokenClass.objects.filter(
                    token=reg_id, kind=DeviceTokenClass.GCM).update(token=new_reg_id)
            else:
                # Since we know the new ID is registered in our system we can just drop the old one.
                logger.info("GCM: Got canonical ref %s, dropping %s" % (new_reg_id, reg_id))

                DeviceTokenClass.objects.filter(token=reg_id, kind=DeviceTokenClass.GCM).delete()

    if 'errors' in res:
        for error, reg_ids in res['errors'].items():
            if error in ['NotRegistered', 'InvalidRegistration']:
                for reg_id in reg_ids:
                    logger.info("GCM: Removing %s" % (reg_id,))
                    # We remove all entries for this token (There
                    # could be multiple for different Zulip servers).
                    DeviceTokenClass.objects.filter(token=reg_id, kind=DeviceTokenClass.GCM).delete()
            else:
                for reg_id in reg_ids:
                    logger.warning("GCM: Delivery to %s failed: %s" % (reg_id, error))

    # python-gcm handles retrying of the unsent messages.
    # Ref: https://github.com/geeknam/python-gcm/blob/master/gcm/gcm.py#L497

#
# Sending to a bouncer
#

def uses_notification_bouncer() -> bool:
    return settings.PUSH_NOTIFICATION_BOUNCER_URL is not None

def send_notifications_to_bouncer(user_profile_id: int,
                                  apns_payload: Dict[str, Any],
                                  gcm_payload: Dict[str, Any],
                                  gcm_options: Dict[str, Any]) -> None:
    post_data = {
        'user_id': user_profile_id,
        'apns_payload': apns_payload,
        'gcm_payload': gcm_payload,
        'gcm_options': gcm_options,
    }
    # Calls zilencer.views.remote_server_notify_push
    send_json_to_push_bouncer('POST', 'push/notify', post_data)

#
# Managing device tokens
#

def num_push_devices_for_user(user_profile: UserProfile, kind: Optional[int]=None) -> PushDeviceToken:
    if kind is None:
        return PushDeviceToken.objects.filter(user=user_profile).count()
    else:
        return PushDeviceToken.objects.filter(user=user_profile, kind=kind).count()

def add_push_device_token(user_profile: UserProfile,
                          token_str: bytes,
                          kind: int,
                          ios_app_id: Optional[str]=None) -> None:
    logger.info("Registering push device: %d %r %d %r",
                user_profile.id, token_str, kind, ios_app_id)

    # If we're sending things to the push notification bouncer
    # register this user with them here
    if uses_notification_bouncer():
        post_data = {
            'server_uuid': settings.ZULIP_ORG_ID,
            'user_id': user_profile.id,
            'token': token_str,
            'token_kind': kind,
        }

        if kind == PushDeviceToken.APNS:
            post_data['ios_app_id'] = ios_app_id

        logger.info("Sending new push device to bouncer: %r", post_data)
        # Calls zilencer.views.register_remote_push_device
        send_to_push_bouncer('POST', 'push/register', post_data)
        return

    try:
        with transaction.atomic():
            PushDeviceToken.objects.create(
                user_id=user_profile.id,
                kind=kind,
                token=token_str,
                ios_app_id=ios_app_id,
                # last_updated is to be renamed to date_created.
                last_updated=timezone_now())
    except IntegrityError:
        pass

def remove_push_device_token(user_profile: UserProfile, token_str: bytes, kind: int) -> None:

    # If we're sending things to the push notification bouncer
    # unregister this user with them here
    if uses_notification_bouncer():
        # TODO: Make this a remove item
        post_data = {
            'server_uuid': settings.ZULIP_ORG_ID,
            'user_id': user_profile.id,
            'token': token_str,
            'token_kind': kind,
        }
        # Calls zilencer.views.unregister_remote_push_device
        send_to_push_bouncer("POST", "push/unregister", post_data)
        return

    try:
        token = PushDeviceToken.objects.get(token=token_str, kind=kind, user=user_profile)
        token.delete()
    except PushDeviceToken.DoesNotExist:
        raise JsonableError(_("Token does not exist"))

#
# Push notifications in general
#

def push_notifications_enabled() -> bool:
    '''True just if this server has configured a way to send push notifications.'''
    if (uses_notification_bouncer()
            and settings.ZULIP_ORG_KEY is not None
            and settings.ZULIP_ORG_ID is not None):  # nocoverage
        # We have the needed configuration to send push notifications through
        # the bouncer.  Better yet would be to confirm that this config actually
        # works -- e.g., that we have ever successfully sent to the bouncer --
        # but this is a good start.
        return True
    if apns_enabled() and gcm_enabled():  # nocoverage
        # We have the needed configuration to send through APNs and GCM directly
        # (i.e., we are the bouncer, presumably.)  Again, assume it actually works.
        return True
    return False

def initialize_push_notifications() -> None:
    if not push_notifications_enabled():
        if settings.DEVELOPMENT and not settings.TEST_SUITE:  # nocoverage
            # Avoid unnecessary spam on development environment startup
            return
        logger.warning("Mobile push notifications are not configured.\n  "
                       "See https://zulip.readthedocs.io/en/latest/"
                       "production/mobile-push-notifications.html")

def get_gcm_alert(message: Message) -> str:
    """
    Determine what alert string to display based on the missed messages.
    """
    sender_str = message.sender.full_name
    if message.recipient.type == Recipient.HUDDLE and message.trigger == 'private_message':
        return "New private group message from %s" % (sender_str,)
    elif message.recipient.type == Recipient.PERSONAL and message.trigger == 'private_message':
        return "New private message from %s" % (sender_str,)
    elif message.is_stream_message() and message.trigger == 'mentioned':
        return "New mention from %s" % (sender_str,)
    else:  # message.is_stream_message() and message.trigger == 'stream_push_notify'
        return "New stream message from %s in %s" % (sender_str, get_display_recipient(message.recipient),)

def get_mobile_push_content(rendered_content: str) -> str:
    def get_text(elem: lxml.html.HtmlElement) -> str:
        # Convert default emojis to their unicode equivalent.
        classes = elem.get("class", "")
        if "emoji" in classes:
            match = re.search(r"emoji-(?P<emoji_code>\S+)", classes)
            if match:
                emoji_code = match.group('emoji_code')
                char_repr = ""
                for codepoint in emoji_code.split('-'):
                    char_repr += chr(int(codepoint, 16))
                return char_repr
        # Handles realm emojis, avatars etc.
        if elem.tag == "img":
            return elem.get("alt", "")
        if elem.tag == 'blockquote':
            return ''  # To avoid empty line before quote text
        return elem.text or ''

    def format_as_quote(quote_text: str) -> str:
        quote_text_list = filter(None, quote_text.split('\n'))  # Remove empty lines
        quote_text = '\n'.join(map(lambda x: "> "+x, quote_text_list))
        quote_text += '\n'
        return quote_text

    def process(elem: lxml.html.HtmlElement) -> str:
        plain_text = get_text(elem)
        sub_text = ''
        for child in elem:
            sub_text += process(child)
        if elem.tag == 'blockquote':
            sub_text = format_as_quote(sub_text)
        plain_text += sub_text
        plain_text += elem.tail or ""
        return plain_text

    if settings.PUSH_NOTIFICATION_REDACT_CONTENT:
        return "***REDACTED***"

    elem = lxml.html.fromstring(rendered_content)
    plain_text = process(elem)
    return plain_text

def truncate_content(content: str) -> Tuple[str, bool]:
    # We use unicode character 'HORIZONTAL ELLIPSIS' (U+2026) instead
    # of three dots as this saves two extra characters for textual
    # content. This function will need to be updated to handle unicode
    # combining characters and tags when we start supporting themself.
    if len(content) <= 200:
        return content, False
    return content[:200] + "…", True

def get_base_payload(realm: Realm) -> Dict[str, Any]:
    '''Common fields for all notification payloads.'''
    data = {}  # type: Dict[str, Any]

    # These will let the app support logging into multiple realms and servers.
    data['server'] = settings.EXTERNAL_HOST
    data['realm_id'] = realm.id
    data['realm_uri'] = realm.uri

    return data

def get_message_payload(message: Message) -> Dict[str, Any]:
    '''Common fields for `message` payloads, for all platforms.'''
    data = get_base_payload(message.sender.realm)

    # `sender_id` is preferred, but some existing versions use `sender_email`.
    data['sender_id'] = message.sender.id
    data['sender_email'] = message.sender.email

    if message.recipient.type == Recipient.STREAM:
        data['recipient_type'] = "stream"
        data['stream'] = get_display_recipient(message.recipient)
        data['topic'] = message.topic_name()
    elif message.recipient.type == Recipient.HUDDLE:
        data['recipient_type'] = "private"
        data['pm_users'] = huddle_users(message.recipient.id)
    else:  # Recipient.PERSONAL
        data['recipient_type'] = "private"

    return data

def get_apns_alert_title(message: Message) -> str:
    """
    On an iOS notification, this is the first bolded line.
    """
    if message.recipient.type == Recipient.HUDDLE:
        recipients = cast(List[Dict[str, Any]], get_display_recipient(message.recipient))
        return ', '.join(sorted(r['full_name'] for r in recipients))
    elif message.is_stream_message():
        return "#%s > %s" % (get_display_recipient(message.recipient), message.topic_name(),)
    # For personal PMs, we just show the sender name.
    return message.sender.full_name

def get_apns_alert_subtitle(message: Message) -> str:
    """
    On an iOS notification, this is the second bolded line.
    """
    if message.trigger == "mentioned":
        return message.sender.full_name + " mentioned you:"
    elif message.recipient.type == Recipient.PERSONAL:
        return ""
    # For group PMs, or regular messages to a stream, just use a colon to indicate this is the sender.
    return message.sender.full_name + ":"

def get_message_payload_apns(user_profile: UserProfile, message: Message) -> Dict[str, Any]:
    '''A `message` payload for iOS, via APNs.'''
    zulip_data = get_message_payload(message)
    zulip_data.update({
        'message_ids': [message.id],
    })

    content, _ = truncate_content(get_mobile_push_content(message.rendered_content))
    apns_data = {
        'alert': {
            'title': get_apns_alert_title(message),
            'subtitle': get_apns_alert_subtitle(message),
            'body': content,
        },
        'sound': 'default',
        'badge': 0,  # TODO: set badge count in a better way
        'custom': {'zulip': zulip_data},
    }
    return apns_data

def get_message_payload_gcm(
        user_profile: UserProfile, message: Message,
) -> Tuple[Dict[str, Any], Dict[str, Any]]:
    '''A `message` payload + options, for Android via GCM/FCM.'''
    data = get_message_payload(message)
    content, truncated = truncate_content(get_mobile_push_content(message.rendered_content))
    data.update({
        'user': user_profile.email,
        'event': 'message',
        'alert': get_gcm_alert(message),
        'zulip_message_id': message.id,  # message_id is reserved for CCS
        'time': datetime_to_timestamp(message.pub_date),
        'content': content,
        'content_truncated': truncated,
        'sender_full_name': message.sender.full_name,
        'sender_avatar_url': absolute_avatar_url(message.sender),
    })
    gcm_options = {'priority': 'high'}
    return data, gcm_options

def get_remove_payload_gcm(
        user_profile: UserProfile, message_ids: List[int],
) -> Tuple[Dict[str, Any], Dict[str, Any]]:
    '''A `remove` payload + options, for Android via GCM/FCM.'''
    gcm_payload = get_base_payload(user_profile.realm)
    gcm_payload.update({
        'event': 'remove',
        'zulip_message_ids': ','.join(str(id) for id in message_ids),
        # Older clients (all clients older than 2019-02-13) look only at
        # `zulip_message_id` and ignore `zulip_message_ids`.  Do our best.
        'zulip_message_id': message_ids[0],
    })
    gcm_options = {'priority': 'normal'}
    return gcm_payload, gcm_options

def handle_remove_push_notification(user_profile_id: int, message_ids: List[int]) -> None:
    """This should be called when a message that had previously had a
    mobile push executed is read.  This triggers a mobile push notifica
    mobile app when the message is read on the server, to remove the
    message from the notification.

    """
    user_profile = get_user_profile_by_id(user_profile_id)
    message_ids = bulk_access_messages_expect_usermessage(user_profile_id, message_ids)
    gcm_payload, gcm_options = get_remove_payload_gcm(user_profile, message_ids)

    if uses_notification_bouncer():
        try:
            send_notifications_to_bouncer(user_profile_id,
                                          {},
                                          gcm_payload,
                                          gcm_options)
        except requests.ConnectionError:  # nocoverage
            def failure_processor(event: Dict[str, Any]) -> None:
                logger.warning(
                    "Maximum retries exceeded for trigger:%s event:push_notification" % (
                        event['user_profile_id']))
    else:
        android_devices = list(PushDeviceToken.objects.filter(
            user=user_profile, kind=PushDeviceToken.GCM))
        if android_devices:
            send_android_push_notification(android_devices, gcm_payload, gcm_options)

    UserMessage.objects.filter(
        user_profile_id=user_profile_id,
        message_id__in=message_ids,
    ).update(
        flags=F('flags').bitand(
            ~UserMessage.flags.active_mobile_push_notification))

@statsd_increment("push_notifications")
def handle_push_notification(user_profile_id: int, missed_message: Dict[str, Any]) -> None:
    """
    missed_message is the event received by the
    zerver.worker.queue_processors.PushNotificationWorker.consume function.
    """
    if not push_notifications_enabled():
        return
    user_profile = get_user_profile_by_id(user_profile_id)
    if not (receives_offline_push_notifications(user_profile) or
            receives_online_notifications(user_profile)):
        return

    user_profile = get_user_profile_by_id(user_profile_id)
    try:
        (message, user_message) = access_message(user_profile, missed_message['message_id'])
    except JsonableError:
        if ArchivedMessage.objects.filter(id=missed_message['message_id']).exists():
            # If the cause is a race with the message being deleted,
            # that's normal and we have no need to log an error.
            return
        logging.error("Unexpected message access failure handling push notifications: %s %s" % (
            user_profile.id, missed_message['message_id']))
        return

    if user_message is not None:
        # If the user has read the message already, don't push-notify.
        #
        # TODO: It feels like this is already handled when things are
        # put in the queue; maybe we should centralize this logic with
        # the `zerver/tornado/event_queue.py` logic?
        if user_message.flags.read:
            return

        # Otherwise, we mark the message as having an active mobile
        # push notification, so that we can send revocation messages
        # later.
        user_message.flags.active_mobile_push_notification = True
        user_message.save(update_fields=["flags"])
    else:
        # Users should only be getting push notifications into this
        # queue for messages they haven't received if they're
        # long-term idle; anything else is likely a bug.
        if not user_profile.long_term_idle:
            logger.error("Could not find UserMessage with message_id %s and user_id %s" % (
                missed_message['message_id'], user_profile_id))
            return

    message.trigger = missed_message['trigger']

    apns_payload = get_message_payload_apns(user_profile, message)
    gcm_payload, gcm_options = get_message_payload_gcm(user_profile, message)
    logger.info("Sending push notifications to mobile clients for user %s" % (user_profile_id,))

    if uses_notification_bouncer():
        try:
            send_notifications_to_bouncer(user_profile_id,
                                          apns_payload,
                                          gcm_payload,
                                          gcm_options)
        except requests.ConnectionError:
            def failure_processor(event: Dict[str, Any]) -> None:
                logger.warning(
                    "Maximum retries exceeded for trigger:%s event:push_notification" % (
                        event['user_profile_id']))
            retry_event('missedmessage_mobile_notifications', missed_message,
                        failure_processor)
        return

    android_devices = list(PushDeviceToken.objects.filter(user=user_profile,
                                                          kind=PushDeviceToken.GCM))

    apple_devices = list(PushDeviceToken.objects.filter(user=user_profile,
                                                        kind=PushDeviceToken.APNS))

    if apple_devices:
        send_apple_push_notification(user_profile.id, apple_devices,
                                     apns_payload)

    if android_devices:
        send_android_push_notification(android_devices, gcm_payload, gcm_options)