import zoneinfo
from email.utils import format_datetime as email_format_datetime
from typing import Any

from django.conf import settings
from django.contrib.auth.signals import user_logged_in, user_logged_out
from django.dispatch import receiver
from django.utils.timezone import get_current_timezone_name as timezone_get_current_timezone_name
from django.utils.timezone import now as timezone_now
from django.utils.translation import gettext as _
from ua_parser import parse_os, parse_user_agent

from confirmation.models import one_click_unsubscribe_link
from zerver.lib.queue import queue_json_publish_rollback_unsafe
from zerver.lib.send_email import FromAddress
from zerver.lib.timestamp import format_datetime_to_string
from zerver.lib.timezone import canonicalize_timezone
from zerver.models import UserProfile

JUST_CREATED_THRESHOLD = 60


def get_device_browser(user_agent: str) -> str | None:
    if "zulip" in user_agent.lower():
        return "Zulip"

    if browser := parse_user_agent(user_agent):
        browser_family = browser.family
        if browser_family == "IE":
            return "Internet Explorer"
        elif browser_family != "Other":
            return browser_family

    return None


def get_device_os(user_agent: str) -> str | None:
    if os := parse_os(user_agent):
        os_family = os.family
        if os_family == "Mac OS X":
            return "macOS"
        elif os_family != "Other":
            return os_family
    return None


@receiver(user_logged_in, dispatch_uid="only_on_login")
def email_on_new_login(sender: Any, user: UserProfile, request: Any, **kwargs: Any) -> None:
    if not user.enable_login_emails:
        return

    if user.delivery_email == "":
        # Do not attempt to send new login emails for users without an email address.
        # The assertions here are to help document the only circumstance under which
        # this condition should be possible.
        assert (
            user.realm.demo_organization_scheduled_deletion_date is not None and user.is_realm_owner
        )
        return

    # We import here to minimize the dependencies of this module,
    # since it runs as part of `manage.py` initialization
    from zerver.context_processors import common_context

    if not settings.SEND_LOGIN_EMAILS:
        return

    if request:
        # If the user's account was just created, avoid sending an email.
        if (timezone_now() - user.date_joined).total_seconds() <= JUST_CREATED_THRESHOLD:
            return

        user_agent = request.headers.get("User-Agent", "")

        context = common_context(user)
        context["user_email"] = user.delivery_email
        user_tz = user.timezone
        if user_tz == "":
            user_tz = timezone_get_current_timezone_name()
        local_time = timezone_now().astimezone(zoneinfo.ZoneInfo(canonicalize_timezone(user_tz)))
        context["login_time"] = format_datetime_to_string(local_time, user.twenty_four_hour_time)
        context["device_ip"] = request.META.get("REMOTE_ADDR") or _("Unknown IP address")
        context["device_os"] = get_device_os(user_agent) or _("an unknown operating system")
        context["device_browser"] = get_device_browser(user_agent) or _("An unknown browser")
        context["unsubscribe_link"] = one_click_unsubscribe_link(user, "login")

        email_dict = {
            "template_prefix": "zerver/emails/notify_new_login",
            "to_user_ids": [user.id],
            "from_name": FromAddress.security_email_from_name(user_profile=user),
            "from_address": FromAddress.NOREPLY,
            "context": context,
            "date": email_format_datetime(local_time),
        }
        queue_json_publish_rollback_unsafe("email_senders", email_dict)


@receiver(user_logged_out)
def clear_call_tokens_on_logout(
    sender: object, *, user: UserProfile | None, **kwargs: object
) -> None:
    # Loaded lazily so django.setup() succeeds before static asset generation
    from zerver.actions.video_calls import do_set_video_call_provider_token

    if user is not None:
        if user.third_party_api_state.get("zoom") is not None:
            do_set_video_call_provider_token(user, "zoom", None)
        if user.third_party_api_state.get("webex") is not None:
            do_set_video_call_provider_token(user, "webex", None)