import logging
import sys
from typing import Any, Callable
from urllib.parse import SplitResult

from django.conf import settings
from django.core.management.base import BaseCommand, CommandError, CommandParser
from tornado import ioloop
from tornado.log import app_log

# We must call zerver.tornado.ioloop_logging.instrument_tornado_ioloop
# before we import anything else from our project in order for our
# Tornado load logging to work; otherwise we might accidentally import
# zerver.lib.queue (which will instantiate the Tornado ioloop) before
# this.
from zerver.tornado.ioloop_logging import instrument_tornado_ioloop

settings.RUNNING_INSIDE_TORNADO = True
instrument_tornado_ioloop()

from zerver.lib.debug import interactive_debug_listen
from zerver.tornado.application import create_tornado_application, setup_tornado_rabbitmq
from zerver.tornado.autoreload import start as zulip_autoreload_start
from zerver.tornado.event_queue import (
    add_client_gc_hook,
    get_wrapped_process_notification,
    missedmessage_hook,
    setup_event_queue,
)
from zerver.tornado.sharding import notify_tornado_queue_name

if settings.USING_RABBITMQ:
    from zerver.lib.queue import TornadoQueueClient, get_queue_client


def handle_callback_exception(callback: Callable[..., Any]) -> None:
    logging.exception("Exception in callback", stack_info=True)
    app_log.error("Exception in callback %r", callback, exc_info=True)

class Command(BaseCommand):
    help = "Starts a Tornado Web server wrapping Django."

    def add_arguments(self, parser: CommandParser) -> None:
        parser.add_argument('addrport', nargs="?",
                            help='[optional port number or ipaddr:port]\n '
                                 '(use multiple ports to start multiple servers)')

        parser.add_argument('--nokeepalive', action='store_true',
                            dest='no_keep_alive',
                            help="Tells Tornado to NOT keep alive http connections.")

        parser.add_argument('--noxheaders', action='store_false',
                            dest='xheaders',
                            help="Tells Tornado to NOT override remote IP with X-Real-IP.")

    def handle(self, addrport: str, **options: bool) -> None:
        interactive_debug_listen()

        import django
        from tornado import httpserver

        if addrport.isdigit():
            addr, port = "", int(addrport)
        else:
            r = SplitResult("", addrport, "", "", "")
            if r.port is None:
                raise CommandError(f"{addrport!r} does not have a valid port number.")
            addr, port = r.hostname or "", r.port

        if not addr:
            addr = '127.0.0.1'

        xheaders = options.get('xheaders', True)
        no_keep_alive = options.get('no_keep_alive', False)

        if settings.DEBUG:
            logging.basicConfig(level=logging.INFO,
                                format='%(asctime)s %(levelname)-8s %(message)s')

        def inner_run() -> None:
            from django.conf import settings
            from django.utils import translation
            translation.activate(settings.LANGUAGE_CODE)

            # We pass display_num_errors=False, since Django will
            # likely display similar output anyway.
            self.check(display_num_errors=False)
            print(f"Tornado server (re)started on port {port}")

            if settings.USING_RABBITMQ:
                queue_client = get_queue_client()
                assert isinstance(queue_client, TornadoQueueClient)
                # Process notifications received via RabbitMQ
                queue_name = notify_tornado_queue_name(port)
                queue_client.start_json_consumer(queue_name,
                                                 get_wrapped_process_notification(queue_name))

            try:
                # Application is an instance of Django's standard wsgi handler.
                application = create_tornado_application()
                if settings.AUTORELOAD:
                    zulip_autoreload_start()

                # start tornado web server in single-threaded mode
                http_server = httpserver.HTTPServer(application,
                                                    xheaders=xheaders,
                                                    no_keep_alive=no_keep_alive)
                http_server.listen(port, address=addr)

                from zerver.tornado.ioloop_logging import logging_data
                logging_data['port'] = str(port)
                setup_event_queue(port)
                add_client_gc_hook(missedmessage_hook)
                setup_tornado_rabbitmq()

                instance = ioloop.IOLoop.instance()

                if django.conf.settings.DEBUG:
                    instance.set_blocking_log_threshold(5)
                    instance.handle_callback_exception = handle_callback_exception
                instance.start()
            except KeyboardInterrupt:
                sys.exit(0)

        inner_run()