#!/usr/bin/python3
"""
A simple script for waiting until an org.kde.StatusNotifierItem host implementation
is available and ready.

Dependencies: dbus-next, tenacity
"""
import asyncio
import logging
import os

from dbus_next.aio import MessageBus
from tenacity import retry, stop_after_delay, wait_fixed

LOG = logging.getLogger("wait-sni-host")
TIMEOUT = int(os.environ.get("SNI_WAIT_TIMEOUT", default=25))


@retry(reraise=True, stop=stop_after_delay(TIMEOUT), wait=wait_fixed(0.5))
async def get_service(bus, name, object_path, interface_name):
    """Wait until the service appears on the bus"""
    introspection = await bus.introspect(name, object_path)
    proxy = bus.get_proxy_object(name, object_path, introspection)
    return proxy.get_interface(interface_name)


async def wait_sni_host(bus: MessageBus):
    """Wait until a StatusNotifierWatcher service is available and has a
    StatusNotifierHost instance"""
    future = asyncio.get_event_loop().create_future()

    async def on_host_registered():
        value = await sni_watcher.get_is_status_notifier_host_registered()
        LOG.debug("StatusNotifierHostRegistered: %s", value)
        if value:
            future.set_result(value)

    sni_watcher = await get_service(bus, "org.kde.StatusNotifierWatcher",
                                    "/StatusNotifierWatcher",
                                    "org.kde.StatusNotifierWatcher")
    sni_watcher.on_status_notifier_host_registered(on_host_registered)
    # fetch initial value
    await on_host_registered()
    return await asyncio.wait_for(future, timeout=TIMEOUT)


async def main():
    """asyncio entrypoint"""
    bus = await MessageBus().connect()
    try:
        await wait_sni_host(bus)
        LOG.info("Successfully waited for org.kde.StatusNotifierHost")
    # pylint: disable=broad-except
    except Exception as err:
        LOG.error("Failed to wait for org.kde.StatusNotifierHost: %s",
                  str(err))


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    asyncio.run(main())