#!/usr/bin/env python3
import signal
import sys
import threading
from pathlib import Path

APP_DIRECTORY = Path('/opt/truf/app')
sys.path.insert(0, str(APP_DIRECTORY))

from host_agent_runtime import FixedHostOperationDispatcher
from host_agent_server import (
    HostAgentServerError,
    inherited_systemd_listener,
    serve_forever,
)


def main():
    if len(sys.argv) != 1:
        raise HostAgentServerError('arguments_forbidden')
    listener = inherited_systemd_listener()
    stop_event = threading.Event()
    dispatcher = FixedHostOperationDispatcher()

    def request_stop(_signum, _frame):
        stop_event.set()

    signal.signal(signal.SIGTERM, request_stop)
    signal.signal(signal.SIGINT, request_stop)
    try:
        with listener:
            serve_forever(
                listener, handler=dispatcher.handle, stop_event=stop_event,
            )
    finally:
        dispatcher.close()
    return 0


if __name__ == '__main__':
    try:
        result = main()
    except BaseException as exc:
        if not isinstance(exc, Exception):
            raise
        print(
            'host operations agent failed (' + type(exc).__name__ + '); details withheld',
            file=sys.stderr,
        )
        result = 1
    raise SystemExit(result)