import signal
import subprocess
import select
from threading import Thread
from typing import Callable

class LinuxPtpObserver:
    def __init__(self, ni: str) -> None:
        self.__ni = ni
        self.__process: subprocess.Popen
        self.__observer_thread: Thread
        self.__observer_cb: Callable | None = None
        pass
    
    def observer_routine(self) -> None:
        if self.__process.stdout is not None:
            pfd = select.poll()
            pfd.register(self.__process.stdout.fileno(), select.POLLIN)
        else:
            return
        
        while self.__process.poll() is None:
            res = pfd.poll()

            if len(res) > 0 and res[0][1] & select.POLLIN:
                data = self.__process.stdout.readline()
                if self.__observer_cb is not None:
                    self.__observer_cb(data)
                

    def start_linuxptp(self, profile: str) -> None:
        cmd = ["sudo", "ptp4l", "--priority1=127", "--priority2=255", "--gmCapable=1", "--neighborPropDelayThresh=100000", 
             "--min_neighbor_prop_delay=-20000000", "--assume_two_step=1", "--ptp_minor_version=0", 
             "-i", self.__ni, "-f", "linuxptp_configs/{:s}.cfg".format(profile), "-m", "-l", "6"]

        self.__process = subprocess.Popen(
            cmd,
            stdout=subprocess.PIPE,
            stdin=subprocess.PIPE,
            text=True
        )

        self.__observer_thread = Thread(target=self.observer_routine)
        self.__observer_thread.start()

    def stop_linuxptp(self) -> None:
        self.__process.send_signal(signal.SIGKILL)
        self.__observer_thread.join()

    def register_observer_callback(self, cb : Callable) -> None:
        self.__observer_cb = cb