import multiprocessing
import time


class Base(multiprocessing.Process):
    def __init__(self):
        super().__init__()
        self.stay_alive = multiprocessing.Event()

    def shutdown(self):
        self.stay_alive.clear()
        self.join()

    @property
    def state(self):
        if self.is_alive():
            return f"{type(self).__name__} - run() running"
        elif not self.is_alive() and self.exitcode == 0:
            return f"{type(self).__name__} - run() completed successfully"
        elif not self.is_alive() and self.exitcode == 1:
            return f"{type(self).__name__} - run() completed unsuccessfully"
        elif not self.is_alive() and self.exitcode is None:
            return f"{type(self).__name__} - run() has not started"
        else:
            return f"{type(self).__name__} - idk"

    # def is_alive(self) -> bool:
    #
    #     self._check_closed()
    #     if self is multiprocessing.process._current_process:
    #         return True
    #     if self._popen is None:
    #         return False
    #
    #     returncode = self._popen.poll()
    #     if returncode is None:
    #         return True
    #     else:
    #         return False


class A(Base):
    def run(self):
        self.stay_alive.set()
        while self.stay_alive.is_set():
            time.sleep(0.1)
        print('A.run() closed')


class B(A):
    def run(self):
        self.stay_alive.set()
        raise Exception


class C(Base):
    def __init__(self, brother):
        super().__init__()
        self.brother = brother

    def run(self):
        print(f"brother - {self.brother.state}")


# Show the states of a successful process
a = A()
print(a.state)
a.start()
print(a.state)
time.sleep(1)

c = C(a)  # View state of A from sibling process
c.start()
time.sleep(2)

a.shutdown()
print(a.state)

#

b = B()
c = C(b)  # View state of A from sibling process
c.start()
print(b.state)

c = C(b)
b.start()  # which will error
time.sleep(1)
c.start()  # View state of A from sibling process
print(b.state)

print(1)