#python3.6

from subprocess import Popen, PIPE
from queue import Queue, Empty
from threading import Thread

class customPopen(Popen):
    # TODO dostep do stderr
    def __init__(self, *args, **kwargs):
        kwargs.setdefault('stdin', PIPE)
        kwargs.setdefault('stdout', PIPE)
        #kwargs.setdefault('stderr', PIPE)
        super(customPopen, self).__init__(*args, **kwargs)

        def reader(stream):
            while self.returncode is None:
                line = stream.readline().decode()
                if line.strip():
                    self.stdout_lines_queue.put(line)

        self.stdout_lines_queue = Queue()
        self.stdout_reader_thread = Thread(target=reader, args=(self.stdout,))
        self.stdout_reader_thread.start()

    def custom_writeline(self, x: str):
        if not x[-1] in ['\n', '\r\n']:
            x += '\n'
        self.stdin.write(x.encode())
        self.stdin.flush()

    def custom_readline(self, timeout=1):
        try:
            return self.stdout_lines_queue.get(timeout=timeout)
        except Empty:
            raise TimeoutError

    def terminate(self):
        self.stdin.close()
        super(customPopen, self).terminate()

    def kill(self):
        self.stdin.close()
        super(customPopen, self).kill()

    def wait(self, timeout=None):
        super(customPopen, self).wait(timeout=timeout)
        self.stdout_reader_thread.join(timeout=timeout)