from PySide6.QtCore import QObject, Signal
from threading import Thread
import subprocess

class ProcManager(QObject):

	process_terminated = Signal(int, str)

	def __init__(self) -> None:
		super(ProcManager, self).__init__()

		self.thre = None
		self.proc = None

	def start(self, proc):
		# this method might override the old process and thread
		self.proc = proc

		self.thre = Thread(target=self.detect_end)
		self.thre.start()

	def stop(self):
		if self.proc:
			self.proc.terminate()

			try:
				self.proc.wait(1)
			except subprocess.TimeoutExpired as e:
				self.proc.kill()

		if self.thre:
			self.thre.join()
			self.thre = None

	def detect_end(self):
		# wait for the process to terminate
		while True:
			try:
				self.proc.wait(1)
				break
			except subprocess.TimeoutExpired as e:
				continue

		returncode = self.proc.returncode
		errorstream = self.proc.stderr.read()
		if isinstance(errorstream, bytes):
			errorstream = errorstream.decode('utf-8')

		self.proc = None

		print('Process Terminated:', returncode, errorstream)

		self.process_terminated.emit(returncode, errorstream)