from concurrent.futures import ThreadPoolExecutor
import time
import threading
import logging
import unittest


class TestThreadPool(unittest.TestCase):
    """
    In ThreadPoolExecutor's submit method, if the name was not provided
    then if there's a idle thread or if re-using a thread , it uses their name
    else: it prefers the thread_name_prefix
    """
    sample = ThreadPoolExecutor(max_workers=2)
    logging.basicConfig(level=logging.DEBUG)

    def check(self, a=69, test_with_name=""):
        logging.info("%s: [%s]", threading.current_thread(), a)
        time.sleep(1)

        if test_with_name:
            self.assertEqual(threading.current_thread().name, test_with_name)

    def test_default_name_thread(self):
        # Running this test alone proves that pool uses thread_name_prefix while
        # creating a thread and if name was not provided
        self.sample.submit(self.check)
        self.sample.submit(self.check, args=(66,))
        self.sample.submit(self.check, "", 66)

    def test_name_thread(self):
        self.sample.submit(self.check, "Test1", 66, "Test1")
        self.sample.submit(self.check, "Test2", test_with_name="Test2")

    def test_shutdown(self):
        self.sample.shutdown()
        logging.info("Closed")


if __name__ == "__main__":
    unittest.main()