#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
import os
import sys
import time
import unittest

from pyspark.serializers import read_int


class DaemonTests(unittest.TestCase):
    def connect(self, port):
        from socket import socket, AF_INET, SOCK_STREAM
        sock = socket(AF_INET, SOCK_STREAM)
        sock.connect(('127.0.0.1', port))
        # send a split index of -1 to shutdown the worker
        sock.send(b"\xFF\xFF\xFF\xFF")
        sock.close()
        return True

    def do_termination_test(self, terminator):
        from subprocess import Popen, PIPE
        from errno import ECONNREFUSED

        # start daemon
        daemon_path = os.path.join(os.path.dirname(__file__), "..", "daemon.py")
        python_exec = sys.executable or os.environ.get("PYSPARK_PYTHON")
        daemon = Popen([python_exec, daemon_path], stdin=PIPE, stdout=PIPE)

        # read the port number
        port = read_int(daemon.stdout)

        # daemon should accept connections
        self.assertTrue(self.connect(port))

        # wait worker process spawned from daemon exit.
        time.sleep(1)

        # request shutdown
        terminator(daemon)
        time.sleep(1)

        # daemon should no longer accept connections
        try:
            self.connect(port)
        except EnvironmentError as exception:
            self.assertEqual(exception.errno, ECONNREFUSED)
        else:
            self.fail("Expected EnvironmentError to be raised")

    def test_termination_stdin(self):
        """Ensure that daemon and workers terminate when stdin is closed."""
        self.do_termination_test(lambda daemon: daemon.stdin.close())

    def test_termination_sigterm(self):
        """Ensure that daemon and workers terminate on SIGTERM."""
        from signal import SIGTERM
        self.do_termination_test(lambda daemon: os.kill(daemon.pid, SIGTERM))


if __name__ == "__main__":
    from pyspark.tests.test_daemon import *  # noqa: F401

    try:
        import xmlrunner  # type: ignore[import]
        testRunner = xmlrunner.XMLTestRunner(output='target/test-reports', verbosity=2)
    except ImportError:
        testRunner = None
    unittest.main(testRunner=testRunner, verbosity=2)