# test_help.py - Ensure scripts can run --help.
#
# Copyright (C) 2010, Stefano Rivera <stefanor@ubuntu.com>
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

import fcntl
import os
import select
import signal
import subprocess
import time
import unittest

from . import get_scripts

TIMEOUT = 5


def load_tests(loader, tests, pattern):  # pylint: disable=unused-argument
    "Give HelpTestCase a chance to populate before loading its test cases"
    suite = unittest.TestSuite()
    HelpTestCase.populate()
    suite.addTests(loader.loadTestsFromTestCase(HelpTestCase))
    return suite


class HelpTestCase(unittest.TestCase):
    @classmethod
    def populate(cls):
        for script in get_scripts():
            setattr(cls, "test_" + script, cls.make_help_tester(script))

    @classmethod
    def make_help_tester(cls, script):
        def tester(self):
            with subprocess.Popen(
                ["./" + script, "--help"],
                close_fds=True,
                stdin=subprocess.DEVNULL,
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE,
            ) as process:
                started = time.time()
                out = []

                fds = [process.stdout.fileno(), process.stderr.fileno()]
                for fd in fds:
                    fcntl.fcntl(
                        fd,
                        fcntl.F_SETFL,
                        fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK,
                    )

                while time.time() - started < TIMEOUT:
                    for fd in select.select(fds, [], fds, TIMEOUT)[0]:
                        out.append(os.read(fd, 1024))
                    if process.poll() is not None:
                        break

                if process.poll() is None:
                    os.kill(process.pid, signal.SIGTERM)
                    time.sleep(1)
                    if process.poll() is None:
                        os.kill(process.pid, signal.SIGKILL)

            self.assertEqual(
                process.poll(),
                0,
                f"{script} failed to return usage within {TIMEOUT} seconds.\n"
                f"Output:\n{b''.join(out)}",
            )

        return tester
