from __future__ import print_function

import os
import time
import sys
from functools import wraps

from pytest import mark

from zmq.tests import BaseZMQTestCase
from zmq.utils.win32 import allow_interrupt


def count_calls(f):
    @wraps(f)
    def _(*args, **kwds):
        try:
            return f(*args, **kwds)
        finally:
            _.__calls__ += 1
    _.__calls__ = 0
    return _


@mark.new_console
class TestWindowsConsoleControlHandler(BaseZMQTestCase):

    @mark.new_console
    @mark.skipif(
        not sys.platform.startswith('win'),
        reason='Windows only test')
    def test_handler(self):
        @count_calls
        def interrupt_polling():
            print('Caught CTRL-C!')

        from ctypes import windll
        from ctypes.wintypes import BOOL, DWORD

        kernel32 = windll.LoadLibrary('kernel32')

        # <http://msdn.microsoft.com/en-us/library/ms683155.aspx>
        GenerateConsoleCtrlEvent = kernel32.GenerateConsoleCtrlEvent
        GenerateConsoleCtrlEvent.argtypes = (DWORD, DWORD)
        GenerateConsoleCtrlEvent.restype = BOOL

        # Simulate CTRL-C event while handler is active.
        try:
            with allow_interrupt(interrupt_polling) as context:
                result = GenerateConsoleCtrlEvent(0, 0)
                # Sleep so that we give time to the handler to
                # capture the Ctrl-C event.
                time.sleep(0.5)
        except KeyboardInterrupt:
            pass
        else:
            if result == 0:
                raise WindowsError()
            else:
                self.fail('Expecting `KeyboardInterrupt` exception!')

        # Make sure our handler was called.
        self.assertEqual(interrupt_polling.__calls__, 1)
