# Copyright 2004-present Facebook. All Rights Reserved.

import errno
import os
import time
import unittest

import silenttestrunner

from mercurial import (
    error,
    vfs,
    worker,
)

from hgext import extutil

locktimeout = 25
locksuccess = 24

class ExtutilTests(unittest.TestCase):
    def testbgcommandnoblock(self):
        '''runbgcommand() should return without waiting for the process to
        finish.'''
        env = os.environ.copy()
        start = time.time()
        extutil.runbgcommand(['sleep', '5'], env)
        end = time.time()
        if end - start >= 1.0:
            self.fail('runbgcommand() took took %s seconds, should have '
                      'returned immediately' % (end - start))

    def testbgcommandfailure1(self):
        '''runbgcommand() should throw if executing the process fails.'''
        env = os.environ.copy()
        try:
            extutil.runbgcommand(['no_such_program', 'arg1', 'arg2'], env)
            self.fail('expected runbgcommand to fail with ENOENT')
        except OSError as ex:
            self.assertEqual(ex.errno, errno.ENOENT)

    def testbgcommandfailure2(self):
        '''runbgcommand() should throw if executing the process fails.'''
        env = os.environ.copy()
        try:
            extutil.runbgcommand([os.devnull, 'arg1', 'arg2'], env)
            self.fail('expected runbgcommand to fail with EACCES')
        except OSError as ex:
            self.assertEqual(ex.errno, errno.EACCES)

    def testflock(self):
        testtmp = os.environ["TESTTMP"]
        opener = vfs.vfs(testtmp)
        name = 'testlock'

        with extutil.flock(opener.join(name), 'testing a lock',
                           timeout=0):
            otherlock = self.otherprocesslock(opener, name)
            self.assertEquals(otherlock, locktimeout,
                              "other process should not have taken the lock")

        otherlock = self.otherprocesslock(opener, name)
        self.assertEquals(otherlock, locksuccess,
                        "other process should have taken the lock")

    def otherprocesslock(self, opener, name):
        pid = os.fork()
        if pid == 0:
            try:
                with extutil.flock(opener.join(name), 'other process lock',
                                   timeout=0):
                    os._exit(locksuccess)
            except error.LockHeld:
                os._exit(locktimeout)
        else:
            p, st = os.waitpid(pid, 0)
            st = worker._exitstatus(st) # Convert back to an int
            return st

if __name__ == '__main__':
    silenttestrunner.main(__name__)