# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
Test strerror
"""

import socket
import os

from twisted.trial.unittest import TestCase
from twisted.internet.tcp import ECONNABORTED
from twisted.python.win32 import _ErrorFormatter, formatError
from twisted.python.runtime import platform


class _MyWindowsException(OSError):
"""
An exception type like L{ctypes.WinError}, but available on all platforms.
"""



class ErrorFormatingTestCase(TestCase):
"""
Tests for C{_ErrorFormatter.formatError}.
"""
probeErrorCode = ECONNABORTED
probeMessage = "correct message value"

def test_strerrorFormatting(self):
"""
L{_ErrorFormatter.formatError} should use L{os.strerror} to format
error messages if it is constructed without any better mechanism.
"""
formatter = _ErrorFormatter(None, None, None)
message = formatter.formatError(self.probeErrorCode)
self.assertEqual(message, os.strerror(self.probeErrorCode))


def test_emptyErrorTab(self):
"""
L{_ErrorFormatter.formatError} should use L{os.strerror} to format
error messages if it is constructed with only an error tab which does
not contain the error code it is called with.
"""
error = 1
# Sanity check
self.assertNotEqual(self.probeErrorCode, error)
formatter = _ErrorFormatter(None, None, {error: 'wrong message'})
message = formatter.formatError(self.probeErrorCode)
self.assertEqual(message, os.strerror(self.probeErrorCode))


def test_errorTab(self):
"""
L{_ErrorFormatter.formatError} should use C{errorTab} if it is supplied
and contains the requested error code.
"""
formatter = _ErrorFormatter(
None, None, {self.probeErrorCode: self.probeMessage})
message = formatter.formatError(self.probeErrorCode)
self.assertEqual(message, self.probeMessage)


def test_formatMessage(self):
"""
L{_ErrorFormatter.formatError} should return the return value of
C{formatMessage} if it is supplied.
"""
formatCalls = []
def formatMessage(errorCode):
formatCalls.append(errorCode)
return self.probeMessage
formatter = _ErrorFormatter(
None, formatMessage, {self.probeErrorCode: 'wrong message'})
message = formatter.formatError(self.probeErrorCode)
self.assertEqual(message, self.probeMessage)
self.assertEqual(formatCalls, [self.probeErrorCode])


def test_winError(self):
"""
L{_ErrorFormatter.formatError} should return the message argument from
the exception L{winError} returns, if L{winError} is supplied.
"""
winCalls = []
def winError(errorCode):
winCalls.append(errorCode)
return _MyWindowsException(errorCode, self.probeMessage)
formatter = _ErrorFormatter(
winError,
lambda error: 'formatMessage: wrong message',
{self.probeErrorCode: 'errorTab: wrong message'})
message = formatter.formatError(self.probeErrorCode)
self.assertEqual(message, self.probeMessage)


def test_fromEnvironment(self):
"""
L{_ErrorFormatter.fromEnvironment} should create an L{_ErrorFormatter}
instance with attributes populated from available modules.
"""
formatter = _ErrorFormatter.fromEnvironment()

if formatter.winError is not None:
from ctypes import WinError
self.assertEqual(
formatter.formatError(self.probeErrorCode),
WinError(self.probeErrorCode).strerror)
formatter.winError = None

if formatter.formatMessage is not None:
from win32api import FormatMessage
self.assertEqual(
formatter.formatError(self.probeErrorCode),
FormatMessage(self.probeErrorCode))
formatter.formatMessage = None

if formatter.errorTab is not None:
from socket import errorTab
self.assertEqual(
formatter.formatError(self.probeErrorCode),
errorTab[self.probeErrorCode])

if platform.getType() != "win32":
test_fromEnvironment.skip = "Test will run only on Windows."


def test_correctLookups(self):
"""
Given an known-good errno, make sure that formatMessage gives results
matching either C{socket.errorTab}, C{ctypes.WinError}, or
C{win32api.FormatMessage}.
"""
acceptable = [socket.errorTab[ECONNABORTED]]
try:
from ctypes import WinError
acceptable.append(WinError(ECONNABORTED).strerror)
except ImportError:
pass
try:
from win32api import FormatMessage
acceptable.append(FormatMessage(ECONNABORTED))
except ImportError:
pass

self.assertIn(formatError(ECONNABORTED), acceptable)

if platform.getType() != "win32":
test_correctLookups.skip = "Test will run only on Windows."