import contextlib
import errno
import sysconfig
import unittest
from unittest import mock
from test import support
from test.support import os_helper
from test.support import socket_helper
from test.support import ResourceDenied
from test.support.warnings_helper import check_no_resource_warning

import os
import socket
import urllib.error
import urllib.request
import sys

support.requires("network")


def _retry_thrice(func, exc, *args, **kwargs):
    for i in range(3):
        try:
            return func(*args, **kwargs)
        except exc as e:
            last_exc = e
            continue
    raise last_exc

def _wrap_with_retry_thrice(func, exc):
    def wrapped(*args, **kwargs):
        return _retry_thrice(func, exc, *args, **kwargs)
    return wrapped

# Connecting to remote hosts is flaky.  Make it more robust by retrying
# the connection several times.
_urlopen_with_retry = _wrap_with_retry_thrice(urllib.request.urlopen,
                                              urllib.error.URLError)


class TransientResource(object):

    """Raise ResourceDenied if an exception is raised while the context manager
    is in effect that matches the specified exception and attributes."""

    def __init__(self, exc, **kwargs):
        self.exc = exc
        self.attrs = kwargs

    def __enter__(self):
        return self

    def __exit__(self, type_=None, value=None, traceback=None):
        """If type_ is a subclass of self.exc and value has attributes matching
        self.attrs, raise ResourceDenied.  Otherwise let the exception
        propagate (if any)."""
        if type_ is not None and issubclass(self.exc, type_):
            for attr, attr_value in self.attrs.items():
                if not hasattr(value, attr):
                    break
                if getattr(value, attr) != attr_value:
                    break
            else:
                raise ResourceDenied("an optional resource is not available")

# Context managers that raise ResourceDenied when various issues
# with the internet connection manifest themselves as exceptions.
# XXX deprecate these and use transient_internet() instead
time_out = TransientResource(OSError, errno=errno.ETIMEDOUT)
socket_peer_reset = TransientResource(OSError, errno=errno.ECONNRESET)
ioerror_peer_reset = TransientResource(OSError, errno=errno.ECONNRESET)


class AuthTests(unittest.TestCase):
    """Tests urllib2 authentication features."""

## Disabled at the moment since there is no page under python.org which
## could be used to HTTP authentication.
#
#    def test_basic_auth(self):
#        import http.client
#
#        test_url = "http://www.python.org/test/test_urllib2/basic_auth"
#        test_hostport = "www.python.org"
#        test_realm = 'Test Realm'
#        test_user = 'test.test_urllib2net'
#        test_password = 'blah'
#
#        # failure
#        try:
#            _urlopen_with_retry(test_url)
#        except urllib2.HTTPError, exc:
#            self.assertEqual(exc.code, 401)
#        else:
#            self.fail("urlopen() should have failed with 401")
#
#        # success
#        auth_handler = urllib2.HTTPBasicAuthHandler()
#        auth_handler.add_password(test_realm, test_hostport,
#                                  test_user, test_password)
#        opener = urllib2.build_opener(auth_handler)
#        f = opener.open('http://localhost/')
#        response = _urlopen_with_retry("http://www.python.org/")
#
#        # The 'userinfo' URL component is deprecated by RFC 3986 for security
#        # reasons, let's not implement it!  (it's already implemented for proxy
#        # specification strings (that is, URLs or authorities specifying a
#        # proxy), so we must keep that)
#        self.assertRaises(http.client.InvalidURL,
#                          urllib2.urlopen, "http://evil:thing@example.com")


class CloseSocketTest(unittest.TestCase):

    def test_close(self):
        # clear _opener global variable
        self.addCleanup(urllib.request.urlcleanup)

        # calling .close() on urllib2's response objects should close the
        # underlying socket
        url = support.TEST_HTTP_URL
        with socket_helper.transient_internet(url):
            response = _urlopen_with_retry(url)
            sock = response.fp
            self.assertFalse(sock.closed)
            response.close()
            self.assertTrue(sock.closed)

class OtherNetworkTests(unittest.TestCase):
    def setUp(self):
        if 0:  # for debugging
            import logging
            logger = logging.getLogger("test_urllib2net")
            logger.addHandler(logging.StreamHandler())

    # XXX The rest of these tests aren't very good -- they don't check much.
    # They do sometimes catch some major disasters, though.

    @support.requires_resource('walltime')
    def test_ftp(self):
        # Testing the same URL twice exercises the caching in CacheFTPHandler
        urls = [
            'ftp://www.pythontest.net/README',
            'ftp://www.pythontest.net/README',
            ('ftp://www.pythontest.net/non-existent-file',
             None, urllib.error.URLError),
            ]
        self._test_urls(urls, self._extra_handlers())

    @support.requires_resource('walltime')
    @unittest.skipIf(sysconfig.get_platform() == 'linux-ppc64le',
                     'leaks on PPC64LE (gh-140691)')
    def test_ftp_no_leak(self):
        # gh-140691: When the data connection (but not control connection)
        # cannot be made established, we shouldn't leave an open socket object.

        class MockError(OSError):
            pass

        orig_create_connection = socket.create_connection
        def patched_create_connection(address, *args, **kwargs):
            """Simulate REJECTing connections to ports other than 21"""
            host, port = address
            if port != 21:
                raise MockError()
            return orig_create_connection(address, *args, **kwargs)

        url = 'ftp://www.pythontest.net/README'
        entry = url, None, urllib.error.URLError
        no_cache_handlers = [urllib.request.FTPHandler()]
        cache_handlers = self._extra_handlers()
        with mock.patch('socket.create_connection', patched_create_connection):
            with check_no_resource_warning(self):
                # Try without CacheFTPHandler
                self._test_urls([entry], handlers=no_cache_handlers,
                                retry=False)
            with check_no_resource_warning(self):
                # Try with CacheFTPHandler (uncached)
                self._test_urls([entry], cache_handlers, retry=False)
            with check_no_resource_warning(self):
                # Try with CacheFTPHandler (cached)
                self._test_urls([entry], cache_handlers, retry=False)
        # Try without the mock: the handler should not use a closed connection
        with check_no_resource_warning(self):
            self._test_urls([url], cache_handlers, retry=False)

    def test_file(self):
        TESTFN = os_helper.TESTFN
        f = open(TESTFN, 'w')
        try:
            f.write('hi there\n')
            f.close()
            urls = [
                urllib.request.pathname2url(os.path.abspath(TESTFN), add_scheme=True),
                ('file:///nonsensename/etc/passwd', None,
                 urllib.error.URLError),
                ]
            self._test_urls(urls, self._extra_handlers(), retry=True)
        finally:
            os.remove(TESTFN)

        self.assertRaises(ValueError, urllib.request.urlopen,'./relative_path/to/file')

    # XXX Following test depends on machine configurations that are internal
    # to CNRI.  Need to set up a public server with the right authentication
    # configuration for test purposes.

##     def test_cnri(self):
##         if socket.gethostname() == 'bitdiddle':
##             localhost = 'bitdiddle.cnri.reston.va.us'
##         elif socket.gethostname() == 'bitdiddle.concentric.net':
##             localhost = 'localhost'
##         else:
##             localhost = None
##         if localhost is not None:
##             urls = [
##                 'file://%s/etc/passwd' % localhost,
##                 'http://%s/simple/' % localhost,
##                 'http://%s/digest/' % localhost,
##                 'http://%s/not/found.h' % localhost,
##                 ]

##             bauth = HTTPBasicAuthHandler()
##             bauth.add_password('basic_test_realm', localhost, 'jhylton',
##                                'password')
##             dauth = HTTPDigestAuthHandler()
##             dauth.add_password('digest_test_realm', localhost, 'jhylton',
##                                'password')

##             self._test_urls(urls, self._extra_handlers()+[bauth, dauth])

    def test_urlwithfrag(self):
        urlwith_frag = "http://www.pythontest.net/index.html#frag"
        with socket_helper.transient_internet(urlwith_frag):
            req = urllib.request.Request(urlwith_frag)
            res = urllib.request.urlopen(req)
            self.assertEqual(res.geturl(),
                    "http://www.pythontest.net/index.html#frag")

    @support.requires_resource('walltime')
    def test_redirect_url_withfrag(self):
        redirect_url_with_frag = "http://www.pythontest.net/redir/with_frag/"
        with socket_helper.transient_internet(redirect_url_with_frag):
            req = urllib.request.Request(redirect_url_with_frag)
            res = urllib.request.urlopen(req)
            self.assertEqual(res.geturl(),
                    "http://www.pythontest.net/elsewhere/#frag")

    def test_custom_headers(self):
        url = support.TEST_HTTP_URL
        with socket_helper.transient_internet(url):
            opener = urllib.request.build_opener()
            request = urllib.request.Request(url)
            self.assertFalse(request.header_items())
            opener.open(request)
            self.assertTrue(request.header_items())
            self.assertTrue(request.has_header('User-agent'))
            request.add_header('User-Agent','Test-Agent')
            opener.open(request)
            self.assertEqual(request.get_header('User-agent'),'Test-Agent')

    def _test_urls(self, urls, handlers, retry=True):
        import time
        import logging
        debug = logging.getLogger("test_urllib2").debug

        urlopen = urllib.request.build_opener(*handlers).open
        if retry:
            urlopen = _wrap_with_retry_thrice(urlopen, urllib.error.URLError)

        for url in urls:
            with self.subTest(url=url):
                if isinstance(url, tuple):
                    url, req, expected_err = url
                else:
                    req = expected_err = None

                if expected_err:
                    context = self.assertRaises(expected_err)
                else:
                    context = contextlib.nullcontext()

                with socket_helper.transient_internet(url):
                    f = None
                    with context:
                        f = urlopen(url, req, support.INTERNET_TIMEOUT)
                    if f is not None:
                        try:
                            with time_out, \
                                 socket_peer_reset, \
                                 ioerror_peer_reset:
                                buf = f.read()
                                debug("read %d bytes" % len(buf))
                        except TimeoutError:
                            print("<timeout: %s>" % url, file=sys.stderr)
                        f.close()
                time.sleep(0.1)

    def _extra_handlers(self):
        handlers = []

        cfh = urllib.request.CacheFTPHandler()
        self.addCleanup(cfh.clear_cache)
        cfh.setTimeout(1)
        handlers.append(cfh)

        return handlers


class TimeoutTest(unittest.TestCase):
    def setUp(self):
        # clear _opener global variable
        self.addCleanup(urllib.request.urlcleanup)

    def test_http_basic(self):
        self.assertIsNone(socket.getdefaulttimeout())
        url = support.TEST_HTTP_URL
        with socket_helper.transient_internet(url, timeout=None):
            u = _urlopen_with_retry(url)
            self.addCleanup(u.close)
            self.assertIsNone(u.fp.raw._sock.gettimeout())

    def test_http_default_timeout(self):
        self.assertIsNone(socket.getdefaulttimeout())
        url = support.TEST_HTTP_URL
        with socket_helper.transient_internet(url):
            socket.setdefaulttimeout(60)
            try:
                u = _urlopen_with_retry(url)
                self.addCleanup(u.close)
            finally:
                socket.setdefaulttimeout(None)
            self.assertEqual(u.fp.raw._sock.gettimeout(), 60)

    def test_http_no_timeout(self):
        self.assertIsNone(socket.getdefaulttimeout())
        url = support.TEST_HTTP_URL
        with socket_helper.transient_internet(url):
            socket.setdefaulttimeout(60)
            try:
                u = _urlopen_with_retry(url, timeout=None)
                self.addCleanup(u.close)
            finally:
                socket.setdefaulttimeout(None)
            self.assertIsNone(u.fp.raw._sock.gettimeout())

    def test_http_timeout(self):
        url = support.TEST_HTTP_URL
        with socket_helper.transient_internet(url):
            u = _urlopen_with_retry(url, timeout=120)
            self.addCleanup(u.close)
            self.assertEqual(u.fp.raw._sock.gettimeout(), 120)

    FTP_HOST = 'ftp://www.pythontest.net/'

    @support.requires_resource('walltime')
    def test_ftp_basic(self):
        self.assertIsNone(socket.getdefaulttimeout())
        with socket_helper.transient_internet(self.FTP_HOST, timeout=None):
            u = _urlopen_with_retry(self.FTP_HOST)
            self.addCleanup(u.close)
            self.assertIsNone(u.fp.fp.raw._sock.gettimeout())

    def test_ftp_default_timeout(self):
        self.assertIsNone(socket.getdefaulttimeout())
        with socket_helper.transient_internet(self.FTP_HOST):
            socket.setdefaulttimeout(60)
            try:
                u = _urlopen_with_retry(self.FTP_HOST)
                self.addCleanup(u.close)
            finally:
                socket.setdefaulttimeout(None)
            self.assertEqual(u.fp.fp.raw._sock.gettimeout(), 60)

    @support.requires_resource('walltime')
    def test_ftp_no_timeout(self):
        self.assertIsNone(socket.getdefaulttimeout())
        with socket_helper.transient_internet(self.FTP_HOST):
            socket.setdefaulttimeout(60)
            try:
                u = _urlopen_with_retry(self.FTP_HOST, timeout=None)
                self.addCleanup(u.close)
            finally:
                socket.setdefaulttimeout(None)
            self.assertIsNone(u.fp.fp.raw._sock.gettimeout())

    @support.requires_resource('walltime')
    def test_ftp_timeout(self):
        with socket_helper.transient_internet(self.FTP_HOST):
            u = _urlopen_with_retry(self.FTP_HOST, timeout=60)
            self.addCleanup(u.close)
            self.assertEqual(u.fp.fp.raw._sock.gettimeout(), 60)


if __name__ == "__main__":
    unittest.main()