from __future__ import absolute_import, division, print_function, with_statement

import collections
from contextlib import closing
import errno
import gzip
import logging
import os
import re
import socket
import ssl
import sys

from tornado.escape import to_unicode
from tornado import gen
from tornado.httpclient import AsyncHTTPClient
from tornado.httputil import HTTPHeaders, ResponseStartLine
from tornado.ioloop import IOLoop
from tornado.log import gen_log
from tornado.concurrent import Future
from tornado.netutil import Resolver, bind_sockets
from tornado.simple_httpclient import SimpleAsyncHTTPClient
from tornado.test.httpclient_test import ChunkHandler, CountdownHandler, HelloWorldHandler, RedirectHandler
from tornado.test import httpclient_test
from tornado.testing import AsyncHTTPTestCase, AsyncHTTPSTestCase, AsyncTestCase, ExpectLog
from tornado.test.util import skipOnTravis, skipIfNoIPv6, refusing_port, unittest, skipBefore35, exec_test
from tornado.web import RequestHandler, Application, asynchronous, url, stream_request_body


class SimpleHTTPClientCommonTestCase(httpclient_test.HTTPClientCommonTestCase):
    def get_http_client(self):
        client = SimpleAsyncHTTPClient(io_loop=self.io_loop,
                                       force_instance=True)
        self.assertTrue(isinstance(client, SimpleAsyncHTTPClient))
        return client


class TriggerHandler(RequestHandler):
    def initialize(self, queue, wake_callback):
        self.queue = queue
        self.wake_callback = wake_callback

    @asynchronous
    def get(self):
        logging.debug("queuing trigger")
        self.queue.append(self.finish)
        if self.get_argument("wake", "true") == "true":
            self.wake_callback()


class HangHandler(RequestHandler):
    @asynchronous
    def get(self):
        pass


class ContentLengthHandler(RequestHandler):
    def get(self):
        self.set_header("Content-Length", self.get_argument("value"))
        self.write("ok")


class HeadHandler(RequestHandler):
    def head(self):
        self.set_header("Content-Length", "7")


class OptionsHandler(RequestHandler):
    def options(self):
        self.set_header("Access-Control-Allow-Origin", "*")
        self.write("ok")


class NoContentHandler(RequestHandler):
    def get(self):
        self.set_status(204)
        self.finish()


class SeeOtherPostHandler(RequestHandler):
    def post(self):
        redirect_code = int(self.request.body)
        assert redirect_code in (302, 303), "unexpected body %r" % self.request.body
        self.set_header("Location", "/see_other_get")
        self.set_status(redirect_code)


class SeeOtherGetHandler(RequestHandler):
    def get(self):
        if self.request.body:
            raise Exception("unexpected body %r" % self.request.body)
        self.write("ok")


class HostEchoHandler(RequestHandler):
    def get(self):
        self.write(self.request.headers["Host"])


class NoContentLengthHandler(RequestHandler):
    @asynchronous
    def get(self):
        if self.request.version.startswith('HTTP/1'):
            # Emulate the old HTTP/1.0 behavior of returning a body with no
            # content-length.  Tornado handles content-length at the framework
            # level so we have to go around it.
            stream = self.request.connection.detach()
            stream.write(b"HTTP/1.0 200 OK\r\n\r\n"
                         b"hello")
            stream.close()
        else:
            self.finish('HTTP/1 required')


class EchoPostHandler(RequestHandler):
    def post(self):
        self.write(self.request.body)


@stream_request_body
class RespondInPrepareHandler(RequestHandler):
    def prepare(self):
        self.set_status(403)
        self.finish("forbidden")


class SimpleHTTPClientTestMixin(object):
    def get_app(self):
        # callable objects to finish pending /trigger requests
        self.triggers = collections.deque()
        return Application([
            url("/trigger", TriggerHandler, dict(queue=self.triggers,
                                                 wake_callback=self.stop)),
            url("/chunk", ChunkHandler),
            url("/countdown/([0-9]+)", CountdownHandler, name="countdown"),
            url("/hang", HangHandler),
            url("/hello", HelloWorldHandler),
            url("/content_length", ContentLengthHandler),
            url("/head", HeadHandler),
            url("/options", OptionsHandler),
            url("/no_content", NoContentHandler),
            url("/see_other_post", SeeOtherPostHandler),
            url("/see_other_get", SeeOtherGetHandler),
            url("/host_echo", HostEchoHandler),
            url("/no_content_length", NoContentLengthHandler),
            url("/echo_post", EchoPostHandler),
            url("/respond_in_prepare", RespondInPrepareHandler),
            url("/redirect", RedirectHandler),
        ], gzip=True)

    def test_singleton(self):
        # Class "constructor" reuses objects on the same IOLoop
        self.assertTrue(SimpleAsyncHTTPClient(self.io_loop) is
                        SimpleAsyncHTTPClient(self.io_loop))
        # unless force_instance is used
        self.assertTrue(SimpleAsyncHTTPClient(self.io_loop) is not
                        SimpleAsyncHTTPClient(self.io_loop,
                                              force_instance=True))
        # different IOLoops use different objects
        with closing(IOLoop()) as io_loop2:
            self.assertTrue(SimpleAsyncHTTPClient(self.io_loop) is not
                            SimpleAsyncHTTPClient(io_loop2))

    def test_connection_limit(self):
        with closing(self.create_client(max_clients=2)) as client:
            self.assertEqual(client.max_clients, 2)
            seen = []
            # Send 4 requests.  Two can be sent immediately, while the others
            # will be queued
            for i in range(4):
                client.fetch(self.get_url("/trigger"),
                             lambda response, i=i: (seen.append(i), self.stop()))
            self.wait(condition=lambda: len(self.triggers) == 2)
            self.assertEqual(len(client.queue), 2)

            # Finish the first two requests and let the next two through
            self.triggers.popleft()()
            self.triggers.popleft()()
            self.wait(condition=lambda: (len(self.triggers) == 2 and
                                         len(seen) == 2))
            self.assertEqual(set(seen), set([0, 1]))
            self.assertEqual(len(client.queue), 0)

            # Finish all the pending requests
            self.triggers.popleft()()
            self.triggers.popleft()()
            self.wait(condition=lambda: len(seen) == 4)
            self.assertEqual(set(seen), set([0, 1, 2, 3]))
            self.assertEqual(len(self.triggers), 0)

    def test_redirect_connection_limit(self):
        # following redirects should not consume additional connections
        with closing(self.create_client(max_clients=1)) as client:
            client.fetch(self.get_url('/countdown/3'), self.stop,
                         max_redirects=3)
            response = self.wait()
            response.rethrow()

    def test_gzip(self):
        # All the tests in this file should be using gzip, but this test
        # ensures that it is in fact getting compressed.
        # Setting Accept-Encoding manually bypasses the client's
        # decompression so we can see the raw data.
        response = self.fetch("/chunk", use_gzip=False,
                              headers={"Accept-Encoding": "gzip"})
        self.assertEqual(response.headers["Content-Encoding"], "gzip")
        self.assertNotEqual(response.body, b"asdfqwer")
        # Our test data gets bigger when gzipped.  Oops.  :)
        # Chunked encoding bypasses the MIN_LENGTH check.
        self.assertEqual(len(response.body), 34)
        f = gzip.GzipFile(mode="r", fileobj=response.buffer)
        self.assertEqual(f.read(), b"asdfqwer")

    def test_max_redirects(self):
        response = self.fetch("/countdown/5", max_redirects=3)
        self.assertEqual(302, response.code)
        # We requested 5, followed three redirects for 4, 3, 2, then the last
        # unfollowed redirect is to 1.
        self.assertTrue(response.request.url.endswith("/countdown/5"))
        self.assertTrue(response.effective_url.endswith("/countdown/2"))
        self.assertTrue(response.headers["Location"].endswith("/countdown/1"))

    def test_header_reuse(self):
        # Apps may reuse a headers object if they are only passing in constant
        # headers like user-agent.  The header object should not be modified.
        headers = HTTPHeaders({'User-Agent': 'Foo'})
        self.fetch("/hello", headers=headers)
        self.assertEqual(list(headers.get_all()), [('User-Agent', 'Foo')])

    def test_see_other_redirect(self):
        for code in (302, 303):
            response = self.fetch("/see_other_post", method="POST", body="%d" % code)
            self.assertEqual(200, response.code)
            self.assertTrue(response.request.url.endswith("/see_other_post"))
            self.assertTrue(response.effective_url.endswith("/see_other_get"))
            # request is the original request, is a POST still
            self.assertEqual("POST", response.request.method)

    @skipOnTravis
    def test_connect_timeout(self):
        timeout = 0.1
        timeout_min, timeout_max = 0.099, 1.0

        class TimeoutResolver(Resolver):
            def resolve(self, *args, **kwargs):
                return Future()  # never completes

        with closing(self.create_client(resolver=TimeoutResolver())) as client:
            client.fetch(self.get_url('/hello'), self.stop,
                         connect_timeout=timeout)
            response = self.wait()
            self.assertEqual(response.code, 599)
            self.assertTrue(timeout_min < response.request_time < timeout_max,
                            response.request_time)
            self.assertEqual(str(response.error), "HTTP 599: Timeout while connecting")

    @skipOnTravis
    def test_request_timeout(self):
        timeout = 0.1
        timeout_min, timeout_max = 0.099, 0.15
        if os.name == 'nt':
            timeout = 0.5
            timeout_min, timeout_max = 0.4, 0.6

        response = self.fetch('/trigger?wake=false', request_timeout=timeout)
        self.assertEqual(response.code, 599)
        self.assertTrue(timeout_min < response.request_time < timeout_max,
                        response.request_time)
        self.assertEqual(str(response.error), "HTTP 599: Timeout during request")
        # trigger the hanging request to let it clean up after itself
        self.triggers.popleft()()

    @skipIfNoIPv6
    def test_ipv6(self):
        try:
            [sock] = bind_sockets(None, '::1', family=socket.AF_INET6)
            port = sock.getsockname()[1]
            self.http_server.add_socket(sock)
        except socket.gaierror as e:
            if e.args[0] == socket.EAI_ADDRFAMILY:
                # python supports ipv6, but it's not configured on the network
                # interface, so skip this test.
                return
            raise
        url = '%s://[::1]:%d/hello' % (self.get_protocol(), port)

        # ipv6 is currently enabled by default but can be disabled
        self.http_client.fetch(url, self.stop, allow_ipv6=False)
        response = self.wait()
        self.assertEqual(response.code, 599)

        self.http_client.fetch(url, self.stop)
        response = self.wait()
        self.assertEqual(response.body, b"Hello world!")

    def xtest_multiple_content_length_accepted(self):
        response = self.fetch("/content_length?value=2,2")
        self.assertEqual(response.body, b"ok")
        response = self.fetch("/content_length?value=2,%202,2")
        self.assertEqual(response.body, b"ok")

        response = self.fetch("/content_length?value=2,4")
        self.assertEqual(response.code, 599)
        response = self.fetch("/content_length?value=2,%202,3")
        self.assertEqual(response.code, 599)

    def test_head_request(self):
        response = self.fetch("/head", method="HEAD")
        self.assertEqual(response.code, 200)
        self.assertEqual(response.headers["content-length"], "7")
        self.assertFalse(response.body)

    def test_options_request(self):
        response = self.fetch("/options", method="OPTIONS")
        self.assertEqual(response.code, 200)
        self.assertEqual(response.headers["content-length"], "2")
        self.assertEqual(response.headers["access-control-allow-origin"], "*")
        self.assertEqual(response.body, b"ok")

    def test_no_content(self):
        response = self.fetch("/no_content")
        self.assertEqual(response.code, 204)
        # 204 status shouldn't have a content-length
        #
        # Tests with a content-length header are included below
        # in HTTP204NoContentTestCase.
        self.assertNotIn("Content-Length", response.headers)

    def test_host_header(self):
        host_re = re.compile(b"^localhost:[0-9]+$")
        response = self.fetch("/host_echo")
        self.assertTrue(host_re.match(response.body))

        url = self.get_url("/host_echo").replace("http://", "http://me:secret@")
        self.http_client.fetch(url, self.stop)
        response = self.wait()
        self.assertTrue(host_re.match(response.body), response.body)

    def test_connection_refused(self):
        cleanup_func, port = refusing_port()
        self.addCleanup(cleanup_func)
        with ExpectLog(gen_log, ".*", required=False):
            self.http_client.fetch("http://127.0.0.1:%d/" % port, self.stop)
            response = self.wait()
        self.assertEqual(599, response.code)

        if sys.platform != 'cygwin':
            # cygwin returns EPERM instead of ECONNREFUSED here
            contains_errno = str(errno.ECONNREFUSED) in str(response.error)
            if not contains_errno and hasattr(errno, "WSAECONNREFUSED"):
                contains_errno = str(errno.WSAECONNREFUSED) in str(response.error)
            self.assertTrue(contains_errno, response.error)
            # This is usually "Connection refused".
            # On windows, strerror is broken and returns "Unknown error".
            expected_message = os.strerror(errno.ECONNREFUSED)
            self.assertTrue(expected_message in str(response.error),
                            response.error)

    def test_queue_timeout(self):
        with closing(self.create_client(max_clients=1)) as client:
            client.fetch(self.get_url('/trigger'), self.stop,
                         request_timeout=10)
            # Wait for the trigger request to block, not complete.
            self.wait()
            client.fetch(self.get_url('/hello'), self.stop,
                         connect_timeout=0.1)
            response = self.wait()

            self.assertEqual(response.code, 599)
            self.assertTrue(response.request_time < 1, response.request_time)
            self.assertEqual(str(response.error), "HTTP 599: Timeout in request queue")
            self.triggers.popleft()()
            self.wait()

    def test_no_content_length(self):
        response = self.fetch("/no_content_length")
        if response.body == b"HTTP/1 required":
            self.skipTest("requires HTTP/1.x")
        else:
            self.assertEquals(b"hello", response.body)

    def sync_body_producer(self, write):
        write(b'1234')
        write(b'5678')

    @gen.coroutine
    def async_body_producer(self, write):
        yield write(b'1234')
        yield gen.Task(IOLoop.current().add_callback)
        yield write(b'5678')

    def test_sync_body_producer_chunked(self):
        response = self.fetch("/echo_post", method="POST",
                              body_producer=self.sync_body_producer)
        response.rethrow()
        self.assertEqual(response.body, b"12345678")

    def test_sync_body_producer_content_length(self):
        response = self.fetch("/echo_post", method="POST",
                              body_producer=self.sync_body_producer,
                              headers={'Content-Length': '8'})
        response.rethrow()
        self.assertEqual(response.body, b"12345678")

    def test_async_body_producer_chunked(self):
        response = self.fetch("/echo_post", method="POST",
                              body_producer=self.async_body_producer)
        response.rethrow()
        self.assertEqual(response.body, b"12345678")

    def test_async_body_producer_content_length(self):
        response = self.fetch("/echo_post", method="POST",
                              body_producer=self.async_body_producer,
                              headers={'Content-Length': '8'})
        response.rethrow()
        self.assertEqual(response.body, b"12345678")

    @skipBefore35
    def test_native_body_producer_chunked(self):
        namespace = exec_test(globals(), locals(), """
        async def body_producer(write):
            await write(b'1234')
            await gen.Task(IOLoop.current().add_callback)
            await write(b'5678')
        """)
        response = self.fetch("/echo_post", method="POST",
                              body_producer=namespace["body_producer"])
        response.rethrow()
        self.assertEqual(response.body, b"12345678")

    @skipBefore35
    def test_native_body_producer_content_length(self):
        namespace = exec_test(globals(), locals(), """
        async def body_producer(write):
            await write(b'1234')
            await gen.Task(IOLoop.current().add_callback)
            await write(b'5678')
        """)
        response = self.fetch("/echo_post", method="POST",
                              body_producer=namespace["body_producer"],
                              headers={'Content-Length': '8'})
        response.rethrow()
        self.assertEqual(response.body, b"12345678")

    def test_100_continue(self):
        response = self.fetch("/echo_post", method="POST",
                              body=b"1234",
                              expect_100_continue=True)
        self.assertEqual(response.body, b"1234")

    def test_100_continue_early_response(self):
        def body_producer(write):
            raise Exception("should not be called")
        response = self.fetch("/respond_in_prepare", method="POST",
                              body_producer=body_producer,
                              expect_100_continue=True)
        self.assertEqual(response.code, 403)

    def test_streaming_follow_redirects(self):
        # When following redirects, header and streaming callbacks
        # should only be called for the final result.
        # TODO(bdarnell): this test belongs in httpclient_test instead of
        # simple_httpclient_test, but it fails with the version of libcurl
        # available on travis-ci. Move it when that has been upgraded
        # or we have a better framework to skip tests based on curl version.
        headers = []
        chunks = []
        self.fetch("/redirect?url=/hello",
                   header_callback=headers.append,
                   streaming_callback=chunks.append)
        chunks = list(map(to_unicode, chunks))
        self.assertEqual(chunks, ['Hello world!'])
        # Make sure we only got one set of headers.
        num_start_lines = len([h for h in headers if h.startswith("HTTP/")])
        self.assertEqual(num_start_lines, 1)


class SimpleHTTPClientTestCase(SimpleHTTPClientTestMixin, AsyncHTTPTestCase):
    def setUp(self):
        super(SimpleHTTPClientTestCase, self).setUp()
        self.http_client = self.create_client()

    def create_client(self, **kwargs):
        return SimpleAsyncHTTPClient(self.io_loop, force_instance=True,
                                     **kwargs)


class SimpleHTTPSClientTestCase(SimpleHTTPClientTestMixin, AsyncHTTPSTestCase):
    def setUp(self):
        super(SimpleHTTPSClientTestCase, self).setUp()
        self.http_client = self.create_client()

    def create_client(self, **kwargs):
        return SimpleAsyncHTTPClient(self.io_loop, force_instance=True,
                                     defaults=dict(validate_cert=False),
                                     **kwargs)

    def test_ssl_options(self):
        resp = self.fetch("/hello", ssl_options={})
        self.assertEqual(resp.body, b"Hello world!")

    @unittest.skipIf(not hasattr(ssl, 'SSLContext'),
                     'ssl.SSLContext not present')
    def test_ssl_context(self):
        resp = self.fetch("/hello",
                          ssl_options=ssl.SSLContext(ssl.PROTOCOL_SSLv23))
        self.assertEqual(resp.body, b"Hello world!")

    def test_ssl_options_handshake_fail(self):
        with ExpectLog(gen_log, "SSL Error|Uncaught exception",
                       required=False):
            resp = self.fetch(
                "/hello", ssl_options=dict(cert_reqs=ssl.CERT_REQUIRED))
        self.assertRaises(ssl.SSLError, resp.rethrow)

    @unittest.skipIf(not hasattr(ssl, 'SSLContext'),
                     'ssl.SSLContext not present')
    def test_ssl_context_handshake_fail(self):
        with ExpectLog(gen_log, "SSL Error|Uncaught exception"):
            ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
            ctx.verify_mode = ssl.CERT_REQUIRED
            resp = self.fetch("/hello", ssl_options=ctx)
        self.assertRaises(ssl.SSLError, resp.rethrow)

    def test_error_logging(self):
        # No stack traces are logged for SSL errors (in this case,
        # failure to validate the testing self-signed cert).
        # The SSLError is exposed through ssl.SSLError.
        with ExpectLog(gen_log, '.*') as expect_log:
            response = self.fetch("/", validate_cert=True)
            self.assertEqual(response.code, 599)
            self.assertIsInstance(response.error, ssl.SSLError)
        self.assertFalse(expect_log.logged_stack)


class CreateAsyncHTTPClientTestCase(AsyncTestCase):
    def setUp(self):
        super(CreateAsyncHTTPClientTestCase, self).setUp()
        self.saved = AsyncHTTPClient._save_configuration()

    def tearDown(self):
        AsyncHTTPClient._restore_configuration(self.saved)
        super(CreateAsyncHTTPClientTestCase, self).tearDown()

    def test_max_clients(self):
        AsyncHTTPClient.configure(SimpleAsyncHTTPClient)
        with closing(AsyncHTTPClient(
                self.io_loop, force_instance=True)) as client:
            self.assertEqual(client.max_clients, 10)
        with closing(AsyncHTTPClient(
                self.io_loop, max_clients=11, force_instance=True)) as client:
            self.assertEqual(client.max_clients, 11)

        # Now configure max_clients statically and try overriding it
        # with each way max_clients can be passed
        AsyncHTTPClient.configure(SimpleAsyncHTTPClient, max_clients=12)
        with closing(AsyncHTTPClient(
                self.io_loop, force_instance=True)) as client:
            self.assertEqual(client.max_clients, 12)
        with closing(AsyncHTTPClient(
                self.io_loop, max_clients=13, force_instance=True)) as client:
            self.assertEqual(client.max_clients, 13)
        with closing(AsyncHTTPClient(
                self.io_loop, max_clients=14, force_instance=True)) as client:
            self.assertEqual(client.max_clients, 14)


class HTTP100ContinueTestCase(AsyncHTTPTestCase):
    def respond_100(self, request):
        self.http1 = request.version.startswith('HTTP/1.')
        if not self.http1:
            request.connection.write_headers(ResponseStartLine('', 200, 'OK'),
                                             HTTPHeaders())
            request.connection.finish()
            return
        self.request = request
        self.request.connection.stream.write(
            b"HTTP/1.1 100 CONTINUE\r\n\r\n",
            self.respond_200)

    def respond_200(self):
        self.request.connection.stream.write(
            b"HTTP/1.1 200 OK\r\nContent-Length: 1\r\n\r\nA",
            self.request.connection.stream.close)

    def get_app(self):
        # Not a full Application, but works as an HTTPServer callback
        return self.respond_100

    def test_100_continue(self):
        res = self.fetch('/')
        if not self.http1:
            self.skipTest("requires HTTP/1.x")
        self.assertEqual(res.body, b'A')


class HTTP204NoContentTestCase(AsyncHTTPTestCase):
    def respond_204(self, request):
        self.http1 = request.version.startswith('HTTP/1.')
        if not self.http1:
            # Close the request cleanly in HTTP/2; it will be skipped anyway.
            request.connection.write_headers(ResponseStartLine('', 200, 'OK'),
                                             HTTPHeaders())
            request.connection.finish()
            return

        # A 204 response never has a body, even if doesn't have a content-length
        # (which would otherwise mean read-until-close).  We simulate here a
        # server that sends no content length and does not close the connection.
        #
        # Tests of a 204 response with no Content-Length header are included
        # in SimpleHTTPClientTestMixin.
        stream = request.connection.detach()
        stream.write(b"HTTP/1.1 204 No content\r\n")
        if request.arguments.get("error", [False])[-1]:
            stream.write(b"Content-Length: 5\r\n")
        else:
            stream.write(b"Content-Length: 0\r\n")
        stream.write(b"\r\n")
        stream.close()

    def get_app(self):
        return self.respond_204

    def test_204_no_content(self):
        resp = self.fetch('/')
        if not self.http1:
            self.skipTest("requires HTTP/1.x")
        self.assertEqual(resp.code, 204)
        self.assertEqual(resp.body, b'')

    def test_204_invalid_content_length(self):
        # 204 status with non-zero content length is malformed
        with ExpectLog(gen_log, ".*Response with code 204 should not have body"):
            response = self.fetch("/?error=1")
            if not self.http1:
                self.skipTest("requires HTTP/1.x")
            if self.http_client.configured_class != SimpleAsyncHTTPClient:
                self.skipTest("curl client accepts invalid headers")
            self.assertEqual(response.code, 599)


class HostnameMappingTestCase(AsyncHTTPTestCase):
    def setUp(self):
        super(HostnameMappingTestCase, self).setUp()
        self.http_client = SimpleAsyncHTTPClient(
            self.io_loop,
            hostname_mapping={
                'www.example.com': '127.0.0.1',
                ('foo.example.com', 8000): ('127.0.0.1', self.get_http_port()),
            })

    def get_app(self):
        return Application([url("/hello", HelloWorldHandler), ])

    def test_hostname_mapping(self):
        self.http_client.fetch(
            'http://www.example.com:%d/hello' % self.get_http_port(), self.stop)
        response = self.wait()
        response.rethrow()
        self.assertEqual(response.body, b'Hello world!')

    def test_port_mapping(self):
        self.http_client.fetch('http://foo.example.com:8000/hello', self.stop)
        response = self.wait()
        response.rethrow()
        self.assertEqual(response.body, b'Hello world!')


class ResolveTimeoutTestCase(AsyncHTTPTestCase):
    def setUp(self):
        # Dummy Resolver subclass that never invokes its callback.
        class BadResolver(Resolver):
            def resolve(self, *args, **kwargs):
                pass

        super(ResolveTimeoutTestCase, self).setUp()
        self.http_client = SimpleAsyncHTTPClient(
            self.io_loop,
            resolver=BadResolver())

    def get_app(self):
        return Application([url("/hello", HelloWorldHandler), ])

    def test_resolve_timeout(self):
        response = self.fetch('/hello', connect_timeout=0.1)
        self.assertEqual(response.code, 599)


class MaxHeaderSizeTest(AsyncHTTPTestCase):
    def get_app(self):
        class SmallHeaders(RequestHandler):
            def get(self):
                self.set_header("X-Filler", "a" * 100)
                self.write("ok")

        class LargeHeaders(RequestHandler):
            def get(self):
                self.set_header("X-Filler", "a" * 1000)
                self.write("ok")

        return Application([('/small', SmallHeaders),
                            ('/large', LargeHeaders)])

    def get_http_client(self):
        return SimpleAsyncHTTPClient(io_loop=self.io_loop, max_header_size=1024)

    def test_small_headers(self):
        response = self.fetch('/small')
        response.rethrow()
        self.assertEqual(response.body, b'ok')

    def test_large_headers(self):
        with ExpectLog(gen_log, "Unsatisfiable read"):
            response = self.fetch('/large')
        self.assertEqual(response.code, 599)


class MaxBodySizeTest(AsyncHTTPTestCase):
    def get_app(self):
        class SmallBody(RequestHandler):
            def get(self):
                self.write("a" * 1024 * 64)

        class LargeBody(RequestHandler):
            def get(self):
                self.write("a" * 1024 * 100)

        return Application([('/small', SmallBody),
                            ('/large', LargeBody)])

    def get_http_client(self):
        return SimpleAsyncHTTPClient(io_loop=self.io_loop, max_body_size=1024 * 64)

    def test_small_body(self):
        response = self.fetch('/small')
        response.rethrow()
        self.assertEqual(response.body, b'a' * 1024 * 64)

    def test_large_body(self):
        with ExpectLog(gen_log, "Malformed HTTP message from None: Content-Length too long"):
            response = self.fetch('/large')
        self.assertEqual(response.code, 599)


class MaxBufferSizeTest(AsyncHTTPTestCase):
    def get_app(self):

        class LargeBody(RequestHandler):
            def get(self):
                self.write("a" * 1024 * 100)

        return Application([('/large', LargeBody)])

    def get_http_client(self):
        # 100KB body with 64KB buffer
        return SimpleAsyncHTTPClient(io_loop=self.io_loop, max_body_size=1024 * 100, max_buffer_size=1024 * 64)

    def test_large_body(self):
        response = self.fetch('/large')
        response.rethrow()
        self.assertEqual(response.body, b'a' * 1024 * 100)


class ChunkedWithContentLengthTest(AsyncHTTPTestCase):
    def get_app(self):

        class ChunkedWithContentLength(RequestHandler):
            def get(self):
                # Add an invalid Transfer-Encoding to the response
                self.set_header('Transfer-Encoding', 'chunked')
                self.write("Hello world")

        return Application([('/chunkwithcl', ChunkedWithContentLength)])

    def get_http_client(self):
        return SimpleAsyncHTTPClient()

    def test_chunked_with_content_length(self):
        # Make sure the invalid headers are detected
        with ExpectLog(gen_log, ("Malformed HTTP message from None: Response "
                                 "with both Transfer-Encoding and Content-Length")):
            response = self.fetch('/chunkwithcl')
        self.assertEqual(response.code, 599)
