from __future__ import absolute_import, division, print_function

import base64
import binascii
from contextlib import closing
import copy
import functools
import sys
import threading
import datetime
from io import BytesIO

from tornado.escape import utf8, native_str
from tornado import gen
from tornado.httpclient import HTTPRequest, HTTPResponse, _RequestProxy, HTTPError, HTTPClient
from tornado.httpserver import HTTPServer
from tornado.ioloop import IOLoop
from tornado.iostream import IOStream
from tornado.log import gen_log
from tornado import netutil
from tornado.stack_context import ExceptionStackContext, NullContext
from tornado.testing import AsyncHTTPTestCase, bind_unused_port, gen_test, ExpectLog
from tornado.test.util import unittest, skipOnTravis
from tornado.web import Application, RequestHandler, url
from tornado.httputil import format_timestamp, HTTPHeaders


class HelloWorldHandler(RequestHandler):
    def get(self):
        name = self.get_argument("name", "world")
        self.set_header("Content-Type", "text/plain")
        self.finish("Hello %s!" % name)


class PostHandler(RequestHandler):
    def post(self):
        self.finish("Post arg1: %s, arg2: %s" % (
            self.get_argument("arg1"), self.get_argument("arg2")))


class PutHandler(RequestHandler):
    def put(self):
        self.write("Put body: ")
        self.write(self.request.body)


class RedirectHandler(RequestHandler):
    def prepare(self):
        self.write('redirects can have bodies too')
        self.redirect(self.get_argument("url"),
                      status=int(self.get_argument("status", "302")))


class ChunkHandler(RequestHandler):
    @gen.coroutine
    def get(self):
        self.write("asdf")
        self.flush()
        # Wait a bit to ensure the chunks are sent and received separately.
        yield gen.sleep(0.01)
        self.write("qwer")


class AuthHandler(RequestHandler):
    def get(self):
        self.finish(self.request.headers["Authorization"])


class CountdownHandler(RequestHandler):
    def get(self, count):
        count = int(count)
        if count > 0:
            self.redirect(self.reverse_url("countdown", count - 1))
        else:
            self.write("Zero")


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


class UserAgentHandler(RequestHandler):
    def get(self):
        self.write(self.request.headers.get('User-Agent', 'User agent not set'))


class ContentLength304Handler(RequestHandler):
    def get(self):
        self.set_status(304)
        self.set_header('Content-Length', 42)

    def _clear_headers_for_304(self):
        # Tornado strips content-length from 304 responses, but here we
        # want to simulate servers that include the headers anyway.
        pass


class PatchHandler(RequestHandler):

    def patch(self):
        "Return the request payload - so we can check it is being kept"
        self.write(self.request.body)


class AllMethodsHandler(RequestHandler):
    SUPPORTED_METHODS = RequestHandler.SUPPORTED_METHODS + ('OTHER',)

    def method(self):
        self.write(self.request.method)

    get = post = put = delete = options = patch = other = method


class SetHeaderHandler(RequestHandler):
    def get(self):
        # Use get_arguments for keys to get strings, but
        # request.arguments for values to get bytes.
        for k, v in zip(self.get_arguments('k'),
                        self.request.arguments['v']):
            self.set_header(k, v)

# These tests end up getting run redundantly: once here with the default
# HTTPClient implementation, and then again in each implementation's own
# test suite.


class HTTPClientCommonTestCase(AsyncHTTPTestCase):
    def get_app(self):
        return Application([
            url("/hello", HelloWorldHandler),
            url("/post", PostHandler),
            url("/put", PutHandler),
            url("/redirect", RedirectHandler),
            url("/chunk", ChunkHandler),
            url("/auth", AuthHandler),
            url("/countdown/([0-9]+)", CountdownHandler, name="countdown"),
            url("/echopost", EchoPostHandler),
            url("/user_agent", UserAgentHandler),
            url("/304_with_content_length", ContentLength304Handler),
            url("/all_methods", AllMethodsHandler),
            url('/patch', PatchHandler),
            url('/set_header', SetHeaderHandler),
        ], gzip=True)

    def test_patch_receives_payload(self):
        body = b"some patch data"
        response = self.fetch("/patch", method='PATCH', body=body)
        self.assertEqual(response.code, 200)
        self.assertEqual(response.body, body)

    @skipOnTravis
    def test_hello_world(self):
        response = self.fetch("/hello")
        self.assertEqual(response.code, 200)
        self.assertEqual(response.headers["Content-Type"], "text/plain")
        self.assertEqual(response.body, b"Hello world!")
        self.assertEqual(int(response.request_time), 0)

        response = self.fetch("/hello?name=Ben")
        self.assertEqual(response.body, b"Hello Ben!")

    def test_streaming_callback(self):
        # streaming_callback is also tested in test_chunked
        chunks = []
        response = self.fetch("/hello",
                              streaming_callback=chunks.append)
        # with streaming_callback, data goes to the callback and not response.body
        self.assertEqual(chunks, [b"Hello world!"])
        self.assertFalse(response.body)

    def test_post(self):
        response = self.fetch("/post", method="POST",
                              body="arg1=foo&arg2=bar")
        self.assertEqual(response.code, 200)
        self.assertEqual(response.body, b"Post arg1: foo, arg2: bar")

    def test_chunked(self):
        response = self.fetch("/chunk")
        self.assertEqual(response.body, b"asdfqwer")

        chunks = []
        response = self.fetch("/chunk",
                              streaming_callback=chunks.append)
        self.assertEqual(chunks, [b"asdf", b"qwer"])
        self.assertFalse(response.body)

    def test_chunked_close(self):
        # test case in which chunks spread read-callback processing
        # over several ioloop iterations, but the connection is already closed.
        sock, port = bind_unused_port()
        with closing(sock):
            def write_response(stream, request_data):
                if b"HTTP/1." not in request_data:
                    self.skipTest("requires HTTP/1.x")
                stream.write(b"""\
HTTP/1.1 200 OK
Transfer-Encoding: chunked

1
1
1
2
0

""".replace(b"\n", b"\r\n"), callback=stream.close)

            def accept_callback(conn, address):
                # fake an HTTP server using chunked encoding where the final chunks
                # and connection close all happen at once
                stream = IOStream(conn)
                stream.read_until(b"\r\n\r\n",
                                  functools.partial(write_response, stream))
            netutil.add_accept_handler(sock, accept_callback)
            self.http_client.fetch("http://127.0.0.1:%d/" % port, self.stop)
            resp = self.wait()
            resp.rethrow()
            self.assertEqual(resp.body, b"12")
            self.io_loop.remove_handler(sock.fileno())

    def test_streaming_stack_context(self):
        chunks = []
        exc_info = []

        def error_handler(typ, value, tb):
            exc_info.append((typ, value, tb))
            return True

        def streaming_cb(chunk):
            chunks.append(chunk)
            if chunk == b'qwer':
                1 / 0

        with ExceptionStackContext(error_handler):
            self.fetch('/chunk', streaming_callback=streaming_cb)

        self.assertEqual(chunks, [b'asdf', b'qwer'])
        self.assertEqual(1, len(exc_info))
        self.assertIs(exc_info[0][0], ZeroDivisionError)

    def test_basic_auth(self):
        self.assertEqual(self.fetch("/auth", auth_username="Aladdin",
                                    auth_password="open sesame").body,
                         b"Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==")

    def test_basic_auth_explicit_mode(self):
        self.assertEqual(self.fetch("/auth", auth_username="Aladdin",
                                    auth_password="open sesame",
                                    auth_mode="basic").body,
                         b"Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==")

    def test_unsupported_auth_mode(self):
        # curl and simple clients handle errors a bit differently; the
        # important thing is that they don't fall back to basic auth
        # on an unknown mode.
        with ExpectLog(gen_log, "uncaught exception", required=False):
            with self.assertRaises((ValueError, HTTPError)):
                response = self.fetch("/auth", auth_username="Aladdin",
                                      auth_password="open sesame",
                                      auth_mode="asdf")
                response.rethrow()

    def test_follow_redirect(self):
        response = self.fetch("/countdown/2", follow_redirects=False)
        self.assertEqual(302, response.code)
        self.assertTrue(response.headers["Location"].endswith("/countdown/1"))

        response = self.fetch("/countdown/2")
        self.assertEqual(200, response.code)
        self.assertTrue(response.effective_url.endswith("/countdown/0"))
        self.assertEqual(b"Zero", response.body)

    def test_credentials_in_url(self):
        url = self.get_url("/auth").replace("http://", "http://me:secret@")
        self.http_client.fetch(url, self.stop)
        response = self.wait()
        self.assertEqual(b"Basic " + base64.b64encode(b"me:secret"),
                         response.body)

    def test_body_encoding(self):
        unicode_body = u"\xe9"
        byte_body = binascii.a2b_hex(b"e9")

        # unicode string in body gets converted to utf8
        response = self.fetch("/echopost", method="POST", body=unicode_body,
                              headers={"Content-Type": "application/blah"})
        self.assertEqual(response.headers["Content-Length"], "2")
        self.assertEqual(response.body, utf8(unicode_body))

        # byte strings pass through directly
        response = self.fetch("/echopost", method="POST",
                              body=byte_body,
                              headers={"Content-Type": "application/blah"})
        self.assertEqual(response.headers["Content-Length"], "1")
        self.assertEqual(response.body, byte_body)

        # Mixing unicode in headers and byte string bodies shouldn't
        # break anything
        response = self.fetch("/echopost", method="POST", body=byte_body,
                              headers={"Content-Type": "application/blah"},
                              user_agent=u"foo")
        self.assertEqual(response.headers["Content-Length"], "1")
        self.assertEqual(response.body, byte_body)

    def test_types(self):
        response = self.fetch("/hello")
        self.assertEqual(type(response.body), bytes)
        self.assertEqual(type(response.headers["Content-Type"]), str)
        self.assertEqual(type(response.code), int)
        self.assertEqual(type(response.effective_url), str)

    def test_header_callback(self):
        first_line = []
        headers = {}
        chunks = []

        def header_callback(header_line):
            if header_line.startswith('HTTP/1.1 101'):
                # Upgrading to HTTP/2
                pass
            elif header_line.startswith('HTTP/'):
                first_line.append(header_line)
            elif header_line != '\r\n':
                k, v = header_line.split(':', 1)
                headers[k.lower()] = v.strip()

        def streaming_callback(chunk):
            # All header callbacks are run before any streaming callbacks,
            # so the header data is available to process the data as it
            # comes in.
            self.assertEqual(headers['content-type'], 'text/html; charset=UTF-8')
            chunks.append(chunk)

        self.fetch('/chunk', header_callback=header_callback,
                   streaming_callback=streaming_callback)
        self.assertEqual(len(first_line), 1, first_line)
        self.assertRegexpMatches(first_line[0], 'HTTP/[0-9]\\.[0-9] 200.*\r\n')
        self.assertEqual(chunks, [b'asdf', b'qwer'])

    def test_header_callback_stack_context(self):
        exc_info = []

        def error_handler(typ, value, tb):
            exc_info.append((typ, value, tb))
            return True

        def header_callback(header_line):
            if header_line.lower().startswith('content-type:'):
                1 / 0

        with ExceptionStackContext(error_handler):
            self.fetch('/chunk', header_callback=header_callback)
        self.assertEqual(len(exc_info), 1)
        self.assertIs(exc_info[0][0], ZeroDivisionError)

    def test_configure_defaults(self):
        defaults = dict(user_agent='TestDefaultUserAgent', allow_ipv6=False)
        # Construct a new instance of the configured client class
        client = self.http_client.__class__(force_instance=True,
                                            defaults=defaults)
        try:
            client.fetch(self.get_url('/user_agent'), callback=self.stop)
            response = self.wait()
            self.assertEqual(response.body, b'TestDefaultUserAgent')
        finally:
            client.close()

    def test_header_types(self):
        # Header values may be passed as character or utf8 byte strings,
        # in a plain dictionary or an HTTPHeaders object.
        # Keys must always be the native str type.
        # All combinations should have the same results on the wire.
        for value in [u"MyUserAgent", b"MyUserAgent"]:
            for container in [dict, HTTPHeaders]:
                headers = container()
                headers['User-Agent'] = value
                resp = self.fetch('/user_agent', headers=headers)
                self.assertEqual(
                    resp.body, b"MyUserAgent",
                    "response=%r, value=%r, container=%r" %
                    (resp.body, value, container))

    def test_multi_line_headers(self):
        # Multi-line http headers are rare but rfc-allowed
        # http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2
        sock, port = bind_unused_port()
        with closing(sock):
            def write_response(stream, request_data):
                if b"HTTP/1." not in request_data:
                    self.skipTest("requires HTTP/1.x")
                stream.write(b"""\
HTTP/1.1 200 OK
X-XSS-Protection: 1;
\tmode=block

""".replace(b"\n", b"\r\n"), callback=stream.close)

            def accept_callback(conn, address):
                stream = IOStream(conn)
                stream.read_until(b"\r\n\r\n",
                                  functools.partial(write_response, stream))
            netutil.add_accept_handler(sock, accept_callback)
            self.http_client.fetch("http://127.0.0.1:%d/" % port, self.stop)
            resp = self.wait()
            resp.rethrow()
            self.assertEqual(resp.headers['X-XSS-Protection'], "1; mode=block")
            self.io_loop.remove_handler(sock.fileno())

    def test_304_with_content_length(self):
        # According to the spec 304 responses SHOULD NOT include
        # Content-Length or other entity headers, but some servers do it
        # anyway.
        # http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5
        response = self.fetch('/304_with_content_length')
        self.assertEqual(response.code, 304)
        self.assertEqual(response.headers['Content-Length'], '42')

    def test_final_callback_stack_context(self):
        # The final callback should be run outside of the httpclient's
        # stack_context.  We want to ensure that there is not stack_context
        # between the user's callback and the IOLoop, so monkey-patch
        # IOLoop.handle_callback_exception and disable the test harness's
        # context with a NullContext.
        # Note that this does not apply to secondary callbacks (header
        # and streaming_callback), as errors there must be seen as errors
        # by the http client so it can clean up the connection.
        exc_info = []

        def handle_callback_exception(callback):
            exc_info.append(sys.exc_info())
            self.stop()
        self.io_loop.handle_callback_exception = handle_callback_exception
        with NullContext():
            self.http_client.fetch(self.get_url('/hello'),
                                   lambda response: 1 / 0)
        self.wait()
        self.assertEqual(exc_info[0][0], ZeroDivisionError)

    @gen_test
    def test_future_interface(self):
        response = yield self.http_client.fetch(self.get_url('/hello'))
        self.assertEqual(response.body, b'Hello world!')

    @gen_test
    def test_future_http_error(self):
        with self.assertRaises(HTTPError) as context:
            yield self.http_client.fetch(self.get_url('/notfound'))
        self.assertEqual(context.exception.code, 404)
        self.assertEqual(context.exception.response.code, 404)

    @gen_test
    def test_future_http_error_no_raise(self):
        response = yield self.http_client.fetch(self.get_url('/notfound'), raise_error=False)
        self.assertEqual(response.code, 404)

    @gen_test
    def test_reuse_request_from_response(self):
        # The response.request attribute should be an HTTPRequest, not
        # a _RequestProxy.
        # This test uses self.http_client.fetch because self.fetch calls
        # self.get_url on the input unconditionally.
        url = self.get_url('/hello')
        response = yield self.http_client.fetch(url)
        self.assertEqual(response.request.url, url)
        self.assertTrue(isinstance(response.request, HTTPRequest))
        response2 = yield self.http_client.fetch(response.request)
        self.assertEqual(response2.body, b'Hello world!')

    def test_all_methods(self):
        for method in ['GET', 'DELETE', 'OPTIONS']:
            response = self.fetch('/all_methods', method=method)
            self.assertEqual(response.body, utf8(method))
        for method in ['POST', 'PUT', 'PATCH']:
            response = self.fetch('/all_methods', method=method, body=b'')
            self.assertEqual(response.body, utf8(method))
        response = self.fetch('/all_methods', method='HEAD')
        self.assertEqual(response.body, b'')
        response = self.fetch('/all_methods', method='OTHER',
                              allow_nonstandard_methods=True)
        self.assertEqual(response.body, b'OTHER')

    def test_body_sanity_checks(self):
        # These methods require a body.
        for method in ('POST', 'PUT', 'PATCH'):
            with self.assertRaises(ValueError) as context:
                resp = self.fetch('/all_methods', method=method)
                resp.rethrow()
            self.assertIn('must not be None', str(context.exception))

            resp = self.fetch('/all_methods', method=method,
                              allow_nonstandard_methods=True)
            self.assertEqual(resp.code, 200)

        # These methods don't allow a body.
        for method in ('GET', 'DELETE', 'OPTIONS'):
            with self.assertRaises(ValueError) as context:
                resp = self.fetch('/all_methods', method=method, body=b'asdf')
                resp.rethrow()
            self.assertIn('must be None', str(context.exception))

            # In most cases this can be overridden, but curl_httpclient
            # does not allow body with a GET at all.
            if method != 'GET':
                resp = self.fetch('/all_methods', method=method, body=b'asdf',
                                  allow_nonstandard_methods=True)
                resp.rethrow()
                self.assertEqual(resp.code, 200)

    # This test causes odd failures with the combination of
    # curl_httpclient (at least with the version of libcurl available
    # on ubuntu 12.04), TwistedIOLoop, and epoll.  For POST (but not PUT),
    # curl decides the response came back too soon and closes the connection
    # to start again.  It does this *before* telling the socket callback to
    # unregister the FD.  Some IOLoop implementations have special kernel
    # integration to discover this immediately.  Tornado's IOLoops
    # ignore errors on remove_handler to accommodate this behavior, but
    # Twisted's reactor does not.  The removeReader call fails and so
    # do all future removeAll calls (which our tests do at cleanup).
    #
    # def test_post_307(self):
    #    response = self.fetch("/redirect?status=307&url=/post",
    #                          method="POST", body=b"arg1=foo&arg2=bar")
    #    self.assertEqual(response.body, b"Post arg1: foo, arg2: bar")

    def test_put_307(self):
        response = self.fetch("/redirect?status=307&url=/put",
                              method="PUT", body=b"hello")
        response.rethrow()
        self.assertEqual(response.body, b"Put body: hello")

    def test_non_ascii_header(self):
        # Non-ascii headers are sent as latin1.
        response = self.fetch("/set_header?k=foo&v=%E9")
        response.rethrow()
        self.assertEqual(response.headers["Foo"], native_str(u"\u00e9"))


class RequestProxyTest(unittest.TestCase):
    def test_request_set(self):
        proxy = _RequestProxy(HTTPRequest('http://example.com/',
                                          user_agent='foo'),
                              dict())
        self.assertEqual(proxy.user_agent, 'foo')

    def test_default_set(self):
        proxy = _RequestProxy(HTTPRequest('http://example.com/'),
                              dict(network_interface='foo'))
        self.assertEqual(proxy.network_interface, 'foo')

    def test_both_set(self):
        proxy = _RequestProxy(HTTPRequest('http://example.com/',
                                          proxy_host='foo'),
                              dict(proxy_host='bar'))
        self.assertEqual(proxy.proxy_host, 'foo')

    def test_neither_set(self):
        proxy = _RequestProxy(HTTPRequest('http://example.com/'),
                              dict())
        self.assertIs(proxy.auth_username, None)

    def test_bad_attribute(self):
        proxy = _RequestProxy(HTTPRequest('http://example.com/'),
                              dict())
        with self.assertRaises(AttributeError):
            proxy.foo

    def test_defaults_none(self):
        proxy = _RequestProxy(HTTPRequest('http://example.com/'), None)
        self.assertIs(proxy.auth_username, None)


class HTTPResponseTestCase(unittest.TestCase):
    def test_str(self):
        response = HTTPResponse(HTTPRequest('http://example.com'),
                                200, headers={}, buffer=BytesIO())
        s = str(response)
        self.assertTrue(s.startswith('HTTPResponse('))
        self.assertIn('code=200', s)


class SyncHTTPClientTest(unittest.TestCase):
    def setUp(self):
        if IOLoop.configured_class().__name__ == 'TwistedIOLoop':
            # TwistedIOLoop only supports the global reactor, so we can't have
            # separate IOLoops for client and server threads.
            raise unittest.SkipTest(
                'Sync HTTPClient not compatible with TwistedIOLoop')
        self.server_ioloop = IOLoop()

        @gen.coroutine
        def init_server():
            sock, self.port = bind_unused_port()
            app = Application([('/', HelloWorldHandler)])
            self.server = HTTPServer(app)
            self.server.add_socket(sock)
        self.server_ioloop.run_sync(init_server)

        self.server_thread = threading.Thread(target=self.server_ioloop.start)
        self.server_thread.start()

        self.http_client = HTTPClient()

    def tearDown(self):
        def stop_server():
            self.server.stop()
            # Delay the shutdown of the IOLoop by several iterations because
            # the server may still have some cleanup work left when
            # the client finishes with the response (this is noticeable
            # with http/2, which leaves a Future with an unexamined
            # StreamClosedError on the loop).
            @gen.coroutine
            def slow_stop():
                # The number of iterations is difficult to predict. Typically,
                # one is sufficient, although sometimes it needs more.
                for i in range(5):
                    yield
                self.server_ioloop.stop()
            self.server_ioloop.add_callback(slow_stop)
        self.server_ioloop.add_callback(stop_server)
        self.server_thread.join()
        self.http_client.close()
        self.server_ioloop.close(all_fds=True)

    def get_url(self, path):
        return 'http://127.0.0.1:%d%s' % (self.port, path)

    def test_sync_client(self):
        response = self.http_client.fetch(self.get_url('/'))
        self.assertEqual(b'Hello world!', response.body)

    def test_sync_client_error(self):
        # Synchronous HTTPClient raises errors directly; no need for
        # response.rethrow()
        with self.assertRaises(HTTPError) as assertion:
            self.http_client.fetch(self.get_url('/notfound'))
        self.assertEqual(assertion.exception.code, 404)


class HTTPRequestTestCase(unittest.TestCase):
    def test_headers(self):
        request = HTTPRequest('http://example.com', headers={'foo': 'bar'})
        self.assertEqual(request.headers, {'foo': 'bar'})

    def test_headers_setter(self):
        request = HTTPRequest('http://example.com')
        request.headers = {'bar': 'baz'}
        self.assertEqual(request.headers, {'bar': 'baz'})

    def test_null_headers_setter(self):
        request = HTTPRequest('http://example.com')
        request.headers = None
        self.assertEqual(request.headers, {})

    def test_body(self):
        request = HTTPRequest('http://example.com', body='foo')
        self.assertEqual(request.body, utf8('foo'))

    def test_body_setter(self):
        request = HTTPRequest('http://example.com')
        request.body = 'foo'
        self.assertEqual(request.body, utf8('foo'))

    def test_if_modified_since(self):
        http_date = datetime.datetime.utcnow()
        request = HTTPRequest('http://example.com', if_modified_since=http_date)
        self.assertEqual(request.headers,
                         {'If-Modified-Since': format_timestamp(http_date)})


class HTTPErrorTestCase(unittest.TestCase):
    def test_copy(self):
        e = HTTPError(403)
        e2 = copy.copy(e)
        self.assertIsNot(e, e2)
        self.assertEqual(e.code, e2.code)

    def test_plain_error(self):
        e = HTTPError(403)
        self.assertEqual(str(e), "HTTP 403: Forbidden")
        self.assertEqual(repr(e), "HTTP 403: Forbidden")

    def test_error_with_response(self):
        resp = HTTPResponse(HTTPRequest('http://example.com/'), 403)
        with self.assertRaises(HTTPError) as cm:
            resp.rethrow()
        e = cm.exception
        self.assertEqual(str(e), "HTTP 403: Forbidden")
        self.assertEqual(repr(e), "HTTP 403: Forbidden")
