import copy
from io import BytesIO
from itertools import chain
from urllib.parse import urlencode

from django.core.exceptions import DisallowedHost
from django.core.handlers.wsgi import LimitedStream, WSGIRequest
from django.http import (
    HttpHeaders,
    HttpRequest,
    RawPostDataException,
    UnreadablePostError,
)
from django.http.multipartparser import MultiPartParserError
from django.http.request import split_domain_port
from django.test import RequestFactory, SimpleTestCase, override_settings
from django.test.client import FakePayload


class RequestsTests(SimpleTestCase):
    def test_httprequest(self):
        request = HttpRequest()
        self.assertEqual(list(request.GET), [])
        self.assertEqual(list(request.POST), [])
        self.assertEqual(list(request.COOKIES), [])
        self.assertEqual(list(request.META), [])

        # .GET and .POST should be QueryDicts
        self.assertEqual(request.GET.urlencode(), "")
        self.assertEqual(request.POST.urlencode(), "")

        # and FILES should be MultiValueDict
        self.assertEqual(request.FILES.getlist("foo"), [])

        self.assertIsNone(request.content_type)
        self.assertIsNone(request.content_params)

    def test_httprequest_full_path(self):
        request = HttpRequest()
        request.path = "/;some/?awful/=path/foo:bar/"
        request.path_info = "/prefix" + request.path
        request.META["QUERY_STRING"] = ";some=query&+query=string"
        expected = "/%3Bsome/%3Fawful/%3Dpath/foo:bar/?;some=query&+query=string"
        self.assertEqual(request.get_full_path(), expected)
        self.assertEqual(request.get_full_path_info(), "/prefix" + expected)

    def test_httprequest_full_path_with_query_string_and_fragment(self):
        request = HttpRequest()
        request.path = "/foo#bar"
        request.path_info = "/prefix" + request.path
        request.META["QUERY_STRING"] = "baz#quux"
        self.assertEqual(request.get_full_path(), "/foo%23bar?baz#quux")
        self.assertEqual(request.get_full_path_info(), "/prefix/foo%23bar?baz#quux")

    def test_httprequest_repr(self):
        request = HttpRequest()
        request.path = "/somepath/"
        request.method = "GET"
        request.GET = {"get-key": "get-value"}
        request.POST = {"post-key": "post-value"}
        request.COOKIES = {"post-key": "post-value"}
        request.META = {"post-key": "post-value"}
        self.assertEqual(repr(request), "<HttpRequest: GET '/somepath/'>")

    def test_httprequest_repr_invalid_method_and_path(self):
        request = HttpRequest()
        self.assertEqual(repr(request), "<HttpRequest>")
        request = HttpRequest()
        request.method = "GET"
        self.assertEqual(repr(request), "<HttpRequest>")
        request = HttpRequest()
        request.path = ""
        self.assertEqual(repr(request), "<HttpRequest>")

    def test_wsgirequest(self):
        request = WSGIRequest(
            {
                "PATH_INFO": "bogus",
                "REQUEST_METHOD": "bogus",
                "CONTENT_TYPE": "text/html; charset=utf8",
                "wsgi.input": BytesIO(b""),
            }
        )
        self.assertEqual(list(request.GET), [])
        self.assertEqual(list(request.POST), [])
        self.assertEqual(list(request.COOKIES), [])
        self.assertEqual(
            set(request.META),
            {
                "PATH_INFO",
                "REQUEST_METHOD",
                "SCRIPT_NAME",
                "CONTENT_TYPE",
                "wsgi.input",
            },
        )
        self.assertEqual(request.META["PATH_INFO"], "bogus")
        self.assertEqual(request.META["REQUEST_METHOD"], "bogus")
        self.assertEqual(request.META["SCRIPT_NAME"], "")
        self.assertEqual(request.content_type, "text/html")
        self.assertEqual(request.content_params, {"charset": "utf8"})

    def test_wsgirequest_with_script_name(self):
        """
        The request's path is correctly assembled, regardless of whether or
        not the SCRIPT_NAME has a trailing slash (#20169).
        """
        # With trailing slash
        request = WSGIRequest(
            {
                "PATH_INFO": "/somepath/",
                "SCRIPT_NAME": "/PREFIX/",
                "REQUEST_METHOD": "get",
                "wsgi.input": BytesIO(b""),
            }
        )
        self.assertEqual(request.path, "/PREFIX/somepath/")
        # Without trailing slash
        request = WSGIRequest(
            {
                "PATH_INFO": "/somepath/",
                "SCRIPT_NAME": "/PREFIX",
                "REQUEST_METHOD": "get",
                "wsgi.input": BytesIO(b""),
            }
        )
        self.assertEqual(request.path, "/PREFIX/somepath/")

    def test_wsgirequest_script_url_double_slashes(self):
        """
        WSGI squashes multiple successive slashes in PATH_INFO, WSGIRequest
        should take that into account when populating request.path and
        request.META['SCRIPT_NAME'] (#17133).
        """
        request = WSGIRequest(
            {
                "SCRIPT_URL": "/mst/milestones//accounts/login//help",
                "PATH_INFO": "/milestones/accounts/login/help",
                "REQUEST_METHOD": "get",
                "wsgi.input": BytesIO(b""),
            }
        )
        self.assertEqual(request.path, "/mst/milestones/accounts/login/help")
        self.assertEqual(request.META["SCRIPT_NAME"], "/mst")

    def test_wsgirequest_with_force_script_name(self):
        """
        The FORCE_SCRIPT_NAME setting takes precedence over the request's
        SCRIPT_NAME environment parameter (#20169).
        """
        with override_settings(FORCE_SCRIPT_NAME="/FORCED_PREFIX/"):
            request = WSGIRequest(
                {
                    "PATH_INFO": "/somepath/",
                    "SCRIPT_NAME": "/PREFIX/",
                    "REQUEST_METHOD": "get",
                    "wsgi.input": BytesIO(b""),
                }
            )
            self.assertEqual(request.path, "/FORCED_PREFIX/somepath/")

    def test_wsgirequest_path_with_force_script_name_trailing_slash(self):
        """
        The request's path is correctly assembled, regardless of whether or not
        the FORCE_SCRIPT_NAME setting has a trailing slash (#20169).
        """
        # With trailing slash
        with override_settings(FORCE_SCRIPT_NAME="/FORCED_PREFIX/"):
            request = WSGIRequest(
                {
                    "PATH_INFO": "/somepath/",
                    "REQUEST_METHOD": "get",
                    "wsgi.input": BytesIO(b""),
                }
            )
            self.assertEqual(request.path, "/FORCED_PREFIX/somepath/")
        # Without trailing slash
        with override_settings(FORCE_SCRIPT_NAME="/FORCED_PREFIX"):
            request = WSGIRequest(
                {
                    "PATH_INFO": "/somepath/",
                    "REQUEST_METHOD": "get",
                    "wsgi.input": BytesIO(b""),
                }
            )
            self.assertEqual(request.path, "/FORCED_PREFIX/somepath/")

    def test_wsgirequest_repr(self):
        request = WSGIRequest({"REQUEST_METHOD": "get", "wsgi.input": BytesIO(b"")})
        self.assertEqual(repr(request), "<WSGIRequest: GET '/'>")
        request = WSGIRequest(
            {
                "PATH_INFO": "/somepath/",
                "REQUEST_METHOD": "get",
                "wsgi.input": BytesIO(b""),
            }
        )
        request.GET = {"get-key": "get-value"}
        request.POST = {"post-key": "post-value"}
        request.COOKIES = {"post-key": "post-value"}
        request.META = {"post-key": "post-value"}
        self.assertEqual(repr(request), "<WSGIRequest: GET '/somepath/'>")

    def test_wsgirequest_path_info(self):
        def wsgi_str(path_info, encoding="utf-8"):
            path_info = path_info.encode(
                encoding
            )  # Actual URL sent by the browser (bytestring)
            path_info = path_info.decode(
                "iso-8859-1"
            )  # Value in the WSGI environ dict (native string)
            return path_info

        # Regression for #19468
        request = WSGIRequest(
            {
                "PATH_INFO": wsgi_str("/سلام/"),
                "REQUEST_METHOD": "get",
                "wsgi.input": BytesIO(b""),
            }
        )
        self.assertEqual(request.path, "/سلام/")

        # The URL may be incorrectly encoded in a non-UTF-8 encoding (#26971)
        request = WSGIRequest(
            {
                "PATH_INFO": wsgi_str("/café/", encoding="iso-8859-1"),
                "REQUEST_METHOD": "get",
                "wsgi.input": BytesIO(b""),
            }
        )
        # Since it's impossible to decide the (wrong) encoding of the URL, it's
        # left percent-encoded in the path.
        self.assertEqual(request.path, "/caf%E9/")

    def test_wsgirequest_copy(self):
        request = WSGIRequest({"REQUEST_METHOD": "get", "wsgi.input": BytesIO(b"")})
        request_copy = copy.copy(request)
        self.assertIs(request_copy.environ, request.environ)

    def test_limited_stream(self):
        # Read all of a limited stream
        stream = LimitedStream(BytesIO(b"test"), 2)
        self.assertEqual(stream.read(), b"te")
        # Reading again returns nothing.
        self.assertEqual(stream.read(), b"")

        # Read a number of characters greater than the stream has to offer
        stream = LimitedStream(BytesIO(b"test"), 2)
        self.assertEqual(stream.read(5), b"te")
        # Reading again returns nothing.
        self.assertEqual(stream.readline(5), b"")

        # Read sequentially from a stream
        stream = LimitedStream(BytesIO(b"12345678"), 8)
        self.assertEqual(stream.read(5), b"12345")
        self.assertEqual(stream.read(5), b"678")
        # Reading again returns nothing.
        self.assertEqual(stream.readline(5), b"")

        # Read lines from a stream
        stream = LimitedStream(BytesIO(b"1234\n5678\nabcd\nefgh\nijkl"), 24)
        # Read a full line, unconditionally
        self.assertEqual(stream.readline(), b"1234\n")
        # Read a number of characters less than a line
        self.assertEqual(stream.readline(2), b"56")
        # Read the rest of the partial line
        self.assertEqual(stream.readline(), b"78\n")
        # Read a full line, with a character limit greater than the line length
        self.assertEqual(stream.readline(6), b"abcd\n")
        # Read the next line, deliberately terminated at the line end
        self.assertEqual(stream.readline(4), b"efgh")
        # Read the next line... just the line end
        self.assertEqual(stream.readline(), b"\n")
        # Read everything else.
        self.assertEqual(stream.readline(), b"ijkl")

        # Regression for #15018
        # If a stream contains a newline, but the provided length
        # is less than the number of provided characters, the newline
        # doesn't reset the available character count
        stream = LimitedStream(BytesIO(b"1234\nabcdef"), 9)
        self.assertEqual(stream.readline(10), b"1234\n")
        self.assertEqual(stream.readline(3), b"abc")
        # Now expire the available characters
        self.assertEqual(stream.readline(3), b"d")
        # Reading again returns nothing.
        self.assertEqual(stream.readline(2), b"")

        # Same test, but with read, not readline.
        stream = LimitedStream(BytesIO(b"1234\nabcdef"), 9)
        self.assertEqual(stream.read(6), b"1234\na")
        self.assertEqual(stream.read(2), b"bc")
        self.assertEqual(stream.read(2), b"d")
        self.assertEqual(stream.read(2), b"")
        self.assertEqual(stream.read(), b"")

    def test_stream_read(self):
        payload = FakePayload("name=value")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            },
        )
        self.assertEqual(request.read(), b"name=value")

    def test_stream_readline(self):
        payload = FakePayload("name=value\nother=string")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            },
        )
        self.assertEqual(request.readline(), b"name=value\n")
        self.assertEqual(request.readline(), b"other=string")

    def test_read_after_value(self):
        """
        Reading from request is allowed after accessing request contents as
        POST or body.
        """
        payload = FakePayload("name=value")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        self.assertEqual(request.POST, {"name": ["value"]})
        self.assertEqual(request.body, b"name=value")
        self.assertEqual(request.read(), b"name=value")

    def test_value_after_read(self):
        """
        Construction of POST or body is not allowed after reading
        from request.
        """
        payload = FakePayload("name=value")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        self.assertEqual(request.read(2), b"na")
        with self.assertRaises(RawPostDataException):
            request.body
        self.assertEqual(request.POST, {})

    def test_non_ascii_POST(self):
        payload = FakePayload(urlencode({"key": "España"}))
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_LENGTH": len(payload),
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "wsgi.input": payload,
            }
        )
        self.assertEqual(request.POST, {"key": ["España"]})

    def test_alternate_charset_POST(self):
        """
        Test a POST with non-utf-8 payload encoding.
        """
        payload = FakePayload(urlencode({"key": "España".encode("latin-1")}))
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_LENGTH": len(payload),
                "CONTENT_TYPE": "application/x-www-form-urlencoded; charset=iso-8859-1",
                "wsgi.input": payload,
            }
        )
        self.assertEqual(request.POST, {"key": ["España"]})

    def test_body_after_POST_multipart_form_data(self):
        """
        Reading body after parsing multipart/form-data is not allowed
        """
        # Because multipart is used for large amounts of data i.e. file uploads,
        # we don't want the data held in memory twice, and we don't want to
        # silence the error by setting body = '' either.
        payload = FakePayload(
            "\r\n".join(
                [
                    "--boundary",
                    'Content-Disposition: form-data; name="name"',
                    "",
                    "value",
                    "--boundary--",
                ]
            )
        )
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "multipart/form-data; boundary=boundary",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        self.assertEqual(request.POST, {"name": ["value"]})
        with self.assertRaises(RawPostDataException):
            request.body

    def test_body_after_POST_multipart_related(self):
        """
        Reading body after parsing multipart that isn't form-data is allowed
        """
        # Ticket #9054
        # There are cases in which the multipart data is related instead of
        # being a binary upload, in which case it should still be accessible
        # via body.
        payload_data = b"\r\n".join(
            [
                b"--boundary",
                b'Content-ID: id; name="name"',
                b"",
                b"value",
                b"--boundary--",
            ]
        )
        payload = FakePayload(payload_data)
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "multipart/related; boundary=boundary",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        self.assertEqual(request.POST, {})
        self.assertEqual(request.body, payload_data)

    def test_POST_multipart_with_content_length_zero(self):
        """
        Multipart POST requests with Content-Length >= 0 are valid and need to
        be handled.
        """
        # According to RFC 9110 Section 8.6 every POST with Content-Length >= 0
        # is a valid request, so ensure that we handle Content-Length == 0.
        payload = FakePayload(
            "\r\n".join(
                [
                    "--boundary",
                    'Content-Disposition: form-data; name="name"',
                    "",
                    "value",
                    "--boundary--",
                ]
            )
        )
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "multipart/form-data; boundary=boundary",
                "CONTENT_LENGTH": 0,
                "wsgi.input": payload,
            }
        )
        self.assertEqual(request.POST, {})

    def test_POST_binary_only(self):
        payload = b"\r\n\x01\x00\x00\x00ab\x00\x00\xcd\xcc,@"
        environ = {
            "REQUEST_METHOD": "POST",
            "CONTENT_TYPE": "application/octet-stream",
            "CONTENT_LENGTH": len(payload),
            "wsgi.input": BytesIO(payload),
        }
        request = WSGIRequest(environ)
        self.assertEqual(request.POST, {})
        self.assertEqual(request.FILES, {})
        self.assertEqual(request.body, payload)

        # Same test without specifying content-type
        environ.update({"CONTENT_TYPE": "", "wsgi.input": BytesIO(payload)})
        request = WSGIRequest(environ)
        self.assertEqual(request.POST, {})
        self.assertEqual(request.FILES, {})
        self.assertEqual(request.body, payload)

    def test_read_by_lines(self):
        payload = FakePayload("name=value")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        self.assertEqual(list(request), [b"name=value"])

    def test_POST_after_body_read(self):
        """
        POST should be populated even if body is read first
        """
        payload = FakePayload("name=value")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        request.body  # evaluate
        self.assertEqual(request.POST, {"name": ["value"]})

    def test_POST_after_body_read_and_stream_read(self):
        """
        POST should be populated even if body is read first, and then
        the stream is read second.
        """
        payload = FakePayload("name=value")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        request.body  # evaluate
        self.assertEqual(request.read(1), b"n")
        self.assertEqual(request.POST, {"name": ["value"]})

    def test_POST_after_body_read_and_stream_read_multipart(self):
        """
        POST should be populated even if body is read first, and then
        the stream is read second. Using multipart/form-data instead of urlencoded.
        """
        payload = FakePayload(
            "\r\n".join(
                [
                    "--boundary",
                    'Content-Disposition: form-data; name="name"',
                    "",
                    "value",
                    "--boundary--" "",
                ]
            )
        )
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "multipart/form-data; boundary=boundary",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        request.body  # evaluate
        # Consume enough data to mess up the parsing:
        self.assertEqual(request.read(13), b"--boundary\r\nC")
        self.assertEqual(request.POST, {"name": ["value"]})

    def test_POST_immutable_for_multipart(self):
        """
        MultiPartParser.parse() leaves request.POST immutable.
        """
        payload = FakePayload(
            "\r\n".join(
                [
                    "--boundary",
                    'Content-Disposition: form-data; name="name"',
                    "",
                    "value",
                    "--boundary--",
                ]
            )
        )
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "multipart/form-data; boundary=boundary",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        self.assertFalse(request.POST._mutable)

    def test_multipart_without_boundary(self):
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "multipart/form-data;",
                "CONTENT_LENGTH": 0,
                "wsgi.input": FakePayload(),
            }
        )
        with self.assertRaisesMessage(
            MultiPartParserError, "Invalid boundary in multipart: None"
        ):
            request.POST

    def test_multipart_non_ascii_content_type(self):
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "multipart/form-data; boundary = \xe0",
                "CONTENT_LENGTH": 0,
                "wsgi.input": FakePayload(),
            }
        )
        msg = (
            "Invalid non-ASCII Content-Type in multipart: multipart/form-data; "
            "boundary = à"
        )
        with self.assertRaisesMessage(MultiPartParserError, msg):
            request.POST

    def test_POST_connection_error(self):
        """
        If wsgi.input.read() raises an exception while trying to read() the
        POST, the exception is identifiable (not a generic OSError).
        """

        class ExplodingBytesIO(BytesIO):
            def read(self, size=-1, /):
                raise OSError("kaboom!")

        payload = b"name=value"
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": ExplodingBytesIO(payload),
            }
        )
        with self.assertRaises(UnreadablePostError):
            request.body

    def test_set_encoding_clears_POST(self):
        payload = FakePayload("name=Hello Günter")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "application/x-www-form-urlencoded",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": payload,
            }
        )
        self.assertEqual(request.POST, {"name": ["Hello Günter"]})
        request.encoding = "iso-8859-16"
        self.assertEqual(request.POST, {"name": ["Hello GĂŒnter"]})

    def test_set_encoding_clears_GET(self):
        payload = FakePayload("")
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "GET",
                "wsgi.input": payload,
                "QUERY_STRING": "name=Hello%20G%C3%BCnter",
            }
        )
        self.assertEqual(request.GET, {"name": ["Hello Günter"]})
        request.encoding = "iso-8859-16"
        self.assertEqual(request.GET, {"name": ["Hello G\u0102\u0152nter"]})

    def test_FILES_connection_error(self):
        """
        If wsgi.input.read() raises an exception while trying to read() the
        FILES, the exception is identifiable (not a generic OSError).
        """

        class ExplodingBytesIO(BytesIO):
            def read(self, size=-1, /):
                raise OSError("kaboom!")

        payload = b"x"
        request = WSGIRequest(
            {
                "REQUEST_METHOD": "POST",
                "CONTENT_TYPE": "multipart/form-data; boundary=foo_",
                "CONTENT_LENGTH": len(payload),
                "wsgi.input": ExplodingBytesIO(payload),
            }
        )
        with self.assertRaises(UnreadablePostError):
            request.FILES

    def test_copy(self):
        request = HttpRequest()
        request_copy = copy.copy(request)
        self.assertIs(request_copy.resolver_match, request.resolver_match)

    def test_deepcopy(self):
        request = RequestFactory().get("/")
        request.session = {}
        request_copy = copy.deepcopy(request)
        request.session["key"] = "value"
        self.assertEqual(request_copy.session, {})


class HostValidationTests(SimpleTestCase):
    poisoned_hosts = [
        "example.com@evil.tld",
        "example.com:dr.frankenstein@evil.tld",
        "example.com:dr.frankenstein@evil.tld:80",
        "example.com:80/badpath",
        "example.com: recovermypassword.com",
    ]

    @override_settings(
        USE_X_FORWARDED_HOST=False,
        ALLOWED_HOSTS=[
            "forward.com",
            "example.com",
            "internal.com",
            "12.34.56.78",
            "[2001:19f0:feee::dead:beef:cafe]",
            "xn--4ca9at.com",
            ".multitenant.com",
            "INSENSITIVE.com",
            "[::ffff:169.254.169.254]",
        ],
    )
    def test_http_get_host(self):
        # Check if X_FORWARDED_HOST is provided.
        request = HttpRequest()
        request.META = {
            "HTTP_X_FORWARDED_HOST": "forward.com",
            "HTTP_HOST": "example.com",
            "SERVER_NAME": "internal.com",
            "SERVER_PORT": 80,
        }
        # X_FORWARDED_HOST is ignored.
        self.assertEqual(request.get_host(), "example.com")

        # Check if X_FORWARDED_HOST isn't provided.
        request = HttpRequest()
        request.META = {
            "HTTP_HOST": "example.com",
            "SERVER_NAME": "internal.com",
            "SERVER_PORT": 80,
        }
        self.assertEqual(request.get_host(), "example.com")

        # Check if HTTP_HOST isn't provided.
        request = HttpRequest()
        request.META = {
            "SERVER_NAME": "internal.com",
            "SERVER_PORT": 80,
        }
        self.assertEqual(request.get_host(), "internal.com")

        # Check if HTTP_HOST isn't provided, and we're on a nonstandard port
        request = HttpRequest()
        request.META = {
            "SERVER_NAME": "internal.com",
            "SERVER_PORT": 8042,
        }
        self.assertEqual(request.get_host(), "internal.com:8042")

        legit_hosts = [
            "example.com",
            "example.com:80",
            "12.34.56.78",
            "12.34.56.78:443",
            "[2001:19f0:feee::dead:beef:cafe]",
            "[2001:19f0:feee::dead:beef:cafe]:8080",
            "xn--4ca9at.com",  # Punycode for öäü.com
            "anything.multitenant.com",
            "multitenant.com",
            "insensitive.com",
            "example.com.",
            "example.com.:80",
            "[::ffff:169.254.169.254]",
        ]

        for host in legit_hosts:
            request = HttpRequest()
            request.META = {
                "HTTP_HOST": host,
            }
            request.get_host()

        # Poisoned host headers are rejected as suspicious
        for host in chain(self.poisoned_hosts, ["other.com", "example.com.."]):
            with self.assertRaises(DisallowedHost):
                request = HttpRequest()
                request.META = {
                    "HTTP_HOST": host,
                }
                request.get_host()

    @override_settings(USE_X_FORWARDED_HOST=True, ALLOWED_HOSTS=["*"])
    def test_http_get_host_with_x_forwarded_host(self):
        # Check if X_FORWARDED_HOST is provided.
        request = HttpRequest()
        request.META = {
            "HTTP_X_FORWARDED_HOST": "forward.com",
            "HTTP_HOST": "example.com",
            "SERVER_NAME": "internal.com",
            "SERVER_PORT": 80,
        }
        # X_FORWARDED_HOST is obeyed.
        self.assertEqual(request.get_host(), "forward.com")

        # Check if X_FORWARDED_HOST isn't provided.
        request = HttpRequest()
        request.META = {
            "HTTP_HOST": "example.com",
            "SERVER_NAME": "internal.com",
            "SERVER_PORT": 80,
        }
        self.assertEqual(request.get_host(), "example.com")

        # Check if HTTP_HOST isn't provided.
        request = HttpRequest()
        request.META = {
            "SERVER_NAME": "internal.com",
            "SERVER_PORT": 80,
        }
        self.assertEqual(request.get_host(), "internal.com")

        # Check if HTTP_HOST isn't provided, and we're on a nonstandard port
        request = HttpRequest()
        request.META = {
            "SERVER_NAME": "internal.com",
            "SERVER_PORT": 8042,
        }
        self.assertEqual(request.get_host(), "internal.com:8042")

        # Poisoned host headers are rejected as suspicious
        legit_hosts = [
            "example.com",
            "example.com:80",
            "12.34.56.78",
            "12.34.56.78:443",
            "[2001:19f0:feee::dead:beef:cafe]",
            "[2001:19f0:feee::dead:beef:cafe]:8080",
            "xn--4ca9at.com",  # Punycode for öäü.com
        ]

        for host in legit_hosts:
            request = HttpRequest()
            request.META = {
                "HTTP_HOST": host,
            }
            request.get_host()

        for host in self.poisoned_hosts:
            with self.assertRaises(DisallowedHost):
                request = HttpRequest()
                request.META = {
                    "HTTP_HOST": host,
                }
                request.get_host()

    @override_settings(USE_X_FORWARDED_PORT=False)
    def test_get_port(self):
        request = HttpRequest()
        request.META = {
            "SERVER_PORT": "8080",
            "HTTP_X_FORWARDED_PORT": "80",
        }
        # Shouldn't use the X-Forwarded-Port header
        self.assertEqual(request.get_port(), "8080")

        request = HttpRequest()
        request.META = {
            "SERVER_PORT": "8080",
        }
        self.assertEqual(request.get_port(), "8080")

    @override_settings(USE_X_FORWARDED_PORT=True)
    def test_get_port_with_x_forwarded_port(self):
        request = HttpRequest()
        request.META = {
            "SERVER_PORT": "8080",
            "HTTP_X_FORWARDED_PORT": "80",
        }
        # Should use the X-Forwarded-Port header
        self.assertEqual(request.get_port(), "80")

        request = HttpRequest()
        request.META = {
            "SERVER_PORT": "8080",
        }
        self.assertEqual(request.get_port(), "8080")

    @override_settings(DEBUG=True, ALLOWED_HOSTS=[])
    def test_host_validation_in_debug_mode(self):
        """
        If ALLOWED_HOSTS is empty and DEBUG is True, variants of localhost are
        allowed.
        """
        valid_hosts = ["localhost", "subdomain.localhost", "127.0.0.1", "[::1]"]
        for host in valid_hosts:
            request = HttpRequest()
            request.META = {"HTTP_HOST": host}
            self.assertEqual(request.get_host(), host)

        # Other hostnames raise a DisallowedHost.
        with self.assertRaises(DisallowedHost):
            request = HttpRequest()
            request.META = {"HTTP_HOST": "example.com"}
            request.get_host()

    @override_settings(ALLOWED_HOSTS=[])
    def test_get_host_suggestion_of_allowed_host(self):
        """
        get_host() makes helpful suggestions if a valid-looking host is not in
        ALLOWED_HOSTS.
        """
        msg_invalid_host = "Invalid HTTP_HOST header: %r."
        msg_suggestion = msg_invalid_host + " You may need to add %r to ALLOWED_HOSTS."
        msg_suggestion2 = (
            msg_invalid_host
            + " The domain name provided is not valid according to RFC 1034/1035"
        )

        for host in [  # Valid-looking hosts
            "example.com",
            "12.34.56.78",
            "[2001:19f0:feee::dead:beef:cafe]",
            "xn--4ca9at.com",  # Punycode for öäü.com
        ]:
            request = HttpRequest()
            request.META = {"HTTP_HOST": host}
            with self.assertRaisesMessage(
                DisallowedHost, msg_suggestion % (host, host)
            ):
                request.get_host()

        for domain, port in [  # Valid-looking hosts with a port number
            ("example.com", 80),
            ("12.34.56.78", 443),
            ("[2001:19f0:feee::dead:beef:cafe]", 8080),
        ]:
            host = "%s:%s" % (domain, port)
            request = HttpRequest()
            request.META = {"HTTP_HOST": host}
            with self.assertRaisesMessage(
                DisallowedHost, msg_suggestion % (host, domain)
            ):
                request.get_host()

        for host in self.poisoned_hosts:
            request = HttpRequest()
            request.META = {"HTTP_HOST": host}
            with self.assertRaisesMessage(DisallowedHost, msg_invalid_host % host):
                request.get_host()

        request = HttpRequest()
        request.META = {"HTTP_HOST": "invalid_hostname.com"}
        with self.assertRaisesMessage(
            DisallowedHost, msg_suggestion2 % "invalid_hostname.com"
        ):
            request.get_host()

    def test_split_domain_port_removes_trailing_dot(self):
        domain, port = split_domain_port("example.com.:8080")
        self.assertEqual(domain, "example.com")
        self.assertEqual(port, "8080")


class BuildAbsoluteURITests(SimpleTestCase):
    factory = RequestFactory()

    def test_absolute_url(self):
        request = HttpRequest()
        url = "https://www.example.com/asdf"
        self.assertEqual(request.build_absolute_uri(location=url), url)

    def test_host_retrieval(self):
        request = HttpRequest()
        request.get_host = lambda: "www.example.com"
        request.path = ""
        self.assertEqual(
            request.build_absolute_uri(location="/path/with:colons"),
            "http://www.example.com/path/with:colons",
        )

    def test_request_path_begins_with_two_slashes(self):
        # //// creates a request with a path beginning with //
        request = self.factory.get("////absolute-uri")
        tests = (
            # location isn't provided
            (None, "http://testserver//absolute-uri"),
            # An absolute URL
            ("http://example.com/?foo=bar", "http://example.com/?foo=bar"),
            # A schema-relative URL
            ("//example.com/?foo=bar", "http://example.com/?foo=bar"),
            # Relative URLs
            ("/foo/bar/", "http://testserver/foo/bar/"),
            ("/foo/./bar/", "http://testserver/foo/bar/"),
            ("/foo/../bar/", "http://testserver/bar/"),
            ("///foo/bar/", "http://testserver/foo/bar/"),
        )
        for location, expected_url in tests:
            with self.subTest(location=location):
                self.assertEqual(
                    request.build_absolute_uri(location=location), expected_url
                )


class RequestHeadersTests(SimpleTestCase):
    ENVIRON = {
        # Non-headers are ignored.
        "PATH_INFO": "/somepath/",
        "REQUEST_METHOD": "get",
        "wsgi.input": BytesIO(b""),
        "SERVER_NAME": "internal.com",
        "SERVER_PORT": 80,
        # These non-HTTP prefixed headers are included.
        "CONTENT_TYPE": "text/html",
        "CONTENT_LENGTH": "100",
        # All HTTP-prefixed headers are included.
        "HTTP_ACCEPT": "*",
        "HTTP_HOST": "example.com",
        "HTTP_USER_AGENT": "python-requests/1.2.0",
    }

    def test_base_request_headers(self):
        request = HttpRequest()
        request.META = self.ENVIRON
        self.assertEqual(
            dict(request.headers),
            {
                "Content-Type": "text/html",
                "Content-Length": "100",
                "Accept": "*",
                "Host": "example.com",
                "User-Agent": "python-requests/1.2.0",
            },
        )

    def test_wsgi_request_headers(self):
        request = WSGIRequest(self.ENVIRON)
        self.assertEqual(
            dict(request.headers),
            {
                "Content-Type": "text/html",
                "Content-Length": "100",
                "Accept": "*",
                "Host": "example.com",
                "User-Agent": "python-requests/1.2.0",
            },
        )

    def test_wsgi_request_headers_getitem(self):
        request = WSGIRequest(self.ENVIRON)
        self.assertEqual(request.headers["User-Agent"], "python-requests/1.2.0")
        self.assertEqual(request.headers["user-agent"], "python-requests/1.2.0")
        self.assertEqual(request.headers["user_agent"], "python-requests/1.2.0")
        self.assertEqual(request.headers["Content-Type"], "text/html")
        self.assertEqual(request.headers["Content-Length"], "100")

    def test_wsgi_request_headers_get(self):
        request = WSGIRequest(self.ENVIRON)
        self.assertEqual(request.headers.get("User-Agent"), "python-requests/1.2.0")
        self.assertEqual(request.headers.get("user-agent"), "python-requests/1.2.0")
        self.assertEqual(request.headers.get("Content-Type"), "text/html")
        self.assertEqual(request.headers.get("Content-Length"), "100")


class HttpHeadersTests(SimpleTestCase):
    def test_basic(self):
        environ = {
            "CONTENT_TYPE": "text/html",
            "CONTENT_LENGTH": "100",
            "HTTP_HOST": "example.com",
        }
        headers = HttpHeaders(environ)
        self.assertEqual(sorted(headers), ["Content-Length", "Content-Type", "Host"])
        self.assertEqual(
            headers,
            {
                "Content-Type": "text/html",
                "Content-Length": "100",
                "Host": "example.com",
            },
        )

    def test_parse_header_name(self):
        tests = (
            ("PATH_INFO", None),
            ("HTTP_ACCEPT", "Accept"),
            ("HTTP_USER_AGENT", "User-Agent"),
            ("HTTP_X_FORWARDED_PROTO", "X-Forwarded-Proto"),
            ("CONTENT_TYPE", "Content-Type"),
            ("CONTENT_LENGTH", "Content-Length"),
        )
        for header, expected in tests:
            with self.subTest(header=header):
                self.assertEqual(HttpHeaders.parse_header_name(header), expected)
