# Source code for treq.client

    import io
    import mimetypes
    import uuid
    import warnings
    from collections.abc import Mapping
    from http.cookiejar import CookieJar, Cookie
    from urllib.parse import quote_plus, urlencode as _urlencode

    from twisted.internet.interfaces import IProtocol
    from twisted.internet.defer import Deferred
    from twisted.python.components import proxyForInterface
    from twisted.python.filepath import FilePath
    from hyperlink import DecodedURL, EncodedURL

    from twisted.web.http_headers import Headers
    from twisted.web.iweb import IBodyProducer, IResponse

    from twisted.web.client import (
        FileBodyProducer,
        RedirectAgent,
        BrowserLikeRedirectAgent,
        ContentDecoderAgent,
        GzipDecoder,
        CookieAgent
    )

    from twisted.python.components import registerAdapter
    from json import dumps as json_dumps

    from treq.auth import add_auth
    from treq import multipart
    from treq.response import _Response
    from requests.cookies import merge_cookies

    _NOTHING = object()

    def urlencode(query, doseq):
        s = _urlencode(query, doseq)
        if not isinstance(s, bytes):
            s = s.encode("ascii")
        return s

    def _scoped_cookiejar_from_dict(url_object, cookie_dict):
        """
        Create a CookieJar from a dictionary whose cookies are all scoped to the
        given URL's origin.

        @note: This does not scope the cookies to any particular path, only the
            host, port, and scheme of the given URL.
        """
        cookie_jar = CookieJar()
        if cookie_dict is None:
            return cookie_jar
        for k, v in cookie_dict.items():
            secure = url_object.scheme == 'https'
            port_specified = not (
                (url_object.scheme == "https" and url_object.port == 443)
                or (url_object.scheme == "http" and url_object.port == 80)
            )
            port = str(url_object.port) if port_specified else None
            domain = url_object.host
            netscape_domain = domain if '.' in domain else domain + '.local'

            cookie_jar.set_cookie(
                Cookie(
                    # Scoping
                    domain=netscape_domain,
                    port=port,
                    secure=secure,
                    port_specified=port_specified,

                    # Contents
                    name=k,
                    value=v,

                    # Constant/always-the-same stuff
                    version=0,
                    path="/",
                    expires=None,
                    discard=False,
                    comment=None,
                    comment_url=None,
                    rfc2109=False,
                    path_specified=False,
                    domain_specified=False,
                    domain_initial_dot=False,
                    rest=[],
                )
            )
        return cookie_jar

    class _BodyBufferingProtocol(proxyForInterface(IProtocol)):
        def __init__(self, original, buffer, finished):
            self.original = original
            self.buffer = buffer
            self.finished = finished

        def dataReceived(self, data):
            self.buffer.append(data)
            self.original.dataReceived(data)

        def connectionLost(self, reason):
            self.original.connectionLost(reason)
            self.finished.errback(reason)

    class _BufferedResponse(proxyForInterface(IResponse)):
        def __init__(self, original):
            self.original = original
            self._buffer = []
            self._waiters = []
            self._waiting = None
            self._finished = False
            self._reason = None

        def _deliverWaiting(self, reason):
            self._reason = reason
            self._finished = True
            for waiter in self._waiters:
                for segment in self._buffer:
                    waiter.dataReceived(segment)
                waiter.connectionLost(reason)

        def deliverBody(self, protocol):
            if self._waiting is None and not self._finished:
                self._waiting = Deferred()
                self._waiting.addBoth(self._deliverWaiting)
                self.original.deliverBody(
                    _BodyBufferingProtocol(
                        protocol,
                        self._buffer,
                        self._waiting
                    )
                )
            elif self._finished:
                for segment in self._buffer:
                    protocol.dataReceived(segment)
                protocol.connectionLost(self._reason)
            else:
                self._waiters.append(protocol)

    class HTTPClient:
        def __init__(self, agent, cookiejar=None,
                     data_to_body_producer=IBodyProducer):
            self._agent = agent
            if cookiejar is None:
                cookiejar = CookieJar()
            self._cookiejar = cookiejar
            self._data_to_body_producer = data_to_body_producer

        def get(self, url, **kwargs):
            """
            See :func:`treq.get()`.
            """
            kwargs.setdefault('_stacklevel', 3)
            return self.request('GET', url, **kwargs)

        def put(self, url, data=None, **kwargs):
            """
            See :func:`treq.put()`.
            """
            kwargs.setdefault('_stacklevel', 3)
            return self.request('PUT', url, data=data, **kwargs)

        def patch(self, url, data=None, **kwargs):
            """
            See :func:`treq.patch()`.
            """
            kwargs.setdefault('_stacklevel', 3)
            return self.request('PATCH', url, data=data, **kwargs)

        def post(self, url, data=None, **kwargs):
            """
            See :func:`treq.post()`.
            """
            kwargs.setdefault('_stacklevel', 3)
            return self.request('POST', url, data=data, **kwargs)

        def head(self, url, **kwargs):
            """
            See :func:`treq.head()`.
            """
            kwargs.setdefault('_stacklevel', 3)
            return self.request('HEAD', url, **kwargs)

        def delete(self, url, **kwargs):
            """
            See :func:`treq.delete()`.
            """
            kwargs.setdefault('_stacklevel', 3)
            return self.request('DELETE', url, **kwargs)

        def request(
            self,
            method,
            url,
            *,
            params=None,
            headers=None,
            data=None,
            files=None,
            json=_NOTHING,
            auth=None,
            cookies=None,
            allow_redirects=True,
            browser_like_redirects=False,
            unbuffered=False,
            reactor=None,
            timeout=None,
            _stacklevel=2,
        ):
            """
            See :func:`treq.request()`.
            """
            method = method.encode('ascii').upper()

            if isinstance(url, DecodedURL):
                parsed_url = url.encoded_url
            elif isinstance(url, EncodedURL):
                parsed_url = url
            elif isinstance(url, str):
                # We use hyperlink in lazy mode so that users can pass arbitrary
                # bytes in the path and querystring.
                parsed_url = EncodedURL.from_text(url)
            else:
                parsed_url = EncodedURL.from_text(url.decode('ascii'))

            # Join parameters provided in the URL
            # and the ones passed as argument.
            if params:
                parsed_url = parsed_url.replace(
                    query=parsed_url.query + tuple(_coerced_query_params(params))
                )

            url = parsed_url.to_uri().to_text().encode('ascii')

            headers = self._request_headers(headers, _stacklevel + 1)

            bodyProducer, contentType = self._request_body(data, files, json,
                                                           stacklevel=_stacklevel + 1)
            if contentType is not None:
                headers.setRawHeaders(b'Content-Type', [contentType])

            if not isinstance(cookies, CookieJar):
                cookies = _scoped_cookiejar_from_dict(parsed_url, cookies)

            cookies = merge_cookies(self._cookiejar, cookies)
            wrapped_agent = CookieAgent(self._agent, cookies)

            if allow_redirects:
                if browser_like_redirects:
                    wrapped_agent = BrowserLikeRedirectAgent(wrapped_agent)
                else:
                    wrapped_agent = RedirectAgent(wrapped_agent)

            wrapped_agent = ContentDecoderAgent(wrapped_agent,
                                                [(b'gzip', GzipDecoder)])

            if auth:
                wrapped_agent = add_auth(wrapped_agent, auth)

            d = wrapped_agent.request(
                method, url, headers=headers,
                bodyProducer=bodyProducer)

            if reactor is None:
                from twisted.internet import reactor
            if timeout:
                delayedCall = reactor.callLater(timeout, d.cancel)

                def gotResult(result):
                    if delayedCall.active():
                        delayedCall.cancel()
                    return result

                d.addBoth(gotResult)

            if not unbuffered:
                d.addCallback(_BufferedResponse)

            return d.addCallback(_Response, cookies)

        def _request_headers(self, headers, stacklevel):
            """
            Convert the *headers* argument to a :class:`Headers` instance

            :returns:
                :class:`twisted.web.http_headers.Headers`
            """
            if isinstance(headers, dict):
                h = Headers({})
                for k, v in headers.items():
                    if isinstance(v, (bytes, str)):
                        h.addRawHeader(k, v)
                    elif isinstance(v, list):
                        h.setRawHeaders(k, v)
                    else:
                        warnings.warn(
                            (
                                "The value of headers key {!r} has non-string type {}"
                                " and will be dropped."
                                " This will raise TypeError in the next treq release."
                            ).format(k, type(v)),
                            DeprecationWarning,
                            stacklevel=stacklevel,
                        )
                return h
            if isinstance(headers, Headers):
                return headers
            if headers is None:
                return Headers({})

            warnings.warn(
                (
                    "headers must be a dict, twisted.web.http_headers.Headers, or None,"
                    " but found {}, which will be ignored."
                    " This will raise TypeError in the next treq release."
                ).format(type(headers)),
                DeprecationWarning,
                stacklevel=stacklevel,
            )
            return Headers({})

        def _request_body(self, data, files, json, stacklevel):
            """
            Here we choose a right producer based on the parameters passed in.

            :params data:
                Arbitrary request body data.

                If *files* is also passed this must be a :class:`dict`,
                a :class:`tuple` or :class:`list` of field tuples as accepted by
                :class:`MultiPartProducer`. The request is assigned a Content-Type
                of ``multipart/form-data``.

                If a :class:`dict`, :class:`list`, or :class:`tuple` it is
                URL-encoded and the request assigned a Content-Type of
                ``application/x-www-form-urlencoded``.

                Otherwise, any non-``None`` value is passed to the client's
                *data_to_body_producer* callable (by default,
                :class:`IBodyProducer`), which accepts file-like objects.

            :params files:
                Files to include in the request body, in any of the several formats
                described in :func:`_convert_files()`.

            :params json:
                JSON-encodable data, or the sentinel `_NOTHING`. The sentinel is
                necessary because ``None`` is a valid JSON value.
            """
            if json is not _NOTHING and (files or data):
                warnings.warn(
                    (
                        "Argument 'json' will be ignored because '{}' was also passed."
                        " This will raise TypeError in the next treq release."
                    ).format("data" if data else "files"),
                    DeprecationWarning,
                    stacklevel=stacklevel,
                )

            if files:
                # If the files keyword is present we will issue a
                # multipart/form-data request as it suits better for cases
                # with files and/or large objects.
                files = list(_convert_files(files))
                boundary = str(uuid.uuid4()).encode('ascii')
                if data:
                    data = _convert_params(data)
                else:
                    data = []

                return (
                    multipart.MultiPartProducer(data + files, boundary=boundary),
                    b'multipart/form-data; boundary=' + boundary,
                )

            # Otherwise stick to x-www-form-urlencoded format
            # as it's generally faster for smaller requests.
            if isinstance(data, (dict, list, tuple)):
                return (
                    self._data_to_body_producer(urlencode(data, doseq=True)),
                    b'application/x-www-form-urlencoded',
                )
            elif data:
                return (
                    self._data_to_body_producer(data),
                    None,
                )

            if json is not _NOTHING:
                return (
                    self._data_to_body_producer(
                        json_dumps(json, separators=(u',', u':')).encode('utf-8'),
                    ),
                    b'application/json; charset=UTF-8',
                )

            return None, None

    def _convert_params(params):
        if hasattr(params, "iteritems"):
            return list(sorted(params.iteritems()))
        elif hasattr(params, "items"):
            return list(sorted(params.items()))
        elif isinstance(params, (tuple, list)):
            return list(params)
        else:
            raise ValueError("Unsupported format")

    def _convert_files(files):
        """
        Files can be passed in a variety of formats:

        * {"fieldname": open("bla.f", "rb")}
        * {"fieldname": ("filename", open("bla.f", "rb"))}
        * {"fieldname": ("filename", "content-type", open("bla.f", "rb"))}
        * Anything that has iteritems method, e.g. MultiDict:
          MultiDict([(name, open()), (name, open())]

        Our goal is to standardize it to unified form of:

        * [(param, (file name, content type, producer))]
        """

        if hasattr(files, "iteritems"):
            files = files.iteritems()
        elif hasattr(files, "items"):
            files = files.items()

        for param, val in files:
            file_name, content_type, fobj = (None, None, None)
            if isinstance(val, tuple):
                if len(val) == 2:
                    file_name, fobj = val
                elif len(val) == 3:
                    file_name, content_type, fobj = val
                else:
                    # NB: This is TypeError for backward compatibility. This case
                    # used to fall through to `IBodyProducer`, below, which raised
                    # TypeError about being unable to coerce None.
                    raise TypeError(
                        (
                            "`files` argument must be a sequence of tuples of"
                            " (file_name, file_obj) or"
                            " (file_name, content_type, file_obj),"
                            " but the {!r} tuple has length {}: {!r}"
                        ).format(param, len(val), val),
                    )
            else:
                fobj = val
                if hasattr(fobj, "name"):
                    file_name = FilePath(fobj.name).basename()

            if not content_type:
                content_type = _guess_content_type(file_name)

            # XXX: Shouldn't this call self._data_to_body_producer?
            yield (param, (file_name, content_type, IBodyProducer(fobj)))

    def _query_quote(v):
        # (Any) -> Text
        """
        Percent-encode a querystring name or value.

        :param v: A value.

        :returns:
            The value, coerced to a string and percent-encoded as appropriate for
            a querystring (with space as ``+``).
        """
        if not isinstance(v, (str, bytes)):
            v = str(v)
        if not isinstance(v, bytes):
            v = v.encode("utf-8")
        q = quote_plus(v)
        return q

    def _coerced_query_params(params):
        """
        Carefully coerce *params* in the same way as `urllib.parse.urlencode()`

        Parameter names and values are coerced to unicode, which is encoded as
        UTF-8 and then percent-encoded. As a special case, `bytes` are directly
        percent-encoded.

        :param params:
            A mapping or sequence of (name, value) two-tuples. The value may be
            a list or tuple of multiple values. Names and values may be pretty much
            any type.

        :returns:
            A generator that yields two-tuples containing percent-encoded text
            strings.
        :rtype:
            Iterator[Tuple[Text, Text]]
        """
        if isinstance(params, Mapping):
            items = params.items()
        else:
            items = params

        for key, values in items:
            key_quoted = _query_quote(key)

            if not isinstance(values, (list, tuple)):
                values = (values,)
            for value in values:
                yield key_quoted, _query_quote(value)

    def _from_bytes(orig_bytes):
        return FileBodyProducer(io.BytesIO(orig_bytes))

    def _from_file(orig_file):
        return FileBodyProducer(orig_file)

    def _guess_content_type(filename):
        if filename:
            guessed = mimetypes.guess_type(filename)[0]
        else:
            guessed = None
        return guessed or 'application/octet-stream'

    registerAdapter(_from_bytes, bytes, IBodyProducer)
    registerAdapter(_from_file, io.BytesIO, IBodyProducer)

    # file()/open() equiv
    registerAdapter(_from_file, io.BufferedReader, IBodyProducer)