# Source code for M2Crypto.m2urllib2

    from __future__ import absolute_import

    """
    M2Crypto enhancement to Python's urllib2 for handling
    'https' url's.

    Code from urllib2 is Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007
    Python Software Foundation; All Rights Reserved

    Summary of changes:
     - Use an HTTPSProxyConnection if the request is going through a proxy.
     - Add the SSL context to the https connection when performing https_open.
     - Add the M2Crypto HTTPSHandler when building a default opener.
    """

    import socket

    from M2Crypto import SSL, httpslib, six

    from M2Crypto.six.moves.urllib_parse import urldefrag, urlparse as url_parse
    from M2Crypto.six.moves.urllib_response import addinfourl
    from typing import Optional  # noqa

    # six.moves doesn't support star imports
    if six.PY3:
        from urllib.request import *  # noqa other modules want to import
        from urllib.error import *  # noqa other modules want to import
    else:
        from urllib2 import *  # noqa

    try:
        mother_class = socket._fileobject
    except AttributeError:
        mother_class = socket.SocketIO

    class _closing_fileobject(mother_class):  # noqa
        """socket._fileobject that propagates self.close() to the socket.

        Python 2.5 provides this as socket._fileobject(sock, close=True).
        """

    # for python 3
    try:
        AbstractHTTPHandler
    except NameError:
        # somehow this won't get imported by the import * above
        import urllib.request
        AbstractHTTPHandler = urllib.request.AbstractHTTPHandler

    class HTTPSHandler(AbstractHTTPHandler):
        def __init__(self, ssl_context=None):
            # type: (SSL.Context) -> None
            AbstractHTTPHandler.__init__(self)

            if ssl_context is not None:
                assert isinstance(ssl_context, SSL.Context), ssl_context
                self.ctx = ssl_context
            else:
                self.ctx = SSL.Context()

        # Copied from urllib2, so we can set the ssl context.
        def https_open(self, req):
            # type: (Request) -> addinfourl
            """Return an addinfourl object for the request, using http_class.

            http_class must implement the HTTPConnection API from httplib.
            The addinfourl return value is a file-like object.  It also
            has methods and attributes including:

                - info(): return a mimetools.Message object for the headers

                - geturl(): return the original request URL

                - code: HTTP status code
            """
            # https://docs.python.org/3.3/library/urllib.request.html#urllib.request.Request.get_host
            try:     # up to python-3.2
                host = req.get_host()
            except AttributeError:  # from python-3.3
                host = req.host
            if not host:
                raise URLError('no host given')

            # Our change: Check to see if we're using a proxy.
            # Then create an appropriate ssl-aware connection.
            full_url = req.get_full_url()
            target_host = url_parse(full_url)[1]

            if target_host != host:
                request_uri = urldefrag(full_url)[0]
                h = httpslib.ProxyHTTPSConnection(host=host, ssl_context=self.ctx)
            else:
                try:     # up to python-3.2
                    request_uri = req.get_selector()
                except AttributeError:  # from python-3.3
                    request_uri = req.selector
                h = httpslib.HTTPSConnection(host=host, ssl_context=self.ctx)
            # End our change
            h.set_debuglevel(self._debuglevel)

            headers = dict(req.headers)
            headers.update(req.unredirected_hdrs)
            # We want to make an HTTP/1.1 request, but the addinfourl
            # class isn't prepared to deal with a persistent connection.
            # It will try to read all remaining data from the socket,
            # which will block while the server waits for the next request.
            # So make sure the connection gets closed after the (only)
            # request.
            headers["Connection"] = "close"
            try:
                h.request(req.get_method(), request_uri, req.data, headers)
                r = h.getresponse()
            except socket.error as err:  # XXX what error?
                raise URLError(err)

            # Pick apart the HTTPResponse object to get the addinfourl
            # object initialized properly.

            # Wrap the HTTPResponse object in socket's file object adapter
            # for Windows.  That adapter calls recv(), so delegate recv()
            # to read().  This weird wrapping allows the returned object to
            # have readline() and readlines() methods.
            r.recv = r.read
            if six.PY2:
                fp = socket._fileobject(r, close=True)
            else:
                r._decref_socketios = lambda: None
                r.ssl = h.sock.ssl
                r._timeout = -1.0
                r.recv_into = r.readinto
                fp = socket.SocketIO(r, 'rb')

            resp = addinfourl(fp, r.msg, req.get_full_url())
            resp.code = r.status
            resp.msg = r.reason
            return resp

        https_request = AbstractHTTPHandler.do_request_

    # Copied from urllib2 with modifications for ssl
    def build_opener(ssl_context=None, *handlers):
        # type: (Optional[SSL.Context], *object) -> OpenerDirector
        """Create an opener object from a list of handlers.

        The opener will use several default handlers, including support
        for HTTP and FTP.

        If any of the handlers passed as arguments are subclasses of the
        default handlers, the default handlers will not be used.
        """

        def isclass(obj):
            return isinstance(obj, type) or hasattr(obj, "__bases__")

        opener = OpenerDirector()
        default_classes = [ProxyHandler, UnknownHandler, HTTPHandler,
                           HTTPDefaultErrorHandler, HTTPRedirectHandler,
                           FTPHandler, FileHandler, HTTPErrorProcessor]
        skip = []
        for klass in default_classes:
            for check in handlers:
                if isclass(check):
                    if issubclass(check, klass):
                        skip.append(klass)
                elif isinstance(check, klass):
                    skip.append(klass)
        for klass in skip:
            default_classes.remove(klass)

        for klass in default_classes:
            opener.add_handler(klass())

        # Add the HTTPS handler with ssl_context
        if HTTPSHandler not in skip:
            opener.add_handler(HTTPSHandler(ssl_context))

        for h in handlers:
            if isclass(h):
                h = h()
            opener.add_handler(h)
        return opener