"""
NTLM authenticating pool, contributed by erikcederstran

Issue #10, see: http://code.google.com/p/urllib3/issues/detail?id=10
"""
from __future__ import absolute_import

from logging import getLogger
from ntlm import ntlm

from .. import HTTPSConnectionPool
from ..packages.six.moves.http_client import HTTPSConnection


log = getLogger(__name__)


class NTLMConnectionPool(HTTPSConnectionPool):
    """
    Implements an NTLM authentication version of an urllib3 connection pool
    """

    scheme = "https"

    def __init__(self, user, pw, authurl, *args, **kwargs):
        """
        authurl is a random URL on the server that is protected by NTLM.
        user is the Windows user, probably in the DOMAIN\\username format.
        pw is the password for the user.
        """
        super(NTLMConnectionPool, self).__init__(*args, **kwargs)
        self.authurl = authurl
        self.rawuser = user
        user_parts = user.split("\\", 1)
        self.domain = user_parts[0].upper()
        self.user = user_parts[1]
        self.pw = pw

    def _new_conn(self):
        # Performs the NTLM handshake that secures the connection. The socket
        # must be kept open while requests are performed.
        self.num_connections += 1
        log.debug(
            "Starting NTLM HTTPS connection no. %d: https://%s%s",
            self.num_connections,
            self.host,
            self.authurl,
        )

        headers = {"Connection": "Keep-Alive"}
        req_header = "Authorization"
        resp_header = "www-authenticate"

        conn = HTTPSConnection(host=self.host, port=self.port)

        # Send negotiation message
        headers[req_header] = "NTLM %s" % ntlm.create_NTLM_NEGOTIATE_MESSAGE(
            self.rawuser
        )
        log.debug("Request headers: %s", headers)
        conn.request("GET", self.authurl, None, headers)
        res = conn.getresponse()
        reshdr = dict(res.getheaders())
        log.debug("Response status: %s %s", res.status, res.reason)
        log.debug("Response headers: %s", reshdr)
        log.debug("Response data: %s [...]", res.read(100))

        # Remove the reference to the socket, so that it can not be closed by
        # the response object (we want to keep the socket open)
        res.fp = None

        # Server should respond with a challenge message
        auth_header_values = reshdr[resp_header].split(", ")
        auth_header_value = None
        for s in auth_header_values:
            if s[:5] == "NTLM ":
                auth_header_value = s[5:]
        if auth_header_value is None:
            raise Exception(
                "Unexpected %s response header: %s" % (resp_header, reshdr[resp_header])
            )

        # Send authentication message
        ServerChallenge, NegotiateFlags = ntlm.parse_NTLM_CHALLENGE_MESSAGE(
            auth_header_value
        )
        auth_msg = ntlm.create_NTLM_AUTHENTICATE_MESSAGE(
            ServerChallenge, self.user, self.domain, self.pw, NegotiateFlags
        )
        headers[req_header] = "NTLM %s" % auth_msg
        log.debug("Request headers: %s", headers)
        conn.request("GET", self.authurl, None, headers)
        res = conn.getresponse()
        log.debug("Response status: %s %s", res.status, res.reason)
        log.debug("Response headers: %s", dict(res.getheaders()))
        log.debug("Response data: %s [...]", res.read()[:100])
        if res.status != 200:
            if res.status == 401:
                raise Exception("Server rejected request: wrong username or password")
            raise Exception("Wrong server response: %s %s" % (res.status, res.reason))

        res.fp = None
        log.debug("Connection established")
        return conn

    def urlopen(
        self,
        method,
        url,
        body=None,
        headers=None,
        retries=3,
        redirect=True,
        assert_same_host=True,
    ):
        if headers is None:
            headers = {}
        headers["Connection"] = "Keep-Alive"
        return super(NTLMConnectionPool, self).urlopen(
            method, url, body, headers, retries, redirect, assert_same_host
        )